Summary:
Previously, the flushes triggered by `WriteBufferManager` could affect
the same CF repeatedly if it happens to get consecutive writes. Such
flushes are not particularly useful for reducing memory usage since
they switch nearly-empty memtables to immutable while they've just begun
filling their first arena block. In fact they may not even reduce the
mutable memory count if they involve replacing one mutable memtable containing
one arena block with a new mutable memtable containing one arena block.
Further, if such switches happen even a few times before a flush finishes,
the immutable memtable limit will be reached and writes will stall.
This PR adds a heuristic to not switch memtables to immutable for CFs
that already have one or more immutable memtables awaiting flush. There
is a memory usage regression if the user continues writing to the same
CF, that DB does not have any CFs eligible for switching, flushes
are not finishing, and the `WriteBufferManager` was constructed with
`allow_stall=false`. Before, it would grow by switching nearly empty
memtables until writes stall. Now, it would grow by filling memtables
until writes stall. This feels like an acceptable behavior change because
users who prefer to stall over violate the memory limit should be using
`allow_stall=true`, which is unaffected by this PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6364
Test Plan:
- Command:
`rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num_multi_db=8 -num_column_families=2 -write_buffer_size=4194304 -db_write_buffer_size=16777216 -compression_type=none -statistics=true -target_file_size_base=4194304 -max_bytes_for_level_base=16777216`
- `rocksdb.db.write.stall` count before this PR: 175
- `rocksdb.db.write.stall` count after this PR: 0
Reviewed By: jay-zhuang
Differential Revision: D20167197
Pulled By: ajkr
fbshipit-source-id: 4a64064e9bc33d57c0a35f15547542d0191d0cb7
Summary:
A flag in WritableFileWriter is introduced to remember error has happened. Subsequent operations will fail with an assertion. Those operations, except Close() are not supposed to be called anyway. This change will help catch bug in tests and stress tests and limit damage of a potential bug of continue writing to a file after a failure.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10489
Test Plan: Fix existing unit tests and watch crash tests for a while.
Reviewed By: anand1976
Differential Revision: D38473277
fbshipit-source-id: 09aafb971e56cfd7f9ef92ad15b883f54acf1366
Summary:
- Right now each read fragments the memtable range tombstones https://github.com/facebook/rocksdb/issues/4808. This PR explores the idea of fragmenting memtable range tombstones in the write path and reads can just read this cached fragmented tombstone without any fragmenting cost. This PR only does the caching for immutable memtable, and does so right before a memtable is added to an immutable memtable list. The fragmentation is done without holding mutex to minimize its performance impact.
- db_bench is updated to print out the number of range deletions executed if there is any.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10380
Test Plan:
- CI, added asserts in various places to check whether a fragmented range tombstone list should have been constructed.
- Benchmark: as this PR only optimizes immutable memtable path, the number of writes in the benchmark is chosen such an immutable memtable is created and range tombstones are in that memtable.
```
single thread:
./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=100000 --max_num_range_tombstones=100
multi_thread
./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=15000 --reads=20000 --threads=32 --max_num_range_tombstones=100
```
Commit 99cdf16464 is included in benchmark result. It was an earlier attempt where tombstones are fragmented for each write operation. Reader threads share it using a shared_ptr which would slow down multi-thread read performance as seen in benchmark results.
Results are averaged over 5 runs.
Single thread result:
| Max # tombstones | main fillrandom micros/op | 99cdf16464 | Post PR | main readrandom micros/op | 99cdf16464 | Post PR |
| ------------- | ------------- |------------- |------------- |------------- |------------- |------------- |
| 0 |6.68 |6.57 |6.72 |4.72 |4.79 |4.54 |
| 1 |6.67 |6.58 |6.62 |5.41 |4.74 |4.72 |
| 10 |6.59 |6.5 |6.56 |7.83 |4.69 |4.59 |
| 100 |6.62 |6.75 |6.58 |29.57 |5.04 |5.09 |
| 1000 |6.54 |6.82 |6.61 |320.33 |5.22 |5.21 |
32-thread result: note that "Max # tombstones" is per thread.
| Max # tombstones | main fillrandom micros/op | 99cdf16464 | Post PR | main readrandom micros/op | 99cdf16464 | Post PR |
| ------------- | ------------- |------------- |------------- |------------- |------------- |------------- |
| 0 |234.52 |260.25 |239.42 |5.06 |5.38 |5.09 |
| 1 |236.46 |262.0 |231.1 |19.57 |22.14 |5.45 |
| 10 |236.95 |263.84 |251.49 |151.73 |21.61 |5.73 |
| 100 |268.16 |296.8 |280.13 |2308.52 |22.27 |6.57 |
Reviewed By: ajkr
Differential Revision: D37916564
Pulled By: cbi42
fbshipit-source-id: 05d6d2e16df26c374c57ddcca13a5bfe9d5b731e
Summary:
Existing DBWALTest.RaceInstallFlushResultsWithWalObsoletion test relies
on a specific interleaving of two background flush threads. We call them
bg1 and bg2, and assume bg1 starts to install flush results ahead of
bg2. After bg1 enters `ProcessManifestWrites`, bg1 waits for bg2 to also
enter `MemTableList::TryInstallMemtableFlushResults()` before bg1 can
proceed with MANIFEST write. However, if bg2 called `SyncClosedLogs()`
and needed to commit to the MANIFEST but falls behind bg1, then bg2
needs to wait for bg1 to finish writing to MANIFEST. This is a circular
dependency.
Fix this by allowing bg2 to start only after bg1 grabs the chance to
sync the WAL and commit to MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10456
Test Plan:
1. make check
2. export TEST_TMPDIR=/dev/shm && gtest-parallel -r 1000 -w 32 ./db_wal_test --gtest_filter=DBWALTest.RaceInstallFlushResultsWithWalObsoletion
Reviewed By: ltamasi
Differential Revision: D38391856
Pulled By: riversand963
fbshipit-source-id: 55f647d5b94e534c008a4dd2fb082675ddf58c96
Summary:
This PR avoids allocations and copies for the result of `GetMergeOperands()` when the average operand size is at least 256 bytes and the total operands size is at least 32KB. The `GetMergeOperands()` already included `PinnableSlice` but was calling `PinSelf()` (i.e., allocating and copying) for each operand. When this optimization takes effect, we instead call `PinSlice()` to skip that allocation and copy. Resources are pinned in order for the `PinnableSlice` to point to valid memory even after `GetMergeOperands()` returns.
The pinned resources include a referenced `SuperVersion`, a `MergingContext`, and a `PinnedIteratorsManager`. They are bundled into a `GetMergeOperandsState`. We use `SharedCleanablePtr` to share that bundle among all `PinnableSlice`s populated by `GetMergeOperands()`. That way, the last `PinnableSlice` to be `Reset()` will cleanup the bundle, including unreferencing the `SuperVersion`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10458
Test Plan:
- new DB level test
- measured benefit/regression in a number of memtable scenarios
Setup command:
```
$ ./db_bench -benchmarks=mergerandom -merge_operator=StringAppendOperator -num=$num -writes=16384 -key_size=16 -value_size=$value_sz -compression_type=none -write_buffer_size=1048576000
```
Benchmark command:
```
./db_bench -threads=$threads -use_existing_db=true -avoid_flush_during_recovery=true -write_buffer_size=1048576000 -benchmarks=readrandomoperands -merge_operator=StringAppendOperator -num=$num -duration=10
```
Worst regression is when a key has many tiny operands:
- Parameters: num=1 (implying 16384 operands per key), value_sz=8, threads=1
- `GetMergeOperands()` latency increases 682 micros -> 800 micros (+17%)
The regression disappears into the noise (<1% difference) if we remove the `Reset()` loop and the size counting loop. The former is arguably needed regardless of this PR as the convention in `Get()` and `MultiGet()` is to `Reset()` the input `PinnableSlice`s at the start. The latter could be optimized to count the size as we accumulate operands rather than after the fact.
Best improvement is when a key has large operands and high concurrency:
- Parameters: num=4 (implying 4096 operands per key), value_sz=2KB, threads=32
- `GetMergeOperands()` latency decreases 11492 micros -> 437 micros (-96%).
Reviewed By: cbi42
Differential Revision: D38336578
Pulled By: ajkr
fbshipit-source-id: 48146d127e04cb7f2d4d2939a2b9dff3aba18258
Summary:
TL;DR: due to a recent change, if you drop a column family,
often that DB will no longer fsync after writing new SST files
to remaining or new column families, which could lead to data
loss on power loss.
More bug detail:
The intent of https://github.com/facebook/rocksdb/issues/10049 was to Close FSDirectory objects at
DB::Close time rather than waiting for DB object destruction.
Unfortunately, it also closes shared FSDirectory objects on
DropColumnFamily (& destroy remaining handles), which can lead
to use-after-Close on FSDirectory shared with remaining column
families. Those "uses" are only Fsyncs (or redundant Closes). In
the default Posix filesystem, an Fsync on a closed FSDirectory is a
quiet no-op. Consequently (under most configurations), if you drop
a column family, that DB will no longer fsync after writing new SST
files to column families sharing the same directory (true under most
configurations).
More fix detail:
Basically, this removes unnecessary Close ops on destroying
ColumnFamilyData. We let `shared_ptr` take care of calling the
destructor at the right time. If the intent was to require Close be
called before destroying FSDirectory, that was not made clear by the
author of FileSystem and was not at all enforced by https://github.com/facebook/rocksdb/issues/10049, which
could have added `assert(fd_ == -1)` to `~PosixDirectory()` but did
not. To keep this fix simple, we relax the unit test for https://github.com/facebook/rocksdb/issues/10049 to allow
timely destruction of FSDirectory to suffice as Close (in
CountedFileSystem). Added a TODO to revisit that.
Also in this PR:
* Added a TODO to share FSDirectory instances between DB and its column
families. (Already shared among column families.)
* Made DB::Close attempt to close all its open FSDirectory objects even
if there is a failure in closing one. Also code clean-up around this
logic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10460
Test Plan:
add an assert to check for use-after-Close. With that
existing tests can detect the misuse. With fix, tests pass (except noted
relaxing of unit test for https://github.com/facebook/rocksdb/issues/10049)
Reviewed By: ajkr
Differential Revision: D38357922
Pulled By: pdillinger
fbshipit-source-id: d42079cadbedf0a969f03389bf586b3b4e1f9137
Summary:
FileMetaData::[min|max]_timestamp are not currently being used or
tracked by RocksDB, even when user-defined timestamp is enabled. Each of
them is a std::string which can occupy 32 bytes. Remove them for now.
They may be added back when we have a pressing need for them. When we do
add them back, consider store them in a more compact way, e.g. one
boolean flag and a byte array of size 16.
Per file min/max timestamp bounds are available as table properties.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10443
Test Plan: make check
Reviewed By: pdillinger
Differential Revision: D38292275
Pulled By: riversand963
fbshipit-source-id: 841dc4e855ad8f8481c80cb020603de9607c9c94
Summary:
This PR changes the default value of
`CompactRangeOptions::exclusive_manual_compaction` from true to false so
manual `CompactRange()`s can run in parallel with other compactions. I
believe no artificial parallelism restriction is the intuitive behavior
so feel the old default value is a trap, which I have fallen into
several times, including yesterday.
`CompactRangeOptions::exclusive_manual_compaction == false` has been
used in both our correctness test and in production for years so should
be reasonably safe.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10317
Reviewed By: jay-zhuang
Differential Revision: D37659392
Pulled By: ajkr
fbshipit-source-id: 504915e978bbe300b79483d064070c75e93d91e5
Summary:
Earlier implementation of round-robin priority can only pick one file at a time and disallows parallel compactions within the same level. In this PR, round-robin compaction policy will expand towards more input files with respecting some additional constraints, which are summarized as follows:
* Constraint 1: We can only pick consecutive files
- Constraint 1a: When a file is being compacted (or some input files are being compacted after expanding), we cannot choose it and have to stop choosing more files
- Constraint 1b: When we reach the last file (with the largest keys), we cannot choose more files (the next file will be the first one with small keys)
* Constraint 2: We should ensure the total compaction bytes (including the overlapped files from the next level) is no more than `mutable_cf_options_.max_compaction_bytes`
* Constraint 3: We try our best to pick as many files as possible so that the post-compaction level size can be just less than `MaxBytesForLevel(start_level_)`
* Constraint 4: If trivial move is allowed, we reuse the logic of `TryNonL0TrivialMove()` instead of expanding files with Constraint 3
More details can be found in `LevelCompactionBuilder::SetupOtherFilesWithRoundRobinExpansion()`.
