65 Commits (f366f90bdb901bf19010c9dd4d92310c320e5b84)

Author	SHA1	Message	Date
Peter Dillinger	126c223714	Remove deprecated block-based filter (#10184) ... Summary: In https://github.com/facebook/rocksdb/issues/9535, release 7.0, we hid the old block-based filter from being created using the public API, because of its inefficiency. Although we normally maintain read compatibility on old DBs forever, filters are not required for reading a DB, only for optimizing read performance. Thus, it should be acceptable to remove this code and the substantial maintenance burden it carries as useful features are developed and validated (such as user timestamp). This change completely removes the code for reading and writing the old block-based filters, net removing about 1370 lines of code no longer needed. Options removed from testing / benchmarking tools. The prior existence is only evident in a couple of places: * `CacheEntryRole::kDeprecatedFilterBlock` - We can update this public API enum in a major release to minimize source code incompatibilities. * A warning is logged when an old table file is opened that used the old block-based filter. This is provided as a courtesy, and would be a pain to unit test, so manual testing should suffice. Unfortunately, sst_dump does not tell you whether a file uses block-based filter, and the structure of the code makes it very difficult to fix. * To detect that case, `kObsoleteFilterBlockPrefix` (renamed from `kFilterBlockPrefix`) for metaindex is maintained (for now). Other notes: * In some cases where numbers are associated with filter configurations, we have had to update the assigned numbers so that they all correspond to something that exists. * Fixed potential stat counting bug by assuming `filter_checked = false` for cases like `filter == nullptr` rather than assuming `filter_checked = true` * Removed obsolete `block_offset` and `prefix_extractor` parameters from several functions. * Removed some unnecessary checks `if (!table_prefix_extractor() && !prefix_extractor)` because the caller guarantees the prefix extractor exists and is compatible Pull Request resolved: https://github.com/facebook/rocksdb/pull/10184 Test Plan: tests updated, manually test new warning in LOG using base version to generate a DB Reviewed By: riversand963 Differential Revision: D37212647 Pulled By: pdillinger fbshipit-source-id: 06ee020d8de3b81260ffc36ad0c1202cbf463a80	2 years ago
Hui Xiao	3573558ec5	Rewrite memory-charging feature's option API (#9926) ... Summary: **Context:** Previous PR https://github.com/facebook/rocksdb/pull/9748, https://github.com/facebook/rocksdb/pull/9073, https://github.com/facebook/rocksdb/pull/8428 added separate flag for each charged memory area. Such API design is not scalable as we charge more and more memory areas. Also, we foresee an opportunity to consolidate this feature with other cache usage related features such as `cache_index_and_filter_blocks` using `CacheEntryRole`. Therefore we decided to consolidate all these flags with `CacheUsageOptions cache_usage_options` and this PR serves as the first step by consolidating memory-charging related flags. **Summary:** - Replaced old API reference with new ones, including making `kCompressionDictionaryBuildingBuffer` opt-out and added a unit test for that - Added missing db bench/stress test for some memory charging features - Renamed related test suite to indicate they are under the same theme of memory charging - Refactored a commonly used mocked cache component in memory charging related tests to reduce code duplication - Replaced the phrases "memory tracking" / "cache reservation" (other than CacheReservationManager-related ones) with "memory charging" for standard description of this feature. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9926 Test Plan: - New unit test for opt-out `kCompressionDictionaryBuildingBuffer` `TEST_F(ChargeCompressionDictionaryBuildingBufferTest, Basic)` - New unit test for option validation/sanitization `TEST_F(CacheUsageOptionsOverridesTest, SanitizeAndValidateOptions)` - CI - db bench (in case querying new options introduces regression) **+0.5% micros/op**: `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_compression_dictionary_building_buffer=1(remove this for comparison) -compression_max_dict_bytes=10000 -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 | egrep 'fillseq'` #-run | (pre-PR) avg micros/op | std micros/op | (post-PR) micros/op | std micros/op | change (%) -- | -- | -- | -- | -- | -- 10 | 3.9711 | 0.264408 | 3.9914 | 0.254563 | 0.5111933721 20 | 3.83905 | 0.0664488 | 3.8251 | 0.0695456 | **-0.3633711465** 40 | 3.86625 | 0.136669 | 3.8867 | 0.143765 | **0.5289363078** - db_stress: `python3 tools/db_crashtest.py blackbox -charge_compression_dictionary_building_buffer=1 -charge_filter_construction=1 -charge_table_reader=1 -cache_size=1` killed as normal Reviewed By: ajkr Differential Revision: D36054712 Pulled By: hx235 fbshipit-source-id: d406e90f5e0c5ea4dbcb585a484ad9302d4302af	3 years ago
sdong	736a7b5433	Remove own ToString() (#9955) ... Summary: ToString() is created as some platform doesn't support std::to_string(). However, we've already used std::to_string() by mistake for 16 months (in db/db_info_dumper.cc). This commit just remove ToString(). Pull Request resolved: https://github.com/facebook/rocksdb/pull/9955 Test Plan: Watch CI tests Reviewed By: riversand963 Differential Revision: D36176799 fbshipit-source-id: bdb6dcd0e3a3ab96a1ac810f5d0188f684064471	3 years ago
Hui Xiao	49623f9c8e	Account memory of big memory users in BlockBasedTable in global memory limit (#9748) ... Summary: **Context:** Through heap profiling, we discovered that `BlockBasedTableReader` objects can accumulate and lead to high memory usage (e.g, `max_open_file = -1`). These memories are currently not saved, not tracked, not constrained and not cache evict-able. As a first step to improve this, similar to https://github.com/facebook/rocksdb/pull/8428, this PR is to track an estimate of `BlockBasedTableReader` object's memory in block cache and fail future creation if the memory usage exceeds the available space of cache at the time of creation. **Summary:** - Approximate big memory users (`BlockBasedTable::Rep` and `TableProperties` )' memory usage in addition to the existing estimated ones (filter block/index block/un-compression dictionary) - Charge all of these memory usages to block cache on `BlockBasedTable::Open()` and release them on `~BlockBasedTable()` as there is no memory usage fluctuation of concern in between - Refactor on CacheReservationManager (and its call-sites) to add concurrent support for BlockBasedTable used in this PR. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9748 Test Plan: - New unit tests - db bench: `OpenDb` : **-0.52% in ms** - Setup `./db_bench -benchmarks=fillseq -db=/dev/shm/testdb -disable_auto_compactions=1 -write_buffer_size=1048576` - Repeated run with pre-change w/o feature and post-change with feature, benchmark `OpenDb`: `./db_bench -benchmarks=readrandom -use_existing_db=1 -db=/dev/shm/testdb -reserve_table_reader_memory=true (remove this when running w/o feature) -file_opening_threads=3 -open_files=-1 -report_open_timing=true| egrep 'OpenDb:'` #-run | (feature-off) avg milliseconds | std milliseconds | (feature-on) avg milliseconds | std milliseconds | change (%) -- | -- | -- | -- | -- | -- 10 | 11.4018 | 5.95173 | 9.47788 | 1.57538 | -16.87382694 20 | 9.23746 | 0.841053 | 9.32377 | 1.14074 | 0.9343477536 40 | 9.0876 | 0.671129 | 9.35053 | 1.11713 | 2.893283155 80 | 9.72514 | 2.28459 | 9.52013 | 1.0894 | -2.108041632 160 | 9.74677 | 0.991234 | 9.84743 | 1.73396 | 1.032752389 320 | 10.7297 | 5.11555 | 10.547 | 1.97692 | **-1.70275031** 640 | 11.7092 | 2.36565 | 11.7869 | 2.69377 | **0.6635807741** - db bench on write with cost to cache in WriteBufferManager (just in case this PR's CRM refactoring accidentally slows down anything in WBM) : `fillseq` : **+0.54% in micros/op** `./db_bench -benchmarks=fillseq -db=/dev/shm/testdb -disable_auto_compactions=1 -cost_write_buffer_to_cache=true -write_buffer_size=10000000000 | egrep 'fillseq'` #-run | (pre-PR) avg micros/op | std micros/op | (post-PR) avg micros/op | std micros/op | change (%) -- | -- | -- | -- | -- | -- 10 | 6.15 | 0.260187 | 6.289 | 0.371192 | 2.260162602 20 | 7.28025 | 0.465402 | 7.37255 | 0.451256 | 1.267813605 40 | 7.06312 | 0.490654 | 7.13803 | 0.478676 | **1.060579461** 80 | 7.14035 | 0.972831 | 7.14196 | 0.92971 | **0.02254791432** - filter bench: `bloom filter`: **-0.78% in ms/key** - ` ./filter_bench -impl=2 -quick -reserve_table_builder_memory=true | grep 'Build avg'` #-run | (pre-PR) avg ns/key | std ns/key | (post-PR) ns/key | std ns/key | change (%) -- | -- | -- | -- | -- | -- 10 | 26.4369 | 0.442182 | 26.3273 | 0.422919 | **-0.4145720565** 20 | 26.4451 | 0.592787 | 26.1419 | 0.62451 | **-1.1465262** - Crash test `python3 tools/db_crashtest.py blackbox --reserve_table_reader_memory=1 --cache_size=1` killed as normal Reviewed By: ajkr Differential Revision: D35136549 Pulled By: hx235 fbshipit-source-id: 146978858d0f900f43f4eb09bfd3e83195e3be28	3 years ago
