Summary:
Add an option to filter out READ or WRITE operations while tracing.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5082
Differential Revision: D14515083
Pulled By: mrmiywj
fbshipit-source-id: 2504c89a9abf1dd629cad44b4104092702d77610
Summary:
This is a feature to sample data-block compressibility and and report them as stats. 1 in N (tunable) blocks is sampled for compressibility using two algorithms:
1. lz4 or snappy for fast compression
2. zstd or zlib for slow but higher compression.
The stats are reported to the caller as raw-bytes and compressed-bytes. The block continues to be compressed for storage using the specified CompressionType.
The db_bench_tool how has a command line option for specifying the sampling rate. It's default value is 0 (no sampling). To test the overhead for a certain value, users can compare the performance of db_bench_tool, varying the sampling rate. It is unlikely to have a noticeable impact for high values like 20.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4842
Differential Revision: D13629011
Pulled By: shobhitdayal
fbshipit-source-id: 14ca668bcab6499b2a1734edf848eb62a4f4fafa
Summary:
JEMALLOC_CXX_THROW is not defined for earlier versions of jemalloc (e.g. 3.6), causing builds to fail on some platforms. Fixing it. Closes#4869
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5053
Differential Revision: D14390034
Pulled By: sagar0
fbshipit-source-id: b2b7a03cd377201ef385eb521f65bae85c558055
Summary:
This reverts commit ee1818081f.
We are not ready to deprecate this feature. revert it for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5034
Differential Revision: D14287246
Pulled By: siying
fbshipit-source-id: e4beafdeaee1c94364fdaa6ba198218d158339f7
Summary:
Right now, users can change statistics.stats_level while DB is running, but TSAN may report
data race. We make stats_level_ to be atomic, and access them using accessors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5030
Differential Revision: D14267519
Pulled By: siying
fbshipit-source-id: 37d7ebeff7a43a406230143422a16af899163f73
Summary:
Statistics cost too much CPU for some use cases. Add two stats levels
so that people can choose to skip two types of expensive stats, timers and
histograms.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5027
Differential Revision: D14252765
Pulled By: siying
fbshipit-source-id: 75ecec9eaa44c06118229df4f80c366115346592
Summary:
This PR adds public `GetStatsHistory` API to retrieve stats history in the form of an std map. The key of the map is the timestamp in microseconds when the stats snapshot is taken, the value is another std map from stats name to stats value (stored in std string). Two DBOptions are introduced: `stats_persist_period_sec` (default 10 minutes) controls the intervals between two snapshots are taken; `max_stats_history_count` (default 10) controls the max number of history snapshots to keep in memory. RocksDB will stop collecting stats snapshots if `stats_persist_period_sec` is set to 0.
(This PR is the in-memory part of https://github.com/facebook/rocksdb/pull/4535)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4748
Differential Revision: D13961471
Pulled By: miasantreble
fbshipit-source-id: ac836d401ecb84ea92216bf9966f969dedf4ad04
Summary:
MyRocks calls `GetForUpdate` on `INSERT`, for unique key check, and in almost all cases GetForUpdate returns empty result. For such cases, whole key bloom filter is helpful.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4985
Differential Revision: D14118257
Pulled By: miasantreble
fbshipit-source-id: d35cb7109c62fd5ad541a26968e3a3e16d3e85ea
Summary:
We introduced ttl option in CompactionOptionsFIFO when ttl-based file
deletion (compaction) was supported only as part of FIFO Compaction. But
with the extension of ttl semantics even to Level compaction,
CompactionOptionsFIFO.ttl can now be deprecated. Instead we will start
using ColumnFamilyOptions.ttl for FIFO compaction as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4965
Differential Revision: D14072960
Pulled By: sagar0
fbshipit-source-id: c98cc2ae695a28136295787cd88d36a220fc219e
Summary:
If `CompressionOptions::max_dict_bytes` and/or `CompressionOptions::zstd_max_train_bytes` are set, `SstFileWriter` will now generate files respecting those options.
I refactored the logic a bit for deciding when to use dictionary compression. Previously we plumbed `is_bottommost_level` down to the table builder and used that. However it was kind of confusing in `SstFileWriter`'s context since we don't know what level the file will be ingested to. Instead, now the higher-level callers (e.g., flush, compaction, file writer) are responsible for building the right `CompressionOptions` to give the table builder.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4978
Differential Revision: D14060763
Pulled By: ajkr
fbshipit-source-id: dc802c327896df2b319dc162d6acc82b9cdb452a
Summary:
as title. For people who continue to need Lua compaction filter, you
can copy the include/rocksdb/utilities/rocks_lua/lua_compaction_filter.h and
utilities/lua/rocks_lua_compaction_filter.cc to your own codebase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4971
Differential Revision: D14047468
Pulled By: riversand963
fbshipit-source-id: 9ad1a6484a7c94e478f1e108127a3184e4069f70
Summary:
Make file ingestion atomic.
as title.
Ingesting external SST files into multiple column families should be atomic. If
a crash occurs and db reopens, either all column families have successfully
ingested the files before the crash, or non of the ingestions have any effect
on the state of the db.
Also add unit tests for atomic ingestion.
Note that the unit test here does not cover the case of incomplete atomic group
in the MANIFEST, which is covered in VersionSetTest already.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4895
Differential Revision: D13718245
Pulled By: riversand963
fbshipit-source-id: 7df97cc483af73ad44dd6993008f99b083852198
Summary:
Our previous approach was to train one compression dictionary per compaction, using the first output SST to train a dictionary, and then applying it on subsequent SSTs in the same compaction. While this was great for minimizing CPU/memory/I/O overhead, it did not achieve good compression ratios in practice. In our most promising potential use case, moderate reductions in a dictionary's scope make a major difference on compression ratio.
So, this PR changes compression dictionary to be scoped per-SST. It accepts the tradeoff during table building to use more memory and CPU. Important changes include:
- The `BlockBasedTableBuilder` has a new state when dictionary compression is in-use: `kBuffered`. In that state it accumulates uncompressed data in-memory whenever `Add` is called.
