Summary:
RocksDB's `Cache` abstraction currently supports two priority levels for items: high (used for frequently accessed/highly valuable SST metablocks like index/filter blocks) and low (used for SST data blocks). Blobs are typically lower-value targets for caching than data blocks, since 1) with BlobDB, data blocks containing blob references conceptually form an index structure which has to be consulted before we can read the blob value, and 2) cached blobs represent only a single key-value, while cached data blocks generally contain multiple KVs. Since we would like to make it possible to use the same backing cache for the block cache and the blob cache, it would make sense to add a new, lower-than-low cache priority level (bottom level) for blobs so data blocks are prioritized over them.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10309
Reviewed By: ltamasi
Differential Revision: D38211655
Pulled By: gangliao
fbshipit-source-id: 65ef33337db4d85277cc6f9782d67c421ad71dd5
Summary:
Allow sufficient subcompactions can be used when the number of input files is less than `max_subcompactions` under round-robin compaction priority.
Test Case:
Add `RoundRobinWithoutAdditionalResources` into `db_compaction_test`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10422
Reviewed By: ajkr
Differential Revision: D38186545
Pulled By: littlepig2013
fbshipit-source-id: b8e5098306f1e5b9561dfafafc8300a38f7fe88e
Summary:
Make the Stale Flush test more robust by explicitly checking the target CF is
flushed. Currently it's flaky because the default CF may have more than 3
SSTs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10409
Test Plan:
the test more likely to fail on a resource limited host:
```
gtest-parallel ./column_family_test --gtest_filter=FormatDef/ColumnFamilyTest.FlushStaleColumnFamilies/0 -r 1000 -w 100
```
Reviewed By: ajkr
Differential Revision: D38116383
Pulled By: jay-zhuang
fbshipit-source-id: e27cc56f76f14d0936504f126104e3d87e3d0d5f
Summary:
If WAL compression is enabled, WAL fragment decompression results are concatenated together in `log::Reader::ReadPhysicalRecord()`. This PR adds checksum handshake to protect memory corruption during the copying process.
`checksum` is renamed to `record_checksum` in `ReadRecord()` to differentiate it from `checksum_` flag that specifies whether CRC32C checksum is verified.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10339
Test Plan: added checksum verification in log_test.cc, `make check -j32`.
Reviewed By: ajkr
Differential Revision: D37763734
Pulled By: cbi42
fbshipit-source-id: c4faa7c76b9ff1df35026edf31adfe4b47ae3154
Summary:
Earlier implementation of round-robin priority can only pick one file at a time and disallows parallel compactions within the same level. In this PR, round-robin compaction policy will expand towards more input files with respecting some additional constraints, which are summarized as follows:
* Constraint 1: We can only pick consecutive files
- Constraint 1a: When a file is being compacted (or some input files are being compacted after expanding), we cannot choose it and have to stop choosing more files
- Constraint 1b: When we reach the last file (with the largest keys), we cannot choose more files (the next file will be the first one with small keys)
* Constraint 2: We should ensure the total compaction bytes (including the overlapped files from the next level) is no more than `mutable_cf_options_.max_compaction_bytes`
* Constraint 3: We try our best to pick as many files as possible so that the post-compaction level size can be just less than `MaxBytesForLevel(start_level_)`
* Constraint 4: If trivial move is allowed, we reuse the logic of `TryNonL0TrivialMove()` instead of expanding files with Constraint 3
More details can be found in `LevelCompactionBuilder::SetupOtherFilesWithRoundRobinExpansion()`.