mrambacher	30b08878d8	Make FilterPolicy Customizable (#9590) ... Summary: Make FilterPolicy into a Customizable class. Allow new FilterPolicy to be discovered through the ObjectRegistry Pull Request resolved: https://github.com/facebook/rocksdb/pull/9590 Reviewed By: pdillinger Differential Revision: D34327367 Pulled By: mrambacher fbshipit-source-id: 37e7edac90ec9457422b72f359ab8ef48829c190	3 years ago
Peter Dillinger	8c681087c7	Refactor FilterPolicies toward Customizable (#9567) ... Summary: Some changes to make it easier to make FilterPolicy customizable. Especially, create distinct classes for the different testing-only and user-facing built-in FilterPolicy modes. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9567 Test Plan: tests updated, with no intended difference in functionality tested. No difference in test performance seen as a result of moving to string-based filter type configuration. Reviewed By: mrambacher Differential Revision: D34234694 Pulled By: pdillinger fbshipit-source-id: 8a94931a9e04c3bcca863a4f524cfd064aaf0122	3 years ago
Peter Dillinger	68a9c186d0	FilterPolicy API changes for 7.0 (#9501) ... Summary: * Inefficient block-based filter is no longer customizable in the public API, though (for now) can still be enabled. * Removed deprecated FilterPolicy::CreateFilter() and FilterPolicy::KeyMayMatch() * Removed `rocksdb_filterpolicy_create()` from C API * Change meaning of nullptr return from GetBuilderWithContext() from "use block-based filter" to "generate no filter in this case." This is a cleaner solution to the proposal in https://github.com/facebook/rocksdb/issues/8250. * Also, when user specifies bits_per_key < 0.5, we now round this down to "no filter" because we expect a filter with >= 80% FP rate is unlikely to be worth the CPU cost of accessing it (esp with cache_index_and_filter_blocks=1 or partition_filters=1). * bits_per_key >= 0.5 and < 1.0 is still rounded up to 1.0 (for 62% FP rate) * This also gives us some support for configuring filters from OPTIONS file as currently saved: `filter_policy=rocksdb.BuiltinBloomFilter`. Opening from such an options file will enable reading filters (an improvement) but not writing new ones. (See Customizable follow-up below.) * Also removed deprecated functions * FilterBitsBuilder::CalculateNumEntry() * FilterPolicy::GetFilterBitsBuilder() * NewExperimentalRibbonFilterPolicy() * Remove default implementations of * FilterBitsBuilder::EstimateEntriesAdded() * FilterBitsBuilder::ApproximateNumEntries() * FilterPolicy::GetBuilderWithContext() * Remove support for "filter_policy=experimental_ribbon" configuration string. * Allow "filter_policy=bloomfilter:n" without bool to discourage use of block-based filter. Some pieces for https://github.com/facebook/rocksdb/issues/9389 Likely follow-up (later PRs): * Refactoring toward FilterPolicy Customizable, so that we can generate filters with same configuration as before when configuring from options file. * Remove support for user enabling block-based filter (ignore `bool use_block_based_builder`) * Some months after this change, we could even remove read support for block-based filter, because it is not critical to DB data preservation. * Make FilterBitsBuilder::FinishV2 to avoid `using FilterBitsBuilder::Finish` mess and add support for specifying a MemoryAllocator (for cache warming) Pull Request resolved: https://github.com/facebook/rocksdb/pull/9501 Test Plan: A number of obsolete tests deleted and new tests or test cases added or updated. Reviewed By: hx235 Differential Revision: D34008011 Pulled By: pdillinger fbshipit-source-id: a39a720457c354e00d5b59166b686f7f59e392aa	3 years ago
Hui Xiao	9110685e8c	Release cache reservation of hash entries of the fall-back Ribbon Filter earlier (#9345) ... Summary: Note: rebase on and merge after https://github.com/facebook/rocksdb/pull/9349, as part of https://github.com/facebook/rocksdb/pull/9342 **Context:** https://github.com/facebook/rocksdb/pull/9073 charged the hash entries' memory in block cache with `CacheReservationHandle`. However, in the edge case where Ribbon Filter falls back to Bloom Filter and swaps its hash entries to the embedded bloom filter object, the handles associated with those entries are not swapped and thus not released as soon as those entries are cleared during Bloom Filter's finish process. Although this is a minor issue since RocksDB internal calls `FilterBitsBuilder->Reset()` right after `FilterBitsBuilder->Finish()` on the main path, which releases all the cache reservation related to both the Ribbon Filter and its embedded Bloom Filter, it still worths this fix to avoid confusion. **Summary:** - Swapped the `CacheReservationHandle` associated with the hash entries on Ribbon Filter's fallback Pull Request resolved: https://github.com/facebook/rocksdb/pull/9345 Test Plan: - Added a unit test to verify the number of cache reservation after clearing hash entries, which failed before the change and now succeeds Reviewed By: pdillinger Differential Revision: D33377225 Pulled By: hx235 fbshipit-source-id: 7487f4c40dfb6ee7928232021f93ef2c5329cffa	3 years ago
Kefu Chai	cc1d4e3d33	gcc-11 and cmake related cleanup (#9286) ... Summary: in hope to get rockdb compiled with GCC-11 without warning * util/bloom_test: init a variable before using it to silence the GCC warning like ``` util/bloom_test.cc:1253:31: error: ‘<anonymous>’ may be used uninitialized [-Werror=maybe-uninitialized] 1253 | Slice key_slice{key_bytes, 8}; | ^ ... include/rocksdb/slice.h:41:3: note: by argument 2 of type ‘const char*’ to ‘rocksdb::Slice::Slice(const char*, size_t)’ declared here 41 | Slice(const char* d, size_t n) : data_(d), size_(n) {} | ^~~~~ util/bloom_test.cc:1249:3: note: ‘<anonymous>’ declared here 1249 | }; | ^ cc1plus: all warnings being treated as errors ``` * cmake: add find_package(uring ...) find liburing in a more consistent way. also it is the encouraged way for finding a library. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9286 Reviewed By: mrambacher Differential Revision: D33165241 Pulled By: jay-zhuang fbshipit-source-id: 9f3487e11b4e40fd8f1c97c8facb24a190e5ce31	3 years ago
Hui Xiao	74544d582f	Account Bloom/Ribbon filter construction memory in global memory limit (#9073) ... 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	3 years ago
Jonathan Albrecht	e970248602	Add support for building on s390x platform (#8962) ... Summary: This PR adds support for building on s390x including updating travis CI. It uses the previous work in https://github.com/facebook/rocksdb/pull/6168 and adds some more changes to get all current tests (make check and jni tests) to pass. The tests were run with snappy, lz4, bzip2 and zstd all compiled in. There are a few pieces still needed to get the travis build working that I don't think I can do. adamretter is this something you could help with? 1. A prebuilt https://rocksdb-deps.s3-us-west-2.amazonaws.com/cmake/cmake-3.14.5-Linux-s390x.deb package 2. A https://hub.docker.com/r/evolvedbinary/rocksjava s390x image Not sure if there is more required for travis. Happy to help in any way I can. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8962 Reviewed By: mrambacher Differential Revision: D31802198 Pulled By: pdillinger fbshipit-source-id: 683511466fa6b505f85ba5a9964a268c6151f0c2	3 years ago
Peter Dillinger	2a383f21f4	Add Bloom/Ribbon hybrid API support (#8679) ... 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	3 years ago
sherriiiliu	7b9ecd4067	fix several MSVC build errors (#8519) ... Summary: Fixed a few MSVC (VCToolsVersion=14.0) build errors and warnings * `DEFINE_string` is a macro and VC compiler complains that it cannot put [ifdef-inside-define](https://stackoverflow.com/questions/5586429/ifdef-inside-define) * `sleep()` is not a recognizable function. Use `FLAGS_env->SleepForMicroseconds` instead * Define precise type in comparison to avoid mismatch warning Pull Request resolved: https://github.com/facebook/rocksdb/pull/8519 Reviewed By: jay-zhuang Differential Revision: D29683086 fbshipit-source-id: 8c80941472089f8daba84ae29597e75e603850e4	3 years ago