- After accumulating target file size bytes or calling `BlockBasedTableBuilder::Finish`, a `BlockBasedTableBuilder` moves to the `kUnbuffered` state. The transition (`EnterUnbuffered()`) involves sampling the buffered data, training a dictionary, and compressing/writing out all buffered data. In the `kUnbuffered` state, a `BlockBasedTableBuilder` behaves the same as before -- blocks are compressed/written out as soon as they fill up.
- Samples are now whole uncompressed data blocks, except the final sample may be a partial data block so we don't breach the user's configured `max_dict_bytes` or `zstd_max_train_bytes`. The dictionary trainer is supposed to work better when we pass it real units of compression. Previously we were passing 64-byte KV samples which was not realistic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4952
Differential Revision: D13967980
Pulled By: ajkr
fbshipit-source-id: 82bea6f7537e1529c7a1a4cdee84585f5949300f
Summary:
Always enable properties block checksum verification for block-based table. For external SST file ingested with 'write_global_seqno==true', we use 'DecodeEntrySlow' to parse its blocks' contents so that the process will not die upon failing the assertion possibly caused by corruption.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4956
Differential Revision: D14012741
Pulled By: riversand963
fbshipit-source-id: 8b766e6f54b36f8f9e074c0e19e0926ec3cce186
Summary:
Implement trace sampling to allow user to specify the sampling frequency, i.e. save one per how many requests, so that a user does not need to log all if he/she is interested in only a sampled set.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4963
Differential Revision: D14011190
Pulled By: tang-jianfeng
fbshipit-source-id: 078b631d9319b67cb089dd2c30e21d0df8dc406a
Summary:
We want to reserve some right that some extra information added manifest
in the future can be forward compatible by previous versions. Now we create a
place holder for that. A bit in tag is added to indicate that a field can be
safely ignored.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4960
Differential Revision: D14000484
Pulled By: siying
fbshipit-source-id: cbf5bad3f9d5ec798f789806f244d1c20d3b66d6
Summary:
We found that the behavior of CompactionFilter::IgnoreSnapshots() = false isn't
what we have expected. We thought that snapshot will always be preserved.
However, we just realized that, if no snapshot is created while compaction
starts, and a snapshot is created after that, the data seen from the snapshot
can successfully be dropped by the compaction. This creates a strange behavior
to the feature, which is hard to explain. Like what is documented in code
comment, this feature is not very useful with snapshot anyway. The decision
is to deprecate the feature.
We keep the function to avoid to break users code. However, we will fail
compactions if false is returned.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4954
Differential Revision: D13981900
Pulled By: siying
fbshipit-source-id: 2db8c2c3865acd86a28dca625945d1481b1d1e36
Summary:
Cuckoo Hash is less useful than we initially expected. Remove it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4953
Differential Revision: D13979264
Pulled By: siying
fbshipit-source-id: 2a60afdaa989f045357398b43a1cc5d46f4492ed
Summary:
before file ingestion (in preparation phase), verify the checksums of
the blocks of the external SST file, including properties block with global
seqno.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4916
Differential Revision: D13863501
Pulled By: riversand963
fbshipit-source-id: dc54697f970e3807832e2460f7228fcc7efe81ee
Summary:
Store_index_in_file is a less useful feature. To simplify the code to maintain, we are dropping the feature.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4914
Differential Revision: D13791883
Pulled By: siying
fbshipit-source-id: d187c5d662584866103e4b77d09dfb925509ae2e
Summary:
- If block cache disabled or not used for meta-blocks, `BlockBasedTableReader::Rep::uncompression_dict` owns the `UncompressionDict`. It is preloaded during `PrefetchIndexAndFilterBlocks`.
- If block cache is enabled and used for meta-blocks, block cache owns the `UncompressionDict`, which holds dictionary and digested dictionary when needed. It is never prefetched though there is a TODO for this in the code. The cache key is simply the compression dictionary block handle.
- New stats for compression dictionary accesses in block cache: "BLOCK_CACHE_COMPRESSION_DICT_*" and "compression_dict_block_read_count"
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4881
Differential Revision: D13663801
Pulled By: ajkr
fbshipit-source-id: bdcc54044e180855cdcc57639b493b0e016c9a3f
Summary:
compaction_pri = kMinOverlappingRatio usually provides much better write amplification than the default.
https://github.com/facebook/rocksdb/pull/4907 fixes one shortcome of this option. Make it default.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4911
Differential Revision: D13789262
Pulled By: siying
fbshipit-source-id: d90acf8c4dede44f00d183ca4c7a210259378269
Summary:
Right now, CompactionPri = kMinOverlappingRatio provides best write amplification, but it doesn't
prioritize files with more tombstones. We combine the two good features: make kMinOverlappingRatio
to boost files with lots of tombstones too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4907
Differential Revision: D13788774
Pulled By: siying
fbshipit-source-id: 1991cbb495fb76c8b529de69896e38d81ed9d9b3
Summary:
Right now, deleting blob files is not rate limited, even if SstFileManger is specified.
On the other hand, rate limiting blob deletion is not supported. With this change, Blob file
deletion will go through SstFileManager too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4904
Differential Revision: D13772545
Pulled By: siying
fbshipit-source-id: bd1b1d0beb26d5167385e00b7ecb8b94b879de84
Summary:
By convention, time_t almost always stores the integral number of seconds since
00:00 hours, Jan 1, 1970 UTC, according to http://www.cplusplus.com/reference/ctime/time_t/.
We surely want more precision than seconds.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4868
Differential Revision: D13633046
Pulled By: riversand963
fbshipit-source-id: 4e01e23a22e8838023c51a91247a286dbf3a5396
Summary:
LDB is frequently used to exam data copied. wal_dir in option file is not modified and it usually points to the path it copied from.
The user experience will be better if when ldb sees wal_dir pointed by the option file doesn't exist, rather than fail, just ignore it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4875
Differential Revision: D13643173
Pulled By: siying
fbshipit-source-id: 2e64d4ea2ec49a6794b9a706b7fc1ba901128bb8
Summary:
Remove some components that we never heard people using them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4101
Differential Revision: D8825431
Pulled By: siying
fbshipit-source-id: 97a12ad3cad4ab12c82741a5ba49669aaa854180
Summary:
Previously for point lookup we decided which file to look into based on user key overlap only. We also did not truncate range tombstones in the point lookup code path. These two ideas did not interact well in cases like this:
- L1 has range tombstone [a, c)#1 and point key b#2. The data is split between file1 with range [a#1,1, b#72057594037927935,15], and file2 with range [b#2, c#1].
