Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11913
The `max_successive_merges` logic currently does not handle wide-column base values correctly, since it uses the `Get` API, which only returns the value of the default column. The patch fixes this by switching to `GetEntity` and passing all columns (if applicable) to the merge operator.
Reviewed By: jaykorean
Differential Revision: D49795097
fbshipit-source-id: 75eb7cc9476226255062cdb3d43ab6bd1cc2faa3
Summary:
Changed `DBOptions::fail_if_options_file_error` default from `false` to
`true`. It is safer to fail an operation by default when it encounters
an error.
Also changed the API doc to list items in the conventional way for listing items in a sentence. The slashes weren't working well as one got dropped, probably because it looked like a typo.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11800
Test Plan: rely on CI
Reviewed By: jowlyzhang
Differential Revision: D49030532
Pulled By: ajkr
fbshipit-source-id: e606062aa25f9063d8c6fb0d03aebca5c2bc56d3
Summary:
RocksDB's primary function is to facilitate read and write operations. Compactions, while essential for minimizing read amplifications and optimizing storage, can sometimes compete with these primary tasks. Especially during periods of high read/write traffic, it's vital to ensure that primary operations receive priority, avoiding any potential disruptions or slowdowns. Conversely, during off-peak times when traffic is minimal, it's an opportune moment to tackle low-priority tasks like TTL based compactions, optimizing resource usage.
In this PR, we are incorporating the concept of off-peak time into RocksDB by introducing `daily_offpeak_time_utc` within the DBOptions. This setting is formatted as "HH:mm-HH:mm" where the first one before "-" is the start time and the second one is the end time, inclusive. It will be later used for resource optimization in subsequent PRs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11893
Test Plan:
- New Unit Test Added - `DBOptionsTest::OffPeakTimes`
- Existing Unit Test Updated - `OptionsTest`, `OptionsSettableTest`
Reviewed By: pdillinger
Differential Revision: D49714553
Pulled By: jaykorean
fbshipit-source-id: fef51ea7c0fede6431c715bff116ddbb567c8752
Summary:
**Context/Summary:**
https://github.com/facebook/rocksdb/pull/11631 introduced an undesired fallback behavior to RocksDB internal prefetching even when FS prefetching return non-OK status other than "Unsupported". We only want to fall back when FS prefetching is not supported.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11897
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D49667055
Pulled By: hx235
fbshipit-source-id: fa36e4e5d6dc9507080217035f9d6ff8e4abda28
Summary:
**Context/Summary:**
https://github.com/facebook/rocksdb/pull/11631 introduced `readahead()` system call for compaction read under non direct IO. When `Options::compaction_readahead_size` is 0, the `readahead()` will issued with a small size (i.e, the block size, by default 4KB)
Benchmarks shows that such readahead() call regresses the compaction read compared with "no readahead()" case (see Test Plan for more).
Therefore we decided to not issue such `readhead() ` when `Options::compaction_readahead_size` is 0.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11887
Test Plan:
Settings: `compaction_readahead_size = 0, use_direct_reads=false`
Setup:
```
TEST_TMPDIR=../ ./db_bench -benchmarks=filluniquerandom -disable_auto_compactions=true -write_buffer_size=1048576 -compression_type=none -value_size=10240 && tar -cf ../dbbench.tar -C ../dbbench/ .
```
Run:
```
for i in $(seq 3); do rm -rf ../dbbench/ && mkdir -p ../dbbench/ && tar -xf ../dbbench.tar -C ../dbbench/ . && sudo bash -c 'sync && echo 3 > /proc/sys/vm/drop_caches' && TEST_TMPDIR=../ /usr/bin/time ./db_bench_{pre_PR11631|PR11631|PR11631_with_improvementPR11887} -benchmarks=compact -use_existing_db=true -db=../dbbench/ -disable_auto_compactions=true -compression_type=none ; done |& grep elapsed
```
pre-PR11631("no readahead()" case):
PR11631:
PR11631+this improvement:
Reviewed By: ajkr
Differential Revision: D49607266
Pulled By: hx235
fbshipit-source-id: 2efa0dc91bac3c11cc2be057c53d894645f683ef
Summary:
Implement block cache lookup to determine readahead_size during scans. It's enabled if auto_readahead_size, block_cache and iterate_upper_bound - all three are set.
Design -
1. Whenever there is a cache miss and FilePrefetchBuffer is called, a callback is made to determine readahead_size for that prefetching.
2. The callback iterates over index and do block cache lookup for each data block handle until existing readahead_size is reached. Then It removes the cache hit data blocks from end to calculate optimized readahead_size.
3. Since index_iter_ is moved, it stores block handles in a queue, and use that queue to get block handle instead of doing index_iter_->Next().
4. This is for Sync scans. Async scans support is in progress.
NOTE:
The issue right now is after Seek and Next, if Prev is called, there is no way to do Prev operation. index_iter_ is already pointing to a different block. So it returns "Not supported" in that case with error message - "auto tuning of readahead size is not supported with Prev op"
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11860
Test Plan:
- Added new unit test
- crash_tests
- Running scans locally to check for any regression
Reviewed By: anand1976
Differential Revision: D49548118
Pulled By: akankshamahajan15
fbshipit-source-id: f1aee409a71b4ad9e5bf3610f43edf30c6630c78
Summary:
Updating the tiered cache (cache allocated using ```NewTieredCache()```) by calling ```SetCapacity()``` on it was not working properly. The initial creation would set the primary cache capacity to the combined primary and compressed secondary cache capacity. But ```SetCapacity()``` would just set the primary cache capacity, with no way to change the secondary cache capacity. Additionally, the API was confusing, since the primary and compressed secondary capacities would be specified separately during creation, but ```SetCapacity``` took the combined capacity.
