Summary:
1. Fix GetOptionsPtr for Wrapped (Inner() != nullptr) Customizable objects. This allows the inner options to be returned via this method.
2. Allow the option type map to be nullptr. This allows objects to be registered as options (for GetOptionsPtr) but not be used by the configuration methods.
Added tests as appropriate.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9213
Reviewed By: zhichao-cao
Differential Revision: D32718882
Pulled By: mrambacher
fbshipit-source-id: 563203d1f006a2629060feb31c5dff9a233e1e83
Summary:
The patch adds a new BlobDB configuration option `blob_compaction_readahead_size`
that can be used to enable prefetching data from blob files during compaction.
This is important when using storage with higher latencies like HDDs or remote filesystems.
If enabled, prefetching is used for all cases when blobs are read during compaction,
namely garbage collection, compaction filters (when the existing value has to be read from
a blob file), and `Merge` (when the value of the base `Put` is stored in a blob file).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9187
Test Plan: Ran `make check` and the stress/crash test.
Reviewed By: riversand963
Differential Revision: D32565512
Pulled By: ltamasi
fbshipit-source-id: 87be9cebc3aa01cc227bec6b5f64d827b8164f5d
Summary:
Note: This PR is the 4th part of a bigger PR stack (https://github.com/facebook/rocksdb/pull/9073) and will rebase/merge only after the first three PRs (https://github.com/facebook/rocksdb/pull/9070, https://github.com/facebook/rocksdb/pull/9071, https://github.com/facebook/rocksdb/pull/9130) merge.
**Context:**
Similar to https://github.com/facebook/rocksdb/pull/8428, this PR is to track memory usage during (new) Bloom Filter (i.e,FastLocalBloom) and Ribbon Filter (i.e, Ribbon128) construction, moving toward the goal of [single global memory limit using block cache capacity](https://github.com/facebook/rocksdb/wiki/Projects-Being-Developed#improving-memory-efficiency). It also constrains the size of the banding portion of Ribbon Filter during construction by falling back to Bloom Filter if that banding is, at some point, larger than the available space in the cache under `LRUCacheOptions::strict_capacity_limit=true`.
The option to turn on this feature is `BlockBasedTableOptions::reserve_table_builder_memory = true` which by default is set to `false`. We [decided](https://github.com/facebook/rocksdb/pull/9073#discussion_r741548409) not to have separate option for separate memory user in table building therefore their memory accounting are all bundled under one general option.
**Summary:**
- Reserved/released cache for creation/destruction of three main memory users with the passed-in `FilterBuildingContext::cache_res_mgr` during filter construction:
- hash entries (i.e`hash_entries`.size(), we bucket-charge hash entries during insertion for performance),
- banding (Ribbon Filter only, `bytes_coeff_rows` +`bytes_result_rows` + `bytes_backtrack`),
- final filter (i.e, `mutable_buf`'s size).
- Implementation details: in order to use `CacheReservationManager::CacheReservationHandle` to account final filter's memory, we have to store the `CacheReservationManager` object and `CacheReservationHandle` for final filter in `XXPH3BitsFilterBuilder` as well as explicitly delete the filter bits builder when done with the final filter in block based table.
- Added option fo run `filter_bench` with this memory reservation feature
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9073
Test Plan:
- Added new tests in `db_bloom_filter_test` to verify filter construction peak cache reservation under combination of `BlockBasedTable::Rep::FilterType` (e.g, `kFullFilter`, `kPartitionedFilter`), `BloomFilterPolicy::Mode`(e.g, `kFastLocalBloom`, `kStandard128Ribbon`, `kDeprecatedBlock`) and `BlockBasedTableOptions::reserve_table_builder_memory`
- To address the concern for slow test: tests with memory reservation under `kFullFilter` + `kStandard128Ribbon` and `kPartitionedFilter` take around **3000 - 6000 ms** and others take around **1500 - 2000 ms**, in total adding **20000 - 25000 ms** to the test suit running locally
- Added new test in `bloom_test` to verify Ribbon Filter fallback on large banding in FullFilter
- Added test in `filter_bench` to verify that this feature does not significantly slow down Bloom/Ribbon Filter construction speed. Local result averaged over **20** run as below:
- FastLocalBloom
- baseline `./filter_bench -impl=2 -quick -runs 20 | grep 'Build avg'`:
- **Build avg ns/key: 29.56295** (DEBUG_LEVEL=1), **29.98153** (DEBUG_LEVEL=0)