The above optimization accelerates the process of moving the compaction cursor, in which the write-amp can be further reduced. While a large compaction may lead to high write stall, we break this large compaction into several subcompactions **regardless of** the `max_subcompactions` limit. The number of subcompactions for round-robin compaction priority is determined through the following steps:
* Step 1: Initialized against `max_output_file_limit`, the number of input files in the start level, and also the range size limit `ranges.size()`
* Step 2: Call `AcquireSubcompactionResources()`when max subcompactions is not sufficient, but we may or may not obtain desired resources, additional number of resources is stored in `extra_num_subcompaction_threads_reserved_`). Subcompaction limit is changed and update `num_planned_subcompactions` with `GetSubcompactionLimit()`
* Step 3: Call `ShrinkSubcompactionResources()` to ensure extra resources can be released (extra resources may exist for round-robin compaction when the number of actual number of subcompactions is less than the number of planned subcompactions)
More details can be found in `CompactionJob::AcquireSubcompactionResources()`,`CompactionJob::ShrinkSubcompactionResources()`, and `CompactionJob::ReleaseSubcompactionResources()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10341
Test Plan: Add `CompactionPriMultipleFilesRoundRobin[1-3]` unit test in `compaction_picker_test.cc` and `RoundRobinSubcompactionsAgainstResources.SubcompactionsUsingResources/[0-4]`, `RoundRobinSubcompactionsAgainstPressureToken.PressureTokenTest/[0-1]` in `db_compaction_test.cc`
Reviewed By: ajkr, hx235
Differential Revision: D37792644
Pulled By: littlepig2013
fbshipit-source-id: 7fecb7c4ffd97b34bbf6e3b760b2c35a772a0657
Summary:
Unit tests still haven't been fixed. Also need to add more tests. But I ran some simple fillrandom db_bench and the partitioning feels reasonable.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10393
Test Plan:
1. Make sure existing tests pass. This should cover some basic sub compaction logic to be correct and the partitioning result is reasonable;
2. Add a new unit test to ApproximateKeyAnchors()
3. Run some db_bench with max_subcompaction = 4 and watch the compaction is indeed partitioned evenly.
Reviewed By: jay-zhuang
Differential Revision: D38043783
fbshipit-source-id: 085008e0f85f9b7c5abff7800307618320efb19f
Summary:
Travis CI is depreciated and haven't been maintained for some time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10407
Reviewed By: ajkr
Differential Revision: D38078382
Pulled By: jay-zhuang
fbshipit-source-id: f42057f2f41f722bdce56bf195f67a94835191fb
Summary:
Minor issue, I just found a few typos on db_test and column_family while reading the code. And I have this PR opened to contribute. :)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10139
Reviewed By: ajkr
Differential Revision: D38007098
Pulled By: jay-zhuang
fbshipit-source-id: 511947b32424c34348184691216640f32c410fb1
Summary:
Previously the "Fragmentation" test didn't cover fragmentation because the WAL data was compressible into trivial size. This PR changes it to use random data so the post-compression size is large enough to require fragmentation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10402
Reviewed By: cbi42
Differential Revision: D38065596
Pulled By: ajkr
fbshipit-source-id: 0d5f89ca14d33546501a74b5d4fafbadc28a46a7
Summary:
GCC-12 has strick check on variables, and thus
build fails when it finds read_req is not properly
initialized (-Werror=maybe-uninitialized). Add
default value to fix this.
Change-Id: Ib8a9085e2d613ee7b943b58a6a58e1bc351725d7
Signed-off-by: Jun He <jun.he@arm.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10312
Reviewed By: riversand963
Differential Revision: D37656997
Pulled By: ajkr
fbshipit-source-id: fe47492c913b34b3a03c04beeec9ec57831dcaff
Summary:
## Problem Summary
RocksDB will acquire the global mutex of db instance for every time when user calls `Write`. When RocksDB schedules a lot of compaction jobs, it will compete the mutex with write thread and it will hurt the write performance.