With this fix, the user always specifies the total budget and compressed secondary cache ratio on creation. Subsequently, `SetCapacity` will distribute the new capacity across the two caches by the same ratio. The `NewTieredCache` API has been changed to take the total cache capacity (inclusive of both the primary and the compressed secondary cache) and the ratio of total capacity to allocate to the compressed cache. These are specified in `TieredCacheOptions`. Any capacity specified in `LRUCacheOptions`, `HyperClockCacheOptions` and `CompressedSecondaryCacheOptions` is ignored. A new API, `UpdateTieredCache` is provided to dynamically update the total capacity, ratio of compressed cache, and admission policy.
Tests:
New unit tests
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11873
Reviewed By: akankshamahajan15
Differential Revision: D49562250
Pulled By: anand1976
fbshipit-source-id: 57033bc713b68d5da6292207765a6b3dbe539ddf
Summary:
With atomic_flush=true, a flush job with younger memtables wait for older memtables to be installed before install its memtables. If the flush for older memtables failed, auto-recovery starts a resume thread which can becomes stuck waiting for all background work to finish (including the flush for younger memtables). If a non-recovery flush starts now and tries to flush, it can make the situation worse since it will fail due to background error but never rollback its memtable: 269478ee46/db/db_impl/db_impl_compaction_flush.cc (L725) This prevents any future flush to pick old memtables.
A more detailed repro is in unit test.
This PR fixes this issue by
1. Ensure we rollback memtables if an atomic flush fails due to background error
2. When there is a background error, abort atomic flushes that are waiting for older memtables to be installed
3. Do not schedule non-recovery flushes when there is a background error that stops background work
There was another issue with atomic_flush=true where DB can hang during DB close, see more in #11867. The fix in this PR, specifically fix 2 above, should be enough to resolve it too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11872
Test Plan: new unit test.
Reviewed By: jowlyzhang
Differential Revision: D49556867
Pulled By: cbi42
fbshipit-source-id: 4a0210ff28a8552a99ece7fbb0f574fd24b4da3f
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11870
Having a large number of merge operands applied at query time can have a significant effect on performance; therefore, applications might want limit the number of deltas for any given key. However, there is currently no way to establish the number of operands for certain types of queries. The ticker `READ_NUM_MERGE_OPERANDS` only provides aggregate (not per-read) information. The `PerfContext` counters `internal_merge_count` and `internal_merge_point_lookup_count` can be used to get this information on a per-query basis for iterators and single point lookups; however, there is no per-key breakdown for `MultiGet` type APIs. The patch addresses this issue by introducing a special kind of OK status which signals that an application-defined threshold on the number of merge operands has been exceeded for a given key. The threshold can be specified on a per-query basis using a new field in `ReadOptions`.
Reviewed By: jaykorean
Differential Revision: D49522786
fbshipit-source-id: 4265b3848d1be5ff313a3e8fb604ddf56411dd2c
Summary:
This PR implements support for a three tier cache - primary block cache, compressed secondary cache, and a nvm (local flash) secondary cache. This allows more effective utilization of the nvm cache, and minimizes the number of reads from local flash by caching compressed blocks in the compressed secondary cache.
The basic design is as follows -
1. A new secondary cache implementation, ```TieredSecondaryCache```, is introduced. It keeps the compressed and nvm secondary caches and manages the movement of blocks between them and the primary block cache. To setup a three tier cache, we allocate a ```CacheWithSecondaryAdapter```, with a ```TieredSecondaryCache``` instance as the secondary cache.
2. The table reader passes both the uncompressed and compressed block to ```FullTypedCacheInterface::InsertFull```, allowing the block cache to optionally store the compressed block.
3. When there's a miss, the block object is constructed and inserted in the primary cache, and the compressed block is inserted into the nvm cache by calling ```InsertSaved```. This avoids the overhead of recompressing the block, as well as avoiding putting more memory pressure on the compressed secondary cache.
4. When there's a hit in the nvm cache, we attempt to insert the block in the compressed secondary cache and the primary cache, subject to the admission policy of those caches (i.e admit on second access). Blocks/items evicted from any tier are simply discarded.
We can easily implement additional admission policies if desired.
Todo (In a subsequent PR):
1. Add to db_bench and run benchmarks
2. Add to db_stress
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11812
Reviewed By: pdillinger
Differential Revision: D49461842
Pulled By: anand1976
fbshipit-source-id: b40ac1330ef7cd8c12efa0a3ca75128e602e3a0b
Summary:
when atomic_flush=false, there are certain cases where we try to install memtable results with already deleted SST files. This can happen when the following sequence events happen:
```
Start Flush0 for memtable M0 to SST0
Start Flush1 for memtable M1 to SST1
Flush 1 returns OK, but don't install to MANIFEST and let whoever flushes M0 to take care of it
Flush0 finishes with a retryable IOError, it rollbacks M0, (incorrectly) does not rollback M1, and deletes SST0 and SST1
Starts Flush2 for M0, it does not pick up M1 since it thought M1 is flushed
Flush2 writes SST2 and finishes OK, tries to install SST2 and SST1
Error opening SST1 since it's already deleted with an error message like the following:
IO error: No such file or directory: While open a file for random read: /tmp/rocksdbtest-501/db_flush_test_3577_4230653031040984171/000011.sst: No such file or directory
```
This happens since:
1. We currently only rollback the memtables that we are flushing in a flush job when atomic_flush=false.
2. Pending output SSTs from previous flushes are deleted since a pending file number is released whenever a flush job is finished no matter of flush status: f42e70bf56/db/db_impl/db_impl_compaction_flush.cc (L3161)
This PR fixes the issue by rollback these pending flushes.
