Summary:
Previously, the flushes triggered by `WriteBufferManager` could affect
the same CF repeatedly if it happens to get consecutive writes. Such
flushes are not particularly useful for reducing memory usage since
they switch nearly-empty memtables to immutable while they've just begun
filling their first arena block. In fact they may not even reduce the
mutable memory count if they involve replacing one mutable memtable containing
one arena block with a new mutable memtable containing one arena block.
Further, if such switches happen even a few times before a flush finishes,
the immutable memtable limit will be reached and writes will stall.
This PR adds a heuristic to not switch memtables to immutable for CFs
that already have one or more immutable memtables awaiting flush. There
is a memory usage regression if the user continues writing to the same
CF, that DB does not have any CFs eligible for switching, flushes
are not finishing, and the `WriteBufferManager` was constructed with
`allow_stall=false`. Before, it would grow by switching nearly empty
memtables until writes stall. Now, it would grow by filling memtables
until writes stall. This feels like an acceptable behavior change because
users who prefer to stall over violate the memory limit should be using
`allow_stall=true`, which is unaffected by this PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6364
Test Plan:
- Command:
`rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num_multi_db=8 -num_column_families=2 -write_buffer_size=4194304 -db_write_buffer_size=16777216 -compression_type=none -statistics=true -target_file_size_base=4194304 -max_bytes_for_level_base=16777216`
- `rocksdb.db.write.stall` count before this PR: 175
- `rocksdb.db.write.stall` count after this PR: 0
Reviewed By: jay-zhuang
Differential Revision: D20167197
Pulled By: ajkr
fbshipit-source-id: 4a64064e9bc33d57c0a35f15547542d0191d0cb7
Summary:
The fix in https://github.com/facebook/rocksdb/issues/10513 was not complete w.r.t range deletion handling. It didn't handle the case where a file with a range tombstone covering a key also overlapped another key in the batch. In that case, ```mget_range``` would be non-empty. However, ```mget_range``` would only have the second key and, therefore, the first key would be skipped when iterating through the range tombstones in ```TableCache::MultiGet```.
Test plan -
1. Add a unit test
2. Run stress tests
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10534
Reviewed By: akankshamahajan15
Differential Revision: D38773880
Pulled By: anand1976
fbshipit-source-id: dae491dbe52e18bbce5179b77b63f20771a66c00
Summary:
RocksDB's `Cache` abstraction currently supports two priority levels for items: high (used for frequently accessed/highly valuable SST metablocks like index/filter blocks) and low (used for SST data blocks). Blobs are typically lower-value targets for caching than data blocks, since 1) with BlobDB, data blocks containing blob references conceptually form an index structure which has to be consulted before we can read the blob value, and 2) cached blobs represent only a single key-value, while cached data blocks generally contain multiple KVs. Since we would like to make it possible to use the same backing cache for the block cache and the blob cache, it would make sense to add a new, lower-than-low cache priority level (bottom level) for blobs so data blocks are prioritized over them.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10461
Reviewed By: siying
Differential Revision: D38672823
Pulled By: ltamasi
fbshipit-source-id: 90cf7362036563d79891f47be2cc24b827482743
Summary:
Fix copyright for two more extra headers to make internal tool happy.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10525
Reviewed By: jay-zhuang
Differential Revision: D38661390
fbshipit-source-id: ab2d055bfd145dfe82b5bae7a6c25cc338c8de94
Summary:
... so that cache keys can be derived from DB manifest data
before reading the file from storage--so that every part of the file
can potentially go in a persistent cache.
See updated comments in cache_key.cc for technical details. Importantly,
the new cache key encoding uses some fancy but efficient math to pack
data into the cache key without depending on the sizes of the various
pieces. This simplifies some existing code creating cache keys, like
cache warming before the file size is known.
This should provide us an essentially permanent mapping between SST
unique IDs and base cache keys, with the ability to "upgrade" SST
unique IDs (and thus cache keys) with new SST format_versions.
These cache keys are of similar, perhaps indistinguishable quality to
the previous generation. Before this change (see "corrected" days
between collision):
```
./cache_bench -stress_cache_key -sck_keep_bits=43
18 collisions after 2 x 90 days, est 10 days between (1.15292e+19 corrected)
```
After this change (keep 43 bits, up through 50, to validate "trajectory"
is ok on "corrected" days between collision):
```
19 collisions after 3 x 90 days, est 14.2105 days between (1.63836e+19 corrected)
16 collisions after 5 x 90 days, est 28.125 days between (1.6213e+19 corrected)
15 collisions after 7 x 90 days, est 42 days between (1.21057e+19 corrected)
15 collisions after 17 x 90 days, est 102 days between (1.46997e+19 corrected)
15 collisions after 49 x 90 days, est 294 days between (2.11849e+19 corrected)
15 collisions after 62 x 90 days, est 372 days between (1.34027e+19 corrected)
15 collisions after 53 x 90 days, est 318 days between (5.72858e+18 corrected)
15 collisions after 309 x 90 days, est 1854 days between (1.66994e+19 corrected)
```
However, the change does modify (probably weaken) the "guaranteed unique" promise from this
> SST files generated in a single process are guaranteed to have unique cache keys, unless/until number session ids * max file number = 2**86
to this (see https://github.com/facebook/rocksdb/issues/10388)
> With the DB id limitation, we only have nice guaranteed unique cache keys for files generated in a single process until biggest session_id_counter and offset_in_file reach combined 64 bits
I don't think this is a practical concern, though.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10394
Test Plan: unit tests updated, see simulation results above
Reviewed By: jay-zhuang
Differential Revision: D38667529
Pulled By: pdillinger
fbshipit-source-id: 49af3fe7f47e5b61162809a78b76c769fd519fba
Summary:
The info LOG file does not currently give any direct
information about the existence of old, live snapshots, nor how to
estimate wall time from a sequence number within the scope of LOG
history. This change addresses both with:
* Logging smallest and largest seqnos for generated SST files, which can
help associate sequence numbers with write time (based on flushes).