- L1's file2 gets compacted to L2.
- User issues `Get()` for b#3.
- L1's file1 is opened and the range tombstone [a, c)#1 is found for b, while no point-key for b is found in L1.
- `Get()` assumes that the range tombstone must cover all data in that range in lower levels, so short circuits and returns `NotFound`.
The solution to this problem is to not look into files that only overlap with the point lookup at a range tombstone sentinel endpoint. In the above example, this would mean not opening L1's file1 or its tombstones during the `Get()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4829
Differential Revision: D13561355
Pulled By: ajkr
fbshipit-source-id: a13c21c816870a2f5d32a48af6dbd719a7d9d19f
Summary:
The original implementation has two problems:
1. f0dda35d7d/db/db_impl_write.cc (L478)f0dda35d7d/db/write_thread.h (L231)
If the callback status of leader of the write_group fails, then the whole write_group will not write to WAL, this may cause data loss.
2. f0dda35d7d/db/write_thread.h (L130)
The annotation says that Writer.status is the status of memtable inserter, but the original implementation use it for another case which is not consistent with the original design. Looks like we can still reuse Writer.status, but we should modify the annotation, so Writer.status is not only the status of memtable inserter.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4838
Differential Revision: D13574070
Pulled By: yiwu-arbug
fbshipit-source-id: a2a2aefcfd329c4c6a91652bf090aaf1ce119c4b
Summary:
- To be consistent with the accounting of other optypes in `TableProperties`, we should count range tombstones in `TableProperties::num_entries` and `TableProperties::num_deletions`.
- Updated assertions in stress test's `OnTableFileCreated` handler to accept files with range tombstones only.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4841
Differential Revision: D13568424
Pulled By: ajkr
fbshipit-source-id: 0139d7806494eda20ece67ec460d2458dbbf6026
Summary:
Avoid locking the DB mutex in order to reference SuperVersions. Instead, we get the thread local cached SuperVersion for each column family in the list. It depends on finding a sequence number that overlaps with all the open memtables. We start with the latest published sequence number, and if any of the memtables is sealed before we can get all the SuperVersions, the process is repeated. After a few times, give up and lock the DB mutex.
Tests:
1. Unit tests
2. make check
3. db_bench -
TEST_TMPDIR=/dev/shm ./db_bench -use_existing_db=true -benchmarks=readrandom -write_buffer_size=4194304 -target_file_size_base=4194304 -max_bytes_for_level_base=16777216 -num=5000000 -reads=1000000 -threads=32 -compression_type=none -cache_size=1048576000 -batch_size=1 -bloom_bits=1
readrandom : 0.167 micros/op 5983920 ops/sec; 426.2 MB/s (1000000 of 1000000 found)
Multireadrandom with batch size 1:
multireadrandom : 0.176 micros/op 5684033 ops/sec; (1000000 of 1000000 found)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4754
Differential Revision: D13363550
Pulled By: anand1976
fbshipit-source-id: 6243e8de7dbd9c8bb490a8eca385da0c855b1dd4
Summary:
Choose to preload some files if options.max_open_files != -1. This can slightly narrow the gap of performance between options.max_open_files is -1 and a large number. To avoid a significant regression to DB reopen speed if options.max_open_files != -1. Limit the files to preload in DB open time to 16.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3340
Differential Revision: D6686945
Pulled By: siying
fbshipit-source-id: 8ec11bbdb46e3d0cdee7b6ad5897a09c5a07869f
Summary:
Previously we were cleaning up range tombstone meta-block by calling `ReleaseCachedEntry`, which wouldn't work if `value != nullptr && cache_handle == nullptr`. This happened at least in the case with mmap reads and block cache both enabled. I noticed `NewDataBlockIterator` intends to handle all these cases, so migrated to that instead of `NewUnfragmentedRangeTombstoneIterator`.
Also changed the table-opening logic to fail on `ReadRangeDelBlock` failure, since that can cause data corruption. Added a test case to verify this behavior. Note the test case does not fail on `TryReopen` because failure to preload table handlers is not considered critical. However, it does fail on any read involving that file since it cannot return correct data.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4810
Differential Revision: D13534296
Pulled By: ajkr
fbshipit-source-id: 55dde1111717cea6ec4bf38418daab81ccef3599
Summary:
If one column family is dropped, we should simply skip it and continue to flush
other active ones.
Currently we use Status::ShutdownInProgress to notify caller of column families
being dropped. In the future, we should consider using a different Status code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4708
Differential Revision: D13378954
Pulled By: riversand963
fbshipit-source-id: 42f248cdf2d32d4c0f677cd39012694b8f1328ca
Summary:
1. DBImplReadOnly::GetLiveFiles should not return NotSupported. Instead, it
should call DBImpl::GetLiveFiles(flush_memtable=false).
2. In DBImp::Recover, we should also recover the OPTIONS file name and/or
number so that an immediate subsequent GetLiveFiles will get the correct
OPTIONS name.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4681
Differential Revision: D13069205
Pulled By: riversand963
fbshipit-source-id: 3e6a0174307d06db5a01feb099b306cea1f7f88a
Summary:
Transaction::GetForUpdate is extended with a do_validate parameter with default value of true. If false it skips validating the snapshot (if there is any) before doing the read. After the read it also returns the latest value (expects the ReadOptions::snapshot to be nullptr). This allows RocksDB applications to use GetForUpdate similarly to how InnoDB does. Similarly ::Merge, ::Put, ::Delete, and ::SingleDelete are extended with assume_exclusive_tracked with default value of false. It true it indicates that call is assumed to be after a ::GetForUpdate(do_validate=false).