Peter Dillinger	95f6add746	Revert Ribbon starting level support from #8198 (#8212) ... Summary: This partially reverts commit 10196d7edc. The problem with this change is because of important filter use cases: FIFO compaction and SST writer. FIFO "compaction" always uses level 0 so would only use Ribbon filters if specifically including level 0 for the Ribbon filter policy. SST writer sets level_at_creation=-1 to indicate unknown level, and this would be treated the same as level 0 unless fixed. We are keeping the part about committing to permanent schema, which is only changes to API comments and HISTORY.md. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8212 Test Plan: CI Reviewed By: jay-zhuang Differential Revision: D27896468 Pulled By: pdillinger fbshipit-source-id: 50a775f7cba5d64fb729d9b982e355864020596e	4 years ago
Peter Dillinger	10196d7edc	Ribbon long-term support, starting level support (#8198) ... Summary: Since the Ribbon filter schema seems good (compatible back to 6.15.0), this change commits to long term support of the SST schema, even though we expect the API for enabling Ribbon to change (still called NewExperimentalRibbonFilterPolicy). This also adds support for "hybrid" configuration in which some levels use Bloom (higher levels, lower numbered) for speed and the rest use Ribbon (lower levels, higher numbered) for memory space efficiency. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8198 Test Plan: unit test added, crash test support Reviewed By: jay-zhuang Differential Revision: D27831232 Pulled By: pdillinger fbshipit-source-id: 90e528677689474d293ed6710b42ba89fbd5b5ab	4 years ago
Peter Dillinger	da6b90ab48	Improve bloom_test bits_per_key flag (#8093) ... Summary: Improved handling of -bits_per_key other than 10, but at least the OptimizeForMemory test is simply not designed for generally handling other settings. (ribbon_test does have a statistical framework for this kind of testing, but it's not important to do that same for Bloom right now.) Closes https://github.com/facebook/rocksdb/issues/7019 Pull Request resolved: https://github.com/facebook/rocksdb/pull/8093 Test Plan: for I in `seq 1 20`; do ./bloom_test --gtest_filter=-*OptimizeForMemory* --bits_per_key=$I &> /dev/null || echo FAILED; done Reviewed By: mrambacher Differential Revision: D27275875 Pulled By: pdillinger fbshipit-source-id: 7362e8ac2c41ea11f639412e4f30c8b375f04388	4 years ago
Peter Dillinger	a8b3b9a20c	Refine Ribbon configuration, improve testing, add Homogeneous (#7879) ... Summary: This change only affects non-schema-critical aspects of the production candidate Ribbon filter. Specifically, it refines choice of internal configuration parameters based on inputs. The changes are minor enough that the schema tests in bloom_test, some of which depend on this, are unaffected. There are also some minor optimizations and refactorings. This would be a schema change for "smash" Ribbon, to fix some known issues with small filters, but "smash" Ribbon is not accessible in public APIs. Unit test CompactnessAndBacktrackAndFpRate updated to test small and medium-large filters. Run with --thoroughness=100 or so for much better detection power (not appropriate for continuous regression testing). Homogenous Ribbon: This change adds internally a Ribbon filter variant we call Homogeneous Ribbon, in collaboration with Stefan Walzer. The expected "result" value for every key is zero, instead of computed from a hash. Entropy for queries not to be false positives comes from free variables ("overhead") in the solution structure, which are populated pseudorandomly. Construction is slightly faster for not tracking result values, and never fails. Instead, FP rate can jump up whenever and whereever entries are packed too tightly. For small structures, we can choose overhead to make this FP rate jump unlikely, as seen in updated unit test CompactnessAndBacktrackAndFpRate. Unlike standard Ribbon, Homogeneous Ribbon seems to scale to arbitrary number of keys when accepting an FP rate penalty for small pockets of high FP rate in the structure. For example, 64-bit ribbon with 8 solution columns and 10% allocated space overhead for slots seems to achieve about 10.5% space overhead vs. information-theoretic minimum based on its observed FP rate with expected pockets of degradation. (FP rate is close to 1/256.) If targeting a higher FP rate with fewer solution columns, Homogeneous Ribbon can be even more space efficient, because the penalty from degradation is relatively smaller. If targeting a lower FP rate, Homogeneous Ribbon is less space efficient, as more allocated overhead is needed to keep the FP rate impact of degradation relatively under control. The new OptimizeHomogAtScale tool in ribbon_test helps to find these optimal allocation overheads for different numbers of solution columns. And Ribbon widths, with 128-bit Ribbon apparently cutting space overheads in half vs. 64-bit. Other misc item specifics: * Ribbon APIs in util/ribbon_config.h now provide configuration data for not just 5% construction failure rate (95% success), but also 50% and 0.1%. * Note that the Ribbon structure does not exhibit "threshold" behavior as standard Xor filter does, so there is a roughly fixed space penalty to cut construction failure rate in half. Thus, there isn't really an "almost sure" setting. * Although we can extrapolate settings for large filters, we don't have a good formula for configuring smaller filters (< 2^17 slots or so), and efforts to summarize with a formula have failed. Thus, small data is hard-coded from updated FindOccupancy tool. * Enhances ApproximateNumEntries for public API Ribbon using more precise data (new API GetNumToAdd), thus a more accurate but not perfect reversal of CalculateSpace. (bloom_test updated to expect the greater precision) * Move EndianSwapValue from coding.h to coding_lean.h to keep Ribbon code easily transferable from RocksDB * Add some missing 'const' to member functions * Small optimization to 128-bit BitParity * Small refactoring of BandingStorage in ribbon_alg.h to support Homogeneous Ribbon * CompactnessAndBacktrackAndFpRate now has an "expand" test: on construction failure, a possible alternative to re-seeding hash functions is simply to increase the number of slots (allocated space overhead) and try again with essentially the same hash values. (Start locations will be different roundings of the same scaled hash values--because fastrange not mod.) This seems to be as effective or more effective than re-seeding, as long as we increase the number of slots (m) by roughly m += m/w where w is the Ribbon width. This way, there is effectively an expansion by one slot for each ribbon-width window in the banding. (This approach assumes that getting "bad data" from your hash function is as unlikely as it naturally should be, e.g. no adversary.) * 32-bit and 16-bit Ribbon configurations are added to ribbon_test for understanding their behavior, e.g. with FindOccupancy. They are not considered useful at this time and not tested with CompactnessAndBacktrackAndFpRate. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7879 Test Plan: unit test updates included Reviewed By: jay-zhuang Differential Revision: D26371245 Pulled By: pdillinger fbshipit-source-id: da6600d90a3785b99ad17a88b2a3027710b4ea3a	4 years ago
sherriiiliu	e017af15c1	Fix testcase failures on windows (#7992) ... Summary: Fixed 5 test case failures found on Windows 10/Windows Server 2016 1. In `flush_job_test`, the DestroyDir function fails in deconstructor because some file handles are still being held by VersionSet. This happens on Windows Server 2016, so need to manually reset versions_ pointer to release all file handles. 2. In `StatsHistoryTest.InMemoryStatsHistoryPurging` test, the capping memory cost of stats_history_size on Windows becomes 14000 bytes with latest changes, not just 13000 bytes. 3. In `SSTDumpToolTest.RawOutput` test, the output file handle is not closed at the end. 4. In `FullBloomTest.OptimizeForMemory` test, ROCKSDB_MALLOC_USABLE_SIZE is undefined on windows so `total_mem` is always equal to `total_size`. The internal memory fragmentation assertion does not apply in this case. 5. In `BlockFetcherTest.FetchAndUncompressCompressedDataBlock` test, XPRESS cannot reach 87.5% compression ratio with original CreateTable method, so I append extra zeros to the string value to enhance compression ratio. Beside, since XPRESS allocates memory internally, thus does not support for custom allocator verification, we will skip the allocator verification for XPRESS Pull Request resolved: https://github.com/facebook/rocksdb/pull/7992 Reviewed By: jay-zhuang Differential Revision: D26615283 Pulled By: ajkr fbshipit-source-id: 3632612f84b99e2b9c77c403b112b6bedf3b125d	4 years ago