* Logging oldest_snapshot_seqno for each compaction, which (along with
that seqno info) helps us to determine how much old data might be kept
around for old (leaked?) snapshots. Including the date here I thought might
be excessive.
I wanted to log the date and seqno of the oldest snapshot with periodic
stats, but the current structure of the code doesn't really support that
because `DumpDBStats` doesn't have access to the DB object.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10454
Test Plan:
manual inspect LOG from
`KEEP_DB=1 ./db_basic_test --gtest_filter=*CompactBetweenSnapshots*`
Reviewed By: ajkr
Differential Revision: D38326948
Pulled By: pdillinger
fbshipit-source-id: 294918ffc04a419844146cd826045321b4d5c038
Summary:
https://github.com/facebook/rocksdb/pull/10057 caused a regression bug: since the base level size is not adjusted based on L0 size anymore, L0 score might become very large. This makes compaction heavily favor L0->L1 compaction against L1->L2 compaction, and cause in some cases, data stuck in L1 without being moved down. We fix calculating a score of L0 by size(L0)/size(L1) in the case where L0 is large..
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10518
Test Plan: run db_bench against data on tmpfs and watch the behavior of data stuck in L1 goes away.
Reviewed By: ajkr
Differential Revision: D38603145
fbshipit-source-id: 4949e52dc28b54aacfe08417c6e6cc7e40a27225
Summary:
New blobdb has a bug in compaction filter, where `blob_value_` is not reset for next iterated key. This will cause blob_value_ not empty and previous value read from blob is passed into the filter function for next key, even if its value is not in blob. Fixed by reseting regardless of key type.
Test Case:
Add `FilterByValueLength` test case in `DBBlobCompactionTest`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10391
Reviewed By: riversand963
Differential Revision: D38629900
Pulled By: ltamasi
fbshipit-source-id: 47d23ff2e5ec697958a210db9e6ceeb8b2fc49fa
Summary:
Some files miss headers. Also some headers are irregular. Fix them to make an internal checkup tool happy.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10519
Reviewed By: jay-zhuang
Differential Revision: D38603291
fbshipit-source-id: 13b1bbd6d48f5ee15ba20da67544396de48238f1
Summary:
Moved linux builds to using docker to avoid CI instability caused by dependency installation site down.
Added the `Dockerfile` which is used to build the image.
The build time is also significantly reduced, because no dependencies installation and with using 2xlarge+ instance for slow build (like tsan test).
Also fixed a few issues detected while building this:
* `DestoryDB()` Status not checked for a few tests
* nullptr might be used in `inlineskiplist.cc`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10496
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D38554200
Pulled By: jay-zhuang
fbshipit-source-id: 16e8fb2bf07b9c84bb27fb18421c4d54f2f248fd
Summary:
A test in db_block_cache_test.cc was skipping ClockCache due to the 16-byte key length requirement. We fixed this. Along the way, we fixed a bug in ApplyToSomeEntries, which assumed the function being applied could modify handle metadata, and thus took an exclusive reference. This is incompatible with calls that need to inspect every element (including externally referenced ones) to gather stats.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10482
Test Plan: ``make -j24 check``
Reviewed By: anand1976
Differential Revision: D38553073
Pulled By: guidotag
fbshipit-source-id: 0ed63fed4d3b89e5056b35b7091fce579f5647ae
Summary:
A flag in WritableFileWriter is introduced to remember error has happened. Subsequent operations will fail with an assertion. Those operations, except Close() are not supposed to be called anyway. This change will help catch bug in tests and stress tests and limit damage of a potential bug of continue writing to a file after a failure.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10489
Test Plan: Fix existing unit tests and watch crash tests for a while.
Reviewed By: anand1976
Differential Revision: D38473277
fbshipit-source-id: 09aafb971e56cfd7f9ef92ad15b883f54acf1366
Summary:
The main purpose is to make debugging easier without sacrificing performance.
Instead of using a boolean variable for `CompactionIterator::valid_`, we can extend it to an `uint8_t`,
using the LSB to denote if the compaction iterator is valid and 4 additional bits to denote where
the iterator is set valid inside `NextFromInput()`. Therefore, when the control flow reaches
`PrepareOutput()` and hits assertion there, we can have a better idea of what has gone wrong.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10505
Test Plan:
make check
```
TEST_TMPDIR=/dev/shm/rocksdb time ./db_bench -compression_type=none -write_buffer_size=1073741824 -benchmarks=fillseq,flush
```
The above command has a 'flush' benchmark which uses `CompactionIterator`. I haven't observed any CPU regression or drop in throughput or latency increase.
Reviewed By: ltamasi
Differential Revision: D38551615
Pulled By: riversand963
fbshipit-source-id: 1250848fc118bb753d71fa9ff8ba840df999f5e0
Summary:
This fix is to replace `AllocateBlock()` with `new`. Once I figure out why `AllocateBlock()` might cause the segfault, I will update the implementation.