The Java APIs are accordingly updated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4680
Differential Revision: D13068508
Pulled By: maysamyabandeh
fbshipit-source-id: f0b59db28f7f6a078b60844d902057140765e67d
Summary:
As titled. Update history to include a recent bug fix in
9be3e6b488.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4753
Differential Revision: D13350286
Pulled By: riversand963
fbshipit-source-id: b6324780dee4cb1757bc2209403a08531c150c08
Summary:
Full block (use_block_based_builder=false) Bloom filter has clear CPU saving benefits but with limitation of using temp memory when building an SST file proportional to the SST file size. We reduced the chance of having large SST files with multi-level universal compaction. Now we change to a default with better performance.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4735
Differential Revision: D13266674
Pulled By: siying
fbshipit-source-id: 7594a4c3e32568a5a2adce22bb0e46553e55c602
Summary:
Fix block based table reader not using memory_allocator when allocating index blocks and compression dictionary blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4678
Differential Revision: D13054594
Pulled By: yiwu-arbug
fbshipit-source-id: 379f25bcc665395662511c4f873f4b7b55104ce2
Summary:
DeleteRange is now ready for production use. Change the header comment to reflect this, and update HISTORY.md with the feature's status.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4709
Differential Revision: D13209055
Pulled By: abhimadan
fbshipit-source-id: 65423eb1a4927cf593c38254cd87c322f73ae137
Summary:
We haven't been populating `NO_FILE_CLOSES` since v1.5.8 even though it was never marked as deprecated. Start populating it again. Conveniently `DeleteTableReader` has an unused `void*` argument that we can use...
Blame: 63f216ee0aCloses#4700.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4703
Differential Revision: D13146769
Pulled By: ajkr
fbshipit-source-id: ad8d6fb0493e701f60a165a3bca1787d255be008
Summary:
…ons (#4676)"
This reverts commit b32d087dbb.
`MemoryAllocator` needs to be with `Cache`, since cache entry can
outlive DB and block based table. The cache needs to hold reference to
memory allocator when deleting cache entry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4697
Differential Revision: D13133490
Pulled By: yiwu-arbug
fbshipit-source-id: 8ef7e8a51263bfd929f892fd062665ff4ce9ce5a
Summary:
Since a range tombstone seen at one level will cover all keys
in the range at lower levels, there was a short-circuiting check in Get
that reported a key was not found at most one file after the range
tombstone was discovered. However, this was incorrect for merge
operands, since a deletion might only cover some merge operands,
which implies that the key should be found. This PR fixes this logic in
the Version portion of Get, and removes the logic from the MemTable
portion of Get, since the perforamnce benefit provided there is minimal.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4698
Differential Revision: D13142484
Pulled By: abhimadan
fbshipit-source-id: cbd74537c806032f2bfa564724d01a80df7c8f10
Summary:
Per offline discussion with siying, `MemoryAllocator` and `Cache` should be decouple. The idea is that memory allocator handles memory allocation, while cache handle cache policy.
It is normal that external cache libraries pack couple the two components for better optimization. If we want to integrate with such library in the future, we can make a wrapper of the library implementing both `Cache` and `MemoryAllocator` interface.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4676
Differential Revision: D13047662
Pulled By: yiwu-arbug
fbshipit-source-id: cd42e246d80ab600b4de47d073f7d2db308ce6dd
Summary:
Currently, `Statistics` can record tick by `recordTick()` whose second parameter is an `uint64_t`.
That means tick can only increase.
If we want to reduce tick, we have to work around like `RecordTick(statistics_, NO_ITERATORS, uint64_t(-1));`.
That's kind of a hack.
So, this PR divide `NO_ITERATORS` into two counters `NO_ITERATOR_CREATED` and `NO_ITERATOR_DELETE`, making the counters increase only.
Fixes#3013 .
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4498
Differential Revision: D10395010
Pulled By: sagar0
fbshipit-source-id: cfb523b22a37411c794b4e9da090f1ae30293db2
Summary:
Use the `DBOptions` that the backup engine already holds to figure out the right `EnvOptions` to use when reading the DB files. This means that, if a user opened a DB instance with `use_direct_reads=true`, then using `BackupEngine` to back up that DB instance will use direct I/O to read files when calculating checksums and copying. Currently the WALs and manifests would still be read using buffered I/O to prevent mixing direct I/O reads with concurrent buffered I/O writes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4640
Differential Revision: D13015268
Pulled By: ajkr
fbshipit-source-id: 77006ad6f3e00ce58374ca4793b785eea0db6269
Summary:
this PR adds two more per-level perf context counters to track
* number of keys returned in Get call, break down by levels
* total processing time at each level during Get call
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4617
Differential Revision: D12898024
Pulled By: miasantreble
fbshipit-source-id: 6b84ef1c8097c0d9e97bee1a774958f56ab4a6c4
Summary:
Move the line `Add xxhash64 checksum support` to `Unreleased` section because it has not been released to 5.17.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4627
Differential Revision: D12944123
Pulled By: riversand963
fbshipit-source-id: 2762857065b9e741c64ff8b6116ca62fe31891d8
Summary:
When evicting an entry form the commit_cache, it is verified against the list of old snapshots to see if it overlaps with any. The list of old snapshots is split into two lists: an efficient concurrent cache and an slow vector protected by a lock. The patch fixes a bug that would stop the search in the cache if it finds any and yet would not include the larger snapshots in the slower list.
An extra info log entry is also removed. The condition to trigger that although very rare is still feasible and should not spam the LOG when that happens.
Fixes#4621
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4639
Differential Revision: D12934989
Pulled By: maysamyabandeh
fbshipit-source-id: 4e0fe8147ba292b554ae78e94c21c2ef31e03e2d
Summary:
This property can help debug why SST files aren't being deleted. Previously we only had the property "rocksdb.is-file-deletions-enabled". However, even when that returned true, obsolete SSTs may still not be deleted due to the coarse-grained mechanism we use to prevent newly created SSTs from being accidentally deleted. That coarse-grained mechanism uses a lower bound file number for SSTs that should not be deleted, and this property exposes that lower bound.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4618
Differential Revision: D12898179
Pulled By: ajkr
fbshipit-source-id: fe68acc041ddbcc9276bbd48976524d95aafc776
Summary:
Since the number of range deletions are reported in
TableProperties, it is confusing to not report the number of merge
operands and point deletions as top-level properties; they are
accessible through the public API, but since they are not the "main"
properties, they do not appear in aggregated table properties, or the
string representation of table properties.
