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4550 commits

Author SHA1 Message Date
Yanqin Jin 2b367fa8cc Fix bug caused by releasing snapshot(s) during compaction (#8608)
Summary:
In debug mode, we are seeing assertion failure as follows

```
db/compaction/compaction_iterator.cc:980: void rocksdb::CompactionIterator::PrepareOutput(): \
Assertion `ikey_.type != kTypeDeletion && ikey_.type != kTypeSingleDeletion' failed.
```

It is caused by releasing earliest snapshot during compaction between the execution of
`NextFromInput()` and `PrepareOutput()`.

In one case, as demonstrated in unit test `WritePreparedTransaction.ReleaseEarliestSnapshotDuringCompaction_WithSD2`,
incorrect result may be returned by a following range scan if we disable assertion, as in opt compilation
level: the SingleDelete marker's sequence number is zeroed out, but the preceding PUT is also
outputted to the SST file after compaction. Due to the logic of DBIter, the PUT will not be
skipped and will be returned by iterator in range scan. https://github.com/facebook/rocksdb/issues/8661 illustrates what happened.

Fix by taking a more conservative approach: make compaction zero out sequence number only
if key is in the earliest snapshot when the compaction starts.

Another assertion failure is
```
Assertion `current_user_key_snapshot_ == last_snapshot' failed.
```

It's caused by releasing the snapshot between the PUT and SingleDelete during compaction.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8608

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D30145645

Pulled By: riversand963

fbshipit-source-id: 699f58e66faf70732ad53810ccef43935d3bbe81
2021-08-17 22:14:20 -07:00
Levi Tamasi 6878cedcc3 Add statistics support to integrated BlobDB (#8667)
Summary:
The patch adds statistics support to the integrated BlobDB implementation,
namely the tickers `BLOB_DB_BLOB_FILE_BYTES_READ` and
`BLOB_DB_GC_{NUM_KEYS,BYTES}_RELOCATED`, and the histograms
`BLOB_DB_(DE)COMPRESSION_MICROS`. (Some other statistics, like
`BLOB_DB_BLOB_FILE_BYTES_WRITTEN`, `BLOB_DB_BLOB_FILE_SYNCED`,
`BLOB_DB_BLOB_FILE_{READ,WRITE,SYNC}_MICROS` were already supported.)
Note that the vast majority of the old BlobDB's tickers/histograms are not
really applicable to the new implementation, since they e.g. pertain to calling
dedicated BlobDB APIs (which the integrated BlobDB does not have) or are
tied to the legacy BlobDB's design of writing blob files synchronously when
a write API is called. Such statistics are marked "legacy BlobDB only" in
`statistics.h`.

Fixes https://github.com/facebook/rocksdb/issues/8645 .

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8667

Test Plan: Ran `make check` and tested the new statistics using `db_bench`.

Reviewed By: riversand963

Differential Revision: D30356884

Pulled By: ltamasi

fbshipit-source-id: 5f8a833faee60401c5643c2f0a6c0415488190a4
2021-08-17 17:22:31 -07:00
Peter Dillinger a207c27809 Stable cache keys using DB session ids in SSTs (#8659)
Summary:
Use DB session ids in SST table properties to make cache keys
stable across DB re-open and copy / move / restore / etc.

These new cache keys are currently only enabled when FileSystem does not
provide GetUniqueId. For now, they are typically larger, so slightly
less efficient.

Relevant to https://github.com/facebook/rocksdb/issues/7405

This change has a minor regression in PersistentCache functionality:
metaindex blocks are no longer cached in PersistentCache. Table properties
blocks already were not but ideally should be. I didn't spent effort to
fix & test these issues because we don't believe PersistentCache is used much
if at all and expect SecondaryCache to replace it. (Though PRs are welcome.)

FIXME: there is more to be fixed for stable cache keys on external SST files

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8659

Test Plan:
new unit test added, which fails when disabling new
functionality

Reviewed By: zhichao-cao

Differential Revision: D30297705

Pulled By: pdillinger

fbshipit-source-id: e8539a5c8802a79340405629870f2e3fb3822d3a
2021-08-16 20:37:20 -07:00
Adam Retter 5de333fd99 Add db_test2 to to ASSERT_STATUS_CHECKED (#8640)
Summary:
This is the `db_test2` parts of https://github.com/facebook/rocksdb/pull/7737 reworked on the latest HEAD.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8640

Reviewed By: akankshamahajan15

Differential Revision: D30303684

Pulled By: mrambacher

fbshipit-source-id: 263e2f82d849bde4048b60aed8b31e7deed4706a
2021-08-16 08:10:32 -07:00
Jay Zhuang c55460c734 Add property LiveSstFilesSizeAtTemperature for tiered storage (#8644)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8644

Reviewed By: siying, zhichao-cao

Differential Revision: D30236535

Pulled By: jay-zhuang

fbshipit-source-id: 1758d1c46d83a5087560fb63d53a016bf999da81
2021-08-15 14:17:45 -07:00
Baptiste Lemaire e51be2c5a1 Improve MemPurge sampling (#8656)
Summary:
Previously, the `MemPurge` sampling function was assessing whether a random entry from a memtable was garbage or not by simply querying the given memtable (see https://github.com/facebook/rocksdb/issues/8628 for more details).
In this diff, I am updating the sampling function by querying not only the memtable the entry was drawn from, but also all subsequent memtables that have a greater memtable ID.
I also added the size of the value for KV entries in the payload/useful payload estimates (which was also one of the reasons why sampling was not as good as mempurging all the time in terms of L0 SST files reduction).
Once these changes were made, I was able to clean obsolete objects and functions from the `MemtableList` struct, and did a bit of cleanup everywhere.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8656

Reviewed By: pdillinger

Differential Revision: D30288583

Pulled By: bjlemaire

fbshipit-source-id: 7646a545ec56f4715949daa59ab5eee74540feb3
2021-08-13 14:35:41 -07:00
Merlin Mao f58d276764 Make TraceRecord and Replayer public (#8611)
Summary:
New public interfaces:
`TraceRecord` and `TraceRecord::Handler`, available in "rocksdb/trace_record.h".
`Replayer`, available in `rocksdb/utilities/replayer.h`.