There is another issue where if a new flush for new memtable starts and finishes after Flush0 finishes. Its output may also be deleted (see more in unit test). It is fixed by checking bg error status before installing a memtable result, and rollback if there is an error.
There is a more efficient fix where we just don't release the pending file output number for flushes that delegate installation. It is more efficient since it does not have to rewrite the flush output file. With the fix in this PR, we can end up with a giant file if a lot of memtables are being flushed together. However, the more efficient fix is a bit more complicated to implement (requires associating such pending file numbers with flush job/memtables) and is more risky since it changes normal flush code path.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11865
Test Plan: * Added repro unit tests.
Reviewed By: anand1976
Differential Revision: D49484922
Pulled By: cbi42
fbshipit-source-id: 25b536c08f4e02e7f1d0f86571663737d2b5d53d
Summary:
This PR makes disabling the compressed secondary cache by setting capacity to 0 a bit more efficient. Previously, inserts/lookups would go to the backing LRUCache before getting rejected due to 0 capacity. With this change, insert/lookup would return from ```CompressedSecondaryCache``` itself.
Tests:
Existing tests
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11863
Reviewed By: akankshamahajan15
Differential Revision: D49476248
Pulled By: anand1976
fbshipit-source-id: f0f17a5e3df7d8bfc06709f8f23c1302056ba590
Summary:
When auto_readahead_size is enabled in async_io, during seek, first buffer will prefetch the data - (current block + readahead till upper_bound). There can be cases where
1. first buffer prefetched all the data till upper bound, or
2. first buffer already has the data from prev seek call
and second buffer prefetch further leading to alignment issues.
This PR fixes that assertion and second buffer won't go for prefetching if first buffer has already prefetched till upper_bound.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11852
Test Plan:
- Added new unit test that failed without this fix.
- crash tests passed locally
Reviewed By: pdillinger
Differential Revision: D49384138
Pulled By: akankshamahajan15
fbshipit-source-id: 54417e909e4d986f1e5a17dbaea059cd4962fd4d
Summary:
**Context:**
As requested, lowest level as well as a map from input file to its table properties among all input files used in table creation (if any) are exposed in `CompactionFilter::Context`.
**Summary:**
This PR contains two commits:
(1) [Refactory](0012777f0e) to make resonating/using what is in `Compaction:: table_properties_` easier
- Separate `Compaction:: table_properties_` into `Compaction:: input_table_properties_` and `Compaction:: output_table_properties_`
- Separate the "set input table properties" logic into `Compaction:: SetInputTableProperties()`) from `Compaction:: GetInputTableProperties`
- Call `Compaction:: SetInputTableProperties()` as soon as possible, which is right after `Compaction::SetInputVersion()`. Bundle these two functions into one `Compaction::FinalizeInputInfo()` to minimize missing one or the other
(2) [Expose more info about input files:](6093e7dfba) `CompactionFilter::Context::input_start_level/input_table_properties`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11857
Test Plan:
- Modify existing UT `
TEST_F(DBTestCompactionFilter, CompactionFilterContextManual)` to cover new logics
Reviewed By: ajkr
Differential Revision: D49402540
Pulled By: hx235
fbshipit-source-id: 469fff50fa0e5964ffa5ea8db0743f61438ea392
Summary:
**Summary:**
When row cache hits and a timestamp is being set in read_options, even though ROW_CACHE entry is hit, the return status is kNotFound.
**Cause of error:**
If timestamp is provided in readoptions, a callback for sequence number checking is registered [here](8fc78a3a9e/db/db_impl/db_impl.cc (L2112)).
Hence the default value set at this [line](694e49cbb1/table/get_context.cc (L611)) prevents get_context from saving value found in cache. Causing the final status to be kNotFound even though the entry exist in both cache and SST file.
**Proposed Solution**
Row cache key contains a sequence number in it. If the key for row cache lookup matches the key in cache, this cache entry should be good to be exposed to user and hence we reuse the sequence number in cache key rather than passing kMaxSequenceNumber.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11816
Reviewed By: ajkr
Differential Revision: D49419029
Pulled By: jowlyzhang
fbshipit-source-id: 6c77e9e751628d7d8e6c389f299e29a11ea824c6
Summary:
Fixes https://github.com/facebook/rocksdb/issues/10257 (also see [here](https://github.com/facebook/rocksdb/pull/10355#issuecomment-1684308556)) by releasing compaction files earlier when writing to manifest in LogAndApply(). This is done by passing in a [callback](ba59751430/db/version_set.h (L1199)) to LogAndApply(). The new Version is created in the same critical section where compaction files are released. When compaction picker is picking compaction based on the new version, these compaction files will already be released.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11764
Test Plan:
* Existing unit tests
* A repro unit test to validate that compaction files are released: `./db_compaction_test --gtest_filter=DBCompactionTest.ReleaseCompactionDuringManifestWrite`
* `python3 ./tools/db_crashtest.py --simple whitebox` with some assertions to check compaction files are released
Reviewed By: ajkr
Differential Revision: D48742152
Pulled By: cbi42
fbshipit-source-id: 7560fd0e723a63fe692234015d2b96850f8b5d77
Summary:
With the async_io option, the Seek happens in 2 phases. Phase 1 starts an asynchronous read on a block cache miss, and phase 2 waits for it to complete and finishes the seek. In both phases, BlockBasedTable::NewDataBlockIterator is called, which tries to lookup the block cache for the data block first before looking in the prefetch buffer. It's optimized by doing the block cache lookup only in the first phase and save some CPU.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11616
Test Plan: Added unit test
Reviewed By: jaykorean
Differential Revision: D47477887
Pulled By: akankshamahajan15
fbshipit-source-id: 0355e0a68fc0ea2eb92340ae42735afcdbcbfd79
Summary:
An internal user wants to be able to dynamically switch between Bloom and Ribbon filters, without a custom FilterPolicy. Making `filter_policy` mutable would actually make issue https://github.com/facebook/rocksdb/issues/10079 worse, because it would be a race on a pointer field, not just on scalars.