This change promotes those two property keys to
`rocksdb/table_properties.h`, adds corresponding uint64 members for
them, deprecates the old access methods `GetDeletedKeys()` and
`GetMergeOperands()` (though they are still usable for now), and removes
`InternalKeyPropertiesCollector`. The property key strings are the same
as before this change, so this should be able to read DBs written from older
versions (though I haven't tested this yet).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4594
Differential Revision: D12826893
Pulled By: abhimadan
fbshipit-source-id: 9e4e4fbdc5b0da161c89582566d184101ba8eb68
Summary:
Rename the interface, as it is mean to be a generic interface for memory allocation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4590
Differential Revision: D10866340
Pulled By: yiwu-arbug
fbshipit-source-id: 85cb753351a40cb856c046aeaa3f3b369eef3d16
Summary:
There was a bug that the user comparator would receive the internal key instead of the user key. The bug was due to RangeMightExistAfterSortedRun expecting user key but receiving internal key when called in GenerateBottommostFiles. The patch augment an existing unit test to reproduce the bug and fixes it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4575
Differential Revision: D10500434
Pulled By: maysamyabandeh
fbshipit-source-id: 858346d2fd102cce9e20516d77338c112bdfe366
Summary:
Level compaction usually performs poorly when the writes so heavy that the level targets can't be guaranteed. With this improvement, we improve level_compaction_dynamic_level_bytes = true so that in the write heavy cases, the level multiplier can be slightly adjusted based on the size of L0.
We keep the behavior the same if number of L0 files is under 2X compaction trigger and the total size is less than options.max_bytes_for_level_base, so that unless write is so heavy that compaction cannot keep up, the behavior doesn't change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4338
Differential Revision: D9636782
Pulled By: siying
fbshipit-source-id: e27fc17a7c29c84b00064cc17536a01dacef7595
Summary:
WriteBatchWithIndex's SeekForPrev() has a bug that we internally place the position just before the seek key rather than after. This makes the iterator to miss the result that is the same as the seek key. Fix it by position the iterator equal or smaller.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4559
Differential Revision: D10468534
Pulled By: siying
fbshipit-source-id: 2fb371ae809c561b60a1c11cef71e1c66fea1f19
Summary:
Current implementation of perf context is level agnostic. Making it hard to do performance evaluation for the LSM tree. This PR adds `PerfContextByLevel` to decompose the counters by level.
This will be helpful when analyzing point and range query performance as well as tuning bloom filter
Also replaced __thread with thread_local keyword for perf_context
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4226
Differential Revision: D10369509
Pulled By: miasantreble
fbshipit-source-id: f1ced4e0de5fcebdb7f9cff36164516bc6382d82
Summary:
When a CompactRange() call for a level is truncated before the end key
is reached, because it exceeds max_compaction_bytes, we need to properly
set the compaction_end parameter to indicate the stop key. The next
CompactRange will use that as the begin key. We set it to the smallest
key of the next file in the level after expanding inputs to get a clean
cut.
Previously, we were setting it before expanding inputs. So we could end
up recompacting some files. In a pathological case, where a single key
has many entries spanning all the files in the level (possibly due to
merge operands without a partial merge operator, thus resulting in
compaction output identical to the input), this would result in
an endless loop over the same set of files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4496
Differential Revision: D10395026
Pulled By: anand1976
fbshipit-source-id: f0c2f89fee29b4b3be53b6467b53abba8e9146a9
Summary:
`CompactionIterator::snapshots_` is ordered by ascending seqnum, just like `DBImpl`'s linked list of snapshots from which it was copied. This PR exploits this ordering to make `findEarliestVisibleSnapshot` do binary search rather than linear scan. This can make flush/compaction significantly faster when many snapshots exist since that function is called on every single key.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4495
Differential Revision: D10386470
Pulled By: ajkr
fbshipit-source-id: 29734991631227b6b7b677e156ac567690118a8b
Summary:
There is a bug when the write queue leader is blocked on a write
delay/stop, and the queue has writers with WriteOptions::no_slowdown set
to true. They are not woken up until the write stall is cleared.
The fix introduces a dummy writer inserted at the tail to indicate a
write stall and prevent further inserts into the queue, and a condition
variable that writers who can tolerate slowdown wait on before adding
themselves to the queue. The leader calls WriteThread::BeginWriteStall()
to add the dummy writer and then walk the queue to fail any writers with
no_slowdown set. Once the stall clears, the leader calls
WriteThread::EndWriteStall() to remove the dummy writer and signal the
condition variable.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4475
Differential Revision: D10285827
Pulled By: anand1976
fbshipit-source-id: 747465e5e7f07a829b1fb0bc1afcd7b93f4ab1a9
Summary:
The controller you requested could not be found. PTAL
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4466
Differential Revision: D10241358
Pulled By: yiwu-arbug
fbshipit-source-id: 99664eb286860a6c8844d50efeb0ef6f0e10dd1e
Summary:
This is a conceptually simple change, but it touches many files to
pass the allocator through function calls.
We introduce CacheAllocator, which can be used by clients to configure
custom allocator for cache blocks. Our motivation is to hook this up
with folly's `JemallocNodumpAllocator`
(f43ce6d686/folly/experimental/JemallocNodumpAllocator.h),
but there are many other possible use cases.
