Summary:
First, we made a small reduction in DURATION_RW as runs were exceeding 1 hour and colliding with subsequent runs.
See Mark Callaghan’s blog post at http://smalldatum.blogspot.com/2023/01/variance-in-rocksdb-benchmarks-on-cloud.html
Configuration parameters which are not consistent with the following email from Mark (see the blog post for more context) have been updated. Where Mark has defined the parameter and we haven't, we define it explicitly. We will need to further monitor for an expected reduction in variance of test times:
To match what I did:
---
nsecs=1800
dbdir=/data/m/rx
resultdir=bm.lc.nt1.cm1.d0
env WRITE_BUFFER_SIZE_MB=16 TARGET_FILE_SIZE_BASE_MB=16 MAX_BYTES_FOR_LEVEL_BASE_MB=64 MAX_BACKGROUND_JOBS=4 NUM_KEYS=20000000 CACHE_SIZE_MB=10240 DURATION_RW=$nsecs DURATION_RO=$nsecs MB_WRITE_PER_SEC=2 NUM_THREADS=1 COMPRESSION_TYPE=none CACHE_INDEX_AND_FILTER_BLOCKS=1 VALUE_SIZE=400 NUMA=1 MIN_LEVEL_TO_COMPRESS=3 COMPACTION_STYLE=leveled bash benchmark_compare.sh $dbdir $resultdir 7.8.fb
env WRITE_BUFFER_SIZE_MB=16 TARGET_FILE_SIZE_BASE_MB=16 MAX_BYTES_FOR_LEVEL_BASE_MB=64 MAX_BACKGROUND_JOBS=4 NUM_KEYS=200000000 CACHE_SIZE_MB=10240 DURATION_RW=$nsecs DURATION_RO=$nsecs MB_WRITE_PER_SEC=2 NUM_THREADS=1 COMPRESSION_TYPE=lz4 CACHE_INDEX_AND_FILTER_BLOCKS=1 VALUE_SIZE=400 NUMA=1 MIN_LEVEL_TO_COMPRESS=3 COMPACTION_STYLE=leveled bash benchmark_compare.sh $dbdir $resultdir 7.8.fb
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11074
Reviewed By: ajkr
Differential Revision: D42969668
Pulled By: cbi42
fbshipit-source-id: 1ea4e6a3901be4016108f93817eb58f74baac21a
Summary:
The patch makes some code quality enhancements in `CompactionIterator::InvokeFilterIfNeeded`
including the renaming of `filter` (which is most likely a remnant of the days before the `FilterV2`
API when the compaction filter used to return a boolean) to `decision`, the removal of some
outdated comments, the elimination of an `error` flag which was only used in one failure case
out of many, as well as some small stylistic improvements. (Some the above will also come in
handy when adding compaction filter support for wide-column entities.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11174
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D42901408
Pulled By: ltamasi
fbshipit-source-id: ab382d59a4990c5dfe1cee219d49e1d80902b666
Summary:
This PR adds logic to the `RunManualCompaction()` loop to check for cancellation before waiting on any conflicting compactions to finish. In case of cancellation, `RunManualCompaction()` no longer waits on conflicting compactions
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11165
Test Plan: repro test case
Reviewed By: cbi42
Differential Revision: D42864058
Pulled By: ajkr
fbshipit-source-id: ea4dd1a8f294abe212905495a8fbe8f07fca3f5a
Summary:
The patch fixes a feature interaction bug between BlobDB and the `GetEntity` API:
without the patch, `GetEntity` would return the blob reference (wrapped into a
single-column entity) instead of the actual blob value.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11162
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D42854092
Pulled By: ltamasi
fbshipit-source-id: f750d0ff57def107da16f545077ddce9860ff21a
Summary:
The previous API comments for LockWAL didn't provide much about why you might want to use it, and didn't really meet what one would infer its contract was. Also, LockWAL was not in db_stress / crash test. In this change:
* Implement a counting semantics for LockWAL()+UnlockWAL(), so that they can safely be used concurrently across threads or recursively within a thread. This should make the API much less bug-prone and easier to use.
* Make sure no UnlockWAL() is needed after non-OK LockWAL() (to match RocksDB conventions)
* Make UnlockWAL() reliably return non-OK when there's no matching LockWAL() (for debug-ability)
* Clarify API comments on LockWAL(), UnlockWAL(), FlushWAL(), and SyncWAL(). Their exact meanings are not obvious, and I don't think it's appropriate to talk about implementation mutexes in the API comments, but about what operations might block each other.