The above optimization accelerates the process of moving the compaction cursor, in which the write-amp can be further reduced. While a large compaction may lead to high write stall, we break this large compaction into several subcompactions **regardless of** the `max_subcompactions` limit. The number of subcompactions for round-robin compaction priority is determined through the following steps:
* Step 1: Initialized against `max_output_file_limit`, the number of input files in the start level, and also the range size limit `ranges.size()`
* Step 2: Call `AcquireSubcompactionResources()`when max subcompactions is not sufficient, but we may or may not obtain desired resources, additional number of resources is stored in `extra_num_subcompaction_threads_reserved_`). Subcompaction limit is changed and update `num_planned_subcompactions` with `GetSubcompactionLimit()`
* Step 3: Call `ShrinkSubcompactionResources()` to ensure extra resources can be released (extra resources may exist for round-robin compaction when the number of actual number of subcompactions is less than the number of planned subcompactions)
More details can be found in `CompactionJob::AcquireSubcompactionResources()`,`CompactionJob::ShrinkSubcompactionResources()`, and `CompactionJob::ReleaseSubcompactionResources()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10341
Test Plan: Add `CompactionPriMultipleFilesRoundRobin[1-3]` unit test in `compaction_picker_test.cc` and `RoundRobinSubcompactionsAgainstResources.SubcompactionsUsingResources/[0-4]`, `RoundRobinSubcompactionsAgainstPressureToken.PressureTokenTest/[0-1]` in `db_compaction_test.cc`
Reviewed By: ajkr, hx235
Differential Revision: D37792644
Pulled By: littlepig2013
fbshipit-source-id: 7fecb7c4ffd97b34bbf6e3b760b2c35a772a0657
Summary:
## Problem Summary
RocksDB will acquire the global mutex of db instance for every time when user calls `Write`. When RocksDB schedules a lot of compaction jobs, it will compete the mutex with write thread and it will hurt the write performance.
## Problem Solution:
I want to use log_write_mutex to replace the global mutex in most case so that we do not acquire it in write-thread unless there is a write-stall event or a write-buffer-full event occur.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7516
Test Plan:
1. make check
2. CI
3. COMPILE_WITH_TSAN=1 make db_stress
make crash_test
make crash_test_with_multiops_wp_txn
make crash_test_with_multiops_wc_txn
make crash_test_with_atomic_flush
Reviewed By: siying
Differential Revision: D36908702
Pulled By: riversand963
fbshipit-source-id: 59b13881f4f5c0a58fd3ca79128a396d9cd98efe
Summary:
`PeriodicWorkScheduler` is a global singleton, which were used to store per-instance setting `record_seqno_time_cadence_`. Move that to db_impl.h which is per-instance.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10383
Reviewed By: siying
Differential Revision: D37928009
Pulled By: jay-zhuang
fbshipit-source-id: e517754f4a9db98798ac04f72033d4b517f734e9
Summary:
Using the Sequence number to time mapping to decide if a key is hot or not in
compaction and place it in the corresponding level.
Note: the feature is not complete, level compaction will run indefinitely until
all penultimate level data is cold and small enough to not trigger compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10370
Test Plan:
CI
* Run basic db_bench for universal compaction manually
Reviewed By: siying
Differential Revision: D37892338
Pulled By: jay-zhuang
fbshipit-source-id: 792bbd91b1ccc2f62b5d14c53118434bcaac4bbe
Summary:
Which will be used for tiered storage to preclude hot data from
compacting to the cold tier (the last level).
Internally, adding seqno to time mapping. A periodic_task is scheduled
to record the current_seqno -> current_time in certain cadence. When
memtable flush, the mapping informaiton is stored in sstable property.
During compaction, the mapping information are merged and get the
approximate time of sequence number, which is used to determine if a key
is recently inserted or not and preclude it from the last level if it's
recently inserted (within the `preclude_last_level_data_seconds`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10338
Test Plan: CI
Reviewed By: siying
Differential Revision: D37810187
Pulled By: jay-zhuang
fbshipit-source-id: 6953be7a18a99de8b1cb3b162d712f79c2b4899f
Summary:
Before this PR, it is required that application open RocksDB secondary
instance with `max_open_files = -1`. This is a hacky workaround that
prevents IOErrors on the seconary instance during point-lookup or range
scan caused by primary instance deleting the table files. This is not
necessary if the application can coordinate the primary and secondaries
so that primary does not delete files that are still being used by the
secondaries. Or users can provide a custom Env/FS implementation that
deletes the files only after all primary and secondary instances
indicate files are obsolete and deleted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10260
Test Plan: make check
Reviewed By: jay-zhuang
Differential Revision: D37462633
Pulled By: riversand963
fbshipit-source-id: 9c2fc939f49663efa61e3d60c8f1e01d64b9d72c
Summary:
The patch builds on https://github.com/facebook/rocksdb/pull/9915 and adds
a new API called `PutEntity` that can be used to write a wide-column entity
to the database. The new API is added to both `DB` and `WriteBatch`. Note
that currently there is no way to retrieve these entities; more precisely, all
read APIs (`Get`, `MultiGet`, and iterator) return `NotSupported` when they
encounter a wide-column entity that is required to answer a query. Read-side
support (as well as other missing functionality like `Merge`, compaction filter,
and timestamp support) will be added in later PRs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10242
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D37369748
Pulled By: ltamasi
fbshipit-source-id: 7f5e412359ed7a400fd80b897dae5599dbcd685d
Summary:
Resolves https://github.com/facebook/rocksdb/issues/10129
I extracted this fix from https://github.com/facebook/rocksdb/issues/7516 since it's also already a bug in main branch, and we want to
separate it from the main part of the PR.
There can be a race condition between two threads. Thread 1 executes
`DBImpl::FindObsoleteFiles()` while thread 2 executes `GetSortedWals()`.
```
Time thread 1 thread 2
| mutex_.lock
| read disable_delete_obsolete_files_
| ...
| wait on log_sync_cv and release mutex_
| mutex_.lock
| ++disable_delete_obsolete_files_
| mutex_.unlock
| mutex_.lock
| while (pending_purge_obsolete_files > 0) { bg_cv.wait;}
| wake up with mutex_ locked
| compute WALs tracked by MANIFEST
| mutex_.unlock
| wake up with mutex_ locked
| ++pending_purge_obsolete_files_
| mutex_.unlock
|
| delete obsolete WAL
| WAL missing but tracked in MANIFEST.
V
```
The fix proposed eliminates the possibility of the above by increasing
`pending_purge_obsolete_files_` before `FindObsoleteFiles()` can possibly release the mutex.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10187
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D37214235
Pulled By: riversand963
fbshipit-source-id: 556ab1b58ae6d19150169dfac4db08195c797184
Summary:
**Summary**
Make the mempurge option flag a Mutable Column Family option flag. Therefore, the mempurge feature can be dynamically toggled.
**Motivation**
RocksDB users prefer having the ability to switch features on and off without having to close and reopen the DB. This is particularly important if the feature causes issues and needs to be turned off. Dynamically changing a DB option flag does not seem currently possible.
Moreover, with this new change, the MemPurge feature can be toggled on or off independently between column families, which we see as a major improvement.
**Content of this PR**
This PR includes removal of the `experimental_mempurge_threshold` flag as a DB option flag, and its re-introduction as a `MutableCFOption` flag. I updated the code to handle dynamic changes of the flag (in particular inside the `FlushJob` file). Additionally, this PR includes a new test to demonstrate the capacity of the code to toggle the MemPurge feature on and off, as well as the addition in the `db_stress` module of 2 different mempurge threshold values (0.0 and 1.0) that can be randomly changed with the `set_option_one_in` flag. This is useful to stress test the dynamic changes.
**Benchmarking**
I will add numbers to prove that there is no performance impact within the next 12 hours.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10011
Reviewed By: pdillinger
Differential Revision: D36462357
Pulled By: bjlemaire
fbshipit-source-id: 5e3d63bdadf085c0572ecc2349e7dd9729ce1802
Summary:
https://github.com/facebook/rocksdb/issues/9984 changes the behavior of RocksDB: if logger creation failed during `SanitizeOptions()`,
`DB::Open()` will fail. However, since `SanitizeOptions()` is called in `DBImpl::DBImpl()`, we cannot
directly expose the error to caller without some additional work.
This is a first version proposal which:
- Adds a new member `init_logger_creation_s` to `DBImpl` to store the result of init logger creation
- Checks the error during `DB::Open()` and return it to caller if non-ok
This is not very ideal. We can alternatively move the logger creation logic out of the `SanitizeOptions()`.
Since `SanitizeOptions()` is used in other places, we need to check whether this change breaks anything
in case other callers of `SanitizeOptions()` assumes that a logger should be created.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10223
Test Plan: make check
Reviewed By: pdillinger
Differential Revision: D37321717
Pulled By: riversand963
fbshipit-source-id: 58042358a86369d606549dd9938933dd47591c4b
Summary:
So that DBImpl::RecoverLogFiles do not have to deal with implementation
details of WalFilter.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10214
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D37299122
Pulled By: riversand963
fbshipit-source-id: acf1a80f1ef75da393d375f55968b2f3ac189816
Summary:
Add `kRoundRobin` as a compaction priority. The implementation is as follows.
- Define a cursor as the smallest Internal key in the successor of the selected file. Add `vector<InternalKey> compact_cursor_` into `VersionStorageInfo` where each element (`InternalKey`) in `compact_cursor_` represents a cursor. In round-robin compaction policy, we just need to select the first file (assuming files are sorted) and also has the smallest InternalKey larger than/equal to the cursor. After a file is chosen, we create a new `Fsize` vector which puts the selected file is placed at the first position in `temp`, the next cursor is then updated as the smallest InternalKey in successor of the selected file (the above logic is implemented in `SortFileByRoundRobin`).
- After a compaction succeeds, typically `InstallCompactionResults()`, we choose the next cursor for the input level and save it to `edit`. When calling `LogAndApply`, we save the next cursor with its level into some local variable and finally apply the change to `vstorage` in `SaveTo` function.
- Cursors are persist pair by pair (<level, InternalKey>) in `EncodeTo` so that they can be reconstructed when reopening. An empty cursor will not be encoded to MANIFEST
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10107
Test Plan: add unit test (`CompactionPriRoundRobin`) in `compaction_picker_test`, add `kRoundRobin` priority in `CompactionPriTest` from `db_compaction_test`, and add `PersistRoundRobinCompactCursor` in `db_compaction_test`
Reviewed By: ajkr
Differential Revision: D37316037
Pulled By: littlepig2013
fbshipit-source-id: 9f481748190ace416079139044e00df2968fb1ee
Summary:
There is currently no caching mechanism for blobs, which is not ideal especially when the database resides on remote storage (where we cannot rely on the OS page cache). As part of this task, we would like to make it possible for the application to configure a blob cache.
In this task, we formally introduced the blob source to RocksDB. BlobSource is a new abstraction layer that provides universal access to blobs, regardless of whether they are in the blob cache, secondary cache, or (remote) storage. Depending on user settings, it always fetch blobs from multi-tier cache and storage with minimal cost.
Note: The new `MultiGetBlob()` implementation is not included in the current PR. To go faster, we aim to create a separate PR for it in parallel!
This PR is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10198
Reviewed By: ltamasi
Differential Revision: D37294735
Pulled By: gangliao
fbshipit-source-id: 9cb50422d9dd1bc03798501c2778b6c7520c7a1e
Summary:
`FlushWAL(true /* sync */)` is used internally and for manual WAL sync. It had a bug when used together with `track_and_verify_wals_in_manifest` where the synced size tracked in MANIFEST was larger than the number of bytes actually synced.