As a reasonable compromise until that is fixed, I am enabling dynamic control over Bloom vs. Ribbon choice by making
RibbonFilterPolicy::bloom_before_level mutable, and doing that safely by using an atomic.
I've also slightly tweaked the interpretation of that field so that setting it to INT_MAX really means "always Bloom."
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11838
Test Plan: unit tests added/extended. crash test updated for SetOptions call and tested under TSAN with amplified probability (lower set_options_one_in).
Reviewed By: ajkr
Differential Revision: D49296284
Pulled By: pdillinger
fbshipit-source-id: e4251c077510df9a9c719876f482448c0d15402a
Summary:
This PR resolves https://github.com/facebook/rocksdb/issues/10487 & https://github.com/facebook/rocksdb/issues/10536, user code needs to call Refresh() periodically.
The main code change is to support range deletions. A range tombstone iterator uses a sequence number as upper bound to decide which range tombstones are effective. During Iterator refresh, this sequence number upper bound needs to be updated for all range tombstone iterators under DBIter and LevelIterator. LevelIterator may create new table iterators and range tombstone iterator during scanning, so it needs to be aware of iterator refresh. The code path that propagates this change is `db_iter_->set_sequence(read_seq) -> MergingIterator::SetRangeDelReadSeqno() -> TruncatedRangeDelIterator::SetRangeDelReadSeqno() and LevelIterator::SetRangeDelReadSeqno()`.
This change also fixes an issue where range tombstone iterators created by LevelIterator may access ReadOptions::snapshot, even though we do not explicitly require users to keep a snapshot alive after creating an Iterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10594
Test Plan:
* New unit tests.
* Add Iterator::Refresh(snapshot) to stress test. Note that this change only adds tests for refreshing to the same snapshot since this is the main target use case.
TODO in a following PR:
* Stress test Iterator::Refresh() to different snapshots or no snapshot.
Reviewed By: ajkr
Differential Revision: D48456896
Pulled By: cbi42
fbshipit-source-id: 2e642c04e91235cc9542ef4cd37b3c20823bd779
Summary:
Update the logic in FilePrefetchBuffer to update `upper_bound_offset_` during reseek. During Reseek, `iterate_upper_bound` can be changed dynamically. So added an API to update that in FilePrefetchBuffer.
Added unit test to confirm the behavior.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11775
Test Plan:
- Check stress tests in case there is any failure after this diff.
- make crash_test -j32 with auto_readahead_size=1 passed locally
Reviewed By: anand1976
Differential Revision: D48815177
Pulled By: akankshamahajan15
fbshipit-source-id: 5f44fbb3af06c86a1c38f139c5fa4543891837f4
Summary:
When `MultiGet` acquires `SuperVersion` via locking the db mutex and get the current `ColumnFamilyData::super_version_`, its corresponding cleanup logic is not correctly done.
It's currently doing this:
`MultiGetColumnFamilyData::cfd->GetSuperVersion().Unref()`
This operates on the most recent `SuperVersion` without locking db mutex , which is not thread safe by itself. And this unref operation is intended for the originally acquired `SuperVersion` instead of the current one. Because a race condition could happen where a new `SuperVersion` is installed in between this `MultiGet`'s ref and unref. When this race condition does happen, it's not sufficient to just unref the `SuperVersion`, `DBImpl::CleanupSuperVersion` should be called instead to properly clean up the `SuperVersion` had this `MultiGet` call be its last reference holder.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11830
Test Plan:
`make all check`
Added a unit test that would originally fail
Reviewed By: ltamasi
Differential Revision: D49287715
Pulled By: jowlyzhang
fbshipit-source-id: 8353636ee11b2e90d85c677a96a92360072644b0
Summary:
`GetEntity` API support for ReadOnly DB and Secondary DB.
- Introduced `GetImpl()` with `GetImplOptions` in `db_impl_readonly` and refactored current `Get()` logic into `GetImpl()` so that look up logic can be reused for `GetEntity()` (Following the same pattern as `DBImpl::Get()` and `DBImpl::GetEntity()`)
- Introduced `GetImpl()` with `GetImplOptions` in `db_impl_secondary` and refactored current `GetImpl()` logic. This is to make `DBImplSecondary::Get/GetEntity` consistent with `DBImpl::Get/GetEntity` and `DBImplReadOnly::Get/GetEntity`
- `GetImpl()` in `db_impl` is now virtual. both `db_impl_readonly` and `db_impl_secondary`'s `Get()` override are no longer needed since all three dbs now have the same `Get()` which calls `GetImpl()` internally.
- `GetImpl()` in `DBImplReadOnly` and `DBImplSecondary` now pass in `columns` instead of `nullptr` in lookup functions like `memtable->get()`
- Introduced `GetEntity()` API in `DBImplReadOnly` and `DBImplSecondary` which simply calls `GetImpl()` with `columns` set in `GetImplOptions`.