## Problem Solution:
I want to use log_write_mutex to replace the global mutex in most case so that we do not acquire it in write-thread unless there is a write-stall event or a write-buffer-full event occur.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7516
Test Plan:
1. make check
2. CI
3. COMPILE_WITH_TSAN=1 make db_stress
make crash_test
make crash_test_with_multiops_wp_txn
make crash_test_with_multiops_wc_txn
make crash_test_with_atomic_flush
Reviewed By: siying
Differential Revision: D36908702
Pulled By: riversand963
fbshipit-source-id: 59b13881f4f5c0a58fd3ca79128a396d9cd98efe
Summary:
To help service owners to manage their memory budget effectively, we have been working towards counting all major memory users inside RocksDB towards a single global memory limit (see e.g. https://github.com/facebook/rocksdb/wiki/Write-Buffer-Manager#cost-memory-used-in-memtable-to-block-cache). The global limit is specified by the capacity of the block-based table's block cache, and is technically implemented by inserting dummy entries ("reservations") into the block cache. The goal of this task is to support charging the memory usage of the new blob cache against this global memory limit when the backing cache of the blob cache and the block cache are different.
This PR is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10321
Reviewed By: ltamasi
Differential Revision: D37913590
Pulled By: gangliao
fbshipit-source-id: eaacf23907f82dc7d18964a3f24d7039a2937a72
Summary:
`PeriodicWorkScheduler` is a global singleton, which were used to store per-instance setting `record_seqno_time_cadence_`. Move that to db_impl.h which is per-instance.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10383
Reviewed By: siying
Differential Revision: D37928009
Pulled By: jay-zhuang
fbshipit-source-id: e517754f4a9db98798ac04f72033d4b517f734e9
Summary:
(PR created for informational/testing purposes only.)
- Fixes lost dynamic updates to GenericRateLimiter bandwidth using `SetBytesPerSecond()`
- Benefit over #10374 is eliminating race conditions with Configurable framework.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10378
Reviewed By: pdillinger
Differential Revision: D37914865
fbshipit-source-id: d4f566d60ec9726d26932388c61671adf0ee0f30
Summary:
Many workloads have temporal locality, where recently written items are read back in a short period of time. When using remote file systems, this is inefficient since it involves network traffic and higher latencies. Because of this, we would like to support prepopulating the blob cache during flush.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10298
Reviewed By: ltamasi
Differential Revision: D37908743
Pulled By: gangliao
fbshipit-source-id: 9feaed234bc719d38f0c02975c1ad19fa4bb37d1
Summary:
I add C API
db/c.cc
rocksdb_sstfilewriter_delete_range
and test it , PASS.
can you review it ? ajkr
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10314
Reviewed By: riversand963
Differential Revision: D37657236
Pulled By: ajkr
fbshipit-source-id: c3b758daa36fbd9133210b011716914dff311278
Summary:
RocksDB supports a two-level cache hierarchy (see https://rocksdb.org/blog/2021/05/27/rocksdb-secondary-cache.html), where items evicted from the primary cache can be spilled over to the secondary cache, or items from the secondary cache can be promoted to the primary one. We have a CacheLib-based non-volatile secondary cache implementation that can be used to improve read latencies and reduce the amount of network bandwidth when using distributed file systems. In addition, we have recently implemented a compressed secondary cache that can be used as a replacement for the OS page cache when e.g. direct I/O is used. The goals of this task are to add support for using a secondary cache with the blob cache and to measure the potential performance gains using `db_bench`.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10349
Reviewed By: ltamasi
Differential Revision: D37896773
Pulled By: gangliao
fbshipit-source-id: 7804619ce4a44b73d9e11ad606640f9385969c84
Summary:
Using the Sequence number to time mapping to decide if a key is hot or not in
compaction and place it in the corresponding level.
Note: the feature is not complete, level compaction will run indefinitely until
all penultimate level data is cold and small enough to not trigger compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10370
Test Plan:
CI
* Run basic db_bench for universal compaction manually
Reviewed By: siying
Differential Revision: D37892338
Pulled By: jay-zhuang
fbshipit-source-id: 792bbd91b1ccc2f62b5d14c53118434bcaac4bbe
Summary:
Which will be used for tiered storage to preclude hot data from
compacting to the cold tier (the last level).