The bug could be repro'd almost immediately with the following crash test command: `python3 tools/db_crashtest.py blackbox --simple --write_buffer_size=524288 --max_bytes_for_level_base=2097152 --target_file_size_base=524288 --duration=3600 --interval=10 --sync_fault_injection=1 --disable_wal=0 --checkpoint_one_in=1000 --max_key=10000 --value_size_mult=33`.
An example error message produced by the above command is shown below. The error sometimes arose from the checkpoint and other times arose from the main stress test DB.
```
Corruption: Size mismatch: WAL (log number: 119) in MANIFEST is 27938 bytes , but actually is 27859 bytes on disk.
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10185
Test Plan:
- repro unit test
- the above crash test command no longer finds the error. It does find a different error after a while longer such as "Corruption: WAL file 481 required by manifest but not in directory list"
Reviewed By: riversand963
Differential Revision: D37200993
Pulled By: ajkr
fbshipit-source-id: 98e0071c1a89f4d009888512ed89f9219779ae5f
Summary:
folly DistributedMutex is faster than standard mutexes though
imposes some static obligations on usage. See
https://github.com/facebook/folly/blob/main/folly/synchronization/DistributedMutex.h
for details. Here we use this alternative for our Cache implementations
(especially LRUCache) for better locking performance, when RocksDB is
compiled with folly.
Also added information about which distributed mutex implementation is
being used to cache_bench output and to DB LOG.
Intended follow-up:
* Use DMutex in more places, perhaps improving API to support non-scoped
locking
* Fix linking with fbcode compiler (needs ROCKSDB_NO_FBCODE=1 currently)
Credit: Thanks Siying for reminding me about this line of work that was previously
left unfinished.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10179
Test Plan:
for correctness, existing tests. CircleCI config updated.
Also Meta-internal buck build updated.
For performance, ran simultaneous before & after cache_bench. Out of three
comparison runs, the middle improvement to ops/sec was +21%:
Baseline: USE_CLANG=1 DEBUG_LEVEL=0 make -j24 cache_bench (fbcode
compiler)
```
Complete in 20.201 s; Rough parallel ops/sec = 1584062
Thread ops/sec = 107176
Operation latency (ns):
Count: 32000000 Average: 9257.9421 StdDev: 122412.04
Min: 134 Median: 3623.0493 Max: 56918500
Percentiles: P50: 3623.05 P75: 10288.02 P99: 30219.35 P99.9: 683522.04 P99.99: 7302791.63
```
New: (add USE_FOLLY=1)
```
Complete in 16.674 s; Rough parallel ops/sec = 1919135 (+21%)
Thread ops/sec = 135487
Operation latency (ns):
Count: 32000000 Average: 7304.9294 StdDev: 108530.28
Min: 132 Median: 3777.6012 Max: 91030902
Percentiles: P50: 3777.60 P75: 10169.89 P99: 24504.51 P99.9: 59721.59 P99.99: 1861151.83
```
Reviewed By: anand1976
Differential Revision: D37182983
Pulled By: pdillinger
fbshipit-source-id: a17eb05f25b832b6a2c1356f5c657e831a5af8d1
Summary:
Added an option, `WriteOptions::protection_bytes_per_key`, that controls how many bytes per key we use for integrity protection in `WriteBatch`. It takes effect when `WriteBatch::GetProtectionBytesPerKey() == 0`.
Currently the only supported value is eight. Invoking a user API with it set to any other nonzero value will result in `Status::NotSupported` returned to the user.
There is also a bug fix for integrity protection with `inplace_callback`, where we forgot to take into account the possible change in varint length when calculating KV checksum for the final encoded buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10037
Test Plan:
- Manual
- Set default value of `WriteOptions::protection_bytes_per_key` to eight and ran `make check -j24`
- Enabled in MyShadow for 1+ week
- Automated
- Unit tests have a `WriteMode` that enables the integrity protection via `WriteOptions`
- Crash test - in most cases, use `WriteOptions::protection_bytes_per_key` to enable integrity protection
Reviewed By: cbi42
Differential Revision: D36614569
Pulled By: ajkr
fbshipit-source-id: 8650087ceac9b61b560f1e5fafe5e1baf9c725fb
Summary:
A consequence of https://github.com/facebook/rocksdb/issues/9990 was requiring a non-empty DB ID to generate
new SST files. But if the DB ID is not tracked in the manifest and the IDENTITY file
is somehow truncated to 0 bytes, then an empty DB ID would be assigned, leading
to crash. This change ensures a non-empty DB ID is assigned and set in the
IDENTITY file.
Also,
* Some light refactoring to clean up the logic
* (I/O efficiency) If the ID is tracked in the manifest and already matches the
IDENTITY file, don't needlessly overwrite the file.
* (Debugging) Log the DB ID to info log on open, because sometimes IDENTITY
can change if DB is moved around (though it would be unusual for info log to
be copied/moved without IDENTITY file)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10173
Test Plan: unit tests expanded/updated
Reviewed By: ajkr
Differential Revision: D37176545
Pulled By: pdillinger
fbshipit-source-id: a9b414cd35bfa33de48af322a36c24538d50bef1
Summary:
This code is unreachable when `ROCKSDB_LITE` not defined. And it cause build fail on my environment VS2019 16.11.15.
```
-- Selecting Windows SDK version 10.0.19041.0 to target Windows 10.0.19044.
-- The CXX compiler identification is MSVC 19.29.30145.0
-- The C compiler identification is MSVC 19.29.30145.0
-- The ASM compiler identification is MSVC
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10146
Reviewed By: akankshamahajan15
Differential Revision: D37112916
Pulled By: ajkr
fbshipit-source-id: e0b2bf3055d6fac1b3fb40b9f02c4cbae3f82757
Summary:
`PinnableSlice` may hold a handle to a cache value which must be released to correctly decrement the ref-counter. However, when `PinnableSlice` variables are reused, e.g. like this:
```
PinnableSlice pin_slice;
db.Get("foo", &pin_slice);
db.Get("foo", &pin_slice);
```
then the second `Get` simply overwrites the old value in `pin_slice` and the handle returned by the first `Get` is _not_ released.
This PR adds `Reset` calls to the `Get`/`MultiGet` calls that accept `PinnableSlice` arguments to ensure proper cleanup of old values.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10166
Reviewed By: hx235
Differential Revision: D37151632
Pulled By: ajkr
fbshipit-source-id: 9dd3c3288300f560531b843f67db11aeb569a9ff
Summary:
In RocksDB, keys are associated with (internal) sequence numbers which denote when the keys are written
to the database. Sequence numbers in different RocksDB instances are unrelated, thus not comparable.
It is nice if we can associate sequence numbers with their corresponding actual timestamps. One thing we can
do is to support user-defined timestamp, which allows the applications to specify the format of custom timestamps
and encode a timestamp with each key. More details can be found at https://github.com/facebook/rocksdb/wiki/User-defined-Timestamp-%28Experimental%29.
This PR provides a different but complementary approach. We can associate rocksdb snapshots (defined in
https://github.com/facebook/rocksdb/blob/7.2.fb/include/rocksdb/snapshot.h#L20) with **user-specified** timestamps.
Since a snapshot is essentially an object representing a sequence number, this PR establishes a bi-directional mapping between sequence numbers and timestamps.
In the past, snapshots are usually taken by readers. The current super-version is grabbed, and a `rocksdb::Snapshot`
object is created with the last published sequence number of the super-version. You can see that the reader actually
has no good idea of what timestamp to assign to this snapshot, because by the time the `GetSnapshot()` is called,
an arbitrarily long period of time may have already elapsed since the last write, which is when the last published
sequence number is written.
This observation motivates the creation of "timestamped" snapshots on the write path. Currently, this functionality is
exposed only to the layer of `TransactionDB`. Application can tell RocksDB to create a snapshot when a transaction
commits, effectively associating the last sequence number with a timestamp. It is also assumed that application will
ensure any two snapshots with timestamps should satisfy the following:
```
snapshot1.seq < snapshot2.seq iff. snapshot1.ts < snapshot2.ts
```
If the application can guarantee that when a reader takes a timestamped snapshot, there is no active writes going on
in the database, then we also allow the user to use a new API `TransactionDB::CreateTimestampedSnapshot()` to create
a snapshot with associated timestamp.
Code example
```cpp
// Create a timestamped snapshot when committing transaction.
txn->SetCommitTimestamp(100);
txn->SetSnapshotOnNextOperation();
txn->Commit();
// A wrapper API for convenience
Status Transaction::CommitAndTryCreateSnapshot(
std::shared_ptr<TransactionNotifier> notifier,
TxnTimestamp ts,
std::shared_ptr<const Snapshot>* ret);
// Create a timestamped snapshot if caller guarantees no concurrent writes
std::pair<Status, std::shared_ptr<const Snapshot>> snapshot = txn_db->CreateTimestampedSnapshot(100);
```
The snapshots created in this way will be managed by RocksDB with ref-counting and potentially shared with
other readers. We provide the following APIs for readers to retrieve a snapshot given a timestamp.
```cpp
// Return the timestamped snapshot correponding to given timestamp. If ts is
// kMaxTxnTimestamp, then we return the latest timestamped snapshot if present.
// Othersise, we return the snapshot whose timestamp is equal to `ts`. If no
// such snapshot exists, then we return null.
std::shared_ptr<const Snapshot> TransactionDB::GetTimestampedSnapshot(TxnTimestamp ts) const;
// Return the latest timestamped snapshot if present.
std::shared_ptr<const Snapshot> TransactionDB::GetLatestTimestampedSnapshot() const;
```
We also provide two additional APIs for stats collection and reporting purposes.
```cpp
Status TransactionDB::GetAllTimestampedSnapshots(
std::vector<std::shared_ptr<const Snapshot>>& snapshots) const;
// Return timestamped snapshots whose timestamps fall in [ts_lb, ts_ub) and store them in `snapshots`.
Status TransactionDB::GetTimestampedSnapshots(
TxnTimestamp ts_lb,
TxnTimestamp ts_ub,
std::vector<std::shared_ptr<const Snapshot>>& snapshots) const;
```
To prevent the number of timestamped snapshots from growing infinitely, we provide the following API to release
timestamped snapshots whose timestamps are older than or equal to a given threshold.
```cpp
void TransactionDB::ReleaseTimestampedSnapshotsOlderThan(TxnTimestamp ts);
```
Before shutdown, RocksDB will release all timestamped snapshots.
Comparison with user-defined timestamp and how they can be combined:
User-defined timestamp persists every key with a timestamp, while timestamped snapshots maintain a volatile
mapping between snapshots (sequence numbers) and timestamps.
Different internal keys with the same user key but different timestamps will be treated as different by compaction,
thus a newer version will not hide older versions (with smaller timestamps) unless they are eligible for garbage collection.
In contrast, taking a timestamped snapshot at a certain sequence number and timestamp prevents all the keys visible in
this snapshot from been dropped by compaction. Here, visible means (seq < snapshot and most recent).
The timestamped snapshot supports the semantics of reading at an exact point in time.