User can use `DB::NewDefaultReplayer()` to create a Replayer to auto/manual replay a trace file.

Unit tests:
- `./db_test2 --gtest_filter="DBTest2.TraceAndReplay"`: Updated with the internal API changes.
- `./db_test2 --gtest_filter="DBTest2.TraceAndManualReplay"`: New for manual replay.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8611

Reviewed By: ajkr

Differential Revision: D30266329

Pulled By: autopear

fbshipit-source-id: 1ecb3cbbedae0f6a67c18f0cc82e002b4d81b6f8
2021-08-11 19:32:46 -07:00
Baptiste Lemaire e3a96c4823 Memtable sampling for mempurge heuristic. (#8628)
Summary:
Changes the API of the MemPurge process: the `bool experimental_allow_mempurge` and `experimental_mempurge_policy` flags have been replaced by a `double experimental_mempurge_threshold` option.
This change of API reflects another major change introduced in this PR: the MemPurgeDecider() function now works by sampling the memtables being flushed to estimate the overall amount of useful payload (payload minus the garbage), and then compare this useful payload estimate with the `double experimental_mempurge_threshold` value.
Therefore, when the value of this flag is `0.0` (default value), mempurge is simply deactivated. On the other hand, a value of `DBL_MAX` would be equivalent to always going through a mempurge regardless of the garbage ratio estimate.
At the moment, a `double experimental_mempurge_threshold` value else than 0.0 or `DBL_MAX` is opnly supported`with the `SkipList` memtable representation.
Regarding the sampling, this PR includes the introduction of a `MemTable::UniqueRandomSample` function that collects (approximately) random entries from the memtable by using the new `SkipList::Iterator::RandomSeek()` under the hood, or by iterating through each memtable entry, depending on the target sample size and the total number of entries.
The unit tests have been readapted to support this new API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8628

Reviewed By: pdillinger

Differential Revision: D30149315

Pulled By: bjlemaire

fbshipit-source-id: 1feef5390c95db6f4480ab4434716533d3947f27
2021-08-10 18:09:03 -07:00
Levi Tamasi f63331ebaf Attempt to deflake DBTestXactLogIterator.TransactionLogIteratorCorruptedLog (#8627)
Summary:
The patch attempts to deflake `DBTestXactLogIterator.TransactionLogIteratorCorruptedLog`
by disabling file deletions while retrieving the list of WAL files and truncating the first WAL file.
This is to prevent the `PurgeObsoleteFiles` call triggered by `GetSortedWalFiles` from
invalidating the result of `GetSortedWalFiles`. The patch also cleans up the test case a bit
and changes it to using `test::TruncateFile` instead of calling the `truncate` syscall directly.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8627

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D30147002

Pulled By: ltamasi

fbshipit-source-id: db11072a4ad8900a2f859cb5294e22b1888c23f6
2021-08-10 11:10:07 -07:00
Jay Zhuang 61f83dfeb7 Add an unittest for tiered storage universal compaction (#8631)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8631

Reviewed By: siying

Differential Revision: D30200385

Pulled By: jay-zhuang

fbshipit-source-id: 0fa2bb15e74ff81762d767f234078e0fe0106c55
2021-08-09 13:44:23 -07:00
sdong e7c24168d8 Move old files to warm tier in FIFO compactions (#8310)
Summary:
Some FIFO users want to keep the data for longer, but the old data is rarely accessed. This feature allows users to configure FIFO compaction so that data older than a threshold is moved to a warm storage tier.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8310

Test Plan: Add several unit tests.

Reviewed By: ajkr

Differential Revision: D28493792

fbshipit-source-id: c14824ea634814dee5278b449ab5c98b6e0b5501
2021-08-09 12:51:14 -07:00
Roy Crihfield d4b75d295f Add more C bindings for OptimisticTransactionDB (#8526)
Summary:
* `rocksdb_optimistictransactiondb_checkpoint_object_create`
* `rocksdb_optimistictransactiondb_write`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8526

Reviewed By: ajkr

Differential Revision: D30076822

Pulled By: jay-zhuang

fbshipit-source-id: a59956a8d5449e75d39a8087fbb2bad148cf697d
2021-08-06 19:10:48 -07:00
Levi Tamasi 87882736ef Fix the sorting of KeyContexts for batched MultiGet (#8633)
Summary:
`CompareKeyContext::operator()` on the trunk has a bug: when comparing
column family IDs, `lhs` is used for both sides of the comparison. This
results in the `KeyContext`s getting sorted solely based on key, which
in turn means that keys with the same column family do not necessarily
form a single range in the sorted list. This violates an assumption of the
batched `MultiGet` logic, leading to the same column family
showing up multiple times in the list of `MultiGetColumnFamilyData`.
The end result is the code attempting to check out the thread-local
`SuperVersion` for the same CF multiple times, causing an
assertion violation in debug builds and memory corruption/crash in
release builds.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8633

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D30169182

Pulled By: ltamasi

fbshipit-source-id: a47710652df7e95b14b40fb710924c11a8478023
2021-08-06 16:27:42 -07:00
Zaorang Yang e95c570047 Fix the wrong comment of level compaction cf paths test (#8533)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8533