Fix the bug that causes ./compressed_secondary_cache_test output following test failures:
```
Note: Google Test filter = CompressedSecondaryCacheTest.MergeChunksIntoValueTest
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from CompressedSecondaryCacheTest
[ RUN ] CompressedSecondaryCacheTest.MergeChunksIntoValueTest
[ OK ] CompressedSecondaryCacheTest.MergeChunksIntoValueTest (1 ms)
[----------] 1 test from CompressedSecondaryCacheTest (1 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (9 ms total)
[ PASSED ] 1 test.
t/run-compressed_secondary_cache_test-CompressedSecondaryCacheTest.MergeChunksIntoValueTest: line 4: 1091086 Segmentation fault (core dumped) TEST_TMPDIR=$d ./compressed_secondary_cache_test --gtest_filter=CompressedSecondaryCacheTest.MergeChunksIntoValueTest
Note: Google Test filter = CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from CompressedSecondaryCacheTest
[ RUN ] CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression
[ OK ] CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression (1 ms)
[----------] 1 test from CompressedSecondaryCacheTest (1 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (2 ms total)
[ PASSED ] 1 test.
t/run-compressed_secondary_cache_test-CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression: line 4: 1090883 Segmentation fault (core dumped) TEST_TMPDIR=$d ./compressed_secondary_cache_test --gtest_filter=CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10507
Test Plan:
Test 1:
```
$make -j 24
$./compressed_secondary_cache_test
```
Test 2:
```
$COMPILE_WITH_ASAN=1 make -j 24
$./compressed_secondary_cache_test
```
Test 3:
```
$COMPILE_WITH_TSAN=1 make -j 24
$./compressed_secondary_cache_test
```
Reviewed By: anand1976
Differential Revision: D38529885
Pulled By: gitbw95
fbshipit-source-id: d903fa3fadbd4d29f9528728c63a4f61c4396890
Summary:
This PR fixes 2 bugs introduced in https://github.com/facebook/rocksdb/issues/10432 -
1. If the bloom filter returned a negative result for all MultiGet keys in a file, the range tombstones in that file were being ignored, resulting in incorrect results if those tombstones covered a key in a higher level.
2. If all the keys in a file were filtered out in `TableCache::MultiGetFilter`, the table cache handle was not being released.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10513
Test Plan: Add a new unit test that fails without this fix
Reviewed By: akankshamahajan15
Differential Revision: D38548739
Pulled By: anand1976
fbshipit-source-id: a741a1e25d2e991d63f038100f126c2dc404a87c
Summary:
We have recently added caching support to BlobDB, and separately,
implemented an optimization where reading blobs from the cache
results in the cache handle being transferred to the target `PinnableSlice`
(as opposed to the contents getting copied). With these changes,
it makes sense to reset the `PinnableSlice` storing the blob value in
`DBIter` as soon as we move to a different iterator position to prevent
us from holding on to the cache handle any longer than necessary.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10490
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D38473630
Pulled By: ltamasi
fbshipit-source-id: 84c045ffac76436c6152fd0f5775b007f4051386
Summary:
The patch adds support for wide-column entities to the existing query
APIs (`Get`, `MultiGet`, and iterator). Namely, when during a query a
wide-column entity is encountered, we will return the value of the default
(anonymous) column as the result. Later, we plan to add wide-column
specific query APIs which will enable retrieving entire wide-column entities
or a subset of their columns.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10483
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D38441881
Pulled By: ltamasi
fbshipit-source-id: 6444e79a31aff2470e866698e3a97985bc2b3543
Summary:
Change tiered compaction feature from `bottommost_temperture` to
`last_level_temperture`. The old option is kept for migration purpose only,
which is behaving the same as `last_level_temperture` and it will be removed in
the next release.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10471
Test Plan: CI
Reviewed By: siying
Differential Revision: D38450621
Pulled By: jay-zhuang
fbshipit-source-id: cc1cdf8bad409376fec0152abc0a64fb72a91527
Summary:
Current universal compaction picker may cause extra size amplification
compaction if there're more hot data on penultimate level. Improve the picker
to skip the last level for size amp calculation if tiered compaction is
enabled, which can
1. avoid extra unnecessary size amp compaction;
2. typically cold tier (the last level) is not size constrained, so skip size
amp for cold tier is intended;
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10467
Test Plan: CI and added unittest
Reviewed By: siying
Differential Revision: D38391350
Pulled By: jay-zhuang
fbshipit-source-id: 103c0731c05e0a7e8f267e9e829d022328be25d2
Summary:
Currently user_defined_timestamp is failing in stress test with
subcompactions. So disabling it for now and will re enable it once its
fixed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10503
Test Plan: make crash_test_with_ts -j32
Reviewed By: riversand963
Differential Revision: D38510485
Pulled By: akankshamahajan15
fbshipit-source-id: 82fd0ec8cf86a96ff6653edd5bad7623cb9e0a15
Summary:
lambda function dynamicly allocates memory from heap if it needs to
capture multiple values, which could be expensive.