- new feature (expected to be similar as above)`./filter_bench -impl=2 -quick -runs 20 -reserve_table_builder_memory=true | grep 'Build avg'`:
- **Build avg ns/key: 30.99046** (DEBUG_LEVEL=1), **30.48867** (DEBUG_LEVEL=0)
- new feature of RibbonFilter with fallback (expected to be similar as above) `./filter_bench -impl=2 -quick -runs 20 -reserve_table_builder_memory=true -strict_capacity_limit=true | grep 'Build avg'` :
- **Build avg ns/key: 31.146975** (DEBUG_LEVEL=1), **30.08165** (DEBUG_LEVEL=0)
- Ribbon128
- baseline `./filter_bench -impl=3 -quick -runs 20 | grep 'Build avg'`:
- **Build avg ns/key: 129.17585** (DEBUG_LEVEL=1), **130.5225** (DEBUG_LEVEL=0)
- new feature (expected to be similar as above) `./filter_bench -impl=3 -quick -runs 20 -reserve_table_builder_memory=true | grep 'Build avg' `:
- **Build avg ns/key: 131.61645** (DEBUG_LEVEL=1), **132.98075** (DEBUG_LEVEL=0)
- new feature of RibbonFilter with fallback (expected to be a lot faster than above due to fallback) `./filter_bench -impl=3 -quick -runs 20 -reserve_table_builder_memory=true -strict_capacity_limit=true | grep 'Build avg'` :
- **Build avg ns/key: 52.032965** (DEBUG_LEVEL=1), **52.597825** (DEBUG_LEVEL=0)
- And the warning message of `"Cache reservation for Ribbon filter banding failed due to cache full"` is indeed logged to console.
Reviewed By: pdillinger
Differential Revision: D31991348
Pulled By: hx235
fbshipit-source-id: 9336b2c60f44d530063da518ceaf56dac5f9df8e
Summary:
RocksDB does auto-readahead for iterators on noticing more than two sequential reads for a table file if user doesn't provide readahead_size. The readahead starts at 8KB and doubles on every additional read up to max_auto_readahead_size. However at each level, if iterator moves over next file, readahead_size starts again from 8KB.
This PR introduces a new ReadOption "adaptive_readahead" which when set true will maintain readahead_size at each level. So when iterator moves from one file to another, new file's readahead_size will continue from previous file's readahead_size instead of scratch. However if reads are not sequential it will fall back to 8KB (default) with no prefetching for that block.
1. If block is found in cache but it was eligible for prefetch (block wasn't in Rocksdb's prefetch buffer), readahead_size will decrease by 8KB.
2. It maintains readahead_size for L1 - Ln levels.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9056
Test Plan:
Added new unit tests
Ran db_bench for "readseq, seekrandom, seekrandomwhilewriting, readrandom" with --adaptive_readahead=true and there was no regression if new feature is enabled.
Reviewed By: anand1976
Differential Revision: D31773640
Pulled By: akankshamahajan15
fbshipit-source-id: 7332d16258b846ae5cea773009195a5af58f8f98
Summary:
To prepare for adding checksum to footer and "context aware"
checksums. This also brings closely related code much closer together.
Recently added `BlockBasedTableBuilder::ComputeBlockTrailer` for testing
is made obsolete in the refactoring, as testing the checksums can happen
at a lower level of abstraction.
Also now checking for unrecognized checksum type on reading footer,
rather than later on use.
Also removed an obsolete function delcaration.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9113
Test Plan:
existing tests worked before refactoring to remove
`ComputeBlockTrailer`. And then refactored+improved tests using it.
Reviewed By: mrambacher
Differential Revision: D32090149
Pulled By: pdillinger
fbshipit-source-id: 2879da683c1498ea85a3b70dace9b6d9f6b47b6e
Summary:
XXH3 - latest hash function that is extremely fast on large
data, easily faster than crc32c on most any x86_64 hardware. In
integrating this hash function, I have handled the compression type byte
in a non-standard way to avoid using the streaming API (extra data
movement and active code size because of hash function complexity). This
approach got a thumbs-up from Yann Collet.
Existing functionality change:
* reject bad ChecksumType in options with InvalidArgument
This change split off from https://github.com/facebook/rocksdb/issues/9058 because context-aware checksum is
likely to be handled through different configuration than ChecksumType.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9069
Test Plan:
tests updated, and substantially expanded. Unit tests now check
that we don't accidentally change the values generated by the checksum
algorithms ("schema test") and that we properly handle
invalid/unrecognized checksum types in options or in file footer.