Reviewed By: ajkr

Differential Revision: D29718067

fbshipit-source-id: b4b91c9271362e7a7d47ddbaf28f56fb537cc668
2021-08-06 15:27:12 -07:00
mrambacher d057e8326d Make MergeOperator+CompactionFilter/Factory into Customizable Classes (#8481)
Summary:
- Changed MergeOperator, CompactionFilter, and CompactionFilterFactory into Customizable classes.
 - Added Options/Configurable/Object Registration for TTL and Cassandra variants
 - Changed the StringAppend MergeOperators to accept a string delimiter rather than a simple char.  Made the delimiter into a configurable option
 - Added tests for new functionality

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8481

Reviewed By: zhichao-cao

Differential Revision: D30136050

Pulled By: mrambacher

fbshipit-source-id: 271d1772835935b6773abaf018ee71e42f9491af
2021-08-06 08:27:25 -07:00
Akanksha Mahajan fd2079938d Dynamically configure BlockBasedTableOptions.prepopulate_block_cache (#8620)
Summary:
Dynamically configure BlockBasedTableOptions.prepopulate_block_cache using DB::SetOptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8620

Test Plan: Added new unit test

Reviewed By: anand1976

Differential Revision: D30091319

Pulled By: akankshamahajan15

fbshipit-source-id: fb586d1848a8dd525bba7b2f9eeac34f2fc6d82c
2021-08-05 19:44:51 -07:00
Levi Tamasi 9b25d26dc8 Attempt to deflake ObsoleteFilesTest.DeleteObsoleteOptionsFile (#8624)
Summary:
We've been seeing occasional crashes on CI while inserting into the
vectors in `ObsoleteFilesTest.DeleteObsoleteOptionsFile`. The crashes
don't reproduce locally (could be either a race or an object lifecycle
issue) but the good news is that the vectors in question are not really
used for anything meaningful by the test. (The assertion about the sizes
of the two vectors being equal is guaranteed to hold, since the two sync
points where they are populated are right after each other.) The patch
simply removes the vectors from the test, alongside the associated
callbacks and sync points.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8624

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D30118485

Pulled By: ltamasi

fbshipit-source-id: 0a4c3d06584e84cd2b1dcc212d274fa1b89cb647
2021-08-05 18:36:16 -07:00
Andrew Kryczka a685a701ca Do not attempt to rename non-existent info log (#8622)
Summary:
Previously we attempted to rename "LOG" to "LOG.old.*" without checking
its existence first. "LOG" had no reason to exist in a new DB.

Errors in renaming a non-existent "LOG" were swallowed via
`PermitUncheckedError()` so things worked. However the storage service's
error monitoring was detecting all these benign rename failures. So it
is better to fix it. Also with this PR we can now distinguish rename failure
for other reasons and return them.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8622

Test Plan: new unit test

Reviewed By: akankshamahajan15

Differential Revision: D30115189

Pulled By: ajkr

fbshipit-source-id: e2f337ffb2bd171be0203172abc8e16e7809b170
2021-08-04 17:25:00 -07:00
Yanqin Jin 0879c24040 Fix NotifyOnFlushCompleted() for atomic flush (#8585)
Summary:
PR https://github.com/facebook/rocksdb/issues/5908 added `flush_jobs_info_` to `FlushJob` to make sure
`OnFlushCompleted()` is called after committing flush results to
MANIFEST. However, `flush_jobs_info_` is not updated in atomic
flush, causing `NotifyOnFlushCompleted()` to skip `OnFlushCompleted()`.

This PR fixes this, in a similar way to https://github.com/facebook/rocksdb/issues/5908 that handles regular flush.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8585

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D29913720

Pulled By: riversand963

fbshipit-source-id: 4ff023c98372fa2c93188d4a5c8a4e9ffa0f4dda
2021-08-03 13:31:10 -07:00
Akanksha Mahajan 8b2f60b668 Cache warming blocks during flush (#8561)
Summary:
Insert warm blocks  (data, uncompressed dict, index and filter blocks) during flush in Block cache which is enabled under option BlockBasedTableOptions.prepopulate_block_cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8561