* Add LockWAL()/UnlockWAL() to db_stress and crash test, mostly to check for assertion failures, but also checks that latest seqno doesn't change while WAL is locked. This is simpler to add when LockWAL() is allowed in multiple threads.
* Remove unnecessary use of sync points in test DBWALTest::LockWal. There was a bug during development of above changes that caused this test to fail sporadically, with and without this sync point change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11143
Test Plan: unit tests added / updated, added to stress/crash test
Reviewed By: ajkr
Differential Revision: D42848627
Pulled By: pdillinger
fbshipit-source-id: 6d976c51791941a31fd8fbf28b0f82e888d9f4b4
Summary:
Seeting this error in stress test:
db_stress: internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:2459: void rocksdb::StressTest::Open(rocksdb::SharedState *): Assertion `txn_db_ == nullptr' failed. Received signal 6 (Aborted)
......
It doesn't appear that txn_db_ is set to nullptr at all. We set ithere.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11164
Test Plan: Run db_stress transaction and non-transation with low kill rate and see restarting without assertion
Reviewed By: ajkr
Differential Revision: D42855662
fbshipit-source-id: 06816d37cce9c94a81cb54ab238fb73aa102ed46
Summary:
Use the user key on sst file for blob verification for `Get` and `MultiGet` instead of the user key passed from caller.
Add tests for `Get` and `MultiGet` operations when user defined timestamp feature is enabled in a BlobDB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11105
Test Plan:
make V=1 db_blob_basic_test
./db_blob_basic_test --gtest_filter="DBBlobTestWithTimestamp.*"
Reviewed By: ltamasi
Differential Revision: D42716487
Pulled By: jowlyzhang
fbshipit-source-id: 5987ecbb7e56ddf46d2467a3649369390789506a
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.
Most of changes were done through following comments:
unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'`
by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147
Test Plan: See CI
Reviewed By: pdillinger
Differential Revision: D42796341
fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11133
Test Plan:
- ran it a few times on a mismatching DB+expected state; verified error messages look right:
```
Verification failed for column family 0 key 000000000000D553000000000000014C0000000000000142 (163988): value_from_db: , value_from_expected: 25E7B53421202322, msg: GetMergeOperands verification: Value not found: NotFound:
Verification failed for column family 0 key 000000000000AAE2787878 (131123): value_from_db: , value_from_expected: B2A69C18B6B7B4B5BABBB8B9BEBFBCBDA2A3A0A1A6A7A4A5, msg: Iterator verification: Value not found: NotFound:
Verification failed for column family 0 key 00000000000080C6000000000000004C78787878 (98409): value_from_db: , value_from_expected: 67AB7E1E636261606F6E6D6C6B6A6968, msg: Get verification: Value not found: NotFound:
```
Reviewed By: hx235
Differential Revision: D42757072
Pulled By: ajkr
fbshipit-source-id: b0a4a0aaa5be5d110434324853ac92aaa6972d89
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11136
Test Plan: the provided unit test used to fail due to `GetMergeOperands()` returning `Status::MergeInProgress()`; it passes now because the `GetMergeOperands()` call returns `Status::OK()`
Reviewed By: pdillinger
Differential Revision: D42759198
Pulled By: ajkr
fbshipit-source-id: 878f9f40ccc1d7e2fe7b1352814bae3a49c19939
Summary:
Migrate derived classes from EnvWrapper to FileSystemWrapper so we can eventually deprecate the storage methods in Env.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11125
Test Plan: CircleCI jobs
Reviewed By: anand1976
Differential Revision: D42732241
Pulled By: akankshamahajan15
fbshipit-source-id: c89a70a79fcfb13e158bf8919b1a87a9de133222
Summary:
Since compressed block cache is removed, those stats are not needed. They are removed in different PR in case there is a problem with it. The stats are removed in the same way in https://github.com/facebook/rocksdb/pull/11131/ . HISTORY.md was already updated by mistake, and it would be correct after merging this PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11135
Test Plan: Watch CI
Reviewed By: ltamasi
Differential Revision: D42757616
fbshipit-source-id: bd7cb782585c8535ce5784295225c376f3011f35
Summary:
Like other versions before, gcc 13 moved some includes around and as a result <cstdint> is no longer transitively included [1]. Explicitly include it for uint{32,64}_t.