DBTestBase::ChangeOptions (etc.) updated from two to one configuration
changing from default CRC32c ChecksumType. The point of this test code
is to detect possible interactions among features, and the likelihood of
some bad interaction being detected by including configurations other
than XXH3 and CRC32c--and then not detected by stress/crash test--is
extremely low.
Stress/crash test also updated (manual run long enough to see it accepts
new checksum type). db_bench also updated for microbenchmarking
checksums.
### Performance microbenchmark (PORTABLE=0 DEBUG_LEVEL=0, Broadwell processor)
./db_bench -benchmarks=crc32c,xxhash,xxhash64,xxh3,crc32c,xxhash,xxhash64,xxh3,crc32c,xxhash,xxhash64,xxh3
crc32c : 0.200 micros/op 5005220 ops/sec; 19551.6 MB/s (4096 per op)
xxhash : 0.807 micros/op 1238408 ops/sec; 4837.5 MB/s (4096 per op)
xxhash64 : 0.421 micros/op 2376514 ops/sec; 9283.3 MB/s (4096 per op)
xxh3 : 0.171 micros/op 5858391 ops/sec; 22884.3 MB/s (4096 per op)
crc32c : 0.206 micros/op 4859566 ops/sec; 18982.7 MB/s (4096 per op)
xxhash : 0.793 micros/op 1260850 ops/sec; 4925.2 MB/s (4096 per op)
xxhash64 : 0.410 micros/op 2439182 ops/sec; 9528.1 MB/s (4096 per op)
xxh3 : 0.161 micros/op 6202872 ops/sec; 24230.0 MB/s (4096 per op)
crc32c : 0.203 micros/op 4924686 ops/sec; 19237.1 MB/s (4096 per op)
xxhash : 0.839 micros/op 1192388 ops/sec; 4657.8 MB/s (4096 per op)
xxhash64 : 0.424 micros/op 2357391 ops/sec; 9208.6 MB/s (4096 per op)
xxh3 : 0.162 micros/op 6182678 ops/sec; 24151.1 MB/s (4096 per op)
As you can see, especially once warmed up, xxh3 is fastest.
### Performance macrobenchmark (PORTABLE=0 DEBUG_LEVEL=0, Broadwell processor)
Test
for I in `seq 1 50`; do for CHK in 0 1 2 3 4; do TEST_TMPDIR=/dev/shm/rocksdb$CHK ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=30000000 -checksum_type=$CHK 2>&1 | grep 'micros/op' | tee -a results-$CHK & done; wait; done
Results (ops/sec)
for FILE in results*; do echo -n "$FILE "; awk '{ s += $5; c++; } END { print 1.0 * s / c; }' < $FILE; done
results-0 252118 # kNoChecksum
results-1 251588 # kCRC32c
results-2 251863 # kxxHash
results-3 252016 # kxxHash64
results-4 252038 # kXXH3
Reviewed By: mrambacher
Differential Revision: D31905249
Pulled By: pdillinger
fbshipit-source-id: cb9b998ebe2523fc7c400eedf62124a78bf4b4d1
Summary:
This commit introduces incremental compaction in univeral style for space amplification. This follows the first improvement mentioned in https://rocksdb.org/blog/2021/04/12/universal-improvements.html . The implemention simply picks up files about size of max_compaction_bytes to compact and execute if the penalty is not too big. More optimizations can be done in the future, e.g. prioritizing between this compaction and other types. But for now, the feature is supposed to be functional and can often reduce frequency of full compactions, although it can introduce penalty.
In order to add cut files more efficiently so that more files from upper levels can be included, SST file cutting threshold (for current file + overlapping parent level files) is set to 1.5X of target file size. A 2MB target file size will generate files like this: https://gist.github.com/siying/29d2676fba417404f3c95e6c013c7de8 Number of files indeed increases but it is not out of control.
Two set of write benchmarks are run:
1. For ingestion rate limited scenario, we can see full compaction is mostly eliminated: https://gist.github.com/siying/959bc1186066906831cf4c808d6e0a19 . The write amp increased from 7.7 to 9.4, as expected. After applying file cutting, the number is improved to 8.9. In another benchmark, the write amp is even better with the incremental approach: https://gist.github.com/siying/d1c16c286d7c59c4d7bba718ca198163
2. For ingestion rate unlimited scenario, incremental compaction turns out to be too expensive most of the time and is not executed, as expected.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8655
Test Plan: Add unit tests to the functionality.