Additionally, this commit cleans up memory allocation in
`util/compression.h`, making sure that all allocations are wrapped in a
unique_ptr as soon as possible.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4437
Differential Revision: D10132814
Pulled By: yiwu-arbug
fbshipit-source-id: be1343a4b69f6048df127939fea9bbc96969f564
Summary:
Previously `CompactFiles` with `CompressionType::kDisableCompressionOption` caused program to crash on assertion failure. This PR fixes the crash by adding support for that setting. Now, that setting will cause RocksDB to choose compression according to the column family's options.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4438
Differential Revision: D10115761
Pulled By: ajkr
fbshipit-source-id: a553c6fa76fa5b6f73b0d165d95640da6f454122
Summary:
The default for index_block_restart_interval is 1 but some use 16 in production. The patch extends crash test to test both values.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4383
Differential Revision: D9887304
Pulled By: maysamyabandeh
fbshipit-source-id: a8d00fea974a79ad563f9f4d9d7b069e9f746a8f
Summary:
TransactionOptions::skip_concurrency_control allows pessimistic transactions to skip the overhead of concurrency control. This could be as an optimization if the application knows that the transaction would not have any conflict with concurrent transactions. It is currently used during recovery assuming (i) application guarantees no conflict between prepared transactions in the WAL (ii) application guarantees that recovered transactions will be rolled back/commit before new transactions start.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4346
Differential Revision: D9759149
Pulled By: maysamyabandeh
fbshipit-source-id: f896e84fa58b0b584be904c7fd3883a41ea3215b
Summary:
Basically at the moment it seems it's possible to cause write stall by calling flush (either manually vis DB::Flush(), or from Backup Engine directly calling FlushMemTable() while background flush may be already happening.
One of the ways to fix it is that in DBImpl::CompactRange() we already check for possible stall and delay flush if needed before we actually proceed to call FlushMemTable(). We can simply move this delay logic to separate method and call it from FlushMemTable.
This is draft patch, for first look; need to check tests/update SyncPoints and most certainly would need to add allow_write_stall method to FlushOptions().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4297
Differential Revision: D9420705
Pulled By: mikhail-antonov
fbshipit-source-id: f81d206b55e1d7b39e4dc64242fdfbceeea03fcc
Summary: For the CURRENT file forged during checkpoint, we were forgetting to `fsync` or `fdatasync` it after its creation. This PR fixes it.
Differential Revision: D9525939
Pulled By: ajkr
fbshipit-source-id: a505483644026ee3f501cfc0dcbe74832165b2e3
Summary:
I have a PR to start calling `OnTableFileCreated` for empty SSTs: #4307. However, it is a behavior change so should not go into a patch release.
This PR adds back a check to make sure range deletions at least exist before starting file creation. This PR should be safe to backport to earlier versions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4311
Differential Revision: D9493734
Pulled By: ajkr
fbshipit-source-id: f0d43cda4cfd904f133cfe3a6eb622f52a9ccbe8
Summary:
The API comment on `OnTableFileCreationStarted` (b6280d01f9/include/rocksdb/listener.h (L331-L333)) led users to believe a call to `OnTableFileCreationStarted` will always be matched with a call to `OnTableFileCreated`. However, we were skipping the `OnTableFileCreated` call in one case: no error happens but also no file is generated since there's no data.
This PR adds the call to `OnTableFileCreated` for that case. The filename will be "(nil)" and the size will be zero.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4307
Differential Revision: D9485201
Pulled By: ajkr
fbshipit-source-id: 2f077ec7913f128487aae2624c69a50762394df6
Summary:
ZSTD's dynamic library exports `ZDICT_trainFromBuffer` symbol since v1.1.3, and its static library exports it since v0.6.1. We don't know whether linkage is static or dynamic, so just require v1.1.3 to use dictionary trainer.
Fixes the issue reported here: https://jira.mariadb.org/browse/MDEV-16525.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4295
Differential Revision: D9417183
Pulled By: ajkr
fbshipit-source-id: 0e89d2f48d9e7f6eee73e7f4572660a9f7122db8
Summary:
Right now, `ldb idump` may have memory out of control if there is a big range of tombstones. Add an option to cut maxinum number of keys in GetAllKeyVersions(), and push down --max_num_ikeys from ldb.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4271
Differential Revision: D9369149
Pulled By: siying
fbshipit-source-id: 7cbb797b7d2fa16573495a7e84937456d3ff25bf
Summary:
This PR addresses issue #3865 and implements the following approach to fix it:
- adds `MergeContext::GetOperandsDirectionForward` and `MergeContext::GetOperandsDirectionBackward` to query merge operands in a specific order
- `MergeContext::GetOperands` becomes a shortcut for `MergeContext::GetOperandsDirectionForward`
- pass `MergeContext::GetOperandsDirectionBackward` to `MergeOperator::ShouldMerge` and document the order
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4266
Differential Revision: D9360750
Pulled By: sagar0
fbshipit-source-id: 20cb73ff017760b062ecdcf4382560767086e092
Summary:
Add hash index support to data blocks, which helps to reduce the CPU utilization of point-lookup operations. This feature is backward compatible with the data block created without the hash index. It is disabled by default unless `BlockBasedTableOptions::data_block_index_type` is set to `data_block_index_type = kDataBlockBinaryAndHash.`
The DB size would be bigger with the hash index option as a hash table is added at the end of each data block. If the hash utilization ratio is 1:1, the space overhead is one byte per key. The hash table utilization ratio is adjustable using `BlockBasedTableOptions::data_block_hash_table_util_ratio`. A lower utilization ratio will improve more on the point-lookup efficiency, but take more space too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4174
Differential Revision: D8965914
Pulled By: fgwu
fbshipit-source-id: 1c6bae5d1fc39c80282d8890a72e9e67bc247198
Summary:
A framework of trace analyzing for RocksDB
After collecting the trace by using the tool of [PR #3837](https://github.com/facebook/rocksdb/pull/3837). User can use the Trace Analyzer to interpret, analyze, and characterize the collected workload.
