Commit Graph

5018 Commits

Author SHA1 Message Date
Jay Zhuang 3f763763aa Change `bottommost_temperture` to `last_level_temperture` (#10471)
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
2022-08-08 14:36:34 -07:00
Jay Zhuang 375534752a Improve universal compaction picker for tiered compaction (#10467)
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
2022-08-08 14:34:36 -07:00
Levi Tamasi 0cc9e98bbb Respect fill_cache when reading blobs in DBIter (#10492)
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
2022-08-08 08:26:33 -07:00
Burton Li e446bc65e6 Remove local static string (#8103)
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
2022-08-05 23:03:51 -07:00
Jay Zhuang edae671ce0 Re-enable SuggestCompactRangeTest and add Universal Compaction test (#10473)
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
2022-08-05 13:16:58 -07:00
Hui Xiao 56dbcb4f72 Deflake ChargeFileMetadataTestWithParam/ChargeFileMetadataTestWithParam.Basic/0 (#10481)
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
2022-08-05 12:58:07 -07:00
Changyu Bi 9d77bf8f7b Fragment memtable range tombstone in the write path (#10380)
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
2022-08-05 12:02:33 -07:00
anand76 bf4532eb5c Break TableReader MultiGet into filter and lookup stages (#10432)
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
2022-08-04 12:51:57 -07:00
Yanqin Jin 538df26fcc Deflake DBWALTest.RaceInstallFlushResultsWithWalObsoletion (#10456)
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
2022-08-04 12:14:28 -07:00
Andrew Kryczka 504fe4de80 Avoid allocations/copies for large `GetMergeOperands()` results (#10458)
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
2022-08-04 00:42:13 -07:00
mpoeter bef3127b00 Fix race in ExitAsBatchGroupLeader with pipelined writes (#9944)
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
2022-08-02 14:52:10 -07:00
Peter Dillinger 27f3af5966 Fix serious FSDirectory use-after-Close bug (missing fsync) (#10460)
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
2022-08-02 10:54:32 -07:00
Levi Tamasi cc8ded6152 Do not put blobs read during compaction into cache (#10457)
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
2022-08-01 19:49:05 -07:00
Yanqin Jin fbfcf5cbcd Remove unused fields from FileMetaData (temporarily) (#10443)
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
2022-08-01 17:56:13 -07:00
Akanksha Mahajan 56463d443d Provide support for subcompactions with user-defined timestamps (#10344)
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
2022-07-31 11:39:16 -07:00
Peter Dillinger 65036e4217 Revert "Add a blob-specific cache priority (#10309)" (#10434)
Summary:
This reverts commit 8d178090be
because of a clear performance regression seen in internal dashboard
https://fburl.com/unidash/tpz75iee

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10434

Reviewed By: ltamasi

Differential Revision: D38256373

Pulled By: pdillinger

fbshipit-source-id: 134aa00f50dd7b1bbe037c227884a351342ec44b
2022-07-29 07:18:15 -07:00
Andrew Kryczka c7ccbb33a6 Allow manual compactions to run in parallel by default (#10317)
Summary:
This PR changes the default value of
`CompactRangeOptions::exclusive_manual_compaction` from true to false so
manual `CompactRange()`s can run in parallel with other compactions. I
believe no artificial parallelism restriction is the intuitive behavior
so feel the old default value is a trap, which I have fallen into
several times, including yesterday.
`CompactRangeOptions::exclusive_manual_compaction == false` has been
used in both our correctness test and in production for years so should
be reasonably safe.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10317

Reviewed By: jay-zhuang

Differential Revision: D37659392

Pulled By: ajkr

fbshipit-source-id: 504915e978bbe300b79483d064070c75e93d91e5
2022-07-28 17:07:36 -07:00
Jay Zhuang 87649d3288 Best efforts recovery to skip empty MANIFEST (#10416)
Summary:
Skip empty MANIFEST fie during best_efforts_recovery.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10416

Test Plan: make failed db_stress test pass

Reviewed By: riversand963

Differential Revision: D38126273

Pulled By: jay-zhuang

fbshipit-source-id: 4498d322b09eaa194dd2cbf9c683d62ab54bfb01
2022-07-27 20:16:38 -07:00
Gang Liao 8d178090be Add a blob-specific cache priority (#10309)
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/10309