Reviewed By: ajkr
Differential Revision: D31787034
fbshipit-source-id: ce813e63b15a61d5a56e97bf8902a1b28e011beb
Summary:
Currently, if Secondary Cache is provided to the lru cache, it is used by default. We add CacheTier to advanced_options.h to describe the cache tier we used. Add a `lowest_used_cache_tier` option to `DBOptions` (immutable) and pass it to BlockBasedTableReader to decide if secondary cache will be used or not. By default it is `CacheTier::kNonVolatileTier`, which means, we always use both block cache (kVolatileTier) and secondary cache (kNonVolatileTier). By set it to `CacheTier::kVolatileTier`, the DB will not use the secondary cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9050
Test Plan: added new tests
Reviewed By: anand1976
Differential Revision: D31744769
Pulled By: zhichao-cao
fbshipit-source-id: a0575ebd23e1c6dfcfc2b4c8578764e73b15bce6
Summary:
Adds changes to DBOptions (comparable to ColumnFamilyOptions) to allow some option values to be ignored on rehydration from the Options file. This is necessary for some customizable classes that were not registered with the ObjectRegistry but are saved/restored from the Options file.
All tests pass. Will run check_format_compatible.sh shortly.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9045
Reviewed By: zhichao-cao
Differential Revision: D31761664
Pulled By: mrambacher
fbshipit-source-id: 300c2251639cce2b223481c3bb2a63877b1f3766
Summary:
The current BlobDB garbage collection logic works by relocating the valid
blobs from the oldest blob files as they are encountered during compaction,
and cleaning up blob files once they contain nothing but garbage. However,
with sufficiently skewed workloads, it is theoretically possible to end up in a
situation when few or no compactions get scheduled for the SST files that contain
references to the oldest blob files, which can lead to increased space amp due
to the lack of GC.
In order to efficiently handle such workloads, the patch adds a new BlobDB
configuration option called `blob_garbage_collection_force_threshold`,
which signals to BlobDB to schedule targeted compactions for the SST files
that keep alive the oldest batch of blob files if the overall ratio of garbage in
the given blob files meets the threshold *and* all the given blob files are
eligible for GC based on `blob_garbage_collection_age_cutoff`. (For example,
if the new option is set to 0.9, targeted compactions will get scheduled if the
sum of garbage bytes meets or exceeds 90% of the sum of total bytes in the
oldest blob files, assuming all affected blob files are below the age-based cutoff.)
The net result of these targeted compactions is that the valid blobs in the oldest
blob files are relocated and the oldest blob files themselves cleaned up (since
*all* SST files that rely on them get compacted away).
These targeted compactions are similar to periodic compactions in the sense
that they force certain SST files that otherwise would not get picked up to undergo
compaction and also in the sense that instead of merging files from multiple levels,
they target a single file. (Note: such compactions might still include neighboring files
from the same level due to the need of having a "clean cut" boundary but they never
include any files from any other level.)
This functionality is currently only supported with the leveled compaction style
and is inactive by default (since the default value is set to 1.0, i.e. 100%).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8994
Test Plan: Ran `make check` and tested using `db_bench` and the stress/crash tests.
Reviewed By: riversand963
Differential Revision: D31489850
Pulled By: ltamasi
fbshipit-source-id: 44057d511726a0e2a03c5d9313d7511b3f0c4eab
Summary:
This header file was including everything and the kitchen sink when it did not need to. This resulted in many places including this header when they needed other pieces instead.
Cleaned up this header to only include what was needed and fixed up the remaining code to include what was now missing.
Hopefully, this sort of code hygiene cleanup will speed up the builds...
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8930
Reviewed By: pdillinger
Differential Revision: D31142788
Pulled By: mrambacher
fbshipit-source-id: 6b45de3f300750c79f751f6227dece9cfd44085d
Summary:
Made SliceTransform into a Customizable class.
Would be nice to write a test that stored and used a custom transform in an SST table.
There are a set of tests (DBBlockFliterTest.PrefixExtractor*, SamePrefixTest.InDomainTest, PrefixTest.PrefixAndWholeKeyTest that run the same with or without a SliceTransform/PrefixFilter. Is this expected?
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8641
Reviewed By: zhichao-cao
Differential Revision: D31142793
Pulled By: mrambacher
fbshipit-source-id: bb08672fccbfdc263dcae21f25a62307e1facda1
Summary:
Made SystemClock into a Customizable class, complete with CreateFromString.
Cleaned up some of the existing SystemClock implementations that were redundant (NoSleep was the same as the internal one for MockEnv).