**Input:**
1. trace file
2. Whole keys space file
**Statistics:**
1. Access count of each operation (Get, Put, Delete, SingleDelete, DeleteRange, Merge) in each column family.
2. Key hotness (access count) of each one
3. Key space separation based on given prefix
4. Key size distribution
5. Value size distribution if appliable
6. Top K accessed keys
7. QPS statistics including the average QPS and peak QPS
8. Top K accessed prefix
9. The query correlation analyzing, output the number of X after Y and the corresponding average time
intervals
**Output:**
1. key access heat map (either in the accessed key space or whole key space)
2. trace sequence file (interpret the raw trace file to line base text file for future use)
3. Time serial (The key space ID and its access time)
4. Key access count distritbution
5. Key size distribution
6. Value size distribution (in each intervals)
7. whole key space separation by the prefix
8. Accessed key space separation by the prefix
9. QPS of each operation and each column family
10. Top K QPS and their accessed prefix range
**Test:**
1. Added the unit test of analyzing Get, Put, Delete, SingleDelete, DeleteRange, Merge
2. Generated the trace and analyze the trace
**Implemented but not tested (due to the limitation of trace_replay):**
1. Analyzing Iterator, supporting Seek() and SeekForPrev() analyzing
2. Analyzing the number of Key found by Get
**Future Work:**
1. Support execution time analyzing of each requests
2. Support cache hit situation and block read situation of Get
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4091
Differential Revision: D9256157
Pulled By: zhichao-cao
fbshipit-source-id: f0ceacb7eedbc43a3eee6e85b76087d7832a8fe6
Summary:
After refactoring in https://github.com/facebook/rocksdb/pull/4158 the properties block is written after the index block. This breaks the existing logic in estimating the index size in partitioned indexes. The patch fixes that by using the accurate index block size, which is available since by the time we write the properties block, the index block is already written.
The patch also fixes an issue in estimating the partition size with format_version=3 which was resulting into partitions smaller than the configured metadata_block_size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4259
Differential Revision: D9274454
Pulled By: maysamyabandeh
fbshipit-source-id: c82d045505cca3e7ed1a44ee1eaa26e4f25a4272
Summary:
Given that index value is a BlockHandle, which is basically an <offset, size> pair we can apply delta encoding on the values. The first value at each index restart interval encoded the full BlockHandle but the rest encode only the size. Refer to IndexBlockIter::DecodeCurrentValue for the detail of the encoding. This reduces the index size which helps using the block cache more efficiently. The feature is enabled with using format_version 4.
The feature comes with a bit of cpu overhead which should be paid back by the higher cache hits due to smaller index block size.
Results with sysbench read-only using 4k blocks and using 16 index restart interval:
Format 2:
19585 rocksdb read-only range=100
Format 3:
19569 rocksdb read-only range=100
Format 4:
19352 rocksdb read-only range=100
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3983
Differential Revision: D8361343
Pulled By: maysamyabandeh
fbshipit-source-id: f882ee082322acac32b0072e2bdbb0b5f854e651
Summary:
Given that we have cut 5.15, we should bump the version number to the next
version, i.e. 5.16.
Also update HISTORY.md
cc sagar0
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4176
Differential Revision: D8977965
Pulled By: riversand963
fbshipit-source-id: 481d75d2f446946f0eb2afb7e94ef894c8c87e1e
Summary:
Fix the issue when pipelined write is enabled, writers can get stuck indefinitely and not able to finish the write. It can show with the following example: Assume there are 4 writers W1, W2, W3, W4 (W1 is the first, W4 is the last).
T1: all writers pending in WAL writer queue:
WAL writer queue: W1, W2, W3, W4
memtable writer queue: empty
T2. W1 finish WAL writer and move to memtable writer queue:
WAL writer queue: W2, W3, W4,
memtable writer queue: W1
T3. W2 and W3 finish WAL write as a batch group. W2 enter ExitAsBatchGroupLeader and move the group to memtable writer queue, but before wake up next leader.
WAL writer queue: W4
memtable writer queue: W1, W2, W3
T4. W1, W2, W3 finish memtable write as a batch group. Note that W2 still in the previous ExitAsBatchGroupLeader, although W1 have done memtable write for W2.
WAL writer queue: W4
memtable writer queue: empty
T5. The thread corresponding to W3 create another writer W3' with the same address as W3.
WAL writer queue: W4, W3'
memtable writer queue: empty
T6. W2 continue with ExitAsBatchGroupLeader. Because the address of W3' is the same as W3, the last writer in its group, it thinks there are no pending writers, so it reset newest_writer_ to null, emptying the queue. W4 and W3' are deleted from the queue and will never be wake up.
The issue exists since pipelined write was introduced in 5.5.0.
Closes#3704
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4143
Differential Revision: D8871599
Pulled By: yiwu-arbug
fbshipit-source-id: 3502674e51066a954a0660257e24ac588f815e2a
Summary:
Now by default, with NewSstFileManager, checkpoints may be corrupted. Disable this feature to avoid this issue.
Closes https://github.com/facebook/rocksdb/pull/4092
Differential Revision: D8729856
Pulled By: siying
fbshipit-source-id: 914c321d6eaf52d8c5981171322d85dd29088307
Summary:
…ression
For `CompressionType` we have options `compression` and `bottommost_compression`. Thus, to make the compression options consitent with the compression type when bottommost_compression is enabled, we add the bottommost_compression_opts
Closes https://github.com/facebook/rocksdb/pull/3985
Reviewed By: riversand963
Differential Revision: D8385911
Pulled By: zhichao-cao
fbshipit-source-id: 07bc533dd61bcf1cef5927d8d62901c13d38d5fc
Summary:
https://github.com/facebook/rocksdb/pull/3881 fixed a bug where PinnableSlice pin mmap files which could be deleted with background compaction. This is however a non-issue for ReadOnlyDB when there is no compaction running and max_open_files is -1. This patch reenables the pinning feature for that case.
Closes https://github.com/facebook/rocksdb/pull/4053
Differential Revision: D8662546
Pulled By: maysamyabandeh
fbshipit-source-id: 402962602eb0f644e17822748332999c3af029fd
Summary:
Add a new table property, rocksdb.num.range-deletions, which tracks the
number of range deletions in a block-based table. Range deletions are no
longer counted in rocksdb.num.entries; as discovered in PR #3778, there
are various code paths that implicitly assume that rocksdb.num.entries
counts only true keys, not range deletions.
/cc ajkr nvanbenschoten
Closes https://github.com/facebook/rocksdb/pull/4016
Differential Revision: D8527575
Pulled By: ajkr
fbshipit-source-id: 92e7edbe78fda53756a558013c9fb496e7764fd7
Summary:
Top-level index in partitioned index/filter blocks are small and could be pinned in memory. So far we use that by cache_index_and_filter_blocks to false. This however make it difficult to keep account of the total memory usage. This patch introduces pin_top_level_index_and_filter which in combination with cache_index_and_filter_blocks=true keeps the top-level index in cache and yet pinned them to avoid cache misses and also cache lookup overhead.