Test Plan: Added unit test

Reviewed By: anand1976

Differential Revision: D29773411

Pulled By: akankshamahajan15

fbshipit-source-id: 6631123c10134340ef0bd7e90baafaa6deba0e66
2021-08-03 12:44:15 -07:00
Baptiste Lemaire b278152261 Fix db stress crash mempurge (#8604)
Summary:
The db_stress crash was caused by a call to `IsFlushPending()` made by a stats function which triggered an `assert([false])`, which I didn't plan when I created the `trigger_flush` bool. It turns out that this bool variable is not useful: I created it because I thought the `imm_flush_needed` atomic bool would actually trigger a flush.
It turns out that this bool is only checked in `IsFlushPending` - this is its only use - and a flush is triggered by either a background thread checking on the imm array, or by an explicit call to `SchedulePendingFlush` which creates a flush request, that is then added to a flush request queue.
In this PR, I reverted the MemtableList::Add function to what it was before my changes.
I tested the fix by running the exact command line that deterministically triggered the assert error (see below), which confirmed that this is where the error was coming from.
I also run `db_crashtest.py whitebox` and `blackbox` for a couple hours locally before committing this PR.
Experiment run:

```./db_stress --acquire_snapshot_one_in=0 --allow_concurrent_memtable_write=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=1 --backup_max_size=104857600 --backup_one_in=100000 --batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=76.90653425292307 --bottommost_compression_type=disable --cache_index_and_filter_blocks=1 --cache_size=1048576 --checkpoint_one_in=1000000 --checksum_type=kCRC32c --clear_column_family_one_in=0 --column_families=1 --compact_files_one_in=1000000 --compact_range_one_in=0 --compaction_ttl=2 --compression_max_dict_buffer_bytes=0 --compression_max_dict_bytes=0 --compression_parallel_threads=1 --compression_type=zstd --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --db=/dev/shm/rocksdb/rocksdb_crashtest_blackbox --db_write_buffer_size=0 --delpercent=4 --delrangepercent=1 --destroy_db_initially=0 --enable_compaction_filter=1 --enable_pipelined_write=0 --expected_values_path=/dev/shm/rocksdb/rocksdb_crashtest_expected --experimental_allow_mempurge=1 --experimental_mempurge_policy=kAlternate --fail_if_options_file_error=1 --file_checksum_impl=none --flush_one_in=1000000 --format_version=2 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=14 --index_type=0 --iterpercent=0 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=False --long_running_snapshots=1 --mark_for_compaction_one_file_in=10 --max_background_compactions=1 --max_bytes_for_level_base=67108864 --max_key=100000000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=64 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=0 --memtablerep=skip_list --mmap_read=0 --mock_direct_io=True --nooverwritepercent=1 --open_files=-1 --open_metadata_write_fault_one_in=8 --open_read_fault_one_in=32 --open_write_fault_one_in=16 --ops_per_thread=100000000 --optimize_filters_for_memory=1 --paranoid_file_checks=0 --partition_filters=0 --partition_pinning=0 --pause_background_one_in=1000000 --periodic_compaction_seconds=1000 --prefix_size=-1 --prefixpercent=0 --progress_reports=0 --read_fault_one_in=0 --readpercent=60 --recycle_log_file_num=1 --reopen=20 --set_options_one_in=0 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=104857600 --sst_file_manager_bytes_per_truncate=0 --subcompactions=3 --sync=1 --sync_fault_injection=False --target_file_size_base=16777216 --target_file_size_multiplier=1 --test_batches_snapshots=0 --top_level_index_pinning=1 --unpartitioned_pinning=3 --use_clock_cache=0 --use_direct_io_for_flush_and_compaction=1 --use_direct_reads=0 --use_full_merge_v1=1 --use_merge=0 --use_multiget=0 --use_ribbon_filter=1 --user_timestamp_size=0 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=100000 --write_buffer_size=33554432 --write_dbid_to_manifest=1 --writepercent=35```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8604

Reviewed By: pdillinger

Differential Revision: D30047295

Pulled By: bjlemaire

fbshipit-source-id: b9e379bfa3d6b9bd2b275725fb0bca4bd81a3dbe
2021-08-02 20:26:35 -07:00
Levi Tamasi 3f7e929865 Fix a race in ColumnFamilyData::UnrefAndTryDelete (#8605)
Summary:
The `ColumnFamilyData::UnrefAndTryDelete` code currently on the trunk
unlocks the DB mutex before destroying the `ThreadLocalPtr` holding
the per-thread `SuperVersion` pointers when the only remaining reference
is the back reference from `super_version_`. The idea behind this was to
break the circular dependency between `ColumnFamilyData` and `SuperVersion`:
when the penultimate reference goes away, `ColumnFamilyData` can clean up
the `SuperVersion`, which can in turn clean up `ColumnFamilyData`. (Assuming there
is a `SuperVersion` and it is not referenced by anything else.) However,
unlocking the mutex throws a wrench in this plan by making it possible for another thread
to jump in and take another reference to the `ColumnFamilyData`, keeping the
object alive in a zombie `ThreadLocalPtr`-less state. This can cause issues like
https://github.com/facebook/rocksdb/issues/8440 ,
https://github.com/facebook/rocksdb/issues/8382 ,
and might also explain the `was_last_ref` assertion failures from the `ColumnFamilySet`
destructor we sometimes observe during close in our stress tests.

Digging through the archives, this unlocking goes way back to 2014 (or earlier). The original
rationale was that `SuperVersionUnrefHandle` used to lock the mutex so it can call
`SuperVersion::Cleanup`; however, this logic turned out to be deadlock-prone.
https://github.com/facebook/rocksdb/pull/3510 fixed the deadlock but left the
unlocking in place. https://github.com/facebook/rocksdb/pull/6147 then introduced
the circular dependency and associated cleanup logic described above (in order
to enable iterators to keep the `ColumnFamilyData` for dropped column families alive),
and moved the unlocking-relocking snippet to its present location in `UnrefAndTryDelete`.
Finally, https://github.com/facebook/rocksdb/pull/7749 fixed a memory leak but
apparently exacerbated the race by (otherwise correctly) switching to `UnrefAndTryDelete`
in `SuperVersion::Cleanup`.