Switch to explictly use local functor from stack.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10453
Test Plan:
CI
db_bench shows ~2-3% read improvement:
```
# before the change
TEST_TMPDIR=/tmp/dbbench4 ./db_bench_main --benchmarks=filluniquerandom,readrandom -compression_type=none -max_background_jobs=12 -num=10000000
readrandom : 8.528 micros/op 117265 ops/sec 85.277 seconds 10000000 operations; 13.0 MB/s (10000000 of 10000000 found)
# after the change
TEST_TMPDIR=/tmp/dbbench5 ./db_bench_new --benchmarks=filluniquerandom,readrandom -compression_type=none -max_background_jobs=12 -num=10000000
readrandom : 8.263 micros/op 121015 ops/sec 82.634 seconds 10000000 operations; 13.4 MB/s (10000000 of 10000000 found)
```
details: https://gist.github.com/jay-zhuang/5ac0628db8fc9cbcb499e056d4cb5918
Micro-benchmark shows a similar improvement ~1-2%:
before the change:
https://gist.github.com/jay-zhuang/9dc0ebf51bbfbf4af82f6193d43cf75b
after the change:
https://gist.github.com/jay-zhuang/fc061f1813cd8f441109ad0b0fe7c185
Reviewed By: ajkr
Differential Revision: D38345056
Pulled By: jay-zhuang
fbshipit-source-id: f3597aeeee338a804d37bf2e81386d5a100665e0
Summary:
Similarly to https://github.com/facebook/rocksdb/pull/10457, we now have
to explicitly set the `fill_cache` read option when reading blobs in
`DBIter` to prevent the cache from getting polluted by queries with
`fill_cache` set to false. (Before we added support for a blob cache,
the setting had not made any difference either way.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10492
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D38476121
Pulled By: ltamasi
fbshipit-source-id: ea5c5e252f83e4a4e2c74156b37d40308d7e0c80
Summary:
Local static string is not friendly to Jemalloc arena aware implementation, as it will be allocated on the arena of the first caller, which causes crash if the allocated arena gets refunded earlier.
P.S. A Jemalloc arena aware implementation is each rocksdb instance only use certain Jemalloc arenas, and arena will be refunded after associated DB instance is destroyed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8103
Reviewed By: ajkr
Differential Revision: D38477235
Pulled By: ltamasi
fbshipit-source-id: a58d32cb647ed64c144b4736fb2d5db27c2c28f9
Summary:
Close the existing logger first to release the existing
handle before renaming the file using the file system.
Since `AutoRollLogger::Flush` pinned down the `logger_`, `logger_` can't be closed unless its
the last reference otherwise it gives seg fault during Flush on file
that has been closed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10488
Test Plan: CircleCI jobs
Reviewed By: ajkr
Differential Revision: D38469249
Pulled By: akankshamahajan15
fbshipit-source-id: dfbdb89b4ac37639aefcc503526f24753445fd3f
Summary:
We are asked to include TOS, Privacy Policy and copyright in the website. Added it.
Also changed the github and twitter link to RocksDB's rather than Facebook Open Source's and link to Meta open source's home page.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10491
Test Plan: Test the website locally.
Reviewed By: jay-zhuang
Differential Revision: D38475212
fbshipit-source-id: f73622f8f3d361b4586221ffb6deac4f4a11bb15
Summary:
The feature `SuggestCompactRange()` is still experimental. Just
re-add the test back.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10473
Test Plan: CI
Reviewed By: akankshamahajan15
Differential Revision: D38427153
Pulled By: jay-zhuang
fbshipit-source-id: 0b4491c947cbce6c18ff147b167e3c678633129a
Summary:
**Context/summary:**
`ChargeFileMetadataTestWithParam/ChargeFileMetadataTestWithParam.Basic/0 ` relies on `DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles` happens before verifying `EXPECT_EQ(file_metadata_charge_only_cache->GetCacheCharge(),
1 * CacheReservationManagerImpl<
CacheEntryRole::kFileMetadata>::GetDummyEntrySize());` or `EXPECT_EQ(file_metadata_charge_only_cache->GetCacheCharge(), 0);` to ensure appropriate cache reservation release is done before checking.
However, this might not be the case under some timing delay and spurious wake-up as coerced below.
```
diff --git a/db/db_impl/db_impl_compaction_flush.cc b/db/db_impl/db_impl_compaction_flush.cc
index 4378f3212..3e4f60853 100644
--- a/db/db_impl/db_impl_compaction_flush.cc
+++ b/db/db_impl/db_impl_compaction_flush.cc
@@ -2989,6 +2989,8 @@ void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
if (job_context.HaveSomethingToClean() ||
job_context.HaveSomethingToDelete() || !log_buffer.IsEmpty()) {
mutex_.Unlock();
+ bg_cv_.SignalAll();
+ usleep(1000);
// Have to flush the info logs before bg_compaction_scheduled_--
// because if bg_flush_scheduled_ becomes 0 and the lock is
// released, the deconstructor of DB can kick in and destroy all the
// states of DB so info_log might not be available after that point.
// It also applies to access other states that DB owns.
log_buffer.FlushBufferToLog();
if (job_context.HaveSomethingToDelete()) {
PurgeObsoleteFiles(job_context);
TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles");
}
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10481
Test Plan:
The test of interest failed often at the above coercion:
After fix, the test of interest passed at the above coercion:
Reviewed By: jay-zhuang
Differential Revision: D38438256
Pulled By: hx235
fbshipit-source-id: de80ecdb250174f00e7c2f5e4d952695ed56f51e
Summary:
- Right now each read fragments the memtable range tombstones https://github.com/facebook/rocksdb/issues/4808. This PR explores the idea of fragmenting memtable range tombstones in the write path and reads can just read this cached fragmented tombstone without any fragmenting cost. This PR only does the caching for immutable memtable, and does so right before a memtable is added to an immutable memtable list. The fragmentation is done without holding mutex to minimize its performance impact.
- db_bench is updated to print out the number of range deletions executed if there is any.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10380
Test Plan:
- CI, added asserts in various places to check whether a fragmented range tombstone list should have been constructed.
- Benchmark: as this PR only optimizes immutable memtable path, the number of writes in the benchmark is chosen such an immutable memtable is created and range tombstones are in that memtable.