Timestamped snapshots can also be used with user-defined timestamp.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9879
Test Plan:
```
make check
TEST_TMPDIR=/dev/shm make crash_test_with_txn
```
Reviewed By: siying
Differential Revision: D35783919
Pulled By: riversand963
fbshipit-source-id: 586ad905e169189e19d3bfc0cb0177a7239d1bd4
Summary:
This PR helps handle the race condition mentioned in this comment thread: https://github.com/facebook/rocksdb/pull/7884#discussion_r572402281 In case where actual full_history_ts_low is higher than the user's requested ts, return a try again message so they don't have the misconception that data between [ts, full_history_ts_low) is kept.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10126
Test Plan:
```
$COMPILE_WITH_ASAN=1 make -j24 all
$./db_with_timestamp_basic_test --gtest_filter=UpdateFullHistoryTsLowTest.ConcurrentUpdate
$ make -j24 check
```
Reviewed By: riversand963
Differential Revision: D37055368
Pulled By: jowlyzhang
fbshipit-source-id: 787fd0984a246540fa03ac227b1d232590d27828
Summary:
The default implementation of Close() function in Directory/FSDirectory classes returns `NotSupported` status. However, we don't want operations that worked in older versions to begin failing after upgrading when run on FileSystems that have not implemented Directory::Close() yet. So we require the upper level that calls Close() function should properly handle "NotSupported" status instead of treating it as an error status.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10127
Reviewed By: ajkr
Differential Revision: D36971112
Pulled By: littlepig2013
fbshipit-source-id: 100f0e6ad1191e1acc1ba6458c566a11724cf466
Summary:
As pointed out by [https://github.com/facebook/rocksdb/pull/8351#discussion_r645765422](https://github.com/facebook/rocksdb/pull/8351#discussion_r645765422), check `manual_compaction_paused` and `manual_compaction_canceled` can be reduced by setting `*canceled` to be true in `DisableManualCompaction()` and `*canceled` to be false in the last time calling `EnableManualCompaction()`.
Changed Tests: The origin `DBTest2.PausingManualCompaction1` uses a callback function to increase `manual_compaction_paused` and the origin CompactionJob/CompactionIterator with `manual_compaction_paused` can detect this. I changed the callback function so that it sets `*canceled` as true if `canceled` is not `nullptr` (to notify CompactionJob/CompactionIterator the compaction has been canceled).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10070
Test Plan: This change does not introduce new features, but some slight difference in compaction implementation. Run the same manual compaction unit tests as before (e.g., PausingManualCompaction[1-4], CancelManualCompaction[1-2], CancelManualCompactionWithListener in db_test2, and db_compaction_test).
Reviewed By: ajkr
Differential Revision: D36949133
Pulled By: littlepig2013
fbshipit-source-id: c5dc4c956fbf8f624003a0f5ad2690240063a821
Summary:
With this change, when a given read timestamp is smaller than the column-family's full_history_ts_low, Get(), MultiGet() and iterators APIs will return Status::InValidArgument().
Test plan
```
$COMPILE_WITH_ASAN=1 make -j24 all
$./db_with_timestamp_basic_test --gtest_filter=DBBasicTestWithTimestamp.UpdateFullHistoryTsLow
$ make -j24 check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10109
Reviewed By: riversand963
Differential Revision: D36901126
Pulled By: jowlyzhang
fbshipit-source-id: 255feb1a66195351f06c1d0e42acb1ff74527f86
Summary:
If caller specifies a non-null `timestamp` argument in `DB::Get()` or a non-null `timestamps` in `DB::MultiGet()`,
RocksDB will return the timestamps of the point tombstones.
Note: DeleteRange is still unsupported.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10056
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D36677956
Pulled By: riversand963
fbshipit-source-id: 2d7af02cc7237b1829cd269086ea895a49d501ae
Summary:
Closing https://github.com/facebook/rocksdb/issues/10080
When `SyncWAL()` calls `MarkLogsSynced()`, even if there is only one active WAL file,
this event should still be added to the MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10087
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D36797580
Pulled By: riversand963
fbshipit-source-id: 24184c9dd606b3939a454ed41de6e868d1519999
Summary:
Currently, the DB directory file descriptor is left open until the deconstruction process (`DB::Close()` does not close the file descriptor). To verify this, comment out the lines between `db_ = nullptr` and `db_->Close()` (line 512, 513, 514, 515 in ldb_cmd.cc) to leak the ``db_'' object, build `ldb` tool and run
```
strace --trace=open,openat,close ./ldb --db=$TEST_TMPDIR --ignore_unknown_options put K1 V1 --create_if_missing
```
There is one directory file descriptor that is not closed in the strace log.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10049
Test Plan: Add a new unit test DBBasicTest.DBCloseAllDirectoryFDs: Open a database with different WAL directory and three different data directories, and all directory file descriptors should be closed after calling Close(). Explicitly call Close() after a directory file descriptor is not used so that the counter of directory open and close should be equivalent.
Reviewed By: ajkr, hx235
Differential Revision: D36722135
Pulled By: littlepig2013
fbshipit-source-id: 07bdc2abc417c6b30997b9bbef1f79aa757b21ff
Summary:
`db_impl.alive_log_files_` is used to track the WAL size in `db_impl.logs_`.
Get the `LogFileNumberSize` obj in `alive_log_files_` the same time as `log_writer` to keep them consistent.
For this issue, it's not safe to do `deque::reverse_iterator::operator*` and `deque::pop_front()` concurrently,
so remove the tail cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10086
Test Plan:
```
# on Windows
gtest-parallel ./db_test --gtest_filter=DBTest.FileCreationRandomFailure -r 1000 -w 100
```
Reviewed By: riversand963
Differential Revision: D36822373
Pulled By: jay-zhuang
fbshipit-source-id: 5e738051dfc7bcf6a15d85ba25e6365df6b6a6af
Summary:
In case of non-TransactionDB and avoid_flush_during_recovery = true, RocksDB won't
flush the data from WAL to L0 for all column families if possible. As a
result, not all column families can increase their log_numbers, and
min_log_number_to_keep won't change.
For transaction DB (.allow_2pc), even with the flush, there may be old WAL files that it must not delete because they can contain data of uncommitted transactions and min_log_number_to_keep won't change.
If we persist a new MANIFEST with
advanced log_numbers for some column families, then during a second
crash after persisting the MANIFEST, RocksDB will see some column
families' log_numbers larger than the corrupted wal, and the "column family inconsistency" error will be hit, causing recovery to fail.
As a solution, RocksDB will persist the new MANIFEST after successfully syncing the new WAL.
If a future recovery starts from the new MANIFEST, then it means the new WAL is successfully synced. Due to the sentinel empty write batch at the beginning, kPointInTimeRecovery of WAL is guaranteed to go after this point.
If future recovery starts from the old MANIFEST, it means the writing the new MANIFEST failed. We won't have the "SST ahead of WAL" error.
Currently, RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. This PR buffers the edits in a structure and writes to a new MANIFEST after recovery is successful
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9922
Test Plan:
1. Update unit tests to fail without this change
2. make crast_test -j
Branch with unit test and no fix https://github.com/facebook/rocksdb/pull/9942 to keep track of unit test (without fix)
Reviewed By: riversand963
Differential Revision: D36043701
Pulled By: akankshamahajan15
fbshipit-source-id: 5760970db0a0920fb73d3c054a4155733500acd9
Summary:
This variable is actually not being used for anything meaningful, thus remove it.
This can make https://github.com/facebook/rocksdb/issues/7516 slightly simpler by reducing the amount of state that must be made lock-free.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10078
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D36779817
Pulled By: riversand963
fbshipit-source-id: ffb0d9ad6149616917ae5e02bb28102cb90fc406
Summary:
For regular db instance and secondary instance, we return error and refuse to open DB if Logger creation fails.
Our current code allows it, but it is really difficult to debug because
there will be no LOG files. The same for OPTIONS file, which will be explored in another PR.
Furthermore, Arena::AllocateAligned(size_t bytes, size_t huge_page_size, Logger* logger) has an
assertion as the following:
```cpp
#ifdef MAP_HUGETLB
if (huge_page_size > 0 && bytes > 0) {
assert(logger != nullptr);
}
#endif
```
It can be removed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9984
Test Plan: make check
Reviewed By: jay-zhuang
Differential Revision: D36347754
Pulled By: riversand963
fbshipit-source-id: 529798c0511d2eaa2f0fd40cf7e61c4cbc6bc57e
Summary:
RocksDB uses the (no longer aptly named) SST file manager (see https://github.com/facebook/rocksdb/wiki/Managing-Disk-Space-Utilization) to track and potentially limit the space used by SST and blob files (as well as to rate-limit the deletion of these data files). The SST file manager tracks the SST and blob file sizes in an in-memory hash map, which has to be rebuilt during DB open. File sizes can be generally obtained by querying the file system; however, there is a performance optimization possibility here since the sizes of SST and blob files are also tracked in the RocksDB MANIFEST, so we can simply pass the file sizes stored there instead of consulting the file system for each file. Currently, this optimization is only implemented for SST files; we would like to extend it to blob files as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10062
Test Plan:
Add unit tests for the change to the test suite
ltamasi riversand963 akankshamahajan15
Reviewed By: ltamasi
Differential Revision: D36726621
Pulled By: gangliao
fbshipit-source-id: 4010dc46ef7306142f1c2e0d1c3bf75b196ef82a
Summary:
This PR adds timestamp support to the secondary DB instance.
With this, these timestamp related APIs are supported:
ReadOptions.timestamp : read should return the latest data visible to this specified timestamp
Iterator::timestamp() : returns the timestamp associated with the key, value
DB:Get(..., std::string* timestamp) : returns the timestamp associated with the key, value in timestamp
Test plan (on devserver):
```
$COMPILE_WITH_ASAN=1 make -j24 all
$./db_secondary_test --gtest_filter=DBSecondaryTestWithTimestamp*
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10061
Reviewed By: riversand963
Differential Revision: D36722915
Pulled By: jowlyzhang
fbshipit-source-id: 644ada39e4e51164a759593478c38285e0c1a666
Summary:
Right now, in FindObsoleteFiles() we build a list of all live SST files from all existing Versions. This is all done in DB mutex, and is O(m*n) where m is number of versions and n is number of files. In some extereme cases, it can take very long. The list is used to see whether a candidate file still shows up in a version. With this commit, every candidate file is directly check against all the versions for file existance. This operation would be O(m*k) where k is number of candidate files. Since is usually small (except perhaps full compaction in universal compaction), this is usually much faster than the previous solution.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10040
Test Plan: TBD
Reviewed By: riversand963
Differential Revision: D36613391
fbshipit-source-id: 3f13b090f755d9b3ae417faec62cd6e798bac1eb
Summary:
This PR fixes the issue of unstable snapshot during external SST file ingestion. Credit ajkr for the following walk through: consider these relevant steps for of IngestExternalFile():
(1) increase seqno while holding mutex -- 677d2b4a8f/db/db_impl/db_impl.cc (L4768)
(2) LogAndApply() -- 677d2b4a8f/db/db_impl/db_impl.cc (L4797-L4798)
(a) write to MANIFEST with mutex released a96a4a2f7b/db/version_set.cc (L4407)
(b) apply to in-memory state with mutex held
A snapshot taken during (2a) will be unstable. In particular, queries against that snapshot will not include data from the ingested file before (2b), and will include data from the ingested file after (2b).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10051
Test Plan:
Added a new unit test: `ExternalSSTFileBasicTest.WriteAfterReopenStableSnapshotWhileLoggingToManifest`.
```
make external_sst_file_basic_test
./external_sst_file_basic_test
```
Reviewed By: ajkr
Differential Revision: D36654033
Pulled By: cbi42
fbshipit-source-id: bf720cca313e0cf211585960f3aff04853a31b96
Summary:
This PR is the second and last part for adding user defined timestamp support to read only DB. Specifically, the change in this PR includes:
- `options.timestamp` respected by `CompactedDBImpl::Get` and `CompactedDBImpl::MultiGet` to return results visible up till that timestamp.
- `CompactedDBImpl::Get(...,std::string* timestsamp)` and `CompactedDBImpl::MultiGet(std::vector<std::string>* timestamps)` return the timestamp(s) associated with the key(s).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10030
Test Plan:
```
$COMPILE_WITH_ASAN=1 make -j24 all
$./db_readonly_with_timestamp_test --gtest_filter="DBReadOnlyTestWithTimestamp.CompactedDB*"
$./db_basic_test --gtest_filter="DBBasicTest.CompactedDB*"
$make all check
```
Reviewed By: riversand963
Differential Revision: D36613926
Pulled By: jowlyzhang
fbshipit-source-id: 5b7ed7fef822708c12e2caf7a8d2deb6a696f0f0
Summary:
info logging with DB Mutex could potentially invoke I/O and cause performance issues. Move three of the cases to use log buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10029
Test Plan: Run existing tests.