Peter Dillinger	239d17a19c	Support optimize_filters_for_memory for Ribbon filter (#7774) ... Summary: Primarily this change refactors the optimize_filters_for_memory code for Bloom filters, based on malloc_usable_size, to also work for Ribbon filters. This change also replaces the somewhat slow but general BuiltinFilterBitsBuilder::ApproximateNumEntries with implementation-specific versions for Ribbon (new) and Legacy Bloom (based on a recently deleted version). The reason is to emphasize speed in ApproximateNumEntries rather than 100% accuracy. Justification: ApproximateNumEntries (formerly CalculateNumEntry) is only used by RocksDB for range-partitioned filters, called each time we start to construct one. (In theory, it should be possible to reuse the estimate, but the abstractions provided by FilterPolicy don't really make that workable.) But this is only used as a heuristic estimate for hitting a desired partitioned filter size because of alignment to data blocks, which have various numbers of unique keys or prefixes. The two factors lead us to prioritize reasonable speed over 100% accuracy. optimize_filters_for_memory adds extra complication, because precisely calculating num_entries for some allowed number of bytes depends on state with optimize_filters_for_memory enabled. And the allocator-agnostic implementation of optimize_filters_for_memory, using malloc_usable_size, means we would have to actually allocate memory, many times, just to precisely determine how many entries (keys) could be added and stay below some size budget, for the current state. (In a draft, I got this working, and then realized the balance of speed vs. accuracy was all wrong.) So related to that, I have made CalculateSpace, an internal-only API only used for testing, non-authoritative also if optimize_filters_for_memory is enabled. This simplifies some code. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7774 Test Plan: unit test updated, and for FilterSize test, range of tested values is greatly expanded (still super fast) Also tested `db_bench -benchmarks=fillrandom,stats -bloom_bits=10 -num=1000000 -partition_index_and_filters -format_version=5 [-optimize_filters_for_memory] [-use_ribbon_filter]` with temporary debug output of generated filter sizes. Bloom+optimize_filters_for_memory: 1 Filter size: 197 (224 in memory) 134 Filter size: 3525 (3584 in memory) 107 Filter size: 4037 (4096 in memory) Total on disk: 904,506 Total in memory: 918,752 Ribbon+optimize_filters_for_memory: 1 Filter size: 3061 (3072 in memory) 110 Filter size: 3573 (3584 in memory) 58 Filter size: 4085 (4096 in memory) Total on disk: 633,021 (-30.0%) Total in memory: 634,880 (-30.9%) Bloom (no offm): 1 Filter size: 261 (320 in memory) 1 Filter size: 3333 (3584 in memory) 240 Filter size: 3717 (4096 in memory) Total on disk: 895,674 (-1% on disk vs. +offm; known tolerable overhead of offm) Total in memory: 986,944 (+7.4% vs. +offm) Ribbon (no offm): 1 Filter size: 2949 (3072 in memory) 1 Filter size: 3381 (3584 in memory) 167 Filter size: 3701 (4096 in memory) Total on disk: 624,397 (-30.3% vs. Bloom) Total in memory: 690,688 (-30.0% vs. Bloom) Note that optimize_filters_for_memory is even more effective for Ribbon filter than for cache-local Bloom, because it can close the unused memory gap even tighter than Bloom filter, because of 16 byte increments for Ribbon vs. 64 byte increments for Bloom. Reviewed By: jay-zhuang Differential Revision: D25592970 Pulled By: pdillinger fbshipit-source-id: 606fdaa025bb790d7e9c21601e8ea86e10541912	4 years ago
Peter Dillinger	003e72b201	Use size_t for filter APIs, protect against overflow (#7726) ... Summary: Deprecate CalculateNumEntry and replace with ApproximateNumEntries (better name) using size_t instead of int and uint32_t, to minimize confusing casts and bad overflow behavior (possible though probably not realistic). Bloom sizes are now explicitly capped at max size supported by implementations: just under 4GiB for fv=5 Bloom, and just under 512MiB for fv<5 Legacy Bloom. This hardening could help to set up for fuzzing. Also, since RocksDB only uses this information as an approximation for trying to hit certain sizes for partitioned filters, it's more important that the function be reasonably fast than for it to be completely accurate. It's hard enough to be 100% accurate for Ribbon (currently reversing CalculateSpace) that adding optimize_filters_for_memory into the mix is just not worth trying to be 100% accurate for num entries for bytes. Also: - Cleaned up filter_policy.h to remove MSVC warning handling and potentially unsafe use of exception for "not implemented" - Correct the number of entries limit beyond which current Ribbon implementation falls back on Bloom instead. - Consistently use "num_entries" rather than "num_entry" - Remove LegacyBloomBitsBuilder::CalculateNumEntry as it's essentially obsolete from general implementation BuiltinFilterBitsBuilder::CalculateNumEntries. - Fix filter_bench to skip some tests that don't make sense when only one or a small number of filters has been generated. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7726 Test Plan: expanded existing unit tests for CalculateSpace / ApproximateNumEntries. Also manually used filter_bench to verify Legacy and fv=5 Bloom size caps work (much too expensive for unit test). Note that the actual bits per key is below requested due to space cap. $ ./filter_bench -impl=0 -bits_per_key=20 -average_keys_per_filter=256000000 -vary_key_count_ratio=0 -m_keys_total_max=256 -allow_bad_fp_rate ... Total size (MB): 511.992 Bits/key stored: 16.777 ... $ ./filter_bench -impl=2 -bits_per_key=20 -average_keys_per_filter=2000000000 -vary_key_count_ratio=0 -m_keys_total_max=2000 ... Total size (MB): 4096 Bits/key stored: 17.1799 ... $ Reviewed By: jay-zhuang Differential Revision: D25239800 Pulled By: pdillinger fbshipit-source-id: f94e6d065efd31e05ec630ae1a82e6400d8390c4	4 years ago
Peter Dillinger	0baa5055f1	Add Ribbon schema test to bloom_test (#7696) ... Summary: These new unit tests should ensure that we don't accidentally change the interpretation of bits for what I call Standard128Ribbon filter internally, available publicly as NewExperimentalRibbonFilterPolicy. There is very little intuitive reason for the values we check against in these tests; I just plug in the right expected values upon watching the test fail initially. Most (but not all) of the tests are essentially "whitebox" "round-trip." We create a filter from fixed keys, and first compare the checksum of those filter bytes against a saved value. We also run queries against other fixed keys, comparing which return false positives against a saved set. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7696 Test Plan: test addition and refactoring only Reviewed By: jay-zhuang Differential Revision: D25082289 Pulled By: pdillinger fbshipit-source-id: b5ca646fdcb5a1c2ad2085eda4a1fd44c4287f67	4 years ago
Peter Dillinger	60af964372	Experimental (production candidate) SST schema for Ribbon filter (#7658) ... Summary: Added experimental public API for Ribbon filter: NewExperimentalRibbonFilterPolicy(). This experimental API will take a "Bloom equivalent" bits per key, and configure the Ribbon filter for the same FP rate as Bloom would have but ~30% space savings. (Note: optimize_filters_for_memory is not yet implemented for Ribbon filter. That can be added with no effect on schema.) Internally, the Ribbon filter is configured using a "one_in_fp_rate" value, which is 1 over desired FP rate. For example, use 100 for 1% FP rate. I'm expecting this will be used in the future for configuring Bloom-like filters, as I expect people to more commonly hold constant the filter accuracy and change the space vs. time trade-off, rather than hold constant the space (per key) and change the accuracy vs. time trade-off, though we might make that available. ### Benchmarking ``` $ ./filter_bench -impl=2 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing Building... Build avg ns/key: 34.1341 Number of filters: 1993 Total size (MB): 238.488 Reported total allocated memory (MB): 262.875 Reported internal fragmentation: 10.2255% Bits/key stored: 10.0029 ---------------------------- Mixed inside/outside