```
single thread:
./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=100000 --max_num_range_tombstones=100
multi_thread
./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=15000 --reads=20000 --threads=32 --max_num_range_tombstones=100
```
Commit 99cdf16464 is included in benchmark result. It was an earlier attempt where tombstones are fragmented for each write operation. Reader threads share it using a shared_ptr which would slow down multi-thread read performance as seen in benchmark results.
Results are averaged over 5 runs.
Single thread result:
| Max # tombstones | main fillrandom micros/op | 99cdf16464 | Post PR | main readrandom micros/op | 99cdf16464 | Post PR |
| ------------- | ------------- |------------- |------------- |------------- |------------- |------------- |
| 0 |6.68 |6.57 |6.72 |4.72 |4.79 |4.54 |
| 1 |6.67 |6.58 |6.62 |5.41 |4.74 |4.72 |
| 10 |6.59 |6.5 |6.56 |7.83 |4.69 |4.59 |
| 100 |6.62 |6.75 |6.58 |29.57 |5.04 |5.09 |
| 1000 |6.54 |6.82 |6.61 |320.33 |5.22 |5.21 |
32-thread result: note that "Max # tombstones" is per thread.
| Max # tombstones | main fillrandom micros/op | 99cdf16464 | Post PR | main readrandom micros/op | 99cdf16464 | Post PR |
| ------------- | ------------- |------------- |------------- |------------- |------------- |------------- |
| 0 |234.52 |260.25 |239.42 |5.06 |5.38 |5.09 |
| 1 |236.46 |262.0 |231.1 |19.57 |22.14 |5.45 |
| 10 |236.95 |263.84 |251.49 |151.73 |21.61 |5.73 |
| 100 |268.16 |296.8 |280.13 |2308.52 |22.27 |6.57 |
Reviewed By: ajkr
Differential Revision: D37916564
Pulled By: cbi42
fbshipit-source-id: 05d6d2e16df26c374c57ddcca13a5bfe9d5b731e
Summary:
Currently, `SetIsInSecondaryCache` is after `Promote`. After `Promote`, a handle can be accessed and its flags can be set. This causes data race.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10472
Test Plan:
unit tests
stress tests
Reviewed By: pdillinger
Differential Revision: D38403991
Pulled By: gitbw95
fbshipit-source-id: 0aaa2d2edeaf5bc799fcce605648fe49eb7119c2
Summary:
This PR is the first step in enhancing the coroutines MultiGet to be able to lookup a batch in parallel across levels. By having a separate TableReader function for probing the bloom filters, we can quickly figure out which overlapping keys from a batch are definitely not in the file and can move on to the next level.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10432
Reviewed By: akankshamahajan15
Differential Revision: D38245910
Pulled By: anand1976
fbshipit-source-id: 3d20db2350378c3fe6f086f0c7ba5ff01d7f04de
Summary:
Existing DBWALTest.RaceInstallFlushResultsWithWalObsoletion test relies
on a specific interleaving of two background flush threads. We call them
bg1 and bg2, and assume bg1 starts to install flush results ahead of
bg2. After bg1 enters `ProcessManifestWrites`, bg1 waits for bg2 to also
enter `MemTableList::TryInstallMemtableFlushResults()` before bg1 can
proceed with MANIFEST write. However, if bg2 called `SyncClosedLogs()`
and needed to commit to the MANIFEST but falls behind bg1, then bg2
needs to wait for bg1 to finish writing to MANIFEST. This is a circular
dependency.
Fix this by allowing bg2 to start only after bg1 grabs the chance to
sync the WAL and commit to MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10456
Test Plan:
1. make check
2. export TEST_TMPDIR=/dev/shm && gtest-parallel -r 1000 -w 32 ./db_wal_test --gtest_filter=DBWALTest.RaceInstallFlushResultsWithWalObsoletion
Reviewed By: ltamasi
Differential Revision: D38391856
Pulled By: riversand963
fbshipit-source-id: 55f647d5b94e534c008a4dd2fb082675ddf58c96
Summary:
This PR avoids allocations and copies for the result of `GetMergeOperands()` when the average operand size is at least 256 bytes and the total operands size is at least 32KB. The `GetMergeOperands()` already included `PinnableSlice` but was calling `PinSelf()` (i.e., allocating and copying) for each operand. When this optimization takes effect, we instead call `PinSlice()` to skip that allocation and copy. Resources are pinned in order for the `PinnableSlice` to point to valid memory even after `GetMergeOperands()` returns.
The pinned resources include a referenced `SuperVersion`, a `MergingContext`, and a `PinnedIteratorsManager`. They are bundled into a `GetMergeOperandsState`. We use `SharedCleanablePtr` to share that bundle among all `PinnableSlice`s populated by `GetMergeOperands()`. That way, the last `PinnableSlice` to be `Reset()` will cleanup the bundle, including unreferencing the `SuperVersion`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10458
Test Plan:
- new DB level test
- measured benefit/regression in a number of memtable scenarios
Setup command:
```
$ ./db_bench -benchmarks=mergerandom -merge_operator=StringAppendOperator -num=$num -writes=16384 -key_size=16 -value_size=$value_sz -compression_type=none -write_buffer_size=1048576000
```
Benchmark command:
```
./db_bench -threads=$threads -use_existing_db=true -avoid_flush_during_recovery=true -write_buffer_size=1048576000 -benchmarks=readrandomoperands -merge_operator=StringAppendOperator -num=$num -duration=10
```
Worst regression is when a key has many tiny operands:
- Parameters: num=1 (implying 16384 operands per key), value_sz=8, threads=1
- `GetMergeOperands()` latency increases 682 micros -> 800 micros (+17%)
The regression disappears into the noise (<1% difference) if we remove the `Reset()` loop and the size counting loop. The former is arguably needed regardless of this PR as the convention in `Get()` and `MultiGet()` is to `Reset()` the input `PinnableSlice`s at the start. The latter could be optimized to count the size as we accumulate operands rather than after the fact.