Reviewed By: jay-zhuang
Differential Revision: D36561694
fbshipit-source-id: cabb93fea299001a6b4c2802fcba3fde27fa062c
Summary:
This PR adds timestamp support to a read only DB instance opened as `DBImplReadOnly`. A follow up PR will add the same support to `CompactedDBImpl`.
With this, read only database has these timestamp related APIs:
`ReadOptions.timestamp` : read should return the latest data visible to this specified timestamp
`Iterator::timestamp()` : returns the timestamp associated with the key, value
`DB:Get(..., std::string* timestamp)` : returns the timestamp associated with the key, value in `timestamp`
Test plan (on devserver):
```
$COMPILE_WITH_ASAN=1 make -j24 all
$./db_with_timestamp_basic_test --gtest_filter=DBBasicTestWithTimestamp.ReadOnlyDB*
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10004
Reviewed By: riversand963
Differential Revision: D36434422
Pulled By: jowlyzhang
fbshipit-source-id: 5d949e65b1ffb845758000e2b310fdd4aae71cfb
Summary:
This PR implements a coroutine version of batched MultiGet in order to concurrently read from multiple SST files in a level using async IO, thus reducing the latency of the MultiGet. The API from the user perspective is still synchronous and single threaded, with the RocksDB part of the processing happening in the context of the caller's thread. In Version::MultiGet, the decision is made whether to call synchronous or coroutine code.
A good way to review this PR is to review the first 4 commits in order - de773b3, 70c2f70, 10b50e1, and 377a597 - before reviewing the rest.
TODO:
1. Figure out how to build it in CircleCI (requires some dependencies to be installed)
2. Do some stress testing with coroutines enabled
No regression in synchronous MultiGet between this branch and main -
```
./db_bench -use_existing_db=true --db=/data/mysql/rocksdb/prefix_scan -benchmarks="readseq,multireadrandom" -key_size=32 -value_size=512 -num=5000000 -batch_size=64 -multiread_batched=true -use_direct_reads=false -duration=60 -ops_between_duration_checks=1 -readonly=true -adaptive_readahead=true -threads=16 -cache_size=10485760000 -async_io=false -multiread_stride=40000 -statistics
```
Branch - ```multireadrandom : 4.025 micros/op 3975111 ops/sec 60.001 seconds 238509056 operations; 2062.3 MB/s (14767808 of 14767808 found)```
Main - ```multireadrandom : 3.987 micros/op 4013216 ops/sec 60.001 seconds 240795392 operations; 2082.1 MB/s (15231040 of 15231040 found)```
More benchmarks in various scenarios are given below. The measurements were taken with ```async_io=false``` (no coroutines) and ```async_io=true``` (use coroutines). For an IO bound workload (with every key requiring an IO), the coroutines version shows a clear benefit, being ~2.6X faster. For CPU bound workloads, the coroutines version has ~6-15% higher CPU utilization, depending on how many keys overlap an SST file.
1. Single thread IO bound workload on remote storage with sparse MultiGet batch keys (~1 key overlap/file) -
No coroutines - ```multireadrandom : 831.774 micros/op 1202 ops/sec 60.001 seconds 72136 operations; 0.6 MB/s (72136 of 72136 found)```
Using coroutines - ```multireadrandom : 318.742 micros/op 3137 ops/sec 60.003 seconds 188248 operations; 1.6 MB/s (188248 of 188248 found)```
2. Single thread CPU bound workload (all data cached) with ~1 key overlap/file -
No coroutines - ```multireadrandom : 4.127 micros/op 242322 ops/sec 60.000 seconds 14539384 operations; 125.7 MB/s (14539384 of 14539384 found)```
Using coroutines - ```multireadrandom : 4.741 micros/op 210935 ops/sec 60.000 seconds 12656176 operations; 109.4 MB/s (12656176 of 12656176 found)```
3. Single thread CPU bound workload with ~2 key overlap/file -
No coroutines - ```multireadrandom : 3.717 micros/op 269000 ops/sec 60.000 seconds 16140024 operations; 139.6 MB/s (16140024 of 16140024 found)```
Using coroutines - ```multireadrandom : 4.146 micros/op 241204 ops/sec 60.000 seconds 14472296 operations; 125.1 MB/s (14472296 of 14472296 found)```
4. CPU bound multi-threaded (16 threads) with ~4 key overlap/file -
No coroutines - ```multireadrandom : 4.534 micros/op 3528792 ops/sec 60.000 seconds 211728728 operations; 1830.7 MB/s (12737024 of 12737024 found) ```
Using coroutines - ```multireadrandom : 4.872 micros/op 3283812 ops/sec 60.000 seconds 197030096 operations; 1703.6 MB/s (12548032 of 12548032 found) ```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9968
Reviewed By: akankshamahajan15
Differential Revision: D36348563
Pulled By: anand1976
fbshipit-source-id: c0ce85a505fd26ebfbb09786cbd7f25202038696
Summary:
Start tracking SST unique id in MANIFEST, which is used to verify with
SST properties to make sure the SST file is not overwritten or
misplaced. A DB option `try_verify_sst_unique_id` is introduced to
enable/disable the verification, if enabled, it opens all SST files
during DB-open to read the unique_id from table properties (default is
false), so it's recommended to use it with `max_open_files = -1` to
pre-open the files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9990
Test Plan: unittests, format-compatible test, mini-crash
Reviewed By: anand1976
Differential Revision: D36381863
Pulled By: jay-zhuang
fbshipit-source-id: 89ea2eb6b35ed3e80ead9c724eb096083eaba63f
Summary:
In case of non-TransactionDB and avoid_flush_during_recovery = true, RocksDB won't
flush the data from WAL to L0 for all column families if possible. As a
result, not all column families can increase their log_numbers, and
min_log_number_to_keep won't change.
For transaction DB (.allow_2pc), even with the flush, there may be old WAL files that it must not delete because they can contain data of uncommitted transactions and min_log_number_to_keep won't change.
If we persist a new MANIFEST with
advanced log_numbers for some column families, then during a second
crash after persisting the MANIFEST, RocksDB will see some column
families' log_numbers larger than the corrupted WAL, and the "column family inconsistency" error will be hit, causing recovery to fail.
This PR update unit tests to emulate the errors and tests are failing without a fix.
Error:
```
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/0
db/corruption_test.cc:1190: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF test_cf
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/0, where GetParam() = (true, false) (91 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/1
db/corruption_test.cc:1190: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF test_cf
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/1, where GetParam() = (false, false) (92 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/2
db/corruption_test.cc:1190: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF test_cf
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/2, where GetParam() = (true, true) (95 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/3
db/corruption_test.cc:1190: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF test_cf
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecovery/3, where GetParam() = (false, true) (92 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/0
db/corruption_test.cc:1354: Failure
TransactionDB::Open(options, txn_db_opts, dbname_, cf_descs, &handles, &txn_db)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/0, where GetParam() = (true, false) (94 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/1
db/corruption_test.cc:1354: Failure
TransactionDB::Open(options, txn_db_opts, dbname_, cf_descs, &handles, &txn_db)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/1, where GetParam() = (false, false) (97 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/2
db/corruption_test.cc:1354: Failure
TransactionDB::Open(options, txn_db_opts, dbname_, cf_descs, &handles, &txn_db)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/2, where GetParam() = (true, true) (94 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/3
db/corruption_test.cc:1354: Failure
TransactionDB::Open(options, txn_db_opts, dbname_, cf_descs, &handles, &txn_db)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.TxnDbCrashDuringRecovery/3, where GetParam() = (false, true) (91 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/0
db/corruption_test.cc:1483: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/0, where GetParam() = (true, false) (93 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/1
db/corruption_test.cc:1483: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/1, where GetParam() = (false, false) (94 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/2
db/corruption_test.cc:1483: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/2, where GetParam() = (true, true) (90 ms)
[ RUN ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/3
db/corruption_test.cc:1483: Failure
DB::Open(options, dbname_, cf_descs, &handles, &db_)
Corruption: SST file is ahead of WALs in CF default
[ FAILED ] CorruptionTest/CrashDuringRecoveryWithCorruptionTest.CrashDuringRecoveryWithFlush/3, where GetParam() = (false, true) (93 ms)
[----------] 12 tests from CorruptionTest/CrashDuringRecoveryWithCorruptionTest (1116 ms total)
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9942
Test Plan: Not needed
Reviewed By: riversand963
Differential Revision: D36324112
Pulled By: akankshamahajan15
fbshipit-source-id: cab2075ac4ebe48f5ef93a6ea162558aa4fc334d
Summary:
ToString() is created as some platform doesn't support std::to_string(). However, we've already used std::to_string() by mistake for 16 months (in db/db_info_dumper.cc). This commit just remove ToString().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9955
Test Plan: Watch CI tests
Reviewed By: riversand963
Differential Revision: D36176799
fbshipit-source-id: bdb6dcd0e3a3ab96a1ac810f5d0188f684064471
Summary:
dont -> don't
refered -> referred
This is a re-run of PR#7785 and acc9679 since these typos keep coming back.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9653
Reviewed By: jay-zhuang
Differential Revision: D34879593
fbshipit-source-id: d7631fb779ea0129beae92abfb838038e60790f8
Summary:
Right now we still don't fully use std::numeric_limits but use a macro, mainly for supporting VS 2013. Right now we only support VS 2017 and up so it is not a problem. The code comment claims that MinGW still needs it. We don't have a CI running MinGW so it's hard to validate. since we now require C++17, it's hard to imagine MinGW would still build RocksDB but doesn't support std::numeric_limits<>.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9954
Test Plan: See CI Runs.
Reviewed By: riversand963
Differential Revision: D36173954
fbshipit-source-id: a35a73af17cdcae20e258cdef57fcf29a50b49e0
Summary:
`VerifyChecksum()` does not specify `largest_seqno` when creating a `TableReader`. As a result, the `TableReader` uses the `TableReaderOptions` default value (0) for `largest_seqno`. This causes the following error when the file has a nonzero global seqno in its properties:
```
Corruption: An external sst file with version 2 have global seqno property with value , while largest seqno in the file is 0
```
This PR fixes this by specifying `largest_seqno` in `VerifyChecksumInternal` with `largest_seqno` from the file metadata.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9919
Test Plan: `make check`
Reviewed By: ajkr
Differential Revision: D36028824
Pulled By: cbi42
fbshipit-source-id: 428d028a79386f46ef97bb6b6051dc76c83e1f2b
Summary:
Left HISTORY.md and unit tests.
Added a new unit test to repro the corruption scenario that this PR fixes, and HISTORY.md line for that.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9906
Reviewed By: riversand963
Differential Revision: D35940093
Pulled By: ajkr
fbshipit-source-id: 9816f99e1ce405ba36f316beb4f6378c37c8c86b
Summary:
Make `DB::GetUpdatesSince` return early if told to scan WALs generated by transactions
with write-prepared or write-unprepared policies (`seq_per_batch` is true), as indicated by
API comment.
Also add checks to `TransactionLogIterator` to clarify some conditions.
No API change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9459
Test Plan:
make check
Closing https://github.com/facebook/rocksdb/issues/1565
Reviewed By: akankshamahajan15
Differential Revision: D33821243
Pulled By: riversand963
fbshipit-source-id: c8b155d020ce0980e2d3b3b1da40b96e65b48d79
Summary:
**This PR does not affect the functionality of `DB` and write-committed transactions.**
`CompactionIterator` uses `KeyCommitted(seq)` to determine if a key in the database is committed.
As the name 'write-committed' implies, if write-committed policy is used, a key exists in the database only if
it is committed. In fact, the implementation of `KeyCommitted()` is as follows:
```
inline bool KeyCommitted(SequenceNumber seq) {
// For non-txn-db and write-committed, snapshot_checker_ is always nullptr.
return snapshot_checker_ == nullptr ||
snapshot_checker_->CheckInSnapshot(seq, kMaxSequence) == SnapshotCheckerResult::kInSnapshot;
}
```
With that being said, we focus on write-prepared/write-unprepared transactions.
A few notes:
- A key can exist in the db even if it's uncommitted. Therefore, we rely on `snapshot_checker_` to determine data visibility. We also require that all writes go through transaction API instead of the raw `WriteBatch` + `Write`, thus at most one uncommitted version of one user key can exist in the database.