The patch simply eliminates the unlocking and relocking, which has been unnecessary
ever since https://github.com/facebook/rocksdb/issues/3510 made `SuperVersionUnrefHandle` lock-free.
This closes the window during which another thread could increase the reference count,
and hopefully fixes the issues above.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8605

Test Plan: Ran `make check` and stress tests locally.

Reviewed By: pdillinger

Differential Revision: D30051035

Pulled By: ltamasi

fbshipit-source-id: 8fe559e4b4ad69fc142579f8bc393ef525918528
2021-08-02 18:12:11 -07:00
yangzaorang 8e91bd90d2 Fix a issue with initializing blob header buffer (#8537)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8537

Reviewed By: ajkr

Differential Revision: D29838132

Pulled By: jay-zhuang

fbshipit-source-id: e3e78d5f85f240a1800ace417a8b634f74488e41
2021-08-02 17:15:06 -07:00
mrambacher ab7f7c9e49 Allow WAL dir to change with db dir (#8582)
Summary:
Prior to this change, the "wal_dir"  DBOption would always be set (defaults to dbname) when the DBOptions were sanitized.  Because of this setitng in the options file, it was not possible to rename/relocate a database directory after it had been created and use the existing options file.

After this change, the "wal_dir" option is only set under specific circumstances.  Methods were added to the ImmutableDBOptions class to see if it is set and if it is set to something other than the dbname.  Additionally, a method was added to retrieve the effective value of the WAL dir (either the option or the dbname/path).

Tests were added to the core and ldb to test that a database could be created and renamed without issue.  Additional tests for various permutations of wal_dir were also added.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8582

Reviewed By: pdillinger, autopear

Differential Revision: D29881122

Pulled By: mrambacher

fbshipit-source-id: 67d3d033dc8813d59917b0a3fba2550c0efd6dfb
2021-07-30 12:16:44 -07:00
Yanqin Jin 066b51126d Several simple local code clean-ups (#8565)
Summary:
This PR tries to remove some unnecessary checks as well as unreachable code blocks to
improve readability. An obvious non-public API method naming typo is also corrected.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8565

Test Plan: make check

Reviewed By: lth

Differential Revision: D29963984

Pulled By: riversand963

fbshipit-source-id: cc96e8f09890e5cfe9b20eadb63bdca5484c150a
2021-07-30 12:07:49 -07:00
Peter Dillinger 1d34cd797e Fix insecure internal API for GetImpl (#8590)
Summary:
Calling the GetImpl function could leave reference to a local
callback function in a field of a parameter struct. As this is
performance-critical code, I'm not going to attempt to sanitize this
code too much, but make the existing hack a bit cleaner by reverting
what it overwrites in the input struct.

Added SaveAndRestore utility class to make that easier.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8590

Test Plan:
added unit test for SaveAndRestore; existing tests for
GetImpl

Reviewed By: riversand963

Differential Revision: D29947983

Pulled By: pdillinger

fbshipit-source-id: 2f608853f970bc06724e834cc84dcc4b8599ddeb
2021-07-29 17:23:01 -07:00
sdong e8f218cb68 DB::GetSortedWalFiles() to ensure file deletion is disabled (#8591)
Summary:
If DB::GetSortedWalFiles() runs without file deletion disbled, file might get deleted in the middle and error is returned to users. It makes the function hard to use. Fix it by disabling file deletion if it is not done.

Fix another minor issue of logging within DB mutex, which should not be done unless a major failure happens.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8591

Test Plan: Run all existing tests

Reviewed By: pdillinger

Differential Revision: D29969412

fbshipit-source-id: d5f42b5271608a35b9b07687ce18157d7447b0de
2021-07-29 11:51:08 -07:00
Peter Dillinger 0804b44fb6 Some fixes and enhancements to ldb repair (#8544)
Summary:
* Basic handling of SST file with just range tombstones rather than
failing assertion about smallest_seqno <= largest_seqno
* Adds --verbose option so that there exists a way to see the INFO
output from Repairer.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8544

Test Plan: unit test added, manual testing for --verbose

Reviewed By: ajkr

Differential Revision: D29954805

Pulled By: pdillinger

fbshipit-source-id: 696af25805fc36cc178b04ba6045922a22625fd9
2021-07-28 16:44:14 -07:00
jimmycleary e0ff365a76 Replace macros in compaction_iterator.cc with inline functions (#8592)
Summary:
Internal task T96186510.

Created new inline member functions in `CompactionIterator`,
`DefinitelyInSnapshot`, `DefinitelyNotInSnapshot`, and
`InEarliestSnapshot` to replace the macros at the top of
`compaction_iterator.cc`.

Placed the definitions in `compaction_iterator.h` in accordance with
Google's style guide for inline functions. Separated the declarations
and definitions, and only placed the `inline` keyword on the
definitions, in line with ISO CPP recommendations.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8592

Test Plan: Ran `make check`.  Successful build and all tests appeared to pass.

Reviewed By: riversand963

Differential Revision: D29966782

Pulled By: jimmycFB

fbshipit-source-id: 3584290bbbabf862e9ab58852281f46d37f58be6
2021-07-28 14:53:29 -07:00
Peter Dillinger 74b7c0d249 Fix use-after-free on implicit temporary FileOptions (#8571)
Summary:
FileOptions has an implicit conversion from EnvOptions and some
internal APIs take `const FileOptions&` and save the reference, which is
counter to Google C++ guidelines,

> Avoid defining functions that require a const reference parameter to outlive the call, because const reference parameters bind to temporaries. Instead, find a way to eliminate the lifetime requirement (for example, by copying the parameter), or pass it by const pointer and document the lifetime and non-null requirements.

This is at least a problem for repair.cc, which passes an EnvOptions to
TableCache(), which would save a reference to the temporary copy as
FileOptions. This was unfortunately only caught as a side effect of
changes in https://github.com/facebook/rocksdb/issues/8544.

This change fixes the repair.cc case and updates the involved internal
APIs that save a reference to use `const FileOptions*` instead.