[1] https://gcc.gnu.org/gcc-13/porting_to.html#header-dep-changes
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11118
Reviewed By: cbi42
Differential Revision: D42711356
Pulled By: ajkr
fbshipit-source-id: 5ea257b85b7017f40fd8fdbce965336da95c55b2
Summary:
Add the most basic support such that trace_analyzer commands no longer fail with
```
Cannot process the write batch in the trace
Cannot process the TraceRecord
PutEntityCF not implemented
Cannot process the trace
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11127
Reviewed By: cbi42
Differential Revision: D42732319
Pulled By: ajkr
fbshipit-source-id: 162d8a31318672a46539b1b042ec25f69b25c4ed
Summary:
PR https://github.com/facebook/rocksdb/issues/11020 fixed a case where it was easy to deadlock the DB with LockWAL() but introduced a bug showing up as a rare assertion failure in the stress test. Specifically, `assert(w->state == STATE_INIT)` in `WriteThread::LinkOne()` called from `BeginWriteStall()`, `DelayWrite()`, `WriteImplWALOnly()`. I haven't been about to generate a unit test that reproduces this failure but I believe the root cause is that DelayWrite() was never meant to be re-entrant, only called from the DB's write_thread_ leader. https://github.com/facebook/rocksdb/issues/11020 introduced a call to DelayWrite() from the nonmem_write_thread_ group leader.
This fix is to make DelayWrite() apply to the specific write queue that it is being called from (inject a dummy write stall entry to the head of the appropriate write queue). WriteController is re-entrant, based on polling and state changes signalled with bg_cv_, so can manage stalling two queues. The only anticipated complication (called out by Andrew in previous PR) is that we don't want timed write delays being injected in parallel for the two queues, because that dimishes the intended throttling effect. Thus, we only allow timed delays for the primary write queue.
HISTORY not updated because this is intended for the same release where the bug was introduced.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11130
Test Plan:
Although I was not able to reproduce the assertion failure, I was able to reproduce a distinct flaw with what I believe is the same root cause: a kind of deadlock if both write queues need to wake up from stopped writes. Only one will be waiting on bg_cv_ (the other waiting in `LinkOne()` for the write queue to open up), so a single SignalAll() will only unblock one of the queues, with the other re-instating the stop until another signal on bg_cv_. A simple unit test is added for this case.
Will also run crash_test_with_multiops_wc_txn for a while looking for issues.
Reviewed By: ajkr
Differential Revision: D42749330
Pulled By: pdillinger
fbshipit-source-id: 4317dd899a93d57c26fd5af7143038f82d4d4d1b
Summary:
These tickers/histograms have been obsolete (and not populated) for a long time.
The patch removes them from the API completely. Note that this means that the
numeric values of the remaining tickers change in the C++ code as they get shifted up.
This should be OK: the values of some existing tickers have changed many times
over the years as items have been added in the middle. (In contrast, the convention
in the Java bindings is to keep the ids, which are not guaranteed to be the same
as the ids on the C++ side, the same across releases.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11123
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D42727793
Pulled By: ltamasi
fbshipit-source-id: e058a155a20b05b45f53e67ee380aece1b43b6c5
Summary:
Migrate ErrorEnv from EnvWrapper to FileSystemWrapper so we can eventually deprecate the storage methods in Env.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11124
Reviewed By: akankshamahajan15
Differential Revision: D42727791
Pulled By: anand1976
fbshipit-source-id: e8362ad624dc28e55c99fc35eda12866755f62c6
Summary:
Compressed block cache is replaced by compressed secondary cache. Remove the feature.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11117
Test Plan: See CI passes
Reviewed By: pdillinger
Differential Revision: D42700164
fbshipit-source-id: 6cbb24e460da29311150865f60ecb98637f9f67d
Summary:
Capture more of the original intent at a high level, without getting bogged down in low-level details.
The old text made some weak promises about handling of LOCK files. There should be no specific concern for LOCK files, because we already rely on LockFile() to create the file if it's not present already. And the lock file is generally size 0, so don't have to worry about truncation. Added a unit test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11085
Test Plan: existing tests, and a new one.