- `CompactionIterator` outputs a key as long as the key is uncommitted.
Due to the above reasons, it is possible that `CompactionIterator` decides to output an uncommitted key without
doing further checks on the key (`NextFromInput()`). By the time the key is being prepared for output, the key becomes
committed because the `snapshot_checker_(seq, kMaxSequence)` becomes true in the implementation of `KeyCommitted()`.
Then `CompactionIterator` will try to zero its sequence number and hit assertion error if the key is a tombstone.
To fix this issue, we should make the `CompactionIterator` see a consistent view of the input keys. Note that
for write-prepared/write-unprepared, the background flush/compaction jobs already take a "job snapshot" before starting
processing keys. The job snapshot is released only after the entire flush/compaction finishes. We can use this snapshot
to determine whether a key is committed or not with minor change to `KeyCommitted()`.
```
inline bool KeyCommitted(SequenceNumber sequence) {
// For non-txn-db and write-committed, snapshot_checker_ is always nullptr.
return snapshot_checker_ == nullptr ||
snapshot_checker_->CheckInSnapshot(sequence, job_snapshot_) ==
SnapshotCheckerResult::kInSnapshot;
}
```
As a result, whether a key is committed or not will remain a constant throughout compaction, causing no trouble
for `CompactionIterator`s assertions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9830
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D35561162
Pulled By: riversand963
fbshipit-source-id: 0e00d200c195240341cfe6d34cbc86798b315b9f
Summary:
Add the ability to cancel remote compaction on the remote side by
setting `OpenAndCompactOptions.canceled` to true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9725
Test Plan: added unittest
Reviewed By: ajkr
Differential Revision: D35018800
Pulled By: jay-zhuang
fbshipit-source-id: be3652f9645e0347df429e42a5614d5a9b3a1ec4
Summary:
Especially after updating to C++17, I don't see a compelling case for
*requiring* any folly components in RocksDB. I was able to purge the existing
hard dependencies, and it can be quite difficult to strip out non-trivial components
from folly for use in RocksDB. (The prospect of doing that on F14 has changed
my mind on the best approach here.)
But this change creates an optional integration where we can plug in
components from folly at compile time, starting here with F14FastMap to replace
std::unordered_map when possible (probably no public APIs for example). I have
replaced the biggest CPU users of std::unordered_map with compile-time
pluggable UnorderedMap which will use F14FastMap when USE_FOLLY is set.
USE_FOLLY is always set in the Meta-internal buck build, and a simulation of
that is in the Makefile for public CI testing. A full folly build is not needed, but
checking out the full folly repo is much simpler for getting the dependency,
and anything else we might want to optionally integrate in the future.
Some picky details:
* I don't think the distributed mutex stuff is actually used, so it was easy to remove.
* I implemented an alternative to `folly::constexpr_log2` (which is much easier
in C++17 than C++11) so that I could pull out the hard dependencies on
`ConstexprMath.h`
* I had to add noexcept move constructors/operators to some types to make
F14's complainUnlessNothrowMoveAndDestroy check happy, and I added a
macro to make that easier in some common cases.
* Updated Meta-internal buck build to use folly F14Map (always)
No updates to HISTORY.md nor INSTALL.md as this is not (yet?) considered a
production integration for open source users.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9546
Test Plan:
CircleCI tests updated so that a couple of them use folly.
Most internal unit & stress/crash tests updated to use Meta-internal latest folly.
(Note: they should probably use buck but they currently use Makefile.)
Example performance improvement: when filter partitions are pinned in cache,
they are tracked by PartitionedFilterBlockReader::filter_map_ and we can build
a test that exercises that heavily. Build DB with
```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters
```
and test with (simultaneous runs with & without folly, ~20 times each to see
convergence)
```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench_folly -readonly -use_existing_db -benchmarks=readrandom -num=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters -duration=40 -pin_l0_filter_and_index_blocks_in_cache
```
Average ops/s no folly: 26229.2
Average ops/s with folly: 26853.3 (+2.4%)
Reviewed By: ajkr
Differential Revision: D34181736
Pulled By: pdillinger
fbshipit-source-id: ffa6ad5104c2880321d8a1aa7187e00ab0d02e94
Summary:
So the user is able to set event listener on the compactor
side.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9821
Test Plan: unittest added
Reviewed By: ajkr
Differential Revision: D35485388
Pulled By: jay-zhuang
fbshipit-source-id: 669d8a3aaee012b75b940470306756c03ffa09b2
Summary:
1) In case of non-TransactionDB and avoid_flush_during_recovery = true, RocksDB won't
flush the data from WAL to L0 for all column families if possible. As a
result, not all column families can increase their log_numbers, and
min_log_number_to_keep won't change.
2) For transaction DB (.allow_2pc), even with the flush, there may be old WAL files that it must not delete because they can contain data of uncommitted transactions and min_log_number_to_keep won't change.
If we persist a new MANIFEST with
advanced log_numbers for some column families, then during a second
crash after persisting the MANIFEST, RocksDB will see some column
families' log_numbers larger than the corrupted wal, and the "column family inconsistency" error will be hit, causing recovery to fail.
As a solution,
1. the corrupted WALs whose numbers are larger than the
corrupted wal and smaller than the new WAL will be moved to archive folder.
2. Currently, RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. This PR buffers the edits in a structure and writes to a new MANIFEST after recovery is successful
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9634
Test Plan:
1. Added new unit tests
2. make crast_test -j
Reviewed By: riversand963
Differential Revision: D34463666
Pulled By: akankshamahajan15
fbshipit-source-id: e233d3af0ed4e2028ca0cf051e5a334a0fdc9d19
Summary:
Options `preserve_deletes` and `iter_start_seqnum` have been removed since 7.0.
This PR removes dead code related to these two removed options.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9825
Test Plan: make check
Reviewed By: akankshamahajan15
Differential Revision: D35517950
Pulled By: riversand963
fbshipit-source-id: 86282ce5ec4087acb94a06a42a1b6d55b1715482
Summary:
For write-prepared/write-unprepared transactions,
GetCommitTimeWriteBatch() can be used only if the transaction is started
with `TransactionOptions::use_only_the_last_commit_time_batch_for_recovery` set
to true. Otherwise, it is possible that multiple uncommitted versions of the
same key exist in the database. During bottommost compaction, RocksDB may
set the sequence numbers of both to zero once they become committed, causing
output SST file to have two identical internal keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9794
Test Plan:
make check
pay special attention to the following
```
transaction_test --gtest_filter=MySQLStyleTransactionTest/MySQLStyleTransactionTest.TransactionStressTest/*
```
Reviewed By: lth
Differential Revision: D35327214
Pulled By: riversand963
fbshipit-source-id: 3bae00a28359c10e96e4c6f676d20de5610d8a0f
Summary:
Right now we log a wrong error when DB::Open() fails. Fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9784
Test Plan: CI runs should pass
Reviewed By: ajkr, riversand963
Differential Revision: D35290203
fbshipit-source-id: ffc640afa27f6b0a2382ee153dc43f28d9e242be
Summary:
There is no need to release-and-acquire immediately when no listener is registered. This is
what we have been doing for `NotifyOnFlushBegin()`, `NotifyOnFlushCompleted()`, `NotifyOnCompactionBegin()`,
`NotifyOnCompactionCompleted()`, and some other `NotifyOnXX` methods in event_helpers.cc.
Do the same for `NotifyOnMemTableSealed ()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9758
Test Plan: make check
Reviewed By: jay-zhuang
Differential Revision: D35159552
Pulled By: riversand963
fbshipit-source-id: 6e0aac50bd5c8f506d809b6638c33a7a28d1e87f
Summary:
much needed
Some other minor tweaks also
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9778
Test Plan: existing tests
Reviewed By: ajkr
Differential Revision: D35258195
Pulled By: pdillinger
fbshipit-source-id: 974ddafc23a540aacceb91da72e81593d818f99c
Summary:
Although ColumnFamilySet comments say that DB mutex can be
freed during iteration, as long as you hold a ref while releasing DB
mutex, this is not quite true because UnrefAndTryDelete might delete cfd
right before it is needed to get ->next_ for the next iteration of the
loop.
This change solves the problem by making a wrapper class that makes such
iteration easier while handling the tricky details of UnrefAndTryDelete
on the previous cfd only after getting next_ in operator++.
FreeDeadColumnFamilies should already have been obsolete; this removes
it for good. Similarly, ColumnFamilySet::iterator doesn't need to check
for cfd with 0 refs, because those are immediately deleted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9730
Test Plan:
was reported with ASAN on unit tests like
DBLogicalBlockSizeCacheTest.CreateColumnFamily (very rare); keep watching
Reviewed By: ltamasi
Differential Revision: D35038143
Pulled By: pdillinger
fbshipit-source-id: 0a5478d5be96c135343a00603711b7df43ae19c9
Summary:
There is a race condition if WAL tracking in the MANIFEST is enabled in a database that disables 2PC.
The race condition is between two background flush threads trying to install flush results to the MANIFEST.
Consider an example database with two column families: "default" (cfd0) and "cf1" (cfd1). Initially,
both column families have one mutable (active) memtable whose data backed by 6.log.
1. Trigger a manual flush for "cf1", creating a 7.log
2. Insert another key to "default", and trigger flush for "default", creating 8.log
3. BgFlushThread1 finishes writing 9.sst
4. BgFlushThread2 finishes writing 10.sst
```
Time BgFlushThread1 BgFlushThread2
| mutex_.Lock()
| precompute min_wal_to_keep as 6
| mutex_.Unlock()
| mutex_.Lock()
| precompute min_wal_to_keep as 6
| join MANIFEST write queue and mutex_.Unlock()
| write to MANIFEST
| mutex_.Lock()
| cfd1->log_number = 7
| Signal bg_flush_2 and mutex_.Unlock()
| wake up and mutex_.Lock()
| cfd0->log_number = 8
| FindObsoleteFiles() with job_context->log_number == 7
| mutex_.Unlock()
| PurgeObsoleteFiles() deletes 6.log
V
```
As shown in the above, BgFlushThread2 thinks that the min wal to keep is 6.log because "cf1" has unflushed data in 6.log (cf1.log_number=6).
Similarly, BgThread1 thinks that min wal to keep is also 6.log because "default" has unflushed data (default.log_number=6).
No WAL deletion will be written to MANIFEST because 6 is equal to `versions_->wals_.min_wal_number_to_keep`,
due to https://github.com/facebook/rocksdb/blob/7.1.fb/db/memtable_list.cc#L513:L514.
The bg flush thread that finishes last will perform file purging. `job_context.log_number` will be evaluated as 7, i.e.
the min wal that contains unflushed data, causing 6.log to be deleted. However, MANIFEST thinks 6.log should still exist.
If you close the db at this point, you won't be able to re-open it if `track_and_verify_wal_in_manifest` is true.
We must handle the case of multiple bg flush threads, and it is difficult for one bg flush thread to know
the correct min wal number until the other bg flush threads have finished committing to the manifest and updated
the `cfd::log_number`.
To fix this issue, we rename an existing variable `min_log_number_to_keep_2pc` to `min_log_number_to_keep`,
and use it to track WAL file deletion in non-2pc mode as well.
This variable is updated only 1) during recovery with mutex held, or 2) in the MANIFEST write thread.
`min_log_number_to_keep` means RocksDB will delete WALs below it, although there may be WALs
above it which are also obsolete. Formally, we will have [min_wal_to_keep, max_obsolete_wal]. During recovery, we
make sure that only WALs above max_obsolete_wal are checked and added back to `alive_log_files_`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9715
Test Plan:
```
make check
```
Also ran stress test below (with asan) to make sure it completes successfully.
```
TEST_TMPDIR=/dev/shm/rocksdb OPT=-g ASAN_OPTIONS=disable_coredump=0 \
CRASH_TEST_EXT_ARGS=--compression_type=zstd SKIP_FORMAT_BUCK_CHECKS=1 \
make J=52 -j52 blackbox_asan_crash_test
```
Reviewed By: ltamasi
Differential Revision: D34984412
Pulled By: riversand963
fbshipit-source-id: c7b21a8d84751bb55ea79c9f387103d21b231005
Summary:
Originally, a corruption will be returned by `DBImpl::WriteImpl(batch...)` if batch is
null. This is inaccurate since there is no data corruption.