Internally, adding seqno to time mapping. A periodic_task is scheduled
to record the current_seqno -> current_time in certain cadence. When
memtable flush, the mapping informaiton is stored in sstable property.
During compaction, the mapping information are merged and get the
approximate time of sequence number, which is used to determine if a key
is recently inserted or not and preclude it from the last level if it's
recently inserted (within the `preclude_last_level_data_seconds`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10338
Test Plan: CI
Reviewed By: siying
Differential Revision: D37810187
Pulled By: jay-zhuang
fbshipit-source-id: 6953be7a18a99de8b1cb3b162d712f79c2b4899f
Summary:
InternalKeyComparator is an internal class which is a simple wrapper of Comparator. https://github.com/facebook/rocksdb/pull/8336 made Comparator customizeable. As a side effect, internal key comparator was made configurable too. This introduces overhead to this simple wrapper. For example, every InternalKeyComparator will have an std::vector attached to it, which consumes memory and possible allocation overhead too.
We remove InternalKeyComparator from being customizable by making InternalKeyComparator not a subclass of Comparator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10342
Test Plan: Run existing CI tests and make sure it doesn't fail
Reviewed By: riversand963
Differential Revision: D37771351
fbshipit-source-id: 917256ee04b2796ed82974549c734fb6c4d8ccee
Summary:
Support per_key_placement for last level compaction, which will
be used for tiered compaction.
* compaction iterator reports which level a key should output to;
* compaction get the output level information and check if it's safe to
output the data to penultimate level;
* all compaction output files will be installed.
* extra internal compaction stats added for penultimate level.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9964
Test Plan:
* Unittest
* db_bench, no significate difference: https://gist.github.com/jay-zhuang/3645f8fb97ec0ab47c10704bb39fd6e4
* microbench manual compaction no significate difference: https://gist.github.com/jay-zhuang/ba679b3e89e24992615ee9eef310e6dd
* run the db_stress multiple times (not covering the new feature) looks good (internal: https://fburl.com/sandcastle/9w84pp2m)
Reviewed By: ajkr
Differential Revision: D36249494
Pulled By: jay-zhuang
fbshipit-source-id: a96da57c8031c1df83e4a7a8567b657a112b80a3
Summary:
Enabled zstd checksum flag in StreamingCompress so that WAL (de)compreression is protected by a checksum per compression frame.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10319
Test Plan:
- `make check`
- WAL perf: average ops/sec over 10 runs is 161226 pre PR and 159635 post PR (1% drop).
```
sudo TEST_TMPDIR=/dev/shm/memtable_write ./db_bench_checksum -benchmarks=fillseq -max_write_buffer_number=100 -num=1000000 -min_write_buffer_number_to_merge=10 -wal_compression=zstd
```
Reviewed By: ajkr
Differential Revision: D37673311
Pulled By: cbi42
fbshipit-source-id: 9f34a3bfc2a82e5c80b1ec63bb339a7465108ec9
Summary:
ClockCache is still in experimental stage, and currently fails some pre-release fbcode tests. See https://www.internalfb.com/diff/D37772011. API calls to construct ClockCache are done via the function NewClockCache. For now, NewClockCache calls will return an LRUCache (with appropriate arguments), which is stable.
The idea that NewClockCache returns nullptr was also floated, but this would be interpreted as unsupported cache, and a default LRUCache would be constructed instead, potentially causing a performance regression that is harder to identify.
A new version of the NewClockCache function was created for our internal tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10351
Test Plan: ``make -j24 check`` and re-run the pre-release tests.