- Introduced `Env::IOActivity::kGetEntity` and set read_options.io_activity to `Env::IOActivity::kGetEntity` for `GetEntity()` operations (in db_impl)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11799
Test Plan:
**Unit Tests**
- Added verification in `DBWideBasicTest::PutEntity` by Reopening DB as ReadOnly with the same setup.
- Added verification in `DBSecondaryTest::ReopenAsSecondary` by calling `PutEntity()` and `GetEntity()` on top of existing `Put()` and `Get()`
- `make -j64 check`
**Crash Tests**
- `python3 tools/db_crashtest.py blackbox --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 --duration=60 --inter
val=10`
- `python3 tools/db_crashtest.py blackbox --simple --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 `
- `python3 tools/db_crashtest.py blackbox --cf_consistency --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 --duration=60 --inter
val=10`
Reviewed By: ltamasi
Differential Revision: D49037040
Pulled By: jaykorean
fbshipit-source-id: a0648253ded6e91af7953de364ed3c6bf163626b
Summary:
**Context/Summary:**
A size amp compaction can select and prevent a large number of L0 files from being selected by other compaction. If such compaction is running long or being queued behind, these L0 files will exist for long. With a few more flushes, we can run into write stop triggered by # L0 files. We've seen this happen on a host with many DBs sharing same thread pool, each of these DBs submits a size amp compaction with (110-180)+ files to the pool upon reopen and with a few more flushes, they hit the 200 L0 write stop condition.
The idea is to exclude some L0 input files in size amp compaction that are harmless to size amp reduction but improve the situation described above.
The exclusion algorithm is in `MightExcludeNewL0sToReduceWriteStop()` with two elements:
1. #L0 to exclude + (level0_stop_writes_trigger - num_l0_input_pre_exclusion) should be in the range of [min_merge_width, max_merge_width].
- This is to ensure we are excluding enough L0 input files but not too many to be qualified to picked for another compaction along with the incoming future L0 files before write stop.
2. Based on (1), further constrain #L0 to exclude based on the post-exclusion compaction score. The goal is to ensure our exclusion will not disqualify the size amp compaction from being a size amp compaction after exclusion.
**Tets plan:** New unit test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11749
Reviewed By: ajkr
Differential Revision: D48850631
Pulled By: hx235
fbshipit-source-id: 2c321036e164087c36319dd5645cbbf6b6152092
Summary:
Existing compaction statistics are `COMPACTION_TIME` and `COMPACTION_CPU_TIME` which are histogram and are logged at the end of a compaction. The new statistics `COMPACTION_CPU_TOTAL_TIME` is for cumulative total compaction time which is updated regularly during a compaction. This allows user to more closely track compaction cpu usage.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11741
Test Plan: * new unit test `DBTestWithParam.CompactionTotalTimeTest`
Reviewed By: ajkr
Differential Revision: D48608094
Pulled By: cbi42
fbshipit-source-id: b597109f3e4bf2237fb5a216b6fd036e5363b4c0
Summary:
During Seek, the iterator seeks every file on L0. In async_io, it submit the requests to seek on every file on L0 asynchronously using RocksDB FilePrefetchBuffer.
However, FilePrefetchBuffer does alignment and reads extra bytes then needed that can increase the throughput.
In case of non direct io, the alignment can be avoided.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11793
Test Plan:
- Added a unit test that fails without this PR.
- make crash_test -j32 completed successfully
Reviewed By: anand1976
Differential Revision: D48985051
Pulled By: akankshamahajan15
fbshipit-source-id: 2d130a9e7c3df9c4fcd0408406e6277ab75a4389
Summary:
This should only affect iterator when
- user uses DeleteRange(),
- An iterator from level L has a non-ok status (such non-ok status may not be caught before the bug fix in https://github.com/facebook/rocksdb/pull/11783), and
- A range tombstone covers a key from level > L and triggers a reseek sets the status_ to OK in SeekImpl()/SeekPrevImpl() e.g. bd6a8340c3/table/merging_iterator.cc (L801)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11786
Differential Revision: D48908830
Pulled By: cbi42
fbshipit-source-id: eb564be375af4e33dc27542eff753260186e6d5d
Summary:
This happens in (Compaction)MergingIterator layer, and can cause data loss during compaction or read/scan return incorrect result
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11782
Reviewed By: ajkr
Differential Revision: D48880575
Pulled By: cbi42
fbshipit-source-id: 2294ad284a6d653d3674bebe55380f12ee4b645b
Summary:
**Context/Summary:**
After https://github.com/facebook/rocksdb/pull/11631, we rely on `compaction_readahead_size` for how much to read ahead for compaction read under non-direct IO case. https://github.com/facebook/rocksdb/pull/11658 therefore also sanitized 0 `compaction_readahead_size` to 2MB under non-direct IO, which is consistent with the existing sanitization with direct IO.
However, this makes disabling compaction readahead impossible as well as add one more scenario to the inconsistent effects between `Options.compaction_readahead_size=0` during DB open and `SetDBOptions("compaction_readahead_size", "0")` .
- `SetDBOptions("compaction_readahead_size", "0")` will disable compaction readahead as its logic never goes through sanitization above while `Options.compaction_readahead_size=0` will go through sanitization.
Therefore we decided to do this PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11762
Test Plan: Modified existing UTs to cover this PR
Reviewed By: ajkr
Differential Revision: D48759560
Pulled By: hx235
fbshipit-source-id: b3f85e58bda362a6fa1dc26bd8a87aa0e171af79
Summary:
For a SST file that uses user-defined timestamp aware comparators, if a lower or upper bound is set, sst_dump tool doesn't handle it well. This PR adds support for that. While working on this `MaybeAddTimestampsToRange` is moved to the udt_util.h file to be shared.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11757
Test Plan:
make all check
for changes in db_impl.cc and db_impl_compaction_flush.cc
for changes in sst_file_dumper.cc, I manually tested this change handles specifying bounds for UDT use cases. It probably should have a unit test file eventually.