Unfortunately, I don't know how to get any of our sanitizers to reliably
report bugs like this, so I can't rule out more existing in our
codebase.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8571

Test Plan:
Test that issues seen with https://github.com/facebook/rocksdb/issues/8544 are fixed (can reproduce on
AWS EC2)

Reviewed By: ajkr

Differential Revision: D29943890

Pulled By: pdillinger

fbshipit-source-id: 95f9c5251548777b4dc994c1a083dd2add5799c9
2021-07-27 21:49:14 -07:00
Peter Dillinger e352bd5742 Fix missing Handle release in TableCache::GetRangeTombstoneIterator (#8589)
Summary:
This appears to be little used code so not a major bug, but is
blocking https://github.com/facebook/rocksdb/issues/8544

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8589

Test Plan:
Added regression test to the end of
DBRangeDelTest::TableEvictedDuringScan. Without this fix, ASAN reports
memory leak.

Reviewed By: ajkr

Differential Revision: D29943623

Pulled By: pdillinger

fbshipit-source-id: f7115fa6d4440aef83888ff609aa03d09216463b
2021-07-27 21:32:11 -07:00
mrambacher 3aee4fbd41 Make EventListener into a Customizable Class (#8473)
Summary:
- Added Type/CreateFromString
- Added ability to load EventListeners to DBOptions
- Since EventListeners did not previously have a Name(), defaulted to "".  If there is no name, the listener cannot be loaded from the ObjectRegistry.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8473

Reviewed By: zhichao-cao

Differential Revision: D29901488

Pulled By: mrambacher

fbshipit-source-id: 2d3a4aa6db1562ac03e7ad41b360e3521d486254
2021-07-27 07:47:02 -07:00
Baptiste Lemaire 4361d6d163 Add simple heuristics for experimental mempurge. (#8583)
Summary:
Add `experimental_mempurge_policy` option flag and introduce two new `MemPurge` (Memtable Garbage Collection) policies: 'ALWAYS' and 'ALTERNATE'. Default value: ALTERNATE.
`ALWAYS`: every flush will first go through a `MemPurge` process. If the output is too big to fit into a single memtable, then the mempurge is aborted and a regular flush process carries on. `ALWAYS` is designed for user that need to reduce the number of L0 SST file created to a strict minimum, and can afford a small dent in performance (possibly hits to CPU usage, read efficiency, and maximum burst write throughput).
`ALTERNATE`: a flush is transformed into a `MemPurge` except if one of the memtables being flushed is the product of a previous `MemPurge`. `ALTERNATE` is a good tradeoff between reduction in number of L0 SST files created and performance. `ALTERNATE` perform particularly well for completely random garbage ratios, or garbage ratios anywhere in (0%,50%], and even higher when there is a wild variability in garbage ratios.
This PR also includes support for `experimental_mempurge_policy` in `db_bench`.
Testing was done locally by replacing all the `MemPurge` policies of the unit tests with `ALTERNATE`, as well as local testing with `db_crashtest.py` `whitebox` and `blackbox`. Overall, if an `ALWAYS` mempurge policy passes the tests, there is no reasons why an `ALTERNATE` policy would fail, and therefore the mempurge policy was set to `ALWAYS` for all mempurge unit tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8583

Reviewed By: pdillinger

Differential Revision: D29888050

Pulled By: bjlemaire

fbshipit-source-id: e2cf26646d66679f6f5fb29842624615610759c1
2021-07-26 11:56:29 -07:00
leipeng 4171e3db9b CompactionJob::Install(): fix log truncation (#8563)
Summary:
event log info may be truncated, the default buffer size is 512, this PR changes buffer size to 8192.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8563

Reviewed By: ajkr

Differential Revision: D29838229

Pulled By: jay-zhuang

fbshipit-source-id: 00c5dea3caff0641a209f02c972e92d65b505f50
2021-07-23 11:39:24 -07:00
Drewryz 3b27725245 Fix a minor issue with initializing the test path (#8555)
Summary:
The PerThreadDBPath has already specified a slash. It does not need to be specified when initializing the test path.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8555

Reviewed By: ajkr

Differential Revision: D29758399

Pulled By: jay-zhuang

fbshipit-source-id: 6d2b878523e3e8580536e2829cb25489844d9011
2021-07-23 08:38:45 -07:00
Baptiste Lemaire c521a9ab2b Retire superfluous functions introduced in earlier mempurge PRs. (#8558)
Summary:
The main challenge to make the memtable garbage collection prototype (nicknamed `mempurge`) was to not get rid of WAL files that contain unflushed (but mempurged) data. That was successfully guaranteed by not writing the VersionEdit to the MANIFEST file after a successful mempurge.
By not writing VersionEdits to the `MANIFEST` file after a succesful mempurge operation, we do not change the earliest log file number that contains unflushed data: `cfd->GetLogNumber()` (`cfd->SetLogNumber()` is only called in `VersionSet::ProcessManifestWrites`). As a result, a number of functions introduced earlier just for the mempurge operation are not obscolete/redundant. (e.g.: `FlushJob::ExtractEarliestLogFileNumber`), and this PR aims at cleaning up all these now-unnecessary functions. In particular, we no longer need to store the earliest log file number in the `MemTable` struct itself. This PR therefore also reverts the `MemTable` struct to its original form.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8558

Test Plan: Already included in `db_flush_test.cc`.

Reviewed By: anand1976

Differential Revision: D29764351

Pulled By: bjlemaire

fbshipit-source-id: 0f43b260fa270251862512f397d3f24ee62e8437
2021-07-22 18:29:13 -07:00
Yanqin Jin 2e5388178f Return error if trying to open secondary on missing or inaccessible primary (#8200)
Summary:
If the primary's CURRENT file is missing or inaccessible, the secondary should not hang
trying repeatedly to switch to the next MANIFEST.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8200

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D27840627

Pulled By: riversand963

fbshipit-source-id: 071fed97cbab1bc5cdefd1dc235e5cd406c174e1
2021-07-22 15:48:58 -07:00
Peter Dillinger 84eef260de Remove TaskLimiterToken::ReleaseOnce for fix (#8567)
Summary:
Rare TSAN and valgrind failures are caused by unnecessary
reading of a field on the TaskLimiterToken::limiter_ for an assertion