Changed MockEnv construction to allow Clock to be passed to the Memory/MockFileSystem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8636
Reviewed By: zhichao-cao
Differential Revision: D30483360
Pulled By: mrambacher
fbshipit-source-id: cd0e3a876c39f8c98fe13374c06e8edbd5b9f2a1
Summary:
Make the Statistics object into a Customizable object. Statistics can now be stored and created to/from the Options file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8637
Reviewed By: zhichao-cao
Differential Revision: D30530550
Pulled By: mrambacher
fbshipit-source-id: 5fc7d01d8431f37b2c205bbbd8342c9f697023bd
Summary:
ManagedObjects are shared pointer objects where RocksDB wants to share a single object between multiple configurations. For example, the Cache may be shared between multiple column families/tables or the Statistics may be shared between multiple databases.
ManagedObjects are stored in the ObjectRegistry by Type (e.g. Cache) and ID. For a given type/ID name, a single object is stored.
APIs were added to get/set/create these objects.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8658
Reviewed By: pdillinger
Differential Revision: D30806273
Pulled By: mrambacher
fbshipit-source-id: 832ac4423b210c4c4b4a456b35897334775d3160
Summary:
This PR does the following:
-> Makes the MemTableRepFactory into a Customizable class and creatable/configurable via CreateFromString
-> Makes the existing implementations compatible with configurations
-> Moves the "SpecialRepFactory" test class into testutil, accessible via the ObjectRegistry or a NewSpecial API
New tests were added to validate the functionality and all existing tests pass. db_bench and memtablerep_bench were hand-tested to verify the functionality in those tools.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8419
Reviewed By: zhichao-cao
Differential Revision: D29558961
Pulled By: mrambacher
fbshipit-source-id: 81b7229636e4e649a0c914e73ac7b0f8454c931c
Summary:
Old typedef syntax is confusing
Most but not all changes with
perl -pi -e 's/typedef (.*) ([a-zA-Z0-9_]+);/using $2 = $1;/g' list_of_files
make format
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8751
Test Plan: existing
Reviewed By: zhichao-cao
Differential Revision: D30745277
Pulled By: pdillinger
fbshipit-source-id: 6f65f0631c3563382d43347896020413cc2366d9
Summary:
The atomic variable "is_prepared_" was keeping Configurable objects from being copy-constructed. Removed the atomic to allow copies.
Since the variable is only changed from false to true (and never back), there is no reason it had to be atomic.
Added tests that simple Configurable and Customizable objects can be put on the stack and copied.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8704
Reviewed By: anand1976
Differential Revision: D30530526
Pulled By: ltamasi
fbshipit-source-id: 4dd4439b3e5ad7fa396573d0b25d9fb709160576
Summary:
This is essentially resurrection and fixing of the part of
https://github.com/facebook/rocksdb/issues/8198 that was reverted in https://github.com/facebook/rocksdb/issues/8212, using data added in https://github.com/facebook/rocksdb/issues/8246. Basically,
when configuring Ribbon filter, you can specify an LSM level before which
Bloom will be used instead of Ribbon. But Bloom is only considered for
Leveled and Universal compaction styles and file going into a known LSM
level. This way, SST file writer, FIFO compaction, etc. use Ribbon filter as
you would expect with NewRibbonFilterPolicy.
So that this can be controlled with a single int value and so that flushes
can be distinguished from intra-L0, we consider flush to go to level -1 for
the purposes of this option. (Explained in API comment.)
I also expect the most common and recommended Ribbon configuration to
use Bloom during flush, to minimize slowing down writes and because according
to my estimates, Ribbon only pays off if the structure lives in memory for
more than an hour. Thus, I have changed the default for NewRibbonFilterPolicy
to be this mild hybrid configuration. I don't really want to add something like
NewHybridFilterPolicy because at least the mild hybrid configuration (Bloom for
flush, Ribbon otherwise) should be considered a natural choice.
C APIs also updated, but because they don't support overloading,
rocksdb_filterpolicy_create_ribbon is kept pure ribbon for clarity and
rocksdb_filterpolicy_create_ribbon_hybrid must be called for a hybrid
configuration. While touching C API, I changed bits per key options from
int to double.
BuiltinFilterPolicy is needed so that LevelThresholdFilterPolicy doesn't inherit
unused fields from BloomFilterPolicy.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8679
Test Plan: new + updated tests, including crash test
Reviewed By: jay-zhuang
Differential Revision: D30445797
Pulled By: pdillinger
fbshipit-source-id: 6f5aeddfd6d79f7e55493b563c2d1d2d568892e1
Summary:
- Fix issue with OptionType::Vector when the nested item is a Customizable with no names
- Fix issue with OptionType::Vector to appropriately wrap the elements in a Vector;
- Fix an issue with nested Customizable object with a null immutable object still appearing in the mutable options;
- Fix/Add tests for null/empty customizable objects
- Move the RegisterTestObjects from customizable_test into testutil.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8566
Reviewed By: zhichao-cao
Differential Revision: D30303724
Pulled By: mrambacher
fbshipit-source-id: 33fa8ea2a3b663210cb356da05e64aab7585b1b5
Summary:
Current internal regression tests pass in an old option flag `experimental_allow_mempurge` to a more recently built db.