Reviewed By: siying
Differential Revision: D42713233
Pulled By: pdillinger
fbshipit-source-id: 2fce7c974d35fac065037c9c4c7326a59c9fe340
Summary:
**Context:**
Concurrent flushes on the same CF can set on `ColumnFamilyData::flush_reason` before each other flush finishes. An symptom is one CF has different flush_reason with others though all of them are in an atomic flush `db_stress: db/db_impl/db_impl_compaction_flush.cc:423: rocksdb::Status rocksdb::DBImpl::AtomicFlushMemTablesToOutputFiles(const rocksdb::autovector<rocksdb::DBImpl::BGFlushArg>&, bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::Env::Priority): Assertion cfd->GetFlushReason() == cfds[0]->GetFlushReason() failed. `
**Summary:**
Suggested by ltamasi, we now refactor and let FlushRequest/Job to own flush_reason as there is no good way to define `ColumnFamilyData::flush_reason` in face of concurrent flushes on the same CF (which wasn't the case a long time ago when `ColumnFamilyData::flush_reason ` first introduced`)
**Tets:**
- new unit test
- make check
- aggressive crash test rehearsal
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11111
Reviewed By: ajkr
Differential Revision: D42644600
Pulled By: hx235
fbshipit-source-id: 8589c8184869d3415e5b780c887f877818a5ebaf
Summary:
Prior to this PR, `FullMergeV2()` can only return `false` to indicate failure, which causes any operation invoking it to fail. During a compaction, such a failure causes the compaction to fail and causes the DB to irreversibly enter read-only mode. Some users asked for a way to allow the merge operator to fail without such widespread damage.
To limit the blast radius of merge operator failures, this PR introduces the `MergeOperationOutput::op_failure_scope` API. When unpopulated (`kDefault`) or set to `kTryMerge`, the merge operator failure handling is the same as before. When set to `kMustMerge`, merge operator failure still causes failure to operations that must merge (`Get()`, iterator, `MultiGet()`, etc.). However, under `kMustMerge`, flushes/compactions can survive merge operator failures by outputting the unmerged input operands.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11092
Reviewed By: siying
Differential Revision: D42525673
Pulled By: ajkr
fbshipit-source-id: 951dc3bf190f86347dccf3381be967565cda52ee
Summary:
Add more coverage in unit tests for async scan. The added unit test fails without PR https://github.com/facebook/rocksdb/pull/10939.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11087
Test Plan: CircleCI jobs status for new unit tests.
Reviewed By: anand1976
Differential Revision: D42487931
Pulled By: akankshamahajan15
fbshipit-source-id: d59ed7666599bd0d2733ac5d76bd70984b54c5a9
Summary:
In this issue [11100](https://github.com/facebook/rocksdb/issues/11100)
I try to upgrade dependencies of [BaikalDB](https://github.com/baidu/BaikalDB) and tool chain to gcc-12.I found that when I build rocksdb v6.26.0(maybe I can use newer version),I found that in file trace_replay/trace_replay.cc,the compiler tell me "error mybe-uninitialized".I dound that it can be fixed very easy,so I make this pull request.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11101
Reviewed By: ajkr
Differential Revision: D42583031
Pulled By: cbi42
fbshipit-source-id: 7f399f09441a30fe88b83cec5e2fd9885bad5c06
Summary:
`InternalIteratorBase::is_mutable_` is not used any more, remove it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11104
Reviewed By: ajkr
Differential Revision: D42582747
Pulled By: cbi42
fbshipit-source-id: d30bf75151fc8414df0ae112a6ec4943b5b7330b
Summary:
Upgrading xxhash.h to latest dev version as of 1/17/2023, which is d7197ddea81364a539051f116ca77926100fc77f This should improve performance on some ARM machines.
I allowed some of our RocksDB-specific changes to be made obsolete where it seemed appropriate, for example
* xxhash.h has its own fallthrough marker (which I hope works for us)
* As in https://github.com/Cyan4973/xxHash/pull/549
Merging and resolving conflicts one way or the other was all that went into this diff. Except I had to mix the two sides around `defined(__loongarch64)`
How I did the upgrade (for future reference), so that I could use usual merge conflict resolution:
```
# New branch to help with merging
git checkout -b xxh_merge_base
# Check out RocksDB revision before last xxhash.h upgrade
git reset --hard 22161b7547652af82a5dc67458de9ca8946ac83d^
# Create a commit with the raw base version from xxHash repo (from xxHash repo)
git show 2c611a76f914828bed675f0f342d6c4199ffee1e:xxhash.h > ../rocksdb/util/xxhash.h
# In RocksDB repo
git commit -a
# Merge in the last xxhash.h upgrade
git merge 22161b7547
# Resolve conflict using committed version
git show 22161b7547652af82a5dc67458de9ca8946ac83d:util/xxhash.h > util/xxhash.h
git commit -a
# Catch up to upstream
git merge upstream/main
# Create a different branch for applying raw upgrade
git checkout -b xxh_upgrade_2023
# Find the RocksDB commit we made for the raw base version from xxHash
git log main..HEAD
# Rewind to it
git reset --hard 2428b727a9
# Copy in latest raw version (from xxHash repo)
cat xxhash.h > ../rocksdb/util/xxhash.h
# Merge in RocksDB changes, use typical tools for conflict resolution
git merge xxh_merge_base
```
Branch https://github.com/facebook/rocksdb/tree/xxhash_merge_base can be used as a base for future xxhash merges.