Closes https://github.com/facebook/rocksdb/pull/4037
Differential Revision: D8596218
Pulled By: maysamyabandeh
fbshipit-source-id: 3a5f7f9ca6b4b525b03ff6bd82354881ae974ad2
Summary:
This PR extends the improvements in #3282 to also work when using Direct IO.
We see **4.5X performance improvement** in seekrandom benchmark doing long range scans, when using direct reads, on flash.
**Description:**
This change improves the performance of iterators doing long range scans (e.g. big/full index or table scans in MyRocks) by using readahead and prefetching additional data on each disk IO, and storing in a local buffer. This prefetching is automatically enabled on noticing more than 2 IOs for the same table file during iteration. The readahead size starts with 8KB and is exponentially increased on each additional sequential IO, up to a max of 256 KB. This helps in cutting down the number of IOs needed to complete the range scan.
**Implementation Details:**
- Used `FilePrefetchBuffer` as the underlying buffer to store the readahead data. `FilePrefetchBuffer` can now take file_reader, readahead_size and max_readahead_size as input to the constructor, and automatically do readahead.
- `FilePrefetchBuffer::TryReadFromCache` can now call `FilePrefetchBuffer::Prefetch` if readahead is enabled.
- `AlignedBuffer` (which is the underlying store for `FilePrefetchBuffer`) now takes a few additional args in `AlignedBuffer::AllocateNewBuffer` to allow copying data from the old buffer.
- Made sure not to re-read partial chunks of data that were already available in the buffer, from device again.
- Fixed a couple of cases where `AlignedBuffer::cursize_` was not being properly kept up-to-date.
**Constraints:**
- Similar to #3282, this gets currently enabled only when ReadOptions.readahead_size = 0 (which is the default value).
- Since the prefetched data is stored in a temporary buffer allocated on heap, this could increase the memory usage if you have many iterators doing long range scans simultaneously.
- Enabled only for user reads, and disabled for compactions. Compaction reads are controlled by the options `use_direct_io_for_flush_and_compaction` and `compaction_readahead_size`, and the current feature takes precautions not to mess with them.
**Benchmarks:**
I used the same benchmark as used in #3282.
Data fill:
```
TEST_TMPDIR=/data/users/$USER/benchmarks/iter ./db_bench -benchmarks=fillrandom -num=1000000000 -compression_type="none" -level_compaction_dynamic_level_bytes
```
Do a long range scan: Seekrandom with large number of nexts
```
TEST_TMPDIR=/data/users/$USER/benchmarks/iter ./db_bench -benchmarks=seekrandom -use_direct_reads -duration=60 -num=1000000000 -use_existing_db -seek_nexts=10000 -statistics -histogram
```
```
Before:
seekrandom : 37939.906 micros/op 26 ops/sec; 29.2 MB/s (1636 of 1999 found)
With this change:
seekrandom : 8527.720 micros/op 117 ops/sec; 129.7 MB/s (6530 of 7999 found)
```
~4.5X perf improvement. Taken on an average of 3 runs.
Closes https://github.com/facebook/rocksdb/pull/3884
Differential Revision: D8082143
Pulled By: sagar0
fbshipit-source-id: 4d7a8561cbac03478663713df4d31ad2620253bb
Summary:
https://github.com/facebook/rocksdb/pull/3764 introduced an optimization feature to skip duplicate prefix entires in full bloom filters. Unfortunately it also introduces a bug in partitioned full filters, where the duplicate prefix should still be inserted if it is in a new partition. The patch fixes the bug by resetting the duplicate detection logic each time a partition is cut.
This bug could result into false negatives, which means that DB could skip an existing key.
Closes https://github.com/facebook/rocksdb/pull/4024
Differential Revision: D8518866
Pulled By: maysamyabandeh
fbshipit-source-id: 044f4d988e606a330ecafd8c79daceb68b8796bf
Summary:
For iterator reads, a `SuperVersion` is pinned to preserve a snapshot of SST files, and `Block`s are pinned to allow `key()` and `value()` to return pointers directly into a RocksDB memory region. This works for both non-mmap reads, where the block owns the memory region, and mmap reads, where the file owns the memory region.
For point reads with `PinnableSlice`, only the `Block` object is pinned. This works for non-mmap reads because the block owns the memory region, so even if the file is deleted after compaction, the memory region survives. However, for mmap reads, file deletion causes the memory region to which the `PinnableSlice` refers to be unmapped. The result is usually a segfault upon accessing the `PinnableSlice`, although sometimes it returned wrong results (I repro'd this a bunch of times with `db_stress`).
This PR copies the value into the `PinnableSlice` when it comes from mmap'd memory. We can tell whether the `Block` owns its memory using `Block::cachable()`, which is unset when reads do not use the provided buffer as is the case with mmap file reads. When that is false we ensure the result of `Get()` is copied.
This feels like a short-term solution as ideally we'd have the `PinnableSlice` pin the mmap'd memory so we can do zero-copy reads. It seemed hard so I chose this approach to fix correctness in the meantime.
Closes https://github.com/facebook/rocksdb/pull/3881
Differential Revision: D8076288
Pulled By: ajkr
fbshipit-source-id: 31d78ec010198723522323dbc6ea325122a46b08
Summary:
Index blocks have the same format as data blocks. The keys therefore similarly to the keys in the data blocks are internal keys, which means that in addition to the user key it also has 8 bytes that encodes sequence number and value type. This extra 8 bytes however is not necessary in index blocks since the index keys act as an separator between two data blocks. The only exception is when the last key of a block and the first key of the next block share the same user key, in which the sequence number is required to act as a separator.
The patch excludes the sequence from index keys only if the above special case does not happen for any of the index keys. It then records that in the property block. The reader looks at the property block to see if it should expect sequence numbers in the keys of the index block.s
Closes https://github.com/facebook/rocksdb/pull/3894
Differential Revision: D8118775
Pulled By: maysamyabandeh
fbshipit-source-id: 915479f028b5799ca91671d67455ecdefbd873bd