Best improvement is when a key has large operands and high concurrency:
- Parameters: num=4 (implying 4096 operands per key), value_sz=2KB, threads=32
- `GetMergeOperands()` latency decreases 11492 micros -> 437 micros (-96%).
Reviewed By: cbi42
Differential Revision: D38336578
Pulled By: ajkr
fbshipit-source-id: 48146d127e04cb7f2d4d2939a2b9dff3aba18258
Summary:
When we try to use RocksDB with plugins as a third-party library for other databases, the plugin folder cannot be compiled correctly because of the wrong PLUGIN_ROOT variable. So we fix this error to ensure that it works perfectly when the directory of RocksDB is not the root directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10446
Reviewed By: jay-zhuang
Differential Revision: D38371321
Pulled By: ajkr
fbshipit-source-id: 0801b7b7dfa87751c8332fb52aac569dcdd72b5d
Co-authored-by: SuperMT <supertempler@gmail.com>
Summary:
RocksDB fails to open database with relative path when length of cwd
is longer than 256 bytes. This happens due to ERANGE in getcwd call.
Here we simply increase buffer size to the most common PATH_MAX value.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10413
Reviewed By: riversand963
Differential Revision: D38189254
Pulled By: ajkr
fbshipit-source-id: 8a0d3a78bbe87645499fbf29fb12bd3d04cd4657
Summary:
### **Summary:**
To minimize the internal fragmentation caused by the variable size of the compressed blocks, the original block is split according to the jemalloc bin size in `Insert()` and then merged back in `Lookup()`. Based on the analysis of the results of the following tests, from the overall internal fragmentation perspective, this PR does mitigate the internal fragmentation issue.
_Do more myshadow tests with the latest commit. I finished several myshadow AB Testing and the results are promising. For the config of 4GB primary cache and 3GB secondary cache, Jemalloc resident stats shows consistently ~0.15GB memory saving; the allocated and active stats show similar memory savings. The CPU usage is almost the same before and after this PR._
To evaluate the issue of memory fragmentations and the benefits of this PR, I conducted two sets of local tests as follows.
**T1**
Keys: 16 bytes each (+ 0 bytes user-defined timestamp)
Values: 100 bytes each (50 bytes after compression)
Entries: 90000000
RawSize: 9956.4 MB (estimated)
FileSize: 5664.8 MB (estimated)
| Test Name | Primary Cache Size (MB) | Compressed Secondary Cache Size (MB) |
| - | - | - |
| T1_3 | 4000 | 4000 |
| T1_4 | 2000 | 3000 |
Populate the DB:
./db_bench --benchmarks=fillrandom --num=90000000 -db=/mem_fragmentation/db_bench_1
Overwrite it to a stable state:
./db_bench --benchmarks=overwrite --num=90000000 -use_existing_db -db=/mem_fragmentation/db_bench_1
Run read tests with differnt cache setting:
T1_3:
MALLOC_CONF="prof:true,prof_stats:true" ../rocksdb/db_bench --benchmarks=seekrandom --threads=16 --num=90000000 -use_existing_db --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=4000000000 -compressed_secondary_cache_size=4000000000 -use_compressed_secondary_cache -db=/mem_fragmentation/db_bench_1 --print_malloc_stats=true > ~/temp/mem_frag/20220710/jemalloc_stats_json_T1_3_20220710 -duration=1800 &
T1_4:
MALLOC_CONF="prof:true,prof_stats:true" ../rocksdb/db_bench --benchmarks=seekrandom --threads=16 --num=90000000 -use_existing_db --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=2000000000 -compressed_secondary_cache_size=3000000000 -use_compressed_secondary_cache -db=/mem_fragmentation/db_bench_1 --print_malloc_stats=true > ~/temp/mem_frag/20220710/jemalloc_stats_json_T1_4_20220710 -duration=1800 &
For T1_3 and T1_4, I also conducted the tests before and after this PR. The following table show the important jemalloc stats.