Reviewed By: pdillinger
Differential Revision: D37802685
Pulled By: guidotag
fbshipit-source-id: 0a8d10612ff21e576f7360cb13e20bc36e244972
Summary:
InternalKeyComparator is a thin wrapper around user comparator. Storing a string for name is relatively expensive to this small wrapper for both CPU and memory usage. Try to remove it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10343
Test Plan: Run existing tests
Reviewed By: ajkr
Differential Revision: D37772469
fbshipit-source-id: d2d106a8d022193058fd7f6b220108e3d94aca34
Summary:
The blob cache enables an optimization on the read path: when a blob is found in the cache, we can avoid copying it into the buffer provided by the application. Instead, we can simply transfer ownership of the cache handle to the target `PinnableSlice`. (Note: this relies on the `Cleanable` interface, which is implemented by `PinnableSlice`.)
This has the potential to save a lot of CPU, especially with large blob values.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10297
Reviewed By: riversand963
Differential Revision: D37640311
Pulled By: gangliao
fbshipit-source-id: 92de0e35cc703d06c87c5c1861cc2899ec52234a
Summary:
Earlier implementation of cutting the output files with a compact cursor under Round-Robin priority uses `Valid()` to determine if the `output_split_key` is valid in `ShouldStopBefore`. This contributes to excessive CPU computation, as pointed out by [this issue](https://github.com/facebook/rocksdb/issues/10315). In this PR, we change the type of `output_split_key` to be `InternalKey*` and set it as `nullptr` if it is not going to be used in `ShouldStopBefore`, `Valid()` condition checking can be avoided using that pointer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10316
Reviewed By: ajkr
Differential Revision: D37661492
Pulled By: littlepig2013
fbshipit-source-id: 66ff1105f3378e5573d3a126fdaff9bb23b5498f
Summary:
I noticed it would clean up some things to have Cache::Insert()
return our MemoryLimit Status instead of Incomplete for the case in
which the capacity limit is reached. I suspect this fixes some existing but
unknown bugs where this Incomplete could be confused with other uses
of Incomplete, especially no_io cases. This is the most suspicious case I
noticed, but was not able to reproduce a bug, in part because the existing
code is not covered by unit tests (FIXME added): 57adbf0e91/table/get_context.cc (L397)
I audited all the existing uses of IsIncomplete and updated those that
seemed relevant.
HISTORY updated with a clear warning to users of strict_capacity_limit=true
to update uses of `IsIncomplete()`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10262
Test Plan: updated unit tests
Reviewed By: hx235
Differential Revision: D37473155
Pulled By: pdillinger
fbshipit-source-id: 4bd9d9353ccddfe286b03ebd0652df8ce20f99cb
Summary:
In leveled compaction, try to trivial move more than one files if possible, up to 4 files or max_compaction_bytes. This is to allow higher write throughput for some use cases where data is loaded in sequential order, where appying compaction results is the bottleneck.
When pick up a file to compact and it doesn't have overlapping files in the next level, try to expand to the next file if there is still no overlapping.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10190
Test Plan:
Add some unit tests.
For performance, Try to run
./db_bench_multi_move --benchmarks=fillseq --compression_type=lz4 --write_buffer_size=5000000 --num=100000000 --value_size=1000 -level_compaction_dynamic_level_bytes
Together with https://github.com/facebook/rocksdb/pull/10188 , stalling will be eliminated in this benchmark.
Reviewed By: jay-zhuang
Differential Revision: D37230647
fbshipit-source-id: 42b260f545c46abc5d90335ac2bbfcd09602b549
Summary:
Before this PR, it is required that application open RocksDB secondary
instance with `max_open_files = -1`. This is a hacky workaround that
prevents IOErrors on the seconary instance during point-lookup or range
scan caused by primary instance deleting the table files. This is not
necessary if the application can coordinate the primary and secondaries
so that primary does not delete files that are still being used by the
secondaries. Or users can provide a custom Env/FS implementation that
deletes the files only after all primary and secondary instances
indicate files are obsolete and deleted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10260
Test Plan: make check
Reviewed By: jay-zhuang
Differential Revision: D37462633
Pulled By: riversand963
fbshipit-source-id: 9c2fc939f49663efa61e3d60c8f1e01d64b9d72c
Summary:
In leveled compaction, L0->L1 trivial move will allow more than one file to be moved in one compaction. This would allow L0 files to be moved down faster when data is loaded in sequential order, making slowdown or stop condition harder to hit. Also seek L0->L1 trivial move when only some files qualify.