queries... Single filter net ns/op: 18.7508 Random filter net ns/op: 258.246 Average FP rate %: 0.968672 ---------------------------- Done. (For more info, run with -legend or -help.) $ ./filter_bench -impl=3 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing Building... Build avg ns/key: 130.851 Number of filters: 1993 Total size (MB): 168.166 Reported total allocated memory (MB): 183.211 Reported internal fragmentation: 8.94626% Bits/key stored: 7.05341 ---------------------------- Mixed inside/outside queries... Single filter net ns/op: 58.4523 Random filter net ns/op: 363.717 Average FP rate %: 0.952978 ---------------------------- Done. (For more info, run with -legend or -help.) ``` 168.166 / 238.488 = 0.705 -> 29.5% space reduction 130.851 / 34.1341 = 3.83x construction time for this Ribbon filter vs. lastest Bloom filter (could make that as little as about 2.5x for less space reduction) ### Working around a hashing "flaw" bloom_test discovered a flaw in the simple hashing applied in StandardHasher when num_starts == 1 (num_slots == 128), showing an excessively high FP rate. The problem is that when many entries, on the order of number of hash bits or kCoeffBits, are associated with the same start location, the correlation between the CoeffRow and ResultRow (for efficiency) can lead to a solution that is "universal," or nearly so, for entries mapping to that start location. (Normally, variance in start location breaks the effective association between CoeffRow and ResultRow; the same value for CoeffRow is effectively different if start locations are different.) Without kUseSmash and with num_starts > 1 (thus num_starts ~= num_slots), this flaw should be completely irrelevant. Even with 10M slots, the chances of a single slot having just 16 (or more) entries map to it--not enough to cause an FP problem, which would be local to that slot if it happened--is 1 in millions. This spreadsheet formula shows that: =1/(10000000*(1 - POISSON(15, 1, TRUE))) As kUseSmash==false (the setting for Standard128RibbonBitsBuilder) is intended for CPU efficiency of filters with many more entries/slots than kCoeffBits, a very reasonable work-around is to disallow num_starts==1 when !kUseSmash, by making the minimum non-zero number of slots 2*kCoeffBits. This is the work-around I've applied. This also means that the new Ribbon filter schema (Standard128RibbonBitsBuilder) is not space-efficient for less than a few hundred entries. Because of this, I have made it fall back on constructing a Bloom filter, under existing schema, when that is more space efficient for small filters. (We can change this in the future if we want.) TODO: better unit tests for this case in ribbon_test, and probably update StandardHasher for kUseSmash case so that it can scale nicely to small filters. ### Other related changes * Add Ribbon filter to stress/crash test * Add Ribbon filter to filter_bench as -impl=3 * Add option string support, as in "filter_policy=experimental_ribbon:5.678;" where 5.678 is the Bloom equivalent bits per key. * Rename internal mode BloomFilterPolicy::kAuto to kAutoBloom * Add a general BuiltinFilterBitsBuilder::CalculateNumEntry based on binary searching CalculateSpace (inefficient), so that subclasses (especially experimental ones) don't have to provide an efficient implementation inverting CalculateSpace. * Minor refactor FastLocalBloomBitsBuilder for new base class XXH3pFilterBitsBuilder shared with new Standard128RibbonBitsBuilder, which allows the latter to fall back on Bloom construction in some extreme cases. * Mostly updated bloom_test for Ribbon filter, though a test like FullBloomTest::Schema is a next TODO to ensure schema stability (in case this becomes production-ready schema as it is). * Add some APIs to ribbon_impl.h for configuring Ribbon filters. Although these are reasonably covered by bloom_test, TODO more unit tests in ribbon_test * Added a "tool" FindOccupancyForSuccessRate to ribbon_test to get data for constructing the linear approximations in GetNumSlotsFor95PctSuccess. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7658 Test Plan: Some unit tests updated but other testing is left TODO. This is considered experimental but laying down schema compatibility as early as possible in case it proves production-quality. Also tested in stress/crash test. Reviewed By: jay-zhuang Differential Revision: D24899349 Pulled By: pdillinger fbshipit-source-id: 9715f3e6371c959d923aea8077c9423c7a9f82b8	4 years ago
Yanqin Jin	394210f280	Remove unused includes (#7604) ... Summary: This is a PR generated **semi-automatically** by an internal tool to remove unused includes and `using` statements. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7604 Test Plan: make check Reviewed By: ajkr Differential Revision: D24579392 Pulled By: riversand963 fbshipit-source-id: c4bfa6c6b08da1de186690d37eb73d8fff45aecd	4 years ago
Peter Dillinger	5b2bbacb6f	Minimize memory internal fragmentation for Bloom filters (#6427) ... Summary: New experimental option BBTO::optimize_filters_for_memory builds filters that maximize their use of "usable size" from malloc_usable_size, which is also used to compute block cache charges. Rather than always "rounding up," we track state in the BloomFilterPolicy object to mix essentially "rounding down" and "rounding up" so that the average FP rate of all generated filters is the same as without the option. (YMMV as heavily accessed filters might be unluckily lower accuracy.) Thus, the option near-minimizes what the block cache considers as "memory used" for a given target Bloom filter false positive rate and Bloom filter implementation. There are no forward or backward compatibility issues with this change, though it only works on the format_version=5 Bloom filter. With Jemalloc, we see about 10% reduction in memory footprint (and block cache charge) for Bloom filters, but 1-2% increase in storage footprint, due to encoding efficiency losses (FP rate is non-linear with bits/key). Why not weighted random round up/down rather than state tracking? By only requiring malloc_usable_size, we don't actually know what the next larger and next smaller usable sizes for the allocator are. We pick a requested size, accept and use whatever usable size it has, and use the difference to inform our next choice. This allows us to narrow in on the right balance without tracking/predicting usable sizes. Why not weight history of generated filter false positive rates by number of keys? This could lead to excess skew in small filters after generating a large filter. Results from filter_bench with jemalloc (irrelevant details omitted): (normal keys/filter, but high variance) $ ./filter_bench -quick -impl=2 -average_keys_per_filter=30000 -vary_key_count_ratio=0.9 Build avg ns/key: 29.6278 Number of filters: 5516 Total size (MB): 200.046 Reported total allocated memory (MB): 220.597 Reported internal fragmentation: 10.2732% Bits/key stored: 10.0097 Average FP rate %: 0.965228 $ ./filter_bench -quick -impl=2 -average_keys_per_filter=30000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory Build avg ns/key: 30.5104 Number of filters: 5464 Total size (MB): 200.015 Reported total allocated memory (MB): 200.322 Reported internal fragmentation: 0.153709% Bits/key stored: 10.1011 Average FP rate %: 0.966313 (very few keys / filter, optimization not as effective due to ~59 byte internal fragmentation in blocked Bloom filter representation) $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000 -vary_key_count_ratio=0.9 Build avg ns/key: 29.5649 Number of filters: 162950 Total size (MB): 200.001 Reported total allocated memory (MB): 224.624 Reported internal fragmentation: 12.3117% Bits/key stored: 10.2951 Average FP rate %: 0.821534 $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory Build avg ns/key: 31.8057 Number of filters: 159849 Total size (MB): 200 Reported total allocated memory (MB): 208.846 Reported internal fragmentation: 4.42297% Bits/key stored: 10.4948 Average FP rate %: 0.811006 (high keys/filter) $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000000 -vary_key_count_ratio=0.9 Build avg ns/key: 29.7017 Number of filters: 164 Total size (MB): 200.352 Reported total allocated memory (MB): 221.5 Reported internal fragmentation: 10.5552% Bits/key stored: 10.0003 Average FP rate %: 0.969358 $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory Build avg ns/key: 30.7131 Number of filters: 160 Total size (MB): 200.928 Reported total allocated memory (MB): 200.938 Reported internal fragmentation: 0.00448054% Bits/key stored: 