Fixes https://github.com/facebook/rocksdb/issues/11073
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11098
Test Plan:
existing tests (e.g. Bloom filter schema stability tests)
Also seems to include a small performance boost on my Intel dev machine, using `./db_bench --benchmarks=xxh3[-X50] 2>&1 | egrep -o 'operations;.*' | sort`
Fastest out of 50 runs, before: 15477.3 MB/s
Fastest out of 50 runs, after: 15850.7 MB/s, and 11 more runs faster than the "before" number
Slowest out of 50 runs, before: 12267.5 MB/s
Slowest out of 50 runs, after: 13897.1 MB/s
More repetitions show the distinction is repeatable
Reviewed By: hx235
Differential Revision: D42560010
Pulled By: pdillinger
fbshipit-source-id: c43ee52f1c5fe0ba3d6d6e4eebb22ded5f5492ea
Summary:
the `last_tombstone_start_user_key` variable in `BuildTable()` and in `CompactionOutputs::AddRangeDels()` may point to a start key that is freed if user-defined timestamp is enabled. This was causing ASAN failure and this PR fixes this issue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11106
Test Plan: Added UT for repro.
Reviewed By: ajkr
Differential Revision: D42590862
Pulled By: cbi42
fbshipit-source-id: c493265ececdf89636d801d55ae929806c4d4b2c
Summary:
Same as title
Error:
```
block_cache_trace_analyzer: ./db/dbformat.h:421: uint64_t rocksdb::GetInternalKeySeqno(const rocksdb::Slice&): Assertion `n >= kNumInternalBytes' failed.
Aborted (core dumped)
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11042
Test Plan:
- Added new unit test which fails without the fix.
- Also ran manually on traces to confirm.
Reviewed By: anand1976
Differential Revision: D42481587
Pulled By: akankshamahajan15
fbshipit-source-id: 7c33eb03a4a4d8ffbabcfbe0efa1e4d11bde3ba2
Summary:
in `CompactionOutputs::ShouldStopBefore()`, TTL-related states, `cur_files_to_cut_for_ttl_` and `next_files_to_cut_for_ttl_`, are not updated if the function returns early. This can cause unnecessary compaction output file cuttings and hence produce smaller output files, which may hurt write amp. See the example in the unit test for how this "unnecessary file cutting" can happen. This PR fixes this issue by moving the code for updating TTL states earlier in `CompactionOutputs::ShouldStopBefore()` so that the states are updated for each key.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11075
Test Plan: - Added new unit test.
Reviewed By: hx235
Differential Revision: D42398739
Pulled By: cbi42
fbshipit-source-id: 09fab66679c1a734abcfc31bcea33dd9aeb9dbc7
Summary:
in `CompactionOutputs::AddRangeDels()`, range tombstones with the same start and end key but different sequence numbers all contribute to compensated range tombstone size. This PR removes this redundancy. This PR also includes a fix from https://github.com/facebook/rocksdb/issues/11067 where a range tombstone that is not within a file's range was being added to the file. This fixes an assertion failure for `icmp.Compare(start, end) <= 0` in VersionSet::ApproximateSize() when calculating compensated range tombstone size. Assertions and a comment/essay was added to reason that no such range tombstone will be added after this fix.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11091
Test Plan:
- Added unit tests
- Stress test with small key range: `python3 tools/db_crashtest.py blackbox --simple --max_key=100 --interval=600 --write_buffer_size=262144 --target_file_size_base=256 --max_bytes_for_level_base=262144 --block_size=128 --value_size_mult=33 --subcompactions=10`
Reviewed By: ajkr
Differential Revision: D42521588
Pulled By: cbi42
fbshipit-source-id: 5bda3fe38997995314e1f7592319af12b69bc4f8
Summary:
This reverts commit f02c708aa3 since it introduced several bugs (see https://github.com/facebook/rocksdb/issues/11078 and https://github.com/facebook/rocksdb/issues/11067 for attempts to fix them) and that I do not have a high confidence to fix all of them and ensure no further ones before the next release branch cut. There are also come existing issue found during bug fixing. We will work on it and try to merge it to the release after.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11089
Test Plan: existing CI.