1. We always try to find L0->L1 trivial move from the oldest files. Keep including newer files, until adding a new file won't trigger a trivial move
2. Modify the trivial move condition so that this compaction would be tagged as trivial move.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10188
Test Plan:
See throughput improvements with db_bench with fast fillseq benchmark and small L0 files:
./db_bench_l0_move --benchmarks=fillseq --compression_type=lz4 --write_buffer_size=5000000 --num=100000000 --value_size=1000 -level_compaction_dynamic_level_bytes
The throughput improved by about 50%. Stalling still happens though.
Reviewed By: jay-zhuang
Differential Revision: D37224743
fbshipit-source-id: 8958d97f22e12bdfc14d2e85930f6fa0070e9659
Summary:
In round-robin compaction priority, when splitting the compaction into sub-compactions, the earlier implementation takes into account the compact cursor to have full use of available sub-compactions. But this may result in unbalanced sub-compactions, so we remove this here. The removal does not affect the cursor-based splitting mechanism within a sub-compaction, and thus the output files are still ensured to be split according to the cursor.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10289
Reviewed By: ajkr
Differential Revision: D37559091
Pulled By: littlepig2013
fbshipit-source-id: b8b45b99f63b09cf873f7f049bcb4ab13871fffc
Summary:
The current level targets for dynamical leveling has a problem: the target level size will dramatically change after a L0->L1 compaction. When there are many L0 bytes, lower level compactions are delayed, but they will be resumed after the L0->L1 compaction finishes, so the expected write amplification benefits might not be realized. The proposal here is to revert the level targetting size, but instead relying on adjusting score for each level to prioritize levels that need to compact most.
Basic idea:
(1) target level size isn't adjusted, but score is adjusted. The reasoning is that with parallel compactions, holding compactions from happening might not be desirable, but we would like the compactions are scheduled from the level we feel most needed. For example, if we have a extra-large L2, we would like all compactions are scheduled for L2->L3 compactions, rather than L4->L5. This gets complicated when a large L0->L1 compaction is going on. Should we compact L2->L3 or L4->L5. So the proposal for that is:
(2) the score is calculated by actual level size / (target size + estimated upper bytes coming down). The reasoning is that if we have a large amount of pending L0/L1 bytes coming down, compacting L2->L3 might be more expensive, as when the L0 bytes are compacted down to L2, the actual L2->L3 fanout would change dramatically. On the other hand, when the amount of bytes coming down to L5, the impacts to L5->L6 fanout are much less. So when calculating target score, we can adjust it by adding estimated downward bytes to the target level size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10057
Test Plan: Repurpose tests VersionStorageInfoTest.MaxBytesForLevelDynamicWithLargeL0_* tests to cover this scenario.
Reviewed By: ajkr
Differential Revision: D37539742
fbshipit-source-id: 9c154cbfe92023f918cf5d80875d8776ad4831a4
Summary:
- [x] Enabled blob caching for MultiGetBlob in RocksDB
- [x] Refactored MultiGetBlob logic and interface in RocksDB
- [x] Cleaned up Version::MultiGetBlob() and moved 'blob'-related code snippets into BlobSource
- [x] Add End-to-end test cases in db_blob_basic_test and also add unit tests in blob_source_test
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10272
Reviewed By: ltamasi
Differential Revision: D37558112
Pulled By: gangliao
fbshipit-source-id: a73a6a94ffdee0024d5b2a39e6d1c1a7d38664db
Summary:
Add load_latest_options() to C api.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10152
Test Plan:
Extend the existing c_test by reopening db using the latest options file
at different parts of the test.