10.1852 Average FP rate %: 0.963387 And from db_bench (block cache) with jemalloc: $ ./db_bench -db=/dev/shm/dbbench.no_optimize -benchmarks=fillrandom -format_version=5 -value_size=90 -bloom_bits=10 -num=2000000 -threads=8 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false $ ./db_bench -db=/dev/shm/dbbench -benchmarks=fillrandom -format_version=5 -value_size=90 -bloom_bits=10 -num=2000000 -threads=8 -optimize_filters_for_memory -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false $ (for FILE in /dev/shm/dbbench.no_optimize/*.sst; do ./sst_dump --file=$FILE --show_properties | grep 'filter block' ; done) | awk '{ t += $4; } END { print t; }' 17063835 $ (for FILE in /dev/shm/dbbench/*.sst; do ./sst_dump --file=$FILE --show_properties | grep 'filter block' ; done) | awk '{ t += $4; } END { print t; }' 17430747 $ #^ 2.1% additional filter storage $ ./db_bench -db=/dev/shm/dbbench.no_optimize -use_existing_db -benchmarks=readrandom,stats -statistics -bloom_bits=10 -num=2000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false -duration=10 -cache_index_and_filter_blocks -cache_size=1000000000 rocksdb.block.cache.index.add COUNT : 33 rocksdb.block.cache.index.bytes.insert COUNT : 8440400 rocksdb.block.cache.filter.add COUNT : 33 rocksdb.block.cache.filter.bytes.insert COUNT : 21087528 rocksdb.bloom.filter.useful COUNT : 4963889 rocksdb.bloom.filter.full.positive COUNT : 1214081 rocksdb.bloom.filter.full.true.positive COUNT : 1161999 $ #^ 1.04 % observed FP rate $ ./db_bench -db=/dev/shm/dbbench -use_existing_db -benchmarks=readrandom,stats -statistics -bloom_bits=10 -num=2000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false -optimize_filters_for_memory -duration=10 -cache_index_and_filter_blocks -cache_size=1000000000 rocksdb.block.cache.index.add COUNT : 33 rocksdb.block.cache.index.bytes.insert COUNT : 8448592 rocksdb.block.cache.filter.add COUNT : 33 rocksdb.block.cache.filter.bytes.insert COUNT : 18220328 rocksdb.bloom.filter.useful COUNT : 5360933 rocksdb.bloom.filter.full.positive COUNT : 1321315 rocksdb.bloom.filter.full.true.positive COUNT : 1262999 $ #^ 1.08 % observed FP rate, 13.6% less memory usage for filters (Due to specific key density, this example tends to generate filters that are "worse than average" for internal fragmentation. "Better than average" cases can show little or no improvement.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/6427 Test Plan: unit test added, 'make check' with gcc, clang and valgrind Reviewed By: siying Differential Revision: D22124374 Pulled By: pdillinger fbshipit-source-id: f3e3aa152f9043ddf4fae25799e76341d0d8714e	4 years ago
sdong	afa3518839	Revert "Update googletest from 1.8.1 to 1.10.0 (#6808)" (#6923) ... Summary: This reverts commit 8d87e9cea1. Based on offline discussions, it's too early to upgrade to gtest 1.10, as it prevents some developers from using an older version of gtest to integrate to some other systems. Revert it for now. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6923 Reviewed By: pdillinger Differential Revision: D21864799 fbshipit-source-id: d0726b1ff649fc911b9378f1763316200bd363fc	5 years ago
Adam Retter	8d87e9cea1	Update googletest from 1.8.1 to 1.10.0 (#6808) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6808 Reviewed By: anand1976 Differential Revision: D21483984 Pulled By: pdillinger fbshipit-source-id: 70c5eff2bd54ddba469761d95e4cd4611fb8e598	5 years ago
Huisheng Liu	07a3f7f008	fix MSVC build failures (#6517) ... Summary: fix a few build warnings that are treated as failures with more strict MSVC warning settings Pull Request resolved: https://github.com/facebook/rocksdb/pull/6517 Differential Revision: D20401325 Pulled By: pdillinger fbshipit-source-id: b44979dfaafdc7b3b8cb44a565400a99b331dd30	5 years ago
sdong	fdf882ded2	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) ... Summary: When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433 Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag. Differential Revision: D19977691 fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e	5 years ago
Peter Dillinger	ca3b6c28c9	Expose and elaborate FilterBuildingContext (#6088) ... Summary: This change enables custom implementations of FilterPolicy to wrap a variety of NewBloomFilterPolicy and select among them based on contextual information such as table level and compaction style. * Moves FilterBuildingContext to public API and elaborates it with more useful data. (It would be nice to put more general options-like data, but at the time this object is constructed, we are using internal APIs ImmutableCFOptions and MutableCFOptions and don't have easy access to ColumnFamilyOptions that I can tell.) * Renames BloomFilterPolicy::GetFilterBitsBuilderInternal to GetBuilderWithContext, because it's now public. * Plumbs through the table's "level_at_creation" for filter building context. * Simplified some tests by adding GetBuilder() to MockBlockBasedTableTester. * Adds test as DBBloomFilterTest.ContextCustomFilterPolicy, including sample wrapper class LevelAndStyleCustomFilterPolicy. * Fixes a cross-test bug in DBBloomFilterTest.OptimizeFiltersForHits where it does not reset perf context. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6088 Test Plan: make check, valgrind on db_bloom_filter_test Differential Revision: D18697817 Pulled By: pdillinger fbshipit-source-id: 5f987a2d7b07cc7a33670bc08ca6b4ca698c1cf4	5 years ago
Peter Dillinger	57f3032285	Allow fractional bits/key in BloomFilterPolicy (#6092) ... Summary: There's no technological impediment to allowing the Bloom filter bits/key to be non-integer (fractional/decimal) values, and it provides finer control over the memory vs. accuracy trade-off. This is especially handy in using the format_version=5 Bloom filter in place of the old one, because bits_per_key=9.55 provides the same accuracy as the old bits_per_key=10. This change not only requires refining the logic for choosing the best num_probes for a given bits/key setting, it revealed a flaw in that logic. As bits/key gets higher, the best num_probes for a cache-local Bloom filter is closer to bpk / 2 than to bpk * 0.69, the best choice for a standard Bloom filter. For example, at 16 bits per key, the best num_probes is 9 (FP rate = 0.0843%) not 11 (FP rate = 0.0884%). This change fixes and refines that logic (for the format_version=5 Bloom filter only, just in case) based on empirical tests to find accuracy inflection points between each num_probes. Although bits_per_key is now specified as a double, the new Bloom filter converts/rounds this to "millibits / key" for predictable/precise internal computations. Just in case of unforeseen compatibility issues, we round to the nearest whole number bits / key for the legacy Bloom filter, so as not to unlock new behaviors for it. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6092 Test Plan: unit tests included Differential Revision: D18711313 Pulled By: pdillinger fbshipit-source-id: 1aa73295f152a995328cb846ef9157ae8a05522a	5 years ago
Peter Dillinger	f059c7d9b9	New Bloom filter implementation for full and partitioned filters (#6007) ... Summary: Adds an improved, replacement Bloom filter implementation (FastLocalBloom) for full and partitioned filters in the block-based table. This replacement is faster and more accurate, especially for high bits per key or millions of keys in a single filter. Speed The improved speed, at least on recent x86_64, comes from * Using fastrange instead of modulo (%) * Using our new hash function (XXH3 preview, added in a previous commit), which is much faster for large keys and only *slightly* slower on keys around 12 bytes if hashing the same size many thousands of times in a row. * Optimizing the Bloom filter queries with AVX2 SIMD operations. (Added AVX2 to the USE_SSE=1 build.) Careful design was required to support (a) SIMD-optimized queries, (b) compatible non-SIMD code that's simple and efficient, (c) flexible choice of number of probes, and (d) essentially maximized accuracy for a cache-local Bloom filter. Probes are made eight at a time, so any number of probes up to 8 is the same speed, then up to 16, etc. * Prefetching cache lines when building the filter. Although this optimization could be applied to the old structure as well, it seems to balance out the small added cost of accumulating 64 bit hashes for adding to the filter rather than 32 bit hashes. Here's nominal speed data from filter_bench (200MB in filters, about 10k keys each, 10 bits filter data / key, 6 probes, avg key size 24 bytes, includes hashing time) on