Reviewed By: ltamasi
Differential Revision: D48668048
Pulled By: jowlyzhang
fbshipit-source-id: 1560465f40e44668d6d82a7439fe9012be0e74a8
Summary:
Implement trimming of readahead_size under a new option ReadOptions.auto_readahead_size. It'll trim the readahead_size during prefetching upto iterate_upper_bound offset only when ReadOptions.iterate_upper_bound is set, therefore reducing the prefetching of data beyond upper_bound.
It's enabled for both implicit auto readahead size and when ReadOptions.readahead_size is specified and for sync and async_io.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11684
Test Plan: Added new unit test
Reviewed By: anand1976
Differential Revision: D48479723
Pulled By: akankshamahajan15
fbshipit-source-id: 2b1703579caf779105e836b580866ffd7db076fc
Summary:
While it's rare, we may run into a scenario where `WaitForCompact()` waits for background jobs indefinitely. For example, not enough space error will add the job back to the queue while WaitForCompact() waits for _all jobs_ including the jobs that are in the queue to be completed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11711
Test Plan:
`DBCompactionWaitForCompactTest::WaitForCompactToTimeout` added
`timeout` option added to the variables for all of the existing DBCompactionWaitForCompactTests
Reviewed By: pdillinger, jowlyzhang
Differential Revision: D48416390
Pulled By: jaykorean
fbshipit-source-id: 7b6a12f705ab6c6dfaf8ad736a484ca654a86106
Summary:
This PR implements a new admission policy for the compressed secondary cache, which includes the functionality of the existing policy, and also admits items evicted from the primary block cache with the hit bit set. Effectively, the new policy works as follows -
1. When an item is demoted from the primary cache without a hit, a placeholder is inserted in the compressed cache. A second demotion will insert the full entry.
2. When an item is promoted from the compressed cache to the primary cache for the first time, a placeholder is inserted in the primary. The second promotion inserts the full entry, while erasing it form the compressed cache.
3. If an item is demoted from the primary cache with the hit bit set, it is immediately inserted in the compressed secondary cache.
The ```TieredVolatileCacheOptions``` has been updated with a new option, ```adm_policy```, which allows the policy to be selected.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11713
Reviewed By: pdillinger
Differential Revision: D48444512
Pulled By: anand1976
fbshipit-source-id: b4cbf8c169a88097dff08e36e8bc4b3088de1492
Summary:
For leveled compaction, RocksDB has a special kind of compaction with reason "kBottommmostFiles" that compacts bottommost level files to clear data held by snapshots (more detail in https://github.com/facebook/rocksdb/issues/3009). Such compactions can happen soon after a relevant snapshot is released. For some use cases, a bottommost file may contain only a small amount of keys that can be cleared, so compacting such a file has a high write amp. In addition, these bottommost files may be compacted in compactions with reason other than "kBottommmostFiles" if we wait for some time (so that enough data is ingested to trigger such a compaction). This PR introduces an option `bottommost_file_compaction_delay` to specify the delay of these bottommost level single file compactions.
* The main change is in `VersionStorageInfo::ComputeBottommostFilesMarkedForCompaction()` where we only add a file to `bottommost_files_marked_for_compaction_` if it oldest_snapshot is larger than its non-zero largest_seqno **and** the file is old enough. Note that if a file is not old enough but its largest_seqno is less than oldest_snapshot, we exclude it from the calculation of `bottommost_files_mark_threshold_`. This makes the change simpler, but such a file's eligibility for compaction will only be checked the next time `ComputeBottommostFilesMarkedForCompaction()` is called. This happens when a new Version is created (compaction, flush, SetOptions()...), a new enough snapshot is released (`VersionStorageInfo::UpdateOldestSnapshot()`) or when a compaction is picked and compaction score has to be re-calculated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11701
Test Plan:
* Add two unit tests to test when bottommost_file_compaction_delay > 0.
* Ran crash test with the new option.
Reviewed By: jaykorean, ajkr
Differential Revision: D48331564
Pulled By: cbi42
fbshipit-source-id: c584f3dc5f6354fce3ed65f4c6366dc450b15ba8
Summary:
Context:
As mentioned in https://github.com/facebook/rocksdb/issues/11436, introducing `close_db` option in `WaitForCompactOptions` to close DB after waiting for compactions to finish. Must be set to true to close the DB upon compactions finishing.
1. `bool close_db = false` added to `WaitForCompactOptions`
2. Introduced `CancelPeriodicTaskSchedulers()` and moved unregistering PeriodicTaskSchedulers to it.`CancelAllBackgroundWork()` calls it now.
3. When close_db option is on, unpersisted data (data in memtable when WAL is disabled) will be flushed in `WaitForCompact()` if flush option is not on (and `mutable_db_options_.avoid_flush_during_shutdown` is not true). The unpersisted data flush in `CancelAllBackgroundWork()` will be skipped because `shutting_down_` flag will be set true before calling `Close()`.
4. Atomic boolean `reject_new_background_jobs_` is introduced to prevent new background jobs from being added during the short period of time after waiting is done and before `shutting_down_` is set by `Close()`.