This flag was retired and removed in a recent PR (https://github.com/facebook/rocksdb/issues/8628), and therefore, the following error comes up : `Failed: Invalid argument: Could not find option: : experimental_allow_mempurge`.
In this PR, I reintroduce the two flags retired in https://github.com/facebook/rocksdb/issues/8628, `experimental_allow_mempurge` and `experimental_mempurge_policy` in `db_options.cc` and mark them both as `kDeprecated`.
This is a temporary fix to save us time to find a long term solution, which hopefully will consist in ignoring options prefixed with `experimental_` that are no longer recognized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8650
Reviewed By: pdillinger
Differential Revision: D30257307
Pulled By: bjlemaire
fbshipit-source-id: 35303655fd2dd9789fd9e3c450e9d8009f3c1f54
Summary:
Changes the API of the MemPurge process: the `bool experimental_allow_mempurge` and `experimental_mempurge_policy` flags have been replaced by a `double experimental_mempurge_threshold` option.
This change of API reflects another major change introduced in this PR: the MemPurgeDecider() function now works by sampling the memtables being flushed to estimate the overall amount of useful payload (payload minus the garbage), and then compare this useful payload estimate with the `double experimental_mempurge_threshold` value.
Therefore, when the value of this flag is `0.0` (default value), mempurge is simply deactivated. On the other hand, a value of `DBL_MAX` would be equivalent to always going through a mempurge regardless of the garbage ratio estimate.
At the moment, a `double experimental_mempurge_threshold` value else than 0.0 or `DBL_MAX` is opnly supported`with the `SkipList` memtable representation.
Regarding the sampling, this PR includes the introduction of a `MemTable::UniqueRandomSample` function that collects (approximately) random entries from the memtable by using the new `SkipList::Iterator::RandomSeek()` under the hood, or by iterating through each memtable entry, depending on the target sample size and the total number of entries.
The unit tests have been readapted to support this new API.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8628
Reviewed By: pdillinger
Differential Revision: D30149315
Pulled By: bjlemaire
fbshipit-source-id: 1feef5390c95db6f4480ab4434716533d3947f27
Summary:
Some FIFO users want to keep the data for longer, but the old data is rarely accessed. This feature allows users to configure FIFO compaction so that data older than a threshold is moved to a warm storage tier.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8310
Test Plan: Add several unit tests.
Reviewed By: ajkr
Differential Revision: D28493792
fbshipit-source-id: c14824ea634814dee5278b449ab5c98b6e0b5501
Summary:
- Changed MergeOperator, CompactionFilter, and CompactionFilterFactory into Customizable classes.
- Added Options/Configurable/Object Registration for TTL and Cassandra variants
- Changed the StringAppend MergeOperators to accept a string delimiter rather than a simple char. Made the delimiter into a configurable option
- Added tests for new functionality
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8481
Reviewed By: zhichao-cao
Differential Revision: D30136050
Pulled By: mrambacher
fbshipit-source-id: 271d1772835935b6773abaf018ee71e42f9491af
Summary:
Prior to this change, the "wal_dir" DBOption would always be set (defaults to dbname) when the DBOptions were sanitized. Because of this setitng in the options file, it was not possible to rename/relocate a database directory after it had been created and use the existing options file.
After this change, the "wal_dir" option is only set under specific circumstances. Methods were added to the ImmutableDBOptions class to see if it is set and if it is set to something other than the dbname. Additionally, a method was added to retrieve the effective value of the WAL dir (either the option or the dbname/path).
Tests were added to the core and ldb to test that a database could be created and renamed without issue. Additional tests for various permutations of wal_dir were also added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8582
Reviewed By: pdillinger, autopear
Differential Revision: D29881122
Pulled By: mrambacher
fbshipit-source-id: 67d3d033dc8813d59917b0a3fba2550c0efd6dfb
Summary:
- Added Type/CreateFromString
- Added ability to load EventListeners to DBOptions
- Since EventListeners did not previously have a Name(), defaulted to "". If there is no name, the listener cannot be loaded from the ObjectRegistry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8473
Reviewed By: zhichao-cao
Differential Revision: D29901488
Pulled By: mrambacher
fbshipit-source-id: 2d3a4aa6db1562ac03e7ad41b360e3521d486254
Summary:
Add `experimental_mempurge_policy` option flag and introduce two new `MemPurge` (Memtable Garbage Collection) policies: 'ALWAYS' and 'ALTERNATE'. Default value: ALTERNATE.