Reviewed By: ajkr
Differential Revision: D42505972
Pulled By: cbi42
fbshipit-source-id: 2f66dcde6b85dc94977b317c2ce513872cfbc153
Summary:
When running `-benchmarks=compact`, `-subcompactions` does not take effect.
`-subcompactions` option comment says it is for L0-L1 compactions, it is natural to extend it to CompactionRangeOptions.max_subcompactions.
This PR set CompactionRangeOptions.max_subcompactions = FLAGS_subcompactions
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11077
Reviewed By: akankshamahajan15
Differential Revision: D42506251
Pulled By: ajkr
fbshipit-source-id: f77c9a99d32ff7af59f3c452c9e16aaeb0360304
Summary:
This is several refactorings bundled into one to avoid having to incrementally re-modify uses of Cache several times. Overall, there are breaking changes to Cache class, and it becomes more of low-level interface for implementing caches, especially block cache. New internal APIs make using Cache cleaner than before, and more insulated from block cache evolution. Hopefully, this is the last really big block cache refactoring, because of rather effectively decoupling the implementations from the uses. This change also removes the EXPERIMENTAL designation on the SecondaryCache support in Cache. It seems reasonably mature at this point but still subject to change/evolution (as I warn in the API docs for Cache).
The high-level motivation for this refactoring is to minimize code duplication / compounding complexity in adding SecondaryCache support to HyperClockCache (in a later PR). Other benefits listed below.
* static_cast lines of code +29 -35 (net removed 6)
* reinterpret_cast lines of code +6 -32 (net removed 26)
## cache.h and secondary_cache.h
* Always use CacheItemHelper with entries instead of just a Deleter. There are several motivations / justifications:
* Simpler for implementations to deal with just one Insert and one Lookup.
* Simpler and more efficient implementation because we don't have to track which entries are using helpers and which are using deleters
* Gets rid of hack to classify cache entries by their deleter. Instead, the CacheItemHelper includes a CacheEntryRole. This simplifies a lot of code (cache_entry_roles.h almost eliminated). Fixes https://github.com/facebook/rocksdb/issues/9428.
* Makes it trivial to adjust SecondaryCache behavior based on kind of block (e.g. don't re-compress filter blocks).
* It is arguably less convenient for many direct users of Cache, but direct users of Cache are now rare with introduction of typed_cache.h (below).
* I considered and rejected an alternative approach in which we reduce customizability by assuming each secondary cache compatible value starts with a Slice referencing the uncompressed block contents (already true or mostly true), but we apparently intend to stack secondary caches. Saving an entry from a compressed secondary to a lower tier requires custom handling offered by SaveToCallback, etc.
* Make CreateCallback part of the helper and introduce CreateContext to work with it (alternative to https://github.com/facebook/rocksdb/issues/10562). This cleans up the interface while still allowing context to be provided for loading/parsing values into primary cache. This model works for async lookup in BlockBasedTable reader (reader owns a CreateContext) under the assumption that it always waits on secondary cache operations to finish. (Otherwise, the CreateContext could be destroyed while async operation depending on it continues.) This likely contributes most to the observed performance improvement because it saves an std::function backed by a heap allocation.
* Use char* for serialized data, e.g. in SaveToCallback, where void* was confusingly used. (We use `char*` for serialized byte data all over RocksDB, with many advantages over `void*`. `memcpy` etc. are legacy APIs that should not be mimicked.)
* Add a type alias Cache::ObjectPtr = void*, so that we can better indicate the intent of the void* when it is to be the object associated with a Cache entry. Related: started (but did not complete) a refactoring to move away from "value" of a cache entry toward "object" or "obj". (It is confusing to call Cache a key-value store (like DB) when it is really storing arbitrary in-memory objects, not byte strings.)
* Remove unnecessary key param from DeleterFn. This is good for efficiency in HyperClockCache, which does not directly store the cache key in memory. (Alternative to https://github.com/facebook/rocksdb/issues/10774)
* Add allocator to Cache DeleterFn. This is a kind of future-proofing change in case we get more serious about using the Cache allocator for memory tracked by the Cache. Right now, only the uncompressed block contents are allocated using the allocator, and a pointer to that allocator is saved as part of the cached object so that the deleter can use it. (See CacheAllocationPtr.) If in the future we are able to "flatten out" our Cache objects some more, it would be good not to have to track the allocator as part of each object.
* Removes legacy `ApplyToAllCacheEntries` and changes `ApplyToAllEntries` signature for Deleter->CacheItemHelper change.