5. `WaitForCompact()` now waits for recovery in progress to complete as well. (flush operations from WAL -> L0 files)
6. Added `close_db_` cases to all existing `WaitForCompactTests`
7. Added a scenario to `DBBasicTest::DBClose`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11497
Test Plan:
- Existing DBCompactionTests
- `WaitForCompactWithOptionToFlushAndCloseDB` added
- Added a scenario to `DBBasicTest::DBClose`
Reviewed By: pdillinger, jowlyzhang
Differential Revision: D46337560
Pulled By: jaykorean
fbshipit-source-id: 0f8c7ee09394847f2af5ea4bdd331b47bcdef0b0
Summary:
RocksDB provides APIs that enable creating SST files offline and then bulk loading them into the LSM tree quickly using metadata operations. Namely, clients can use the `SstFileWriter` class for the offline data preparation and then the IngestExternalFile family of APIs to perform the bulk loading. However, `SstFileWriter` currently does not support creating files with wide-column data in them. This PR adds `PutEntity` API implementation to `SstFileWriter` to support creating files with wide-column data.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11688
Test Plan: - `BasicWideColumn` test added in external_sst_file_test
Reviewed By: ltamasi
Differential Revision: D48243779
Pulled By: jaykorean
fbshipit-source-id: 1697e5bd67121a648c03946f867416a94be0cadf
Summary:
**Context/Summary:**
- Similar to https://github.com/facebook/rocksdb/pull/11288 but for user read such as `Get(), MultiGet(), DBIterator::XXX(), Verify(File)Checksum()`.
- For this, I refactored some user-facing `MultiGet` calls in `TransactionBase` and various types of `DB` so that it does not call a user-facing `Get()` but `GetImpl()` for passing the `ReadOptions::io_activity` check (see PR conversation)
- New user read stats breakdown are guarded by `kExceptDetailedTimers` since measurement shows they have 4-5% regression to the upstream/main.
- Misc
- More refactoring: with https://github.com/facebook/rocksdb/pull/11288, we complete passing `ReadOptions/IOOptions` to FS level. So we can now replace the previously [added](https://github.com/facebook/rocksdb/pull/9424) `rate_limiter_priority` parameter in `RandomAccessFileReader`'s `Read/MultiRead/Prefetch()` with `IOOptions::rate_limiter_priority`
- Also, `ReadAsync()` call time is measured in `SST_READ_MICRO` now
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11444
Test Plan:
- CI fake db crash/stress test
- Microbenchmarking
**Build** `make clean && ROCKSDB_NO_FBCODE=1 DEBUG_LEVEL=0 make -jN db_basic_bench`
- google benchmark version: 604f6fd3f4
- db_basic_bench_base: upstream
- db_basic_bench_pr: db_basic_bench_base + this PR
- asyncread_db_basic_bench_base: upstream + [db basic bench patch for IteratorNext](https://github.com/facebook/rocksdb/compare/main...hx235:rocksdb:micro_bench_async_read)
- asyncread_db_basic_bench_pr: asyncread_db_basic_bench_base + this PR
**Test**
Get
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_{null_stat|base|pr} --benchmark_filter=DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1/negative_query:0/enable_filter:0/mmap:1/threads:1 --benchmark_repetitions=1000
```
Result
```
Coming soon
```
AsyncRead
```
TEST_TMPDIR=/dev/shm ./asyncread_db_basic_bench_{base|pr} --benchmark_filter=IteratorNext/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1/async_io:1/include_detailed_timers:0 --benchmark_repetitions=1000 > syncread_db_basic_bench_{base|pr}.out
```
Result
```
Base:
1956,1956,1968,1977,1979,1986,1988,1988,1988,1990,1991,1991,1993,1993,1993,1993,1994,1996,1997,1997,1997,1998,1999,2001,2001,2002,2004,2007,2007,2008,
PR (2.3% regression, due to measuring `SST_READ_MICRO` that wasn't measured before):
1993,2014,2016,2022,2024,2027,2027,2028,2028,2030,2031,2031,2032,2032,2038,2039,2042,2044,2044,2047,2047,2047,2048,2049,2050,2052,2052,2052,2053,2053,
```
Reviewed By: ajkr
Differential Revision: D45918925
Pulled By: hx235
fbshipit-source-id: 58a54560d9ebeb3a59b6d807639692614dad058a
Summary:
When `num_levels` > 65, we may be shifting more than 63 bits in FileTtlBooster. This can give errors like: `runtime error: shift exponent 98 is too large for 64-bit type 'uint64_t' (aka 'unsigned long')`. This PR makes a quick fix for this issue by taking a min in the shifting component. This issue should be rare since it requires a user using a large `num_levels`. I'll follow up with a more complex fix if needed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11673
Test Plan: * Add a unit test that produce the above error before this PR. Need to compile it with ubsan: `COMPILE_WITH_UBSAN=1 OPT="-fsanitize-blacklist=.circleci/ubsan_suppression_list.txt" ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 compaction_picker_test`
Reviewed By: hx235
Differential Revision: D48074386
Pulled By: cbi42
fbshipit-source-id: 25e59df7e93f20e0793cffb941de70ac815d9392
Summary:
**Context/Summary:**
After https://github.com/facebook/rocksdb/pull/11631, file hint is not longer needed for compaction read. Therefore we can deprecate `Options::access_hint_on_compaction_start`. As this is a public API change, we should first mark the relevant APIs (including the Java's) deprecated and remove it in next major release 9.0.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11658
Test Plan: No code change
Reviewed By: ajkr
Differential Revision: D47997856
Pulled By: hx235
fbshipit-source-id: 16e015ae7728c224b1caef73143aa9915668f4ac
Summary:
Add a mutable column family option `memtable_max_range_deletions`. When non-zero, RocksDB will try to flush the current memtable after it has at least `memtable_max_range_deletions` range deletions. Java API is added and crash test is updated accordingly to randomly enable this option.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11358
Test Plan:
* New unit test: `DBRangeDelTest.MemtableMaxRangeDeletions`
* Ran crash test `python3 ./tools/db_crashtest.py whitebox --simple --memtable_max_range_deletions=20` and saw logs showing flushed memtables usually with 20 range deletions.