Return `Status::InvalidArgument()` instead.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9744
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D35086268
Pulled By: riversand963
fbshipit-source-id: 677397b007a53bc25210eac0178d49c9797b5951
Summary:
On CircleCI MacOS instances, we have been seeing the following assertion error:
```
Assertion failed: (alive_log_files_tail_ == alive_log_files_.rbegin()), function WriteToWAL, file /Users/distiller/project/db/db_impl/db_impl_write.cc, line 1213.
Received signal 6 (Abort trap: 6)
#0 0x1
https://github.com/facebook/rocksdb/issues/1 abort (in libsystem_c.dylib) + 120
https://github.com/facebook/rocksdb/issues/2 err (in libsystem_c.dylib) + 0
https://github.com/facebook/rocksdb/issues/3 rocksdb::DBImpl::WriteToWAL(rocksdb::WriteBatch const&, rocksdb::log::Writer*, unsigned long long*, unsigned long long*, rocksdb::Env::IOPriority, bool, bool) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:1213)
https://github.com/facebook/rocksdb/issues/4 rocksdb::DBImpl::WriteToWAL(rocksdb::WriteThread::WriteGroup const&, rocksdb::log::Writer*, unsigned long long*, bool, bool, unsigned long long) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:1251)
https://github.com/facebook/rocksdb/issues/5 rocksdb::DBImpl::WriteImpl(rocksdb::WriteOptions const&, rocksdb::WriteBatch*, rocksdb::WriteCallback*, unsigned long long*, unsigned long long, bool, unsigned long long*, unsigned long, rocksdb::PreReleaseCallback*) (in librocksdb.7.0.0.dylib) (db_impl_ rite.cc:421)
https://github.com/facebook/rocksdb/issues/6 rocksdb::DBImpl::Write(rocksdb::WriteOptions const&, rocksdb::WriteBatch*) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:109)
https://github.com/facebook/rocksdb/issues/7 rocksdb::DB::Put(rocksdb::WriteOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:2159)
https://github.com/facebook/rocksdb/issues/8 rocksdb::DBImpl::Put(rocksdb::WriteOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:37)
https://github.com/facebook/rocksdb/issues/9 rocksdb::DB::Put(rocksdb::WriteOptions const&, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) (in librocksdb.7.0.0.dylib) (db.h:382)
https://github.com/facebook/rocksdb/issues/10 rocksdb::DBBasicTestWithTimestampPrefixSeek_IterateWithPrefix_Test::TestBody() (in db_with_timestamp_basic_test) (db_with_timestamp_basic_test.cc:2926)
https://github.com/facebook/rocksdb/issues/11 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3899)
https://github.com/facebook/rocksdb/issues/12 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3935)
https://github.com/facebook/rocksdb/issues/13 testing::Test::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:3980)
https://github.com/facebook/rocksdb/issues/14 testing::TestInfo::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:4153)
https://github.com/facebook/rocksdb/issues/15 testing::TestCase::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:4266)
https://github.com/facebook/rocksdb/issues/16 testing::internal::UnitTestImpl::RunAllTests() (in db_with_timestamp_basic_test) (gtest-all.cc:6632)
https://github.com/facebook/rocksdb/issues/17 bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3899)
https://github.com/facebook/rocksdb/issues/18 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3935)
https://github.com/facebook/rocksdb/issues/19 testing::UnitTest::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:6242)
https://github.com/facebook/rocksdb/issues/20 RUN_ALL_TESTS() (in db_with_timestamp_basic_test) (gtest.h:22110)
https://github.com/facebook/rocksdb/issues/21 main (in db_with_timestamp_basic_test) (db_with_timestamp_basic_test.cc:3150)
https://github.com/facebook/rocksdb/issues/22 start (in libdyld.dylib) + 1
```
It's likely caused by concurrent, unprotected access to the deque, even though `back()` is never popped,
and we are comparing `rbegin()` with a cached `riterator`. To be safe, do the comparison only if we have mutex.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9717
Test Plan:
One example
Ssh to one CircleCI MacOS instance.
```
gtest-parallel -r 1000 -w 8 ./db_test --gtest_filter=DBTest.FlushesInParallelWithCompactRange
```
Reviewed By: pdillinger
Differential Revision: D34990696
Pulled By: riversand963
fbshipit-source-id: 62dd48ae6fedbda53d0a64d73de9b948b4c26eee
Summary:
Fix and enhance the background error recovery logic to handle the
following situations -
1. Background read errors during flush/compaction (previously was
resulting in unrecoverable state)
2. Fix auto recovery failure on read/write errors during atomic flush.
It was failing due to a bug in setting the resuming_from_bg_err variable
in AtomicFlushMemTablesToOutputFiles.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9679
Test Plan: Add new unit tests in error_handler_fs_test
Reviewed By: riversand963
Differential Revision: D34770097
Pulled By: anand1976
fbshipit-source-id: 136da973a28d684b9c74bdf668519b0cbbbe1742
Summary:
In https://github.com/facebook/rocksdb/issues/9659, when `DisableManualCompaction()` is issued, the foreground
manual compaction thread does not have to wait background compaction
thread to finish. Which could be a problem that the user re-enable
manual compaction with `EnableManualCompaction()`, it may re-enable the
BG compaction which supposed be cancelled.
This patch makes the FG compaction wait on
`manual_compaction_state.done`, which either be set by BG compaction or
Unschedule callback. Then when FG manual compaction thread returns, it
should not have BG compaction running. So shared_ptr is no longer needed
for `manual_compaction_state`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9694
Test Plan: a StressTest and unittest
Reviewed By: ajkr
Differential Revision: D34885472
Pulled By: jay-zhuang
fbshipit-source-id: e6476175b43e8c59cd49f5c09241036a0716c274
Summary:
PR9686 makes `WriteToWAL()` call `assert(...!=rend())` while not holding
db mutex or log mutex. Another thread may concurrently call
`pop_front()`, causing race condition.
To fix, assert only if mutex is held.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9698
Test Plan: COMPILE_WITH_TSAN=1 make check
Reviewed By: jay-zhuang
Differential Revision: D34898535
Pulled By: riversand963
fbshipit-source-id: 1ddfa5bf1b6ae8d409cab6ff6e1b5321c6803da9
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9686
According to https://www.cplusplus.com/reference/deque/deque/back/,
"
The container is accessed (neither the const nor the non-const versions modify the container).
The last element is potentially accessed or modified by the caller. Concurrently accessing or modifying other elements is safe.
"
Also according to https://www.cplusplus.com/reference/deque/deque/pop_front/,
"
The container is modified.
The first element is modified. Concurrently accessing or modifying other elements is safe (although see iterator validity above).
"
In RocksDB, we never pop the last element of `DBImpl::alive_log_files_`. We have been
exploiting this fact and the above two properties when ensuring correctness when
`DBImpl::alive_log_files_` may be accessed concurrently. Specifically, it can be accessed
in the write path when db mutex is released. Sometimes, the log_mute_ is held. It can also be accessed in `FindObsoleteFiles()`
when db mutex is always held. It can also be accessed
during recovery when db mutex is also held.
Given the fact that we never pop the last element of alive_log_files_, we currently do not
acquire additional locks when accessing it in `WriteToWAL()` as follows
```
alive_log_files_.back().AddSize(log_entry.size());
```
This is problematic.
Check source code of deque.h
```
back() _GLIBCXX_NOEXCEPT
{
__glibcxx_requires_nonempty();
...
}
pop_front() _GLIBCXX_NOEXCEPT
{
...
if (this->_M_impl._M_start._M_cur
!= this->_M_impl._M_start._M_last - 1)
{
...
++this->_M_impl._M_start._M_cur;
}
...
}
```
`back()` will actually call `__glibcxx_requires_nonempty()` first.
If `__glibcxx_requires_nonempty()` is enabled and not an empty macro,
it will call `empty()`
```
bool empty() {
return this->_M_impl._M_finish == this->_M_impl._M_start;
}
```
You can see that it will access `this->_M_impl._M_start`, racing with `pop_front()`.
Therefore, TSAN will actually catch the bug in this case.
To be able to use TSAN on our library and unit tests, we should always coordinate
concurrent accesses to STL containers properly.
We need to pass information about db mutex and log mutex into `WriteToWAL()`, otherwise
it's impossible to know which mutex to acquire inside the function.
To fix this, we can catch the tail of `alive_log_files_` by reference, so that we do not have to call `back()` in `WriteToWAL()`.
Reviewed By: pdillinger
Differential Revision: D34780309
fbshipit-source-id: 1def9821f0c437f2736c6a26445d75890377889b
Summary:
https://github.com/facebook/rocksdb/issues/9625 didn't change the unschedule condition which was waiting for the background thread to clean-up the compaction.
make sure we only unschedule the task when it's scheduled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9659
Reviewed By: ajkr
Differential Revision: D34651820
Pulled By: jay-zhuang
fbshipit-source-id: 23f42081b15ec8886cd81cbf131b116e0c74dc2f
Summary:
Timer crash when multiple DB instances doing heavy DB open and close
operations concurrently. Which is caused by adding a timer task with
smaller timestamp than the current running task. Fix it by moving the
getting new task timestamp part within timer mutex protection.
And other fixes:
- Disallow adding duplicated function name to timer
- Fix a minor memory leak in timer when a running task is cancelled
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9656
Reviewed By: ajkr
Differential Revision: D34626296
Pulled By: jay-zhuang
fbshipit-source-id: 6b6d96a5149746bf503546244912a9e41a0c5f6b
Summary:
As disscussed in (https://github.com/facebook/rocksdb/issues/9223), Here added a new API named DB::OpenAndTrimHistory, this API will open DB and trim data to the timestamp specofied by **trim_ts** (The data with newer timestamp than specified trim bound will be removed). This API should only be used at a timestamp-enabled db instance recovery.
And this PR implemented a new iterator named HistoryTrimmingIterator to support trimming history with a new API named DB::OpenAndTrimHistory. HistoryTrimmingIterator wrapped around the underlying InternalITerator such that keys whose timestamps newer than **trim_ts** should not be returned to the compaction iterator while **trim_ts** is not null.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9410
Reviewed By: ltamasi
Differential Revision: D34410207
Pulled By: riversand963
fbshipit-source-id: e54049dc234eccd673244c566b15df58df5a6236
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9629
Pessimistic transactions use pessimistic concurrency control, i.e. locking. Keys are
locked upon first operation that writes the key or has the intention of writing. For example,
`PessimisticTransaction::Put()`, `PessimisticTransaction::Delete()`,
`PessimisticTransaction::SingleDelete()` will write to or delete a key, while
`PessimisticTransaction::GetForUpdate()` is used by application to indicate
to RocksDB that the transaction has the intention of performing write operation later
in the same transaction.
Pessimistic transactions support two-phase commit (2PC). A transaction can be
`Prepared()`'ed and then `Commit()`. The prepare phase is similar to a promise: once
`Prepare()` succeeds, the transaction has acquired the necessary resources to commit.
The resources include locks, persistence of WAL, etc.
Write-committed transaction is the default pessimistic transaction implementation. In
RocksDB write-committed transaction, `Prepare()` will write data to the WAL as a prepare
section. `Commit()` will write a commit marker to the WAL and then write data to the
memtables. While writing to the memtables, different keys in the transaction's write batch
will be assigned different sequence numbers in ascending order.
Until commit/rollback, the transaction holds locks on the keys so that no other transaction
can write to the same keys. Furthermore, the keys' sequence numbers represent the order
in which they are committed and should be made visible. This is convenient for us to
implement support for user-defined timestamps.