`ALWAYS`: every flush will first go through a `MemPurge` process. If the output is too big to fit into a single memtable, then the mempurge is aborted and a regular flush process carries on. `ALWAYS` is designed for user that need to reduce the number of L0 SST file created to a strict minimum, and can afford a small dent in performance (possibly hits to CPU usage, read efficiency, and maximum burst write throughput).
`ALTERNATE`: a flush is transformed into a `MemPurge` except if one of the memtables being flushed is the product of a previous `MemPurge`. `ALTERNATE` is a good tradeoff between reduction in number of L0 SST files created and performance. `ALTERNATE` perform particularly well for completely random garbage ratios, or garbage ratios anywhere in (0%,50%], and even higher when there is a wild variability in garbage ratios.
This PR also includes support for `experimental_mempurge_policy` in `db_bench`.
Testing was done locally by replacing all the `MemPurge` policies of the unit tests with `ALTERNATE`, as well as local testing with `db_crashtest.py` `whitebox` and `blackbox`. Overall, if an `ALWAYS` mempurge policy passes the tests, there is no reasons why an `ALTERNATE` policy would fail, and therefore the mempurge policy was set to `ALWAYS` for all mempurge unit tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8583
Reviewed By: pdillinger
Differential Revision: D29888050
Pulled By: bjlemaire
fbshipit-source-id: e2cf26646d66679f6f5fb29842624615610759c1
Summary:
Try avoid expensive updating options operation if
`SetDBOptions()` does not change any option value.
Skip updating is not guaranteed, for example, changing `bytes_per_sync`
to `0` may still trigger updating, as the value could be sanitized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8518
Test Plan: added unittest
Reviewed By: riversand963
Differential Revision: D29672639
Pulled By: jay-zhuang
fbshipit-source-id: b7931de62ceea6f1bdff0d1209adf1197d3ed1f4
Summary:
Some URIs for creating instances (ala SecondaryCache) use complex URIs like (cache://name;prop=value). These URIs were treated as name-value properties. With this change, if the URI does not contain an "id=XX" setting, it will be treated as a single string value (and not an ID and map of name-value properties).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8547
Reviewed By: anand1976
Differential Revision: D29741386
Pulled By: mrambacher
fbshipit-source-id: 0621f62bec3a6699a7b66c7c0b5634b2856653aa
Summary:
Made the EncryptionProvider and BlockCipher classes inherit from Customizable. Added/fixed the CreateFromString method to these classes to create instances from builtin or registered classes. Added tests to verify that instances can be registered and retrieved as appropriate.
Added the ability to configure the builtin (CTR, ROT13) classes from configurable properties. Added the appropriate tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8354
Reviewed By: zhichao-cao
Differential Revision: D29558949
Pulled By: mrambacher
fbshipit-source-id: c20286b32d179777e060f51a58943e9b0cf81d04
Summary:
Implement an experimental feature called "MemPurge", which consists in purging "garbage" bytes out of a memtable and reuse the memtable struct instead of making it immutable and eventually flushing its content to storage.
The prototype is by default deactivated and is not intended for use. It is intended for correctness and validation testing. At the moment, the "MemPurge" feature can be switched on by using the `options.experimental_allow_mempurge` flag. For this early stage, when the allow_mempurge flag is set to `true`, all the flush operations will be rerouted to perform a MemPurge. This is a temporary design decision that will give us the time to explore meaningful heuristics to use MemPurge at the right time for relevant workloads . Moreover, the current MemPurge operation only supports `Puts`, `Deletes`, `DeleteRange` operations, and handles `Iterators` as well as `CompactionFilter`s that are invoked at flush time .
Three unit tests are added to `db_flush_test.cc` to test if MemPurge works correctly (and checks that the previously mentioned operations are fully supported thoroughly tested).