Reviewed By: akankshamahajan15
Differential Revision: D37305225
Pulled By: ajkr
fbshipit-source-id: 8b3bab73f56fa6fcbdba45aae393145d007b3962
Summary:
If the internal iterator is not valid, `SeekToLast` with iter_start_ts should have `valid_` is false without assertion failure.
Test plan
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10279
Reviewed By: ltamasi
Differential Revision: D37539393
Pulled By: riversand963
fbshipit-source-id: 8e94057838f8a05144fad5768f4d62f1893ec315
Summary:
This is the initial step in the development of a lock-free clock cache. This PR includes the base hash table design (which we mostly ported over from FastLRUCache) and the clock eviction algorithm. Importantly, it's still _not_ lock-free---all operations use a shard lock. Besides the locking, there are other features left as future work:
- Remove keys from the handles. Instead, use 128-bit bijective hashes of them for handle comparisons, probing (we need two 32-bit hashes of the key for double hashing) and sharding (we need one 6-bit hash).
- Remove the clock_usage_ field, which is updated on every lookup. Even if it were atomically updated, it could cause memory invalidations across cores.
- Middle insertions into the clock list.
- A test that exercises the clock eviction policy.
- Update the Java API of ClockCache and Java calls to C++.
Along the way, we improved the code and comments quality of FastLRUCache. These changes are relatively minor.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10273
Test Plan: ``make -j24 check``
Reviewed By: pdillinger
Differential Revision: D37522461
Pulled By: guidotag
fbshipit-source-id: 3d70b737dbb70dcf662f00cef8c609750f083943
Summary:
Currently, when installing a new super version, when stalling condition triggers, we compare estimated compaction bytes to previously, and if the new value is larger or equal to the previous one, we reduce the slowdown write rate. However, if concurrent compactions happen, the same value might be used. The result is that, although some compactions reduce estimated compaction bytes, we treat them as a signal for further slowing down. In some cases, it causes slowdown rate drops all the way to the minimum, far lower than needed.
Fix the bug by not triggering a re-calculation if a new super version doesn't have Version or a memtable change. With this fix, number of compaction finishes are still undercounted in this algorithm, but it is still better than the current bug where they are negatively counted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10270
Test Plan: Run a benchmark where the slowdown rate is dropped to minimal unnessarily and see it is back to a normal value.
Reviewed By: ajkr
Differential Revision: D37497327
fbshipit-source-id: 9bca961cc38fed965c3af0fa6c9ca0efaa7637c4
Summary:
Resolves https://github.com/facebook/rocksdb/issues/9761
With this PR, applications can create an iterator with the following
```cpp
ReadOptions read_opts;
read_opts.timestamp = &ts_ub;
read_opts.iter_start_ts = &ts_lb;
auto* it = db->NewIterator(read_opts);
it->SeekToLast();
// or it->SeekForPrev("foo");
it->Prev();
...
```
The application can access different versions of the same user key via `key()`, `value()`, and `timestamp()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10200
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D37258074
Pulled By: riversand963
fbshipit-source-id: 3f0b866ade50dcff7ef60d506397a9dd6ec91565
Summary:
Most of the properties listed as required for prefix extractors
are not really required but offer some conveniences. This updates API
comments to clarify actual requirements, and adds tests to demonstrate
how previously presumed requirements can be safely violated.
This might seem like a useless exercise, but this relaxing of requirements
would be needed if we generalize prefixes to group keys not just at the
byte level but also based on bits or arbitrary value ranges. For
applications without a "natural" prefix size, having only byte-level
granularity often means one prefix size to the next differs in magnitude
by a factor of 256.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10245
Test Plan: Tests added, also covering missing Iterator cases from https://github.com/facebook/rocksdb/issues/10244
Reviewed By: bjlemaire
Differential Revision: D37371559
Pulled By: pdillinger
fbshipit-source-id: ab2dd719992eea7656e9042cf8542393e02fa244
Jay Zhuang