## typed_cache.h
Adds various "typed" interfaces to the Cache as internal APIs, so that most uses of Cache can use simple type safe code without casting and without explicit deleters, etc. Almost all of the non-test, non-glue code uses of Cache have been migrated. (Follow-up work: CompressedSecondaryCache deserves deeper attention to migrate.) This change expands RocksDB's internal usage of metaprogramming and SFINAE (https://en.cppreference.com/w/cpp/language/sfinae).
The existing usages of Cache are divided up at a high level into these new interfaces. See updated existing uses of Cache for examples of how these are used.
* PlaceholderCacheInterface - Used for making cache reservations, with entries that have a charge but no value.
* BasicTypedCacheInterface<TValue> - Used for primary cache storage of objects of type TValue, which can be cleaned up with std::default_delete<TValue>. The role is provided by TValue::kCacheEntryRole or given in an optional template parameter.
* FullTypedCacheInterface<TValue, TCreateContext> - Used for secondary cache compatible storage of objects of type TValue. In addition to BasicTypedCacheInterface constraints, we require TValue::ContentSlice() to return persistable data. This simplifies usage for the normal case of simple secondary cache compatibility (can give you a Slice to the data already in memory). In addition to TCreateContext performing the role of Cache::CreateContext, it is also expected to provide a factory function for creating TValue.
* For each of these, there's a "Shared" version (e.g. FullTypedSharedCacheInterface) that holds a shared_ptr to the Cache, rather than assuming external ownership by holding only a raw `Cache*`.
These interfaces introduce specific handle types for each interface instantiation, so that it's easy to see what kind of object is controlled by a handle. (Ultimately, this might not be worth the extra complexity, but it seems OK so far.)
Note: I attempted to make the cache 'charge' automatically inferred from the cache object type, such as by expecting an ApproximateMemoryUsage() function, but this is not so clean because there are cases where we need to compute the charge ahead of time and don't want to re-compute it.
## block_cache.h
This header is essentially the replacement for the old block_like_traits.h. It includes various things to support block cache access with typed_cache.h for block-based table.
## block_based_table_reader.cc
Before this change, accessing the block cache here was an awkward mix of static polymorphism (template TBlocklike) and switch-case on a dynamic BlockType value. This change mostly unifies on static polymorphism, relying on minor hacks in block_cache.h to distinguish variants of Block. We still check BlockType in some places (especially for stats, which could be improved in follow-up work) but at least the BlockType is a static constant from the template parameter. (No more awkward partial redundancy between static and dynamic info.) This likely contributes to the overall performance improvement, but hasn't been tested in isolation.
The other key source of simplification here is a more unified system of creating block cache objects: for directly populating from primary cache and for promotion from secondary cache. Both use BlockCreateContext, for context and for factory functions.
## block_based_table_builder.cc, cache_dump_load_impl.cc
Before this change, warming caches was super ugly code. Both of these source files had switch statements to basically transition from the dynamic BlockType world to the static TBlocklike world. None of that mess is needed anymore as there's a new, untyped WarmInCache function that handles all the details just as promotion from SecondaryCache would. (Fixes `TODO akanksha: Dedup below code` in block_based_table_builder.cc.)
## Everything else
Mostly just updating Cache users to use new typed APIs when reasonably possible, or changed Cache APIs when not.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10975
Test Plan:
tests updated
Performance test setup similar to https://github.com/facebook/rocksdb/issues/10626 (by cache size, LRUCache when not "hyper" for HyperClockCache):