Since column families with and without timestamps can co-exist in the same database,
a transaction may or may not involve timestamps. Based on this observation, we add two
optional members to each `PessimisticTransaction`, `read_timestamp_` and
`commit_timestamp_`. If no key in the transaction's write batch has timestamp, then
setting these two variables do not have any effect. For the rest of this commit, we discuss
only the cases when these two variables are meaningful.
read_timestamp_ is used mainly for validation, and should be set before first call to
`GetForUpdate()`. Otherwise, the latter will return non-ok status. `GetForUpdate()` calls
`TryLock()` that can verify if another transaction has written the same key since
`read_timestamp_` till this call to `GetForUpdate()`. If another transaction has indeed
written the same key, then validation fails, and RocksDB allows this transaction to
refine `read_timestamp_` by increasing it. Note that a transaction can still use `Get()`
with a different timestamp to read, but the result of the read should not be used to
determine data that will be written later.
commit_timestamp_ must be set after finishing writing and before transaction commit.
This applies to both 2PC and non-2PC cases. In the case of 2PC, it's usually set after
prepare phase succeeds.
We currently require that the commit timestamp be chosen after all keys are locked. This
means we disallow the `TransactionDB`-level APIs if user-defined timestamp is used
by the transaction. Specifically, calling `PessimisticTransactionDB::Put()`,
`PessimisticTransactionDB::Delete()`, `PessimisticTransactionDB::SingleDelete()`,
etc. will return non-ok status because they specify timestamps before locking the keys.
Users are also prompted to use the `Transaction` APIs when they receive the non-ok status.
Reviewed By: ltamasi
Differential Revision: D31822445
fbshipit-source-id: b82abf8e230216dc89cc519564a588224a88fd43
Summary:
- Make `compression_per_level` dynamical changeable with `SetOptions`;
- Fix a bug that `compression_per_level` is not used for flush;
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9658
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D34700749
Pulled By: jay-zhuang
fbshipit-source-id: a23b9dfa7ad03d393c1d71781d19e91de796f49c
Summary:
This bug affects use cases that meet the following conditions
- (has only the default column family or disables WAL) and
- has at least one event listener
- atomic flush is NOT affected.
If the above conditions meet, then RocksDB can release the db mutex before picking all the
existing memtables to flush. In the meantime, a snapshot can be created and db's sequence
number can still be incremented. The upcoming flush will ignore this snapshot.
A later read using this snapshot can return incorrect result.
To fix this issue, we call the listeners callbacks after picking the memtables so that we avoid
creating snapshots during this interval.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9648
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D34555456
Pulled By: riversand963
fbshipit-source-id: 1438981e9f069a5916686b1a0ad7627f734cf0ee
Summary:
PR https://github.com/facebook/rocksdb/issues/9557 introduced a race condition between manual compaction
foreground thread and background compaction thread.
This PR adds the ability to really unschedule manual compaction from
thread-pool queue by differentiate tag name for manual compaction and
other tasks.
Also fix an issue that db `close()` didn't cancel the manual compaction thread.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9625
Test Plan: unittest not hang
Reviewed By: ajkr
Differential Revision: D34410811
Pulled By: jay-zhuang
fbshipit-source-id: cb14065eabb8cf1345fa042b5652d4f788c0c40c
Summary:
We found a case of cacheline bouncing due to writers locking/unlocking `mutex_` and readers accessing `block_cache_tracer_`. We discovered it only after the issue was fixed by https://github.com/facebook/rocksdb/issues/9462 shifting the `DBImpl` members such that `mutex_` and `block_cache_tracer_` were naturally placed in separate cachelines in our regression testing setup. This PR forces the cacheline alignment of `mutex_` so we don't accidentally reintroduce the problem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9637
Reviewed By: riversand963
Differential Revision: D34502233
Pulled By: ajkr
fbshipit-source-id: 46aa313b7fe83e80c3de254e332b6fb242434c07
Summary:
**Context:**
As part of https://github.com/facebook/rocksdb/pull/6949, file deletion is disabled for faulty database on the IOError of MANIFEST write/sync and [re-enabled again during `DBImpl::Resume()` if all recovery is completed](e66199d848 (diff-d9341fbe2a5d4089b93b22c5ed7f666bc311b378c26d0786f4b50c290e460187R396)). Before re-enabling file deletion, it `assert(versions_->io_status().ok());`, which IMO assumes `versions_` is **the** `version_` in the recovery process.
However, this is not necessarily true due to `s = error_handler_.ClearBGError();` happening before that assertion can unblock some foreground thread by [`EventHelpers::NotifyOnErrorRecoveryEnd()`](3122cb4358/db/error_handler.cc (L552-L553)) as part of the `ClearBGError()`. That foreground thread can do whatever it wants including closing/reopening the db and clean up that same `versions_`.
As a consequence, `assert(versions_->io_status().ok());`, will access `io_status()` of a nullptr and test like `DBErrorHandlingFSTest.MultiCFWALWriteError` becomes flaky. The unblocked foreground thread (in this case, the testing thread) proceeds to [reopen the db](https://github.com/facebook/rocksdb/blob/6.29.fb/db/error_handler_fs_test.cc?fbclid=IwAR1kQOxSbTUmaHQPAGz5jdMHXtDsDFKiFl8rifX-vIz4B23Y0S9jBkssSCg#L1494), where [`versions_` gets reset to nullptr](https://github.com/facebook/rocksdb/blob/6.29.fb/db/db_impl/db_impl.cc?fbclid=IwAR2uRhwBiPKgmE9q_6CM2mzbfwjoRgsGpXOrHruSJUDcAKc9rYZtVSvKdOY#L678) as part of the old db clean-up. If this happens right before `assert(versions_->io_status().ok()); ` gets excuted in the background thread, then we can see error like
```
db/db_impl/db_impl.cc:420:5: runtime error: member call on null pointer of type 'rocksdb::VersionSet'
assert(versions_->io_status().ok());
```
**Summary:**
- I proposed to call `s = error_handler_.ClearBGError();` after we know it's fine to wake up foreground, which I think is right before we LOG `ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");`
- As the context, the orignal https://github.com/facebook/rocksdb/pull/3997 introducing `DBImpl::Resume()` calls `s = error_handler_.ClearBGError();` very close to calling `ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");` while the later https://github.com/facebook/rocksdb/pull/6949 distances these two calls a bit.
- And it seems fine to me that `s = error_handler_.ClearBGError();` happens after `EnableFileDeletions(/*force=*/true);` at least syntax-wise since these two functions are orthogonal. And it also seems okay to me that we re-enable file deletion before `s = error_handler_.ClearBGError();`, which basically is resetting some state variables.
- In addition, to preserve the previous behavior of https://github.com/facebook/rocksdb/pull/6949 where status of re-enabling file deletion is not taken account into the general status of resuming the db, I separated `enable_file_deletion_s` from the general `s`
- In addition, to make `ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");` more clear, I separated it into its own if-block.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9496
Test Plan:
- Manually reproduce the assertion failure in`DBErrorHandlingFSTest.MultiCFWALWriteError` by injecting sleep like below so that it's more likely for `assert(versions_->io_status().ok());` to execute after [reopening the db](https://github.com/facebook/rocksdb/blob/6.29.fb/db/error_handler_fs_test.cc?fbclid=IwAR1kQOxSbTUmaHQPAGz5jdMHXtDsDFKiFl8rifX-vIz4B23Y0S9jBkssSCg#L1494) in the foreground (i.e, testing) thread
```
sleep(1);
assert(versions_->io_status().ok());
```
`python3 gtest-parallel/gtest_parallel.py -r 100 -w 100 rocksdb/error_handler_fs_test --gtest_filter=DBErrorHandlingFSTest.MultiCFWALWriteError`
```
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from DBErrorHandlingFSTest
[ RUN ] DBErrorHandlingFSTest.MultiCFWALWriteError
Received signal 11 (Segmentation fault)
#0 rocksdb/error_handler_fs_test() [0x5818a4] rocksdb::DBImpl::ResumeImpl(rocksdb::DBRecoverContext) /data/users/huixiao/rocksdb/db/db_impl/db_impl.cc:421
https://github.com/facebook/rocksdb/issues/1 rocksdb/error_handler_fs_test() [0x6379ff] rocksdb::ErrorHandler::RecoverFromBGError(bool) /data/users/huixiao/rocksdb/db/error_handler.cc:600
https://github.com/facebook/rocksdb/issues/2 rocksdb/error_handler_fs_test() [0x7c5362] rocksdb::SstFileManagerImpl::ClearError() /data/users/huixiao/rocksdb/file/sst_file_manager_impl.cc:310
https://github.com/facebook/rocksdb/issues/3 rocksdb/error_handler_fs_test()
```
- The assertion failure does not happen with PR
`python3 gtest-parallel/gtest_parallel.py -r 100 -w 100 rocksdb/error_handler_fs_test --gtest_filter=DBErrorHandlingFSTest.MultiCFWALWriteError`
`[100/100] DBErrorHandlingFSTest.MultiCFWALWriteError (43785 ms) `
Reviewed By: riversand963, anand1976
Differential Revision: D33990099
Pulled By: hx235
fbshipit-source-id: 2e0259a471fa8892ff177da91b3e1c0792dd7bab
Summary:
When WAL compression is enabled, add a record (new record type) to store the compression type to indicate that all subsequent records are compressed. The log reader will store the compression type when this record is encountered and use the type to uncompress the subsequent records. Compress and uncompress to be implemented in subsequent diffs.
Enabled WAL compression in some WAL tests to check for regressions. Some tests that rely on offsets have been disabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9556
Reviewed By: anand1976
Differential Revision: D34308216
Pulled By: sidroyc
fbshipit-source-id: 7f10595e46f3277f1ea2d309fbf95e2e935a8705
Summary:
Users can set the priority for file reads associated with their operation by setting `ReadOptions::rate_limiter_priority` to something other than `Env::IO_TOTAL`. Rate limiting `VerifyChecksum()` and `VerifyFileChecksums()` is the motivation for this PR, so it also includes benchmarks and minor bug fixes to get that working.
`RandomAccessFileReader::Read()` already had support for rate limiting compaction reads. I changed that rate limiting to be non-specific to compaction, but rather performed according to the passed in `Env::IOPriority`. Now the compaction read rate limiting is supported by setting `rate_limiter_priority = Env::IO_LOW` on its `ReadOptions`.
There is no default value for the new `Env::IOPriority` parameter to `RandomAccessFileReader::Read()`. That means this PR goes through all callers (in some cases multiple layers up the call stack) to find a `ReadOptions` to provide the priority. There are TODOs for cases I believe it would be good to let user control the priority some day (e.g., file footer reads), and no TODO in cases I believe it doesn't matter (e.g., trace file reads).
The API doc only lists the missing cases where a file read associated with a provided `ReadOptions` cannot be rate limited. For cases like file ingestion checksum calculation, there is no API to provide `ReadOptions` or `Env::IOPriority`, so I didn't count that as missing.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9424
Test Plan:
- new unit tests
- new benchmarks on ~50MB database with 1MB/s read rate limit and 100ms refill interval; verified with strace reads are chunked (at 0.1MB per chunk) and spaced roughly 100ms apart.
- setup command: `./db_bench -benchmarks=fillrandom,compact -db=/tmp/testdb -target_file_size_base=1048576 -disable_auto_compactions=true -file_checksum=true`
- benchmarks command: `strace -ttfe pread64 ./db_bench -benchmarks=verifychecksum,verifyfilechecksums -use_existing_db=true -db=/tmp/testdb -rate_limiter_bytes_per_sec=1048576 -rate_limit_bg_reads=1 -rate_limit_user_ops=true -file_checksum=true`
- crash test using IO_USER priority on non-validation reads with https://github.com/facebook/rocksdb/issues/9567 reverted: `python3 tools/db_crashtest.py blackbox --max_key=1000000 --write_buffer_size=524288 --target_file_size_base=524288 --level_compaction_dynamic_level_bytes=true --duration=3600 --rate_limit_bg_reads=true --rate_limit_user_ops=true --rate_limiter_bytes_per_sec=10485760 --interval=10`
Reviewed By: hx235
Differential Revision: D33747386
Pulled By: ajkr
fbshipit-source-id: a2d985e97912fba8c54763798e04f006ccc56e0c