Reviewed By: ajkr
Differential Revision: D46582680
Pulled By: cbi42
fbshipit-source-id: f23d6fa8d8264ecf0a18d55c113ba03f5e2504da
Summary:
Updated the main branch for the 8.5.fb branch cut. Also made unreleased_history/release.sh backdate to the last commit instead of the current date in case the release manager is a laggard like myself.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11642
Reviewed By: cbi42
Differential Revision: D47783574
Pulled By: ajkr
fbshipit-source-id: 4e2a80f5ccd542dc7dd0d22dfd7e59cb136325a1
Summary:
## Context checksum
All RocksDB checksums currently use 32 bits of checking
power, which should be 1 in 4 billion false negative (FN) probability (failing to
detect corruption). This is true for random corruptions, and in some cases
small corruptions are guaranteed to be detected. But some possible
corruptions, such as in storage metadata rather than storage payload data,
would have a much higher FN rate. For example:
* Data larger than one SST block is replaced by data from elsewhere in
the same or another SST file. Especially with block_align=true, the
probability of exact block size match is probably around 1 in 100, making
the FN probability around that same. Without `block_align=true` the
probability of same block start location is probably around 1 in 10,000,
for FN probability around 1 in a million.
To solve this problem in new format_version=6, we add "context awareness"
to block checksum checks. The stored and expected checksum value is
modified based on the block's position in the file and which file it is in. The
modifications are cleverly chosen so that, for example
* blocks within about 4GB of each other are guaranteed to use different context
* blocks that are offset by exactly some multiple of 4GiB are guaranteed to use
different context
* files generated by the same process are guaranteed to use different context
for the same offsets, until wrap-around after 2^32 - 1 files
Thus, with format_version=6, if a valid SST block and checksum is misplaced,
its checksum FN probability should be essentially ideal, 1 in 4B.
## Footer checksum
This change also adds checksum protection to the SST footer (with
format_version=6), for the first time without relying on whole file checksum.
To prevent a corruption of the format_version in the footer (e.g. 6 -> 5) to
defeat the footer checksum, we change much of the footer data format
including an "extended magic number" in format_version 6 that would be
interpreted as empty index and metaindex block handles in older footer
versions. We also change the encoding of handles to free up space for
other new data in footer.
## More detail: making space in footer
In order to keep footer the same size in format_version=6 (avoid change to IO
patterns), we have to free up some space for new data. We do this two ways:
* Metaindex block handle is encoded down to 4 bytes (from 10) by assuming
it immediately precedes the footer, and by assuming it is < 4GB.
* Index block handle is moved into metaindex. (I don't know why it was
in footer to begin with.)
## Performance
In case of small performance penalty, I've made a "pay as you go" optimization
to compensate: replace `MutableCFOptions` in BlockBasedTableBuilder::Rep
with the only field used in that structure after construction: `prefix_extractor`.
This makes the PR an overall performance improvement (results below).
Nevertheless I'm seeing essentially no difference going from fv=5 to fv=6,
even including that improvement for both. That's based on extreme case table
write performance testing, many files with many blocks. This is relatively
checksum intensive (small blocks) and salt generation intensive (small files).
```
(for I in `seq 1 100`; do TEST_TMPDIR=/dev/shm/dbbench2 ./db_bench -benchmarks=fillseq -memtablerep=vector -disable_wal=1 -allow_concurrent_memtable_write=false -num=3000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -write_buffer_size=100000 -compression_type=none -block_size=1000; done) 2>&1 | grep micros/op | tee out
awk '{ tot += $5; n += 1; } END { print int(1.0 * tot / n) }' < out
```
Each value below is ops/s averaged over 100 runs, run simultaneously with competing
configuration for load fairness
Before -> after (both fv=5): 483530 -> 483673 (negligible)
Re-run 1: 480733 -> 485427 (1.0% faster)
Re-run 2: 483821 -> 484541 (0.1% faster)
Before (fv=5) -> after (fv=6): 482006 -> 485100 (0.6% faster)
Re-run 1: 482212 -> 485075 (0.6% faster)
Re-run 2: 483590 -> 484073 (0.1% faster)
After fv=5 -> after fv=6: 483878 -> 485542 (0.3% faster)
Re-run 1: 485331 -> 483385 (0.4% slower)
Re-run 2: 485283 -> 483435 (0.4% slower)
Re-run 3: 483647 -> 486109 (0.5% faster)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9058
Test Plan:
unit tests included (table_test, db_properties_test, salt in env_test). General DB tests
and crash test updated to test new format_version.
Also temporarily updated the default format version to 6 and saw some test failures. Almost all
were due to an inadvertent additional read in VerifyChecksum to verify the index block checksum,
though it's arguably a bug that VerifyChecksum does not appear to (re-)verify the index block
checksum, just assuming it was verified in opening the index reader (probably *usually* true but
probably not always true). Some other concerns about VerifyChecksum are left in FIXME
comments. The only remaining test failure on change of default (in block_fetcher_test) now
has a comment about how to upgrade the test.
The format compatibility test does not need updating because we have not updated the default
format_version.
Reviewed By: ajkr, mrambacher
Differential Revision: D33100915
Pulled By: pdillinger
fbshipit-source-id: 8679e3e572fa580181a737fd6d113ed53c5422ee
Levi Tamasi