Reviewed By: ltamasi

Differential Revision: D38211655

Pulled By: gangliao

fbshipit-source-id: 65ef33337db4d85277cc6f9782d67c421ad71dd5
2022-07-27 19:09:24 -07:00
Jay Zhuang 6a0010eb46 ldb to display public unique id and dump work with key range (#10417)
Summary:
2 ldb command improvements:
1. `ldb manifest_dump --verbose` display both the internal unique id and public id. which is useful to manually check sst_unique_id between manifest and SST;
2. `ldb dump` has `--from/to` option, but not working. Add support for that.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10417

Test Plan:
run the command locally
```
$ ldb manifest_dump --path=MANIFEST-000026 --verbose
...
AddFile: 0 18 1023 'bar' seq:6, type:1 .. 'foo' seq:5, type:1 oldest_ancester_time:1658787615 file_creation_time:1658787615 file_checksum: file_checksum_func_name: Unknown unique_id(internal): {8800772265202404198,16149248642318466463} public_unique_id: F3E0A029B631D7D4-6E402DE08E771780
```
```
$ ldb dump --path=000036.sst --from=key000006 --to=key000009
Sst file format: block-based
'key000006' seq:2411, type:1 => value6
'key000007' seq:2412, type:1 => value7
'key000008' seq:2413, type:1 => value8
...
```

Reviewed By: ajkr

Differential Revision: D38136140

Pulled By: jay-zhuang

fbshipit-source-id: 8be6eeaa07ff9f089e33011ebe90fd0b69d33bf3
2022-07-26 20:40:18 -07:00
Zichen Zhu c945a9a664 Allow sufficient subcompactions under round-robin compaction priority (#10422)
Summary:
Allow sufficient subcompactions can be used when the number of input files is less than `max_subcompactions` under round-robin compaction priority.

Test Case:
Add `RoundRobinWithoutAdditionalResources` into `db_compaction_test`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10422

Reviewed By: ajkr

Differential Revision: D38186545

Pulled By: littlepig2013

fbshipit-source-id: b8e5098306f1e5b9561dfafafc8300a38f7fe88e
2022-07-26 20:37:34 -07:00
Jay Zhuang 3134471457 Deflake FlushStaleColumnFamilies test (#10409)
Summary:
Make the Stale Flush test more robust by explicitly checking the target CF is
flushed.  Currently it's flaky because the default CF may have more than 3
SSTs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10409

Test Plan:
the test more likely to fail on a resource limited host:
```
gtest-parallel ./column_family_test --gtest_filter=FormatDef/ColumnFamilyTest.FlushStaleColumnFamilies/0 -r 1000 -w 100
```

Reviewed By: ajkr

Differential Revision: D38116383

Pulled By: jay-zhuang

fbshipit-source-id: e27cc56f76f14d0936504f126104e3d87e3d0d5f
2022-07-26 12:50:27 -07:00
Changyu Bi 2fc6df37d6 Add checksum handshake for WAL fragment decompression (#10339)
Summary:
If WAL compression is enabled, WAL fragment decompression results are concatenated together in `log::Reader::ReadPhysicalRecord()`. This PR adds checksum handshake to protect memory corruption during the copying process.

`checksum` is renamed to `record_checksum` in `ReadRecord()` to differentiate it from `checksum_` flag that specifies whether CRC32C checksum is verified.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10339

Test Plan: added checksum verification in log_test.cc, `make check -j32`.

Reviewed By: ajkr

Differential Revision: D37763734

Pulled By: cbi42

fbshipit-source-id: c4faa7c76b9ff1df35026edf31adfe4b47ae3154
2022-07-25 16:27:26 -07:00
Zichen Zhu 8860fc902a Support subcmpct using reserved resources for round-robin priority (#10341)
Summary:
Earlier implementation of round-robin priority can only pick one file at a time and disallows parallel compactions within the same level. In this PR, round-robin compaction policy will expand towards more input files with respecting some additional constraints, which are summarized as follows:
 * Constraint 1: We can only pick consecutive files
   - Constraint 1a: When a file is being compacted (or some input files are being compacted after expanding), we cannot choose it and have to stop choosing more files
   - Constraint 1b: When we reach the last file (with the largest keys), we cannot choose more files (the next file will be the first one with small keys)
 * Constraint 2: We should ensure the total compaction bytes (including the overlapped files from the next level) is no more than `mutable_cf_options_.max_compaction_bytes`
 * Constraint 3: We try our best to pick as many files as possible so that the post-compaction level size can be just less than `MaxBytesForLevel(start_level_)`
 * Constraint 4: If trivial move is allowed, we reuse the logic of `TryNonL0TrivialMove()` instead of expanding files with Constraint 3