Skylake DE (relatively low clock speed): $ ./filter_bench -quick -impl=2 -net_includes_hashing # New Bloom filter Build avg ns/key: 47.7135 Mixed inside/outside queries... Single filter net ns/op: 26.2825 Random filter net ns/op: 150.459 Average FP rate %: 0.954651 $ ./filter_bench -quick -impl=0 -net_includes_hashing # Old Bloom filter Build avg ns/key: 47.2245 Mixed inside/outside queries... Single filter net ns/op: 63.2978 Random filter net ns/op: 188.038 Average FP rate %: 1.13823 Similar build time but dramatically faster query times on hot data (63 ns to 26 ns), and somewhat faster on stale data (188 ns to 150 ns). Performance differences on batched and skewed query loads are between these extremes as expected. The only other interesting thing about speed is "inside" (query key was added to filter) vs. "outside" (query key was not added to filter) query times. The non-SIMD implementations are substantially slower when most queries are "outside" vs. "inside". This goes against what one might expect or would have observed years ago, as "outside" queries only need about two probes on average, due to short-circuiting, while "inside" always have num_probes (say 6). The problem is probably the nastily unpredictable branch. The SIMD implementation has few branches (very predictable) and has pretty consistent running time regardless of query outcome. Accuracy The generally improved accuracy (re: Issue https://github.com/facebook/rocksdb/issues/5857) comes from a better design for probing indices within a cache line (re: Issue https://github.com/facebook/rocksdb/issues/4120) and improved accuracy for millions of keys in a single filter from using a 64-bit hash function (XXH3p). Design details in code comments. Accuracy data (generalizes, except old impl gets worse with millions of keys): Memory bits per key: FP rate percent old impl -> FP rate percent new impl 6: 5.70953 -> 5.69888 8: 2.45766 -> 2.29709 10: 1.13977 -> 0.959254 12: 0.662498 -> 0.411593 16: 0.353023 -> 0.0873754 24: 0.261552 -> 0.0060971 50: 0.225453 -> ~0.00003 (less than 1 in a million queries are FP) Fixes https://github.com/facebook/rocksdb/issues/5857 Fixes https://github.com/facebook/rocksdb/issues/4120 Unlike the old implementation, this implementation has a fixed cache line size (64 bytes). At 10 bits per key, the accuracy of this new implementation is very close to the old implementation with 128-byte cache line size. If there's sufficient demand, this implementation could be generalized. Compatibility Although old releases would see the new structure as corrupt filter data and read the table as if there's no filter, we've decided only to enable the new Bloom filter with new format_version=5. This provides a smooth path for automatic adoption over time, with an option for early opt-in. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6007 Test Plan: filter_bench has been used thoroughly to validate speed, accuracy, and correctness. Unit tests have been carefully updated to exercise new and old implementations, as well as the logic to select an implementation based on context (format_version). Differential Revision: D18294749 Pulled By: pdillinger fbshipit-source-id: d44c9db3696e4d0a17caaec47075b7755c262c5f	5 years ago
Peter Dillinger	685e895652	Prepare filter tests for more implementations (#5967) ... Summary: This change sets up for alternate implementations underlying BloomFilterPolicy: * Refactor BloomFilterPolicy and expose in internal .h file so that it's easy to iterate over / select implementations for testing, regardless of what the best public interface will look like. Most notably updated db_bloom_filter_test to use this. * Hide FullFilterBitsBuilder from unit tests (alternate derived classes planned); expose the part important for testing (CalculateSpace), as abstract class BuiltinFilterBitsBuilder. (Also cleaned up internally exposed interface to CalculateSpace.) * Rename BloomTest -> BlockBasedBloomTest for clarity (despite ongoing confusion between block-based table and block-based filter) * Assert that block-based filter construction interface is only used on BloomFilterPolicy appropriately constructed. (A couple of tests updated to add ", true".) Pull Request resolved: https://github.com/facebook/rocksdb/pull/5967 Test Plan: make check Differential Revision: D18138704 Pulled By: pdillinger fbshipit-source-id: 55ef9273423b0696309e251f50b8c1b5e9ec7597	5 years ago
Peter Dillinger	013babc685	Clean up some filter tests and comments (#5960) ... Summary: Some filtering tests were unfriendly to new implementations of FilterBitsBuilder because of dynamic_cast to FullFilterBitsBuilder. Most of those have now been cleaned up, worked around, or at least changed from crash on dynamic_cast failure to individual test failure. Also put some clarifying comments on filter-related APIs. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5960 Test Plan: make check Differential Revision: D18121223 Pulled By: pdillinger fbshipit-source-id: e83827d9d5d96315d96f8e25a99cd70f497d802c	5 years ago
Peter Dillinger	dd19014a7a	FilterPolicy consolidation, part 1/2 (#5963) ... Summary: The parts that are used to implement FilterPolicy / NewBloomFilterPolicy and not used other than for the block-based table should be consolidated under table/block_based/filter_policy*. I don't foresee sharing these APIs with e.g. the Plain Table because they don't expose hashes for reuse in indexing. This change is step 1 of 2: (a) mv table/full_filter_bits_builder.h to table/block_based/filter_policy_internal.h which I expect to expand soon to internally reveal more implementation details for testing. (b) consolidate eventual contents of table/block_based/filter_policy.cc in util/bloom.cc, which has the most elaborate revision history (see step 2 ...) Step 2 soon to follow: mv util/bloom.cc table/block_based/filter_policy.cc This gets its own PR so that git has the best chance of following the rename for blame purposes. Note that low-level shared implementation details of Bloom filters are in util/bloom_impl.h. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5963 Test Plan: make check Differential Revision: D18121199 Pulled By: pdillinger fbshipit-source-id: 8f21732c3d8909777e3240e4ac3123d73140326a	5 years ago
Peter Dillinger	5f8f2fda0e	Refactor / clean up / optimize FullFilterBitsReader (#5941) ... Summary: FullFilterBitsReader, after creating in BloomFilterPolicy, was responsible for decoding metadata bits. This meant that FullFilterBitsReader::MayMatch had some metadata checks in order to implement "always true" or "always false" functionality in the case of inconsistent or trivial metadata. This made for ugly mixing-of-concerns code and probably had some runtime cost. It also didn't really support plugging in alternative filter implementations with extensions to the existing metadata schema. BloomFilterPolicy::GetFilterBitsReader is now (exclusively) responsible for decoding filter metadata bits and constructing appropriate instances deriving from FilterBitsReader. "Always false" and "always true" derived classes allow FullFilterBitsReader not to be concerned with handling of trivial or inconsistent metadata. This also makes for easy expansion to alternative filter implementations in new, alternative derived classes. This change makes calls to FilterBitsReader::MayMatch *necessarily* virtual because there's now more than one built-in implementation. Compared with the previous implementation's extra 'if' checks in MayMatch, there's no consistent performance difference, measured by (an older revision of) filter_bench (differences here seem to be within noise): Inside queries... - Dry run (407) ns/op: 35.9996 + Dry run (407) ns/op: 35.2034 - Single filter ns/op: 47.5483 + Single filter ns/op: 47.4034 - Batched, prepared ns/op: 43.1559 + Batched, prepared ns/op: 42.2923 ... - Random filter ns/op: 150.697 + Random filter ns/op: 149.403 ---------------------------- Outside queries... - Dry run (980) ns/op: 34.6114 + Dry run (980) ns/op: 34.0405 - Single filter ns/op: 56.8326 + Single filter ns/op: 55.8414 - Batched, prepared ns/op: 48.2346 + Batched, prepared ns/op: 47.5667 - Random filter ns/op: 155.377 + Random filter ns/op: 153.942 Average FP rate %: 1.1386 Also, the FullFilterBitsReader ctor was responsible for a surprising amount of CPU in production, due in part to inefficient determination of the CACHE_LINE_SIZE used to construct the filter being read. The overwhelming common case (same as my CACHE_LINE_SIZE) is now substantially optimized, as shown with filter_bench with -new_reader_every=1 (old option - see below) (repeatable result): Inside queries... - Dry run (453) ns/op: 118.799 + Dry run (453) ns/op: 105.869 - Single filter ns/op: 82.5831 + Single filter ns/op: 74.2509 ... - Random filter ns/op: 224.936 + Random filter ns/op: 194.833 ---------------------------- Outside queries... - Dry run (aa1) ns/op: 118.503 + Dry run (aa1) ns/op: 104.925 - Single filter ns/op: 90.3023 + Single filter ns/op: 83.425 ... - Random filter ns/op: 220.455 + Random filter ns/op: 175.7 Average FP rate %: 1.13886 However PR#5936 has/will reclaim most of this cost. After that PR, the optimization of this code path is likely negligible, but nonetheless it's clear we aren't making performance any worse. Also fixed inadequate check of consistency between filter data size and num_lines. (Unit test updated.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/5941 Test Plan: previously added unit tests FullBloomTest.CorruptFilters and FullBloomTest.RawSchema Differential Revision: D18018353 Pulled By: pdillinger fbshipit-source-id: 8e04c2b4a7d93223f49a237fd52ef2483929ed9c	5 years ago