34MB 1thread base.hyper -> kops/s: 0.745 io_bytes/op: 2.52504e+06 miss_ratio: 0.140906 max_rss_mb: 76.4844
34MB 1thread new.hyper -> kops/s: 0.751 io_bytes/op: 2.5123e+06 miss_ratio: 0.140161 max_rss_mb: 79.3594
34MB 1thread base -> kops/s: 0.254 io_bytes/op: 1.36073e+07 miss_ratio: 0.918818 max_rss_mb: 45.9297
34MB 1thread new -> kops/s: 0.252 io_bytes/op: 1.36157e+07 miss_ratio: 0.918999 max_rss_mb: 44.1523
34MB 32thread base.hyper -> kops/s: 7.272 io_bytes/op: 2.88323e+06 miss_ratio: 0.162532 max_rss_mb: 516.602
34MB 32thread new.hyper -> kops/s: 7.214 io_bytes/op: 2.99046e+06 miss_ratio: 0.168818 max_rss_mb: 518.293
34MB 32thread base -> kops/s: 3.528 io_bytes/op: 1.35722e+07 miss_ratio: 0.914691 max_rss_mb: 264.926
34MB 32thread new -> kops/s: 3.604 io_bytes/op: 1.35744e+07 miss_ratio: 0.915054 max_rss_mb: 264.488
233MB 1thread base.hyper -> kops/s: 53.909 io_bytes/op: 2552.35 miss_ratio: 0.0440566 max_rss_mb: 241.984
233MB 1thread new.hyper -> kops/s: 62.792 io_bytes/op: 2549.79 miss_ratio: 0.044043 max_rss_mb: 241.922
233MB 1thread base -> kops/s: 1.197 io_bytes/op: 2.75173e+06 miss_ratio: 0.103093 max_rss_mb: 241.559
233MB 1thread new -> kops/s: 1.199 io_bytes/op: 2.73723e+06 miss_ratio: 0.10305 max_rss_mb: 240.93
233MB 32thread base.hyper -> kops/s: 1298.69 io_bytes/op: 2539.12 miss_ratio: 0.0440307 max_rss_mb: 371.418
233MB 32thread new.hyper -> kops/s: 1421.35 io_bytes/op: 2538.75 miss_ratio: 0.0440307 max_rss_mb: 347.273
233MB 32thread base -> kops/s: 9.693 io_bytes/op: 2.77304e+06 miss_ratio: 0.103745 max_rss_mb: 569.691
233MB 32thread new -> kops/s: 9.75 io_bytes/op: 2.77559e+06 miss_ratio: 0.103798 max_rss_mb: 552.82
1597MB 1thread base.hyper -> kops/s: 58.607 io_bytes/op: 1449.14 miss_ratio: 0.0249324 max_rss_mb: 1583.55
1597MB 1thread new.hyper -> kops/s: 69.6 io_bytes/op: 1434.89 miss_ratio: 0.0247167 max_rss_mb: 1584.02
1597MB 1thread base -> kops/s: 60.478 io_bytes/op: 1421.28 miss_ratio: 0.024452 max_rss_mb: 1589.45
1597MB 1thread new -> kops/s: 63.973 io_bytes/op: 1416.07 miss_ratio: 0.0243766 max_rss_mb: 1589.24
1597MB 32thread base.hyper -> kops/s: 1436.2 io_bytes/op: 1357.93 miss_ratio: 0.0235353 max_rss_mb: 1692.92
1597MB 32thread new.hyper -> kops/s: 1605.03 io_bytes/op: 1358.04 miss_ratio: 0.023538 max_rss_mb: 1702.78
1597MB 32thread base -> kops/s: 280.059 io_bytes/op: 1350.34 miss_ratio: 0.023289 max_rss_mb: 1675.36
1597MB 32thread new -> kops/s: 283.125 io_bytes/op: 1351.05 miss_ratio: 0.0232797 max_rss_mb: 1703.83
Almost uniformly improving over base revision, especially for hot paths with HyperClockCache, up to 12% higher throughput seen (1597MB, 32thread, hyper). The improvement for that is likely coming from much simplified code for providing context for secondary cache promotion (CreateCallback/CreateContext), and possibly from less branching in block_based_table_reader. And likely a small improvement from not reconstituting key for DeleterFn.
Reviewed By: anand1976
Differential Revision: D42417818
Pulled By: pdillinger
fbshipit-source-id: f86bfdd584dce27c028b151ba56818ad14f7a432
Summary:
valgrind build for `ExternalSSTFileBasicTest/ExternalSSTFileBasicTest.IngestFileWithMixedValueType` and `ExternalSSTFileBasicTest/ExternalSSTFileBasicTest.IngestFileWithGlobalSeqnoPickedSeqno` started failing (see error message in T141554665). I could not repro but I suspect it is due to file ingestion range overlapping with ongoing compaction, which caused a new global seqno being assigned after https://github.com/facebook/rocksdb/issues/10988.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11070
Test Plan: monitor future valgrind tests result.
Reviewed By: hx235
Differential Revision: D42319056
Pulled By: cbi42
fbshipit-source-id: acbcd841a2a15e36b278f39ba514f4b9a6ee43ca
Summary:
Before this pr, the destruction order is `shared` -> `db_`(StressTest destruction) -> `stress`, but `compaction_filter` of `db_` will hold the `shared` pointer, so `shared` maybe used after free.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11059
Reviewed By: hx235
Differential Revision: D42297366
Pulled By: ajkr
fbshipit-source-id: 17b314635359acacd5ba62f9db5f955f451133f7