More details can be found in `LevelCompactionBuilder::SetupOtherFilesWithRoundRobinExpansion()`.

The above optimization accelerates the process of moving the compaction cursor, in which the write-amp can be further reduced. While a large compaction may lead to high write stall, we break this large compaction into several subcompactions **regardless of** the `max_subcompactions` limit.  The number of subcompactions for round-robin compaction priority is determined through the following steps:
* Step 1: Initialized against `max_output_file_limit`, the number of input files in the start level, and also the range size limit `ranges.size()`
* Step 2: Call `AcquireSubcompactionResources()`when max subcompactions is not sufficient, but we may or may not obtain desired resources, additional number of resources is stored in `extra_num_subcompaction_threads_reserved_`). Subcompaction limit is changed and update `num_planned_subcompactions` with `GetSubcompactionLimit()`
* Step 3: Call `ShrinkSubcompactionResources()` to ensure extra resources can be released (extra resources may exist for round-robin compaction when the number of actual number of subcompactions is less than the number of planned subcompactions)

More details can be found in `CompactionJob::AcquireSubcompactionResources()`,`CompactionJob::ShrinkSubcompactionResources()`, and `CompactionJob::ReleaseSubcompactionResources()`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10341

Test Plan: Add `CompactionPriMultipleFilesRoundRobin[1-3]` unit test in `compaction_picker_test.cc` and `RoundRobinSubcompactionsAgainstResources.SubcompactionsUsingResources/[0-4]`, `RoundRobinSubcompactionsAgainstPressureToken.PressureTokenTest/[0-1]` in `db_compaction_test.cc`

Reviewed By: ajkr, hx235

Differential Revision: D37792644

Pulled By: littlepig2013

fbshipit-source-id: 7fecb7c4ffd97b34bbf6e3b760b2c35a772a0657
2022-07-24 11:12:44 -07:00
sdong 252bea405e Improve SubCompaction Partitioning (#10393)
Summary:
Unit tests still haven't been fixed. Also need to add more tests. But I ran some simple fillrandom db_bench and the partitioning feels reasonable.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10393

Test Plan:
1. Make sure existing tests pass. This should cover some basic sub compaction logic to be correct and the partitioning result is reasonable;
2. Add a new unit test to ApproximateKeyAnchors()
3. Run some db_bench with max_subcompaction = 4 and watch the compaction is indeed partitioned evenly.

Reviewed By: jay-zhuang

Differential Revision: D38043783

fbshipit-source-id: 085008e0f85f9b7c5abff7800307618320efb19f
2022-07-23 17:38:49 -07:00
Jay Zhuang fcccc412d7 Remove Travis CI (#10407)
Summary:
Travis CI is depreciated and haven't been maintained for some time.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10407

Reviewed By: ajkr

Differential Revision: D38078382

Pulled By: jay-zhuang

fbshipit-source-id: f42057f2f41f722bdce56bf195f67a94835191fb
2022-07-22 20:16:45 -07:00
Yu Zhao 00540916 bfc737da21 fix typos in some code and comment (#10139)
Summary:
Minor issue, I just found a few typos on db_test and column_family while reading the code. And I have this PR opened to contribute.  :)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10139

Reviewed By: ajkr

Differential Revision: D38007098

Pulled By: jay-zhuang

fbshipit-source-id: 511947b32424c34348184691216640f32c410fb1
2022-07-22 19:25:52 -07:00
Andrew Kryczka 7b44724205 Fix WAL compression fragmentation test (#10402)
Summary:
Previously the "Fragmentation" test didn't cover fragmentation because the WAL data was compressible into trivial size. This PR changes it to use random data so the post-compression size is large enough to require fragmentation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10402

Reviewed By: cbi42

Differential Revision: D38065596

Pulled By: ajkr

fbshipit-source-id: 0d5f89ca14d33546501a74b5d4fafbadc28a46a7
2022-07-22 11:05:55 -07:00
Jun He 5cf18c7634 Fix build error due to uninitialized read_req (#10312)
Summary:
GCC-12 has strick check on variables, and thus
build fails when it finds read_req is not properly
initialized (-Werror=maybe-uninitialized). Add
default value to fix this.