after the token has been released and the limiter destroyed. To simplify
we can simply destroy the token before triggering DB shutdown
(potentially destroying the limiter). This makes the ReleaseOnce logic
unnecessary.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8567

Test Plan: watch for more failures in CI

Reviewed By: ajkr

Differential Revision: D29811795

Pulled By: pdillinger

fbshipit-source-id: 135549ebb98fe4f176d1542ed85d5bd6350a40b3
2021-07-21 17:37:53 -07:00
Jay Zhuang 42eaa45c1b Avoid updating option if there's no value updated (#8518)
Summary:
Try avoid expensive updating options operation if
`SetDBOptions()` does not change any option value.
Skip updating is not guaranteed, for example, changing `bytes_per_sync`
to `0` may still trigger updating, as the value could be sanitized.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8518

Test Plan: added unittest

Reviewed By: riversand963

Differential Revision: D29672639

Pulled By: jay-zhuang

fbshipit-source-id: b7931de62ceea6f1bdff0d1209adf1197d3ed1f4
2021-07-21 13:45:59 -07:00
Zhichao Cao 87e82a41a9 Fix incorrect Status::NoSpace() status check (#8504)
Summary:
If we want to check whether a Status s is NoSpace() or not, we should check the subcode instread of using s==Status::NoSpace(). Fix some of the incorrect check in the ErrorHandler.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8504

Test Plan: make check

Reviewed By: anand1976

Differential Revision: D29601764

Pulled By: zhichao-cao

fbshipit-source-id: cdab56a827891c23746bba9cbb53f169fe35f086
2021-07-20 18:09:51 -07:00
sdong 9e885939a3 Change to code for trimmed memtable history is to released outside DB mutex (#8530)
Summary:
Currently, the code shows that we delete memtables immedately after it is trimmed from history. Although it should never happen as the super version still holds the memtable, which is only switched after it, it feels a good practice not to do it, but use clean it up in the standard way: put it to WriteContext and clean it after DB mutex.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8530

Test Plan: Run all existing tests.

Reviewed By: ajkr

Differential Revision: D29703410

fbshipit-source-id: 21d8068ac6377de4b6fa7a89697195742659fde4
2021-07-16 19:28:48 -07:00
Peter Dillinger df5dc73bec Don't hold DB mutex for block cache entry stat scans (#8538)
Summary:
I previously didn't notice the DB mutex was being held during
block cache entry stat scans, probably because I primarily checked for
read performance regressions, because they require the block cache and
are traditionally latency-sensitive.

This change does some refactoring to avoid holding DB mutex and to
avoid triggering and waiting for a scan in GetProperty("rocksdb.cfstats").
Some tests have to be updated because now the stats collector is
populated in the Cache aggressively on DB startup rather than lazily.
(I hope to clean up some of this added complexity in the future.)

This change also ensures proper treatment of need_out_of_mutex for
non-int DB properties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8538

Test Plan:
Added unit test logic that uses sync points to fail if the DB mutex
is held during a scan, covering the various ways that a scan might be
triggered.

Performance test - the known impact to holding the DB mutex is on
TransactionDB, and the easiest way to see the impact is to hack the
scan code to almost always miss and take an artificially long time
scanning. Here I've injected an unconditional 5s sleep at the call to
ApplyToAllEntries.

Before (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     433.219 micros/op 2308 ops/sec;    0.1 MB/s ( transactions:78999 aborts:0)
    rocksdb.db.write.micros P50 : 16.135883 P95 : 36.622503 P99 : 66.036115 P100 : 5000614.000000 COUNT : 149677 SUM : 8364856
    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     448.802 micros/op 2228 ops/sec;    0.1 MB/s ( transactions:75999 aborts:0)
    rocksdb.db.write.micros P50 : 16.629221 P95 : 37.320607 P99 : 72.144341 P100 : 5000871.000000 COUNT : 143995 SUM : 13472323

Notice the 5s P100 write time.

After (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     303.645 micros/op 3293 ops/sec;    0.1 MB/s ( transactions:98999 aborts:0)
    rocksdb.db.write.micros P50 : 16.061871 P95 : 33.978834 P99 : 60.018017 P100 : 616315.000000 COUNT : 187619 SUM : 4097407
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     310.383 micros/op 3221 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.270026 P95 : 35.786844 P99 : 64.302878 P100 : 603088.000000 COUNT : 183819 SUM : 4095918

P100 write is now ~0.6s. Not good, but it's the same even if I completely bypass all the scanning code:

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     311.365 micros/op 3211 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.274362 P95 : 36.221184 P99 : 68.809783 P100 : 649808.000000 COUNT : 183819 SUM : 4156767
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     308.395 micros/op 3242 ops/sec;    0.1 MB/s ( transactions:97999 aborts:0)
    rocksdb.db.write.micros P50 : 16.106222 P95 : 37.202403 P99 : 67.081875 P100 : 598091.000000 COUNT : 185714 SUM : 4098832

No substantial difference.

Reviewed By: siying

Differential Revision: D29738847

Pulled By: pdillinger

fbshipit-source-id: 1c5c155f5a1b62e4fea0fd4eeb515a8b7474027b
2021-07-16 14:13:08 -07:00
Mark Rambacher 42ba60b3ba Make EncryptionProvider and BlockCipher into Customizable objects (#8354)
Summary:
Made the EncryptionProvider and BlockCipher classes inherit from Customizable.  Added/fixed the CreateFromString method to these classes to create instances from builtin or registered classes.  Added tests to verify that instances can be registered and retrieved as appropriate.

Added the ability to configure the builtin (CTR, ROT13) classes from configurable properties.  Added the appropriate tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8354

Reviewed By: zhichao-cao

Differential Revision: D29558949

Pulled By: mrambacher

fbshipit-source-id: c20286b32d179777e060f51a58943e9b0cf81d04
2021-07-16 07:58:51 -07:00
Baptiste Lemaire 206845c057 Mempurge support for wal (#8528)
Summary:
In this PR, `mempurge` is made compatible with the Write Ahead Log: in case of recovery, the DB is now capable of recovering the data that was "mempurged" and kept in the `imm()` list of immutable memtables.