| Test Name | T1_3 | T1_3 after mem defrag | T1_4 | T1_4 after mem defrag |
| - | - | - | - | - |
| allocated (MB) | 8728 | 8076 | 5518 | 5043 |
| available (MB) | 8753 | 8092 | 5536 | 5051 |
| external fragmentation rate | 0.003 | 0.002 | 0.003 | 0.0016 |
| resident (MB) | 8956 | 8365 | 5655 | 5235 |
**T2**
Keys: 32 bytes each (+ 0 bytes user-defined timestamp)
Values: 256 bytes each (128 bytes after compression)
Entries: 40000000
RawSize: 10986.3 MB (estimated)
FileSize: 6103.5 MB (estimated)
| Test Name | Primary Cache Size (MB) | Compressed Secondary Cache Size (MB) |
| - | - | - |
| T2_3 | 4000 | 4000 |
| T2_4 | 2000 | 3000 |
Create DB (10GB):
./db_bench -benchmarks=fillrandom -use_direct_reads=true -num=40000000 -key_size=32 -value_size=256 -db=/mem_fragmentation/db_bench_2
Overwrite it to a stable state:
./db_bench --benchmarks=overwrite --num=40000000 -use_existing_db -key_size=32 -value_size=256 -db=/mem_fragmentation/db_bench_2
Run read tests with differnt cache setting:
T2_3:
MALLOC_CONF="prof:true,prof_stats:true" ./db_bench --benchmarks="mixgraph" -use_direct_io_for_flush_and_compaction=true -use_direct_reads=true -cache_size=4000000000 -compressed_secondary_cache_size=4000000000 -use_compressed_secondary_cache -keyrange_dist_a=14.18 -keyrange_dist_b=-2.917 -keyrange_dist_c=0.0164 -keyrange_dist_d=-0.08082 -keyrange_num=30 -value_k=0.2615 -value_sigma=25.45 -iter_k=2.517 -iter_sigma=14.236 -mix_get_ratio=0.85 -mix_put_ratio=0.14 -mix_seek_ratio=0.01 -sine_mix_rate_interval_milliseconds=5000 -sine_a=1000 -sine_b=0.000073 -sine_d=400000 -reads=80000000 -num=40000000 -key_size=32 -value_size=256 -use_existing_db=true -db=/mem_fragmentation/db_bench_2 --print_malloc_stats=true > ~/temp/mem_frag/jemalloc_stats_T2_3 -duration=1800 &
T2_4:
MALLOC_CONF="prof:true,prof_stats:true" ./db_bench --benchmarks="mixgraph" -use_direct_io_for_flush_and_compaction=true -use_direct_reads=true -cache_size=2000000000 -compressed_secondary_cache_size=3000000000 -use_compressed_secondary_cache -keyrange_dist_a=14.18 -keyrange_dist_b=-2.917 -keyrange_dist_c=0.0164 -keyrange_dist_d=-0.08082 -keyrange_num=30 -value_k=0.2615 -value_sigma=25.45 -iter_k=2.517 -iter_sigma=14.236 -mix_get_ratio=0.85 -mix_put_ratio=0.14 -mix_seek_ratio=0.01 -sine_mix_rate_interval_milliseconds=5000 -sine_a=1000 -sine_b=0.000073 -sine_d=400000 -reads=80000000 -num=40000000 -key_size=32 -value_size=256 -use_existing_db=true -db=/mem_fragmentation/db_bench_2 --print_malloc_stats=true > ~/temp/mem_frag/jemalloc_stats_T2_4 -duration=1800 &
For T2_3 and T2_4, I also conducted the tests before and after this PR. The following table show the important jemalloc stats.
| Test Name | T2_3 | T2_3 after mem defrag | T2_4 | T2_4 after mem defrag |
| - | - | - | - | - |
| allocated (MB) | 8425 | 8093 | 5426 | 5149 |
| available (MB) | 8489 | 8138 | 5435 | 5158 |
| external fragmentation rate | 0.008 | 0.0055 | 0.0017 | 0.0017 |
| resident (MB) | 8676 | 8392 | 5541 | 5321 |
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10287
Test Plan: Unit tests.
Reviewed By: anand1976
Differential Revision: D37743362
Pulled By: gitbw95
fbshipit-source-id: 0010c5af08addeacc5ebbc4ffe5be882fb1d38ad
Summary:
Resolves https://github.com/facebook/rocksdb/issues/9692
This PR adds a unit test that reproduces the race described in https://github.com/facebook/rocksdb/issues/9692 and an according fix.
The unit test does not have any assertions, because I could not find a reliable and save way to assert that the writers list does not form a cycle. So with the old (buggy) code, the test would simply hang, while with the fix the test passes successfully.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9944
Reviewed By: pdillinger
Differential Revision: D36134604
Pulled By: riversand963
fbshipit-source-id: ef636c5a79ddbef18658ab2f19ca9210a427324a
Summary:
TL;DR: due to a recent change, if you drop a column family,
often that DB will no longer fsync after writing new SST files
to remaining or new column families, which could lead to data
loss on power loss.
More bug detail:
The intent of https://github.com/facebook/rocksdb/issues/10049 was to Close FSDirectory objects at
DB::Close time rather than waiting for DB object destruction.
Unfortunately, it also closes shared FSDirectory objects on
DropColumnFamily (& destroy remaining handles), which can lead
to use-after-Close on FSDirectory shared with remaining column
families. Those "uses" are only Fsyncs (or redundant Closes). In
the default Posix filesystem, an Fsync on a closed FSDirectory is a
quiet no-op. Consequently (under most configurations), if you drop
a column family, that DB will no longer fsync after writing new SST
files to column families sharing the same directory (true under most
configurations).
More fix detail:
Basically, this removes unnecessary Close ops on destroying
ColumnFamilyData. We let `shared_ptr` take care of calling the
destructor at the right time. If the intent was to require Close be
called before destroying FSDirectory, that was not made clear by the
author of FileSystem and was not at all enforced by https://github.com/facebook/rocksdb/issues/10049, which
could have added `assert(fd_ == -1)` to `~PosixDirectory()` but did
not. To keep this fix simple, we relax the unit test for https://github.com/facebook/rocksdb/issues/10049 to allow
timely destruction of FSDirectory to suffice as Close (in
CountedFileSystem). Added a TODO to revisit that.
Also in this PR:
* Added a TODO to share FSDirectory instances between DB and its column
families. (Already shared among column families.)
* Made DB::Close attempt to close all its open FSDirectory objects even
if there is a failure in closing one. Also code clean-up around this
logic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10460
Test Plan:
add an assert to check for use-after-Close. With that
existing tests can detect the misuse. With fix, tests pass (except noted
relaxing of unit test for https://github.com/facebook/rocksdb/issues/10049)
Reviewed By: ajkr
Differential Revision: D38357922
Pulled By: pdillinger
fbshipit-source-id: d42079cadbedf0a969f03389bf586b3b4e1f9137
Summary:
If a db_bench process gets hung or runaway on a machine, that
could prevent regression_test.sh from ever making progress. To fix that,
regression_test.sh will now kill any db_bench process that is >12 hours
old. Also made this more reliable by not using string matching (grep) to
get db_bench process IDs.