Change-Id: Ib8a9085e2d613ee7b943b58a6a58e1bc351725d7
Signed-off-by: Jun He <jun.he@arm.com>

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10312

Reviewed By: riversand963

Differential Revision: D37656997

Pulled By: ajkr

fbshipit-source-id: fe47492c913b34b3a03c04beeec9ec57831dcaff
2022-07-22 09:24:13 -07:00
LIU HU 8885b0537b Fix underflow in FIFOCompactionPicker (#10386)
Summary:
Fix https://github.com/facebook/rocksdb/issues/10133

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10386

Reviewed By: riversand963

Differential Revision: D38067265

Pulled By: ajkr

fbshipit-source-id: 3a99a98ac5d7ac37581b5b636fbfa7901563d834
2022-07-22 09:20:35 -07:00
Wallace 1e9bf25f61 Do not hold mutex when write keys if not necessary (#7516)
Summary:
## Problem Summary
RocksDB will acquire the global mutex of db instance for every time when user calls `Write`.  When RocksDB schedules a lot of compaction jobs,   it will compete the mutex with write thread and it will hurt the write performance.

## Problem Solution:
I want to use log_write_mutex to replace the global mutex in most case so that we do not acquire it in write-thread unless there is a write-stall event or a write-buffer-full event occur.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7516

Test Plan:
1. make check
2. CI
3. COMPILE_WITH_TSAN=1 make db_stress
make crash_test
make crash_test_with_multiops_wp_txn
make crash_test_with_multiops_wc_txn
make crash_test_with_atomic_flush

Reviewed By: siying

Differential Revision: D36908702

Pulled By: riversand963

fbshipit-source-id: 59b13881f4f5c0a58fd3ca79128a396d9cd98efe
2022-07-21 13:35:36 -07:00
Gang Liao 0b6bc101ba Charge blob cache usage against the global memory limit (#10321)
Summary:
To help service owners to manage their memory budget effectively, we have been working towards counting all major memory users inside RocksDB towards a single global memory limit (see e.g. https://github.com/facebook/rocksdb/wiki/Write-Buffer-Manager#cost-memory-used-in-memtable-to-block-cache). The global limit is specified by the capacity of the block-based table's block cache, and is technically implemented by inserting dummy entries ("reservations") into the block cache. The goal of this task is to support charging the memory usage of the new blob cache against this global memory limit when the backing cache of the blob cache and the block cache are different.

This PR is a part of https://github.com/facebook/rocksdb/issues/10156

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10321

Reviewed By: ltamasi

Differential Revision: D37913590

Pulled By: gangliao

fbshipit-source-id: eaacf23907f82dc7d18964a3f24d7039a2937a72
2022-07-18 23:26:57 -07:00
Jay Zhuang 18a61a1734 Fix seqno->time worker not scheduled with multi DB instances (#10383)
Summary:
`PeriodicWorkScheduler` is a global singleton, which were used to store per-instance setting `record_seqno_time_cadence_`. Move that to db_impl.h which is per-instance.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10383

Reviewed By: siying

Differential Revision: D37928009

Pulled By: jay-zhuang

fbshipit-source-id: e517754f4a9db98798ac04f72033d4b517f734e9
2022-07-18 19:08:39 -07:00
Andrew Kryczka 25cc564ff7 Make RateLimiter not Customizable (#10378)
Summary:
(PR created for informational/testing purposes only.)