Peter Dillinger	93edd51c4a	bloom_test.cc: include <array> (#5920) ... Summary: Fix build failure on some platforms, reported in issue https://github.com/facebook/rocksdb/issues/5914 Pull Request resolved: https://github.com/facebook/rocksdb/pull/5920 Test Plan: make bloom_test && ./bloom_test Differential Revision: D17918328 Pulled By: pdillinger fbshipit-source-id: b822004d4442de0171db2aeff433677783f7b94e	5 years ago
Peter Dillinger	9f54446525	Fix type in shift operation in bloom_test (#5882) ... Summary: Broken type for shift in PR#5834. Fixing code means fixing expected values in test. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5882 Test Plan: thisisthetest Differential Revision: D17746136 Pulled By: pdillinger fbshipit-source-id: d3c456ed30b433d55fcab6fc7d836940fe3b46b8	5 years ago
Peter Dillinger	9e4913ce9d	Add FullBloomTest.CorruptFilters,RawSchema (#5834) ... Summary: There was significant untested logic in FullFilterBitsReader in the handling of serialized Bloom filter bits that cannot be generated by FullFilterBitsBuilder in the current compilation. These now test many of those corner-case behaviors, including bad metadata or filters created with different cache line size than the current compiled-in value. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5834 Test Plan: thisisthetest Differential Revision: D17726372 Pulled By: pdillinger fbshipit-source-id: fb7b8003b5a8e6fb4666fe95206128f3d5835fc7	5 years ago
sdong	e8263dbdaa	Apply formatter to recent 200+ commits. (#5830) ... Summary: Further apply formatter to more recent commits. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830 Test Plan: Run all existing tests. Differential Revision: D17488031 fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab	5 years ago
Peter Dillinger	68626249c3	Refactor/consolidate legacy Bloom implementation details (#5784) ... Summary: Refactoring to consolidate implementation details of legacy Bloom filters. This helps to organize and document some related, obscure code. Also added make/cpp var TEST_CACHE_LINE_SIZE so that it's easy to compile and run unit tests for non-native cache line size. (Fixed a related test failure in db_properties_test.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/5784 Test Plan: make check, including Recently added Bloom schema unit tests (in ./plain_table_db_test && ./bloom_test), and including with TEST_CACHE_LINE_SIZE=128U and TEST_CACHE_LINE_SIZE=256U. Tested the schema tests with temporary fault injection into new implementations. Some performance testing with modified unit tests suggest a small to moderate improvement in speed. Differential Revision: D17381384 Pulled By: pdillinger fbshipit-source-id: ee42586da996798910fc45ac0b6289147f16d8df	5 years ago
Peter Dillinger	d3a6726f02	Revert changes from PR#5784 accidentally in PR#5780 (#5810) ... Summary: This will allow us to fix history by having the code changes for PR#5784 properly attributed to it. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5810 Differential Revision: D17400231 Pulled By: pdillinger fbshipit-source-id: 2da8b1cdf2533cfedb35b5526eadefb38c291f09	5 years ago
Peter Dillinger	aa2486b23c	Refactor some confusing logic in PlainTableReader ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5780 Test Plan: existing plain table unit test Differential Revision: D17368629 Pulled By: pdillinger fbshipit-source-id: f25409cdc2f39ebe8d5cbb599cf820270e6b5d26	5 years ago
Peter Dillinger	108c619acb	Add regression test for serialized Bloom filters (#5778) ... Summary: Check that we don't accidentally change the on-disk format of existing Bloom filter implementations, including for various CACHE_LINE_SIZE (by changing temporarily). Pull Request resolved: https://github.com/facebook/rocksdb/pull/5778 Test Plan: thisisthetest Differential Revision: D17269630 Pulled By: pdillinger fbshipit-source-id: c77017662f010a77603b7d475892b1f0d5563d8b	5 years ago
HouBingjian	ac97e6930f	bloom test check fail on arm (#5745) ... Summary: FullFilterBitsBuilder::CalculateSpace use CACHE_LINE_SIZE which is 64@X86 but 128@ARM64 when it run bloom_test.FullVaryingLengths it failed on ARM64 server, the assert can be fixed by change 128->CACHE_LINE_SIZE*2 as merged ASSERT_LE(FilterSize(), (size_t)((length * 10 / 8) + CACHE_LINE_SIZE * 2 + 5)) << length; run bloom_test before fix: /root/rocksdb-master/util/bloom_test.cc:281: Failure Expected: (FilterSize()) <= ((size_t)((length * 10 / 8) + 128 + 5)), actual: 389 vs 383 200 [ FAILED ] FullBloomTest.FullVaryingLengths (32 ms) [----------] 4 tests from FullBloomTest (32 ms total) [----------] Global test environment tear-down [==========] 7 tests from 2 test cases ran. (116 ms total) [ PASSED ] 6 tests. [ FAILED ] 1 test, listed below: [ FAILED ] FullBloomTest.FullVaryingLengths after fix: Filters: 37 good, 0 mediocre [ OK ] FullBloomTest.FullVaryingLengths (90 ms) [----------] 4 tests from FullBloomTest (90 ms total) [----------] Global test environment tear-down [==========] 7 tests from 2 test cases ran. (174 ms total) [ PASSED ] 7 tests. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5745 Differential Revision: D17076047 fbshipit-source-id: e7beb5d55d4855fceb2b84bc8119a6b0759de635	5 years ago
Siying Dong	000b9ec217	Move some logging related files to logging/ (#5387) ... Summary: Many logging related source files are under util/. It will be more structured if they are together. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387 Differential Revision: D15579036 Pulled By: siying fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f	6 years ago
Siying Dong	8843129ece	Move some memory related files from util/ to memory/ (#5382) ... Summary: Move arena, allocator, and memory tools under util to a separate memory/ directory. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5382 Differential Revision: D15564655 Pulled By: siying fbshipit-source-id: 9cd6b5d0d3d52b39606e19221fa154596e5852a5	6 years ago
Siying Dong	e9e0101ca4	Move test related files under util/ to test_util/ (#5377) ... Summary: There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo ve them to a new directory test_util/, so that util/ is cleaner. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377 Differential Revision: D15551366 Pulled By: siying fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c	6 years ago
Michael Liu	ca89ac2ba9	Apply modernize-use-override (2nd iteration) ... Summary: Use C++11’s override and remove virtual where applicable. Change are automatically generated. Reviewed By: Orvid Differential Revision: D14090024 fbshipit-source-id: 1e9432e87d2657e1ff0028e15370a85d1739ba2a	6 years ago
Andrew Kryczka	63f1c0a57d	fix gflags namespace ... Summary: I started adding gflags support for cmake on linux and got frustrated that I'd need to duplicate the build_detect_platform logic, which determines namespace based on attempting compilation. We can do it differently -- use the GFLAGS_NAMESPACE macro if available, and if not, that indicates it's an old gflags version without configurable namespace so we can simply hardcode "google". Closes https://github.com/facebook/rocksdb/pull/3212 Differential Revision: D6456973 Pulled By: ajkr fbshipit-source-id: 3e6d5bde3ca00d4496a120a7caf4687399f5d656	7 years ago
Siying Dong	3c327ac2d0	Change RocksDB License ... Summary: Closes https://github.com/facebook/rocksdb/pull/2589 Differential Revision: D5431502 Pulled By: siying fbshipit-source-id: 8ebf8c87883daa9daa54b2303d11ce01ab1f6f75	7 years ago