I also had to make some other updates to get local runs working
reliably:
* Fix some quoting hell and other dubious complexity with db_bench_cmd
* Only save a DB for re-use when building it passes
* Report failed command in more cases
* Add safeguards against "rm -rf ."
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10441
Test Plan:
manual (local and remote), with temporary changes e.g. to have
a manageable age threshold etc.
Reviewed By: riversand963
Differential Revision: D38285537
Pulled By: pdillinger
fbshipit-source-id: 4d598876aedc38ac4bd9d8ddf32c5995d8e44db8
Summary:
During compaction, blobs are currently read using the default
`ReadOptions`, which has the `fill_cache` flag set to true. Earlier,
this didn't make any difference since we didn't have a blob cache;
however, now we have to explicitly set this flag to false to avoid
polluting the cache during compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10457
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D38333528
Pulled By: ltamasi
fbshipit-source-id: 5b4d49a1e39543bee73c7df2aa9194fb101875e2
Summary:
FileMetaData::[min|max]_timestamp are not currently being used or
tracked by RocksDB, even when user-defined timestamp is enabled. Each of
them is a std::string which can occupy 32 bytes. Remove them for now.
They may be added back when we have a pressing need for them. When we do
add them back, consider store them in a more compact way, e.g. one
boolean flag and a byte array of size 16.
Per file min/max timestamp bounds are available as table properties.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10443
Test Plan: make check
Reviewed By: pdillinger
Differential Revision: D38292275
Pulled By: riversand963
fbshipit-source-id: 841dc4e855ad8f8481c80cb020603de9607c9c94
Summary:
EnvLogger was built to replace PosixLogger that supports multiple Envs. Make FileSystem use EnvLogger by default, remove Posix FS specific implementation and remove PosixLogger code,
Some hacky changes are made to make sure iostats are not polluted by logging, in order to pass existing unit tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10436
Test Plan: Run db_bench and watch info log files.
Reviewed By: anand1976
Differential Revision: D38259855
fbshipit-source-id: 67d65874bfba7a33535b6d0dd0ed92cbbc9888b8
Summary:
The secondary cache is randomly disabled or enabled with CompressedSecondaryCache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10442
Test Plan: - To test that the CompressedSecondaryCache is used and the stress test runs successfully, run `make -j24 CRASH_TEST_EXT_ARGS=—duration=960 blackbox_crash_test `
Reviewed By: anand1976
Differential Revision: D38290796
Pulled By: gitbw95
fbshipit-source-id: bb7027b39e0ed9c0c62835abe09e759898130ec8
Summary:
The subcompaction logic currently picks file boundaries as subcompaction boundaries. This is not compatible with user-defined timestamps because of two issues.
Issue1: ReadOptions.iterate_lower_bound and ReadOptions.iterate_upper_bound contains timestamps which results in assertion failure as BlockBasedTableIterator expects bounds to be without timestamps. As result, because of wrong comparison end key is returned as user_key resulting in assertion failure.
Issue2: Since it might result in two keys that only differ by user timestamp getting processed by two different subcompactions (and thus two different CompactionIterator state machines), which in turn can cause data correction issues.
This PR provide support to reenable subcompactions with user-defined timestamps.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10344
Test Plan:
Added new unit test
- Without fix for Issue1 unit test MultipleSubCompactions fails with error:
```
db_with_timestamp_compaction_test: ./db/compaction/clipping_iterator.h:247: void rocksdb::ClippingIterat│
or::AssertBounds(): Assertion `!valid_ || !end_ || cmp_->Compare(key(), *end_) < 0' failed.
Received signal 6 (Aborted) │
#0 /usr/local/fbcode/platform009/lib/libc.so.6(gsignal+0x100) [0x7f8fbbbfe530] db_with_timestamp_compaction_test: ./db/compaction/clipping_iterator.h:247: void rocksdb::ClippingIterator::AssertBounds(): Assertion `!valid_ || !end_ || cmp_->Compare(key(), *end_) < 0' failed.
Aborted (core dumped)
```
Ran stress test
`make crash_test_with_ts -j32`
Reviewed By: riversand963
Differential Revision: D38220841
Pulled By: akankshamahajan15
fbshipit-source-id: 5d5cae2bd37fcaeba1e77fce0a69070ad4158ccb
Summary:
If a secondary cache is configured, its possible that a cache lookup will get a hit in the secondary cache. In that case, the ```LRUCacheShard::Lookup``` doesn't immediately update the ```total_charge``` for the item handle if the ```wait``` parameter is false (i.e caller will call later to check the completeness). However, ```BlockBasedTable::GetEntryFromCache``` assumes the handle is complete and calls ```UpdateCacheHitMetrics```, which checks the usage of the cache item and fails the assert in https://github.com/facebook/rocksdb/blob/main/cache/lru_cache.h#L237 (```assert(total_charge >= meta_charge)```).
To fix this, we call ```UpdateCacheHitMetrics``` later in ```MultiGet```, after waiting for all cache lookup completions.
Test plan -
Run crash test with changes from https://github.com/facebook/rocksdb/issues/10160
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10440
Reviewed By: gitbw95
Differential Revision: D38283968
Pulled By: anand1976
fbshipit-source-id: 31c54ef43517726c6e5fdda81899b364241dd7e1
Andrew Kryczka