- Fixes lost dynamic updates to GenericRateLimiter bandwidth using `SetBytesPerSecond()`
- Benefit over #10374 is eliminating race conditions with Configurable framework.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10378

Reviewed By: pdillinger

Differential Revision: D37914865

fbshipit-source-id: d4f566d60ec9726d26932388c61671adf0ee0f30
2022-07-18 14:48:42 -07:00
Gang Liao ec4ebeff30 Support prepopulating/warming the blob cache (#10298)
Summary:
Many workloads have temporal locality, where recently written items are read back in a short period of time. When using remote file systems, this is inefficient since it involves network traffic and higher latencies. Because of this, we would like to support prepopulating the blob cache during flush.

This task is a part of https://github.com/facebook/rocksdb/issues/10156

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10298

Reviewed By: ltamasi

Differential Revision: D37908743

Pulled By: gangliao

fbshipit-source-id: 9feaed234bc719d38f0c02975c1ad19fa4bb37d1
2022-07-17 07:13:59 -07:00
sg20180546 f5ef36a29a add sstfilewriter_delete_range (#10314)
Summary:
I add C API
db/c.cc
rocksdb_sstfilewriter_delete_range

and test it , PASS.
 can you review it ? ajkr

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10314

Reviewed By: riversand963

Differential Revision: D37657236

Pulled By: ajkr

fbshipit-source-id: c3b758daa36fbd9133210b011716914dff311278
2022-07-16 19:35:46 -07:00
Gang Liao 95ef007adc Support using secondary cache with the blob cache (#10349)
Summary:
RocksDB supports a two-level cache hierarchy (see https://rocksdb.org/blog/2021/05/27/rocksdb-secondary-cache.html), where items evicted from the primary cache can be spilled over to the secondary cache, or items from the secondary cache can be promoted to the primary one. We have a CacheLib-based non-volatile secondary cache implementation that can be used to improve read latencies and reduce the amount of network bandwidth when using distributed file systems. In addition, we have recently implemented a compressed secondary cache that can be used as a replacement for the OS page cache when e.g. direct I/O is used. The goals of this task are to add support for using a secondary cache with the blob cache and to measure the potential performance gains using `db_bench`.

This task is a part of https://github.com/facebook/rocksdb/issues/10156

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10349

Reviewed By: ltamasi

Differential Revision: D37896773

Pulled By: gangliao

fbshipit-source-id: 7804619ce4a44b73d9e11ad606640f9385969c84
2022-07-16 03:54:37 -07:00
Jay Zhuang faa0f9723c Tiered compaction: integrate Seqno time mapping with per key placement (#10370)
Summary:
Using the Sequence number to time mapping to decide if a key is hot or not in
compaction and place it in the corresponding level.

Note: the feature is not complete, level compaction will run indefinitely until
all penultimate level data is cold and small enough to not trigger compaction.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10370

Test Plan:
CI
* Run basic db_bench for universal compaction manually

Reviewed By: siying

Differential Revision: D37892338

Pulled By: jay-zhuang

fbshipit-source-id: 792bbd91b1ccc2f62b5d14c53118434bcaac4bbe
2022-07-15 19:01:30 -07:00
Jay Zhuang fb579a221c Remove fixed TODO (#10241)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10241

Reviewed By: gitbw95

Differential Revision: D37369726

Pulled By: jay-zhuang

fbshipit-source-id: 1e94f0e2433aee42e9871043fa434291ce948eac
2022-07-15 14:47:36 -07:00
Jay Zhuang dcb6a3be4e Add helper function to get debug type name (#10243)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10243

Reviewed By: riversand963

Differential Revision: D37370236

Pulled By: jay-zhuang

fbshipit-source-id: 6e7a6fadf45fdfb5afe97b3f6fe4acf1260d4a86
2022-07-15 14:42:00 -07:00
Jay Zhuang 69a18b9bad VerifySstUniqueIds status is overrided for multi CFs (#10247)
Summary:
There's bug that basically we only report the last CF's
VerifySstUniqueIds() result:
https://github.com/facebook/rocksdb/pull/9990#discussion_r877268810

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10247

Test Plan: CI

Reviewed By: pdillinger

Differential Revision: D37384265

Pulled By: jay-zhuang

fbshipit-source-id: d462ad0eab39c9145c45a3db9c45539d5d76f7dd
2022-07-15 11:50:30 -07:00
Jay Zhuang a3acf2ef87 Add seqno to time mapping (#10338)
Summary:
Which will be used for tiered storage to preclude hot data from
compacting to the cold tier (the last level).
Internally, adding seqno to time mapping. A periodic_task is scheduled
to record the current_seqno -> current_time in certain cadence. When
memtable flush, the mapping informaiton is stored in sstable property.
During compaction, the mapping information are merged and get the
approximate time of sequence number, which is used to determine if a key
is recently inserted or not and preclude it from the last level if it's
recently inserted (within the `preclude_last_level_data_seconds`).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10338