The twist was to add a uint64_t to the `memtable` struct to store the number of the earliest log file containing entries from the `memtable`. When a `Flush` operation is replaced with a `MemPurge`, the `VersionEdit` (which usually contains the new min log file number to pick up for recovery and the level 0 file path of the newly created SST file) is no longer appended to the manifest log, and every time the `deleteWal` method is called, a check is made on the list of immutable memtables.
This PR also includes a unit test that verifies that no data is lost upon Reopening of the database when the mempurge feature is activated. This extensive unit test includes two column families, with valid data contained in the imm() at time of "crash"/reopening (recovery).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8528

Reviewed By: pdillinger

Differential Revision: D29701097

Pulled By: bjlemaire

fbshipit-source-id: 072a900fb6ccc1edcf5eef6caf88f3060238edf9
2021-07-15 17:49:13 -07:00
longlijian 803a40d412 Delete legacy code not used any more. (#8508)
Summary:
The removed function in this PR,  just only have declared and dose not have any reference used.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8508

Reviewed By: mrambacher

Differential Revision: D29649033

Pulled By: jay-zhuang

fbshipit-source-id: df98143b73d6c184a2a60c9f7ea2548a065ee35d
2021-07-14 16:04:56 -07:00
hongrubb 870033291a Fix Get() return status when block cache is disabled (#8485)
Summary:
This PR is for https://github.com/facebook/rocksdb/issues/8453

We need to update `s = biter.status();`  when `biter.status().IsIncomplete()` is true. By doing this, can fix the problem in issue.
Besides, we still need to update `db_statistics`  in `get_context.ReportCounters()` before return back.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8485

Reviewed By: jay-zhuang

Differential Revision: D29604835

Pulled By: ajkr

fbshipit-source-id: c7f2f1cd058223ce1b507ec05d57cf264b9c9710
2021-07-13 18:13:24 -07:00
bjlemaire 955b80e84f Add WARN/INFO for mempurge output status. (#8514)
Summary:
The MemPurge output status can either be an Abort if the mempurge is aborted due to the new_mem memtable reaching more than the target capacity (currently 60%), or for other reasons. As a result, in the log, we want to differentiate between an abort status, which in this PR only leads to a ROCKS_LOG_INFO, and any other status, which in this PR leads to a ROCKS_LOG_WARN.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8514

Reviewed By: pdillinger

Differential Revision: D29662446

Pulled By: bjlemaire

fbshipit-source-id: c9bec8e238ebc7ecb14fbbddf580e6887e281c16
2021-07-12 10:42:14 -07:00
Dmitry Vorobev 0b75b22321 Implement missing Handler methods in ColumnFamilyCollector. (#8456)
Summary:
When db is open as secondary, there are basically 2 step process:
1) Collect column families from wal log
2) Apply changes to Memtable
In case primary db is TransactionDB instance, wal log will contain some additional data, like noop, etc. ColumnFamilyCollector doesn't implement methods to handle these, so it fails to open a wal log written by TransactionDB. (Everything works fine with standard DB::Open).
Memtable recovery process knows how to handle such wal logs, so only missing piece seems to be ColumnFamilyCollector.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8456

Reviewed By: ajkr

Differential Revision: D29455945

Pulled By: mrambacher

fbshipit-source-id: 5b29560fcbc008e17e95d0dc4b07558f3d63e26f
2021-07-12 09:23:45 -07:00
anand76 d1b70b05a6 Avoid passing existing BG error to WriteStatusCheck (#8511)
Summary:
In ```DBImpl::WriteImpl()```, we call ```PreprocessWrite()``` which, among other things, checks the BG error and returns it set. This return status is later on passed to ```WriteStatusCheck()```, which calls ```SetBGError()```. This results in a spurious call, and info logs, on every user write request. We should avoid passing the ```PreprocessWrite()``` return status to ```WriteStatusCheck()```, as the former would have called ```SetBGError()``` already if it encountered any new errors, such as error when creating a new WAL file.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8511

Test Plan: Run existing tests

Reviewed By: zhichao-cao

Differential Revision: D29639917

Pulled By: anand1976

fbshipit-source-id: 19234163969e1645dbeb273712aaf5cd9ea2b182
2021-07-11 22:37:52 -07:00
Baptiste Lemaire 837705ad80 Make mempurge a background process (equivalent to in-memory compaction). (#8505)
Summary:
In https://github.com/facebook/rocksdb/issues/8454, I introduced a new process baptized `MemPurge` (memtable garbage collection). This new PR is built upon this past mempurge prototype.
In this PR, I made the `mempurge` process a background task, which provides superior performance since the mempurge process does not cling on the db_mutex anymore, and addresses severe restrictions from the past iteration (including a scenario where the past mempurge was failling, when a memtable was mempurged but was still referred to by an iterator/snapshot/...).
Now the mempurge process ressembles an in-memory compaction process: the stack of immutable memtables is filtered out, and the useful payload is used to populate an output memtable. If the output memtable is filled at more than 60% capacity (arbitrary heuristic) the mempurge process is aborted and a regular flush process takes place, else the output memtable is kept in the immutable memtable stack. Note that adding this output memtable to the `imm()` memtable stack does not trigger another flush process, so that the flush thread can go to sleep at the end of a successful mempurge.
MemPurge is activated by making the `experimental_allow_mempurge` flag `true`. When activated, the `MemPurge` process will always happen when the flush reason is `kWriteBufferFull`.
The 3 unit tests confirm that this process supports `Put`, `Get`, `Delete`, `DeleteRange` operators and is compatible with `Iterators` and `CompactionFilters`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8505

Reviewed By: pdillinger

Differential Revision: D29619283

Pulled By: bjlemaire

fbshipit-source-id: 8a99bee76b63a8211bff1a00e0ae32360aaece95
2021-07-09 17:23:59 -07:00