One noticeable design decision is the timing of the MemPurge operation in the memtable workflow: for this prototype, the mempurge happens when the memtable is switched (and usually made immutable). This is an inefficient process because it implies that the entirety of the MemPurge operation happens while holding the db_mutex. Future commits will make the MemPurge operation a background task (akin to the regular flush operation) and aim at drastically enhancing the performance of this operation. The MemPurge is also not fully "WAL-compatible" yet, but when the WAL is full, or when the regular MemPurge operation fails (or when the purged memtable still needs to be flushed), a regular flush operation takes place. Later commits will also correct these behaviors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8454
Reviewed By: anand1976
Differential Revision: D29433971
Pulled By: bjlemaire
fbshipit-source-id: 6af48213554e35048a7e03816955100a80a26dc5
Summary:
Added the Customizable::ConfigureNewObject method. The method will configure the object if options are found and invoke PrepareOptions if the flag is set properly.
Added tests to test that PrepareOptions is properly called and to test if PrepareOptions fails.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8468
Reviewed By: zhichao-cao
Differential Revision: D29494703
Pulled By: mrambacher
fbshipit-source-id: d5767dee5d7a98620ac66190262101cd0aa9d2b7
Summary:
If a Customizable option was not mutable, it would still appear in the list of mutable options when serialized. This meant that when the immutable options were used to configure another immutable object, an "option not changeable" status would be returned.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8457
Reviewed By: zhichao-cao
Differential Revision: D29428298
Pulled By: mrambacher
fbshipit-source-id: 3945b0b822f8e5955a7c5590fe64dfd5bc1fe6a0
Summary:
This PR prepopulates warm/hot data blocks which are already in memory
into block cache at the time of flush. On a flush, the data block that is
in memory (in memtables) get flushed to the device. If using Direct IO,
additional IO is incurred to read this data back into memory again, which
is avoided by enabling newly added option.
Right now, this is enabled only for flush for data blocks. We plan to
expand this option to cover compactions in the future and for other types
of blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8242
Test Plan: Add new unit test
Reviewed By: anand1976
Differential Revision: D28521703
Pulled By: akankshamahajan15
fbshipit-source-id: 7219d6958821cedce689a219c3963a6f1a9d5f05
Summary:
Marked the Ribbon filter and optimize_filters_for_memory features
as production-ready, each enabling memory savings for Bloom-like filters.
Use `NewRibbonFilterPolicy` in place of `NewBloomFilterPolicy` to use
Ribbon filters instead of Bloom, or `ribbonfilter` in place of
`bloomfilter` in configuration string.
Some small refactoring in db_stress.
Removed/refactored unused code in db_bench, in part preparing for future
default possibly being different from "disabled."
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8408
Test Plan:
Lots of prior automated, ad-hoc, and "real world" testing.
Updated tests for new API names. Quick db_bench test:
bloom fillrandom
77730 ops/sec
rocksdb.block.cache.filter.bytes.insert COUNT : 89929384
ribbon fillrandom
71492 ops/sec
rocksdb.block.cache.filter.bytes.insert COUNT : 64531384
Reviewed By: mrambacher
Differential Revision: D29140805
Pulled By: pdillinger
fbshipit-source-id: d742c922722421678f95ad85eeb0aaebc9f5e49a
Summary:
- Added CreateFromString method to Env and FilesSystem to replace LoadEnv/Load. This method/signature is a precursor to making these classes extend Customizable.
- Added CreateFromSystem to Env. This method standardizes creating an Env from the environment variables. Previously, some places would check TEST_ENV_URI and others would also check TEST_FS_URI. Now the code is more command/standardized.
- Added CreateFromFlags to Env. These method allows Env to be create from string options (such as GFLAGS options) in a more standard way.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8174
Reviewed By: zhichao-cao
Differential Revision: D28999603
Pulled By: mrambacher
fbshipit-source-id: 88e6911e7e91f908458a7fe10a20e93ecbc275fb
Summary:
Makes the Comparator class into a Customizable object. Added/Updated the CreateFromString method to create Comparators. Added test for using the ObjectRegistry to create one.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8336
Reviewed By: jay-zhuang
Differential Revision: D28999612
Pulled By: mrambacher
fbshipit-source-id: bff2cb2814eeb9fef6a00fddc61d6e34b6fbcf2e
Summary:
When a memtable is flushed, it will validate number of entries it reads, and compare the number with how many entries inserted into memtable. This serves as one sanity c\
heck against memory corruption. This change will also allow more counters to be added in the future for better validation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8288
Test Plan: Pass all existing tests
Reviewed By: ajkr
Differential Revision: D28369194
fbshipit-source-id: 7ff870380c41eab7f99eee508550dcdce32838ad
Summary:
The functions will be used for remote compaction parameter
input and result.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8247
Test Plan: `make check`
Reviewed By: ajkr
Differential Revision: D28104680
Pulled By: jay-zhuang
fbshipit-source-id: c0a5178e6277125118384278efea2acbf90aa6cb