Test Plan: CI

Reviewed By: siying

Differential Revision: D37810187

Pulled By: jay-zhuang

fbshipit-source-id: 6953be7a18a99de8b1cb3b162d712f79c2b4899f
2022-07-14 21:49:34 -07:00
sdong c8b20d469d Make InternalKeyComparator not configurable (#10342)
Summary:
InternalKeyComparator is an internal class which is a simple wrapper of Comparator. https://github.com/facebook/rocksdb/pull/8336 made Comparator customizeable. As a side effect, internal key comparator was made configurable too. This introduces overhead to this simple wrapper. For example, every InternalKeyComparator will have an std::vector attached to it, which consumes memory and possible allocation overhead too.
We remove InternalKeyComparator from being customizable by making InternalKeyComparator not a subclass of Comparator.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10342

Test Plan: Run existing CI tests and make sure it doesn't fail

Reviewed By: riversand963

Differential Revision: D37771351

fbshipit-source-id: 917256ee04b2796ed82974549c734fb6c4d8ccee
2022-07-14 10:09:31 -07:00
Jay Zhuang 6ce0b2ca34 Tiered Compaction: per key placement support (#9964)
Summary:
Support per_key_placement for last level compaction, which will
be used for tiered compaction.
* compaction iterator reports which level a key should output to;
* compaction get the output level information and check if it's safe to
  output the data to penultimate level;
* all compaction output files will be installed.
* extra internal compaction stats added for penultimate level.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9964

Test Plan:
* Unittest
* db_bench, no significate difference: https://gist.github.com/jay-zhuang/3645f8fb97ec0ab47c10704bb39fd6e4
* microbench manual compaction no significate difference: https://gist.github.com/jay-zhuang/ba679b3e89e24992615ee9eef310e6dd
* run the db_stress multiple times (not covering the new feature) looks good (internal: https://fburl.com/sandcastle/9w84pp2m)

Reviewed By: ajkr

Differential Revision: D36249494

Pulled By: jay-zhuang

fbshipit-source-id: a96da57c8031c1df83e4a7a8567b657a112b80a3
2022-07-13 20:54:49 -07:00
Changyu Bi 5f9fe7f21e Added WAL compression checksum (#10319)
Summary:
Enabled zstd checksum flag in StreamingCompress so that WAL (de)compreression is protected by a checksum per compression frame.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10319

Test Plan:
- `make check`
- WAL perf: average ops/sec over 10 runs is 161226 pre PR and 159635 post PR (1% drop).
```
sudo TEST_TMPDIR=/dev/shm/memtable_write ./db_bench_checksum -benchmarks=fillseq -max_write_buffer_number=100 -num=1000000 -min_write_buffer_number_to_merge=10 -wal_compression=zstd
```

Reviewed By: ajkr

Differential Revision: D37673311

Pulled By: cbi42

fbshipit-source-id: 9f34a3bfc2a82e5c80b1ec63bb339a7465108ec9
2022-07-13 15:29:20 -07:00
Guido Tagliavini Ponce 9645e66fc9 Temporarily return a LRUCache from NewClockCache (#10351)
Summary:
ClockCache is still in experimental stage, and currently fails some pre-release fbcode tests. See https://www.internalfb.com/diff/D37772011. API calls to construct ClockCache are done via the function NewClockCache. For now, NewClockCache calls will return an LRUCache (with appropriate arguments), which is stable.

The idea that NewClockCache returns nullptr was also floated, but this would be interpreted as unsupported cache, and a default LRUCache would be constructed instead, potentially causing a performance regression that is harder to identify.

A new version of the NewClockCache function was created for our internal tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10351

Test Plan: ``make -j24 check`` and re-run the pre-release tests.

Reviewed By: pdillinger

Differential Revision: D37802685

Pulled By: guidotag

fbshipit-source-id: 0a8d10612ff21e576f7360cb13e20bc36e244972
2022-07-13 08:45:44 -07:00
Yanqin Jin b283f041f5 Stop tracking syncing live WAL for performance (#10330)
Summary:
With https://github.com/facebook/rocksdb/issues/10087, applications calling `SyncWAL()` or writing with `WriteOptions::sync=true` can suffer
from performance regression. This PR reverts to original behavior of tracking the syncing of closed WALs.
After we revert back to old behavior, recovery, whether kPointInTime or kAbsoluteConsistency, may fail to
detect corruption in synced WALs if the corruption is in the live WAL.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10330

Test Plan:
make check

Before https://github.com/facebook/rocksdb/issues/10087
```bash
fillsync     :     750.269 micros/op 1332 ops/sec 75.027 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync     :     776.492 micros/op 1287 ops/sec 77.649 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 2 runs] : 1310 (± 44) ops/sec;    0.1 (± 0.0) MB/sec
fillsync     :     805.625 micros/op 1241 ops/sec 80.563 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 3 runs] : 1287 (± 51) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [AVG    3 runs] : 1287 (± 51) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [MEDIAN 3 runs] : 1287 ops/sec;    0.1 MB/sec
```

Before this PR and after https://github.com/facebook/rocksdb/issues/10087
```bash
fillsync     :    1479.601 micros/op 675 ops/sec 147.960 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync     :    1626.080 micros/op 614 ops/sec 162.608 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 2 runs] : 645 (± 59) ops/sec;    0.1 (± 0.0) MB/sec
fillsync     :    1588.402 micros/op 629 ops/sec 158.840 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 3 runs] : 640 (± 35) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [AVG    3 runs] : 640 (± 35) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [MEDIAN 3 runs] : 629 ops/sec;    0.1 MB/sec
```

After this PR
```bash
fillsync     :     749.621 micros/op 1334 ops/sec 74.962 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync     :     865.577 micros/op 1155 ops/sec 86.558 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 2 runs] : 1244 (± 175) ops/sec;    0.1 (± 0.0) MB/sec
fillsync     :     845.837 micros/op 1182 ops/sec 84.584 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 3 runs] : 1223 (± 109) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [AVG    3 runs] : 1223 (± 109) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [MEDIAN 3 runs] : 1182 ops/sec;    0.1 MB/sec
```

Reviewed By: ajkr

Differential Revision: D37725212

Pulled By: riversand963

fbshipit-source-id: 8fa7d13b3c7662be5d56351c42caf3266af937ae
2022-07-12 17:16:57 -07:00
sdong 769b156e65 Remove customized naming from InternalKeyComparator (#10343)
Summary:
InternalKeyComparator is a thin wrapper around user comparator. Storing a string for name is relatively expensive to this small wrapper for both CPU and memory usage. Try to remove it.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10343

Test Plan: Run existing tests

Reviewed By: ajkr

Differential Revision: D37772469

fbshipit-source-id: d2d106a8d022193058fd7f6b220108e3d94aca34
2022-07-12 13:30:35 -07:00
Yanqin Jin 7e2004a123 Remove unused variables (#10327)
Summary:
As title.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10327

Test Plan: make check

Reviewed By: gitbw95

Differential Revision: D37699040

Pulled By: riversand963

fbshipit-source-id: 305a88628907a47dea53c4d9aec9c2f5bb9b58df
2022-07-11 13:55:23 -07:00
Gang Liao c987eb4712 Eliminate the copying of blobs when serving reads from the cache (#10297)
Summary:
The blob cache enables an optimization on the read path: when a blob is found in the cache, we can avoid copying it into the buffer provided by the application. Instead, we can simply transfer ownership of the cache handle to the target `PinnableSlice`. (Note: this relies on the `Cleanable` interface, which is implemented by `PinnableSlice`.)

This has the potential to save a lot of CPU, especially with large blob values.

This task is a part of https://github.com/facebook/rocksdb/issues/10156

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10297

Reviewed By: riversand963

Differential Revision: D37640311

Pulled By: gangliao

fbshipit-source-id: 92de0e35cc703d06c87c5c1861cc2899ec52234a
2022-07-06 18:57:29 -07:00