176 Commits (f706a9c199118fdf57031d57ebb975764bcebcd3)

Author	SHA1	Message	Date
Andrew Kryczka	babe56ddba	Add rate limiter priority to ReadOptions (#9424) ... Summary: Users can set the priority for file reads associated with their operation by setting `ReadOptions::rate_limiter_priority` to something other than `Env::IO_TOTAL`. Rate limiting `VerifyChecksum()` and `VerifyFileChecksums()` is the motivation for this PR, so it also includes benchmarks and minor bug fixes to get that working. `RandomAccessFileReader::Read()` already had support for rate limiting compaction reads. I changed that rate limiting to be non-specific to compaction, but rather performed according to the passed in `Env::IOPriority`. Now the compaction read rate limiting is supported by setting `rate_limiter_priority = Env::IO_LOW` on its `ReadOptions`. There is no default value for the new `Env::IOPriority` parameter to `RandomAccessFileReader::Read()`. That means this PR goes through all callers (in some cases multiple layers up the call stack) to find a `ReadOptions` to provide the priority. There are TODOs for cases I believe it would be good to let user control the priority some day (e.g., file footer reads), and no TODO in cases I believe it doesn't matter (e.g., trace file reads). The API doc only lists the missing cases where a file read associated with a provided `ReadOptions` cannot be rate limited. For cases like file ingestion checksum calculation, there is no API to provide `ReadOptions` or `Env::IOPriority`, so I didn't count that as missing. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9424 Test Plan: - new unit tests - new benchmarks on ~50MB database with 1MB/s read rate limit and 100ms refill interval; verified with strace reads are chunked (at 0.1MB per chunk) and spaced roughly 100ms apart. - setup command: `./db_bench -benchmarks=fillrandom,compact -db=/tmp/testdb -target_file_size_base=1048576 -disable_auto_compactions=true -file_checksum=true` - benchmarks command: `strace -ttfe pread64 ./db_bench -benchmarks=verifychecksum,verifyfilechecksums -use_existing_db=true -db=/tmp/testdb -rate_limiter_bytes_per_sec=1048576 -rate_limit_bg_reads=1 -rate_limit_user_ops=true -file_checksum=true` - crash test using IO_USER priority on non-validation reads with https://github.com/facebook/rocksdb/issues/9567 reverted: `python3 tools/db_crashtest.py blackbox --max_key=1000000 --write_buffer_size=524288 --target_file_size_base=524288 --level_compaction_dynamic_level_bytes=true --duration=3600 --rate_limit_bg_reads=true --rate_limit_user_ops=true --rate_limiter_bytes_per_sec=10485760 --interval=10` Reviewed By: hx235 Differential Revision: D33747386 Pulled By: ajkr fbshipit-source-id: a2d985e97912fba8c54763798e04f006ccc56e0c	3 years ago
Hui Xiao	443d8ef094	Fix PinSelf() read-after-free in DB::GetMergeOperands() (#9507) ... Summary: **Context:** Running the new test `DBMergeOperandTest.MergeOperandReadAfterFreeBug` prior to this fix surfaces the read-after-free bug of PinSef() as below: ``` READ of size 8 at 0x60400002529d thread T0 https://github.com/facebook/rocksdb/issues/5 0x7f199a in rocksdb::PinnableSlice::PinSelf(rocksdb::Slice const&) include/rocksdb/slice.h:171 https://github.com/facebook/rocksdb/issues/6 0x7f199a in rocksdb::DBImpl::GetImpl(rocksdb::ReadOptions const&, rocksdb::Slice const&, rocksdb::DBImpl::GetImplOptions&) db/db_impl/db_impl.cc:1919 https://github.com/facebook/rocksdb/issues/7 0x540d63 in rocksdb::DBImpl::GetMergeOperands(rocksdb::ReadOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::PinnableSlice*, rocksdb::GetMergeOperandsOptions*, int*) db/db_impl/db_impl.h:203 freed by thread T0 here: https://github.com/facebook/rocksdb/issues/3 0x1191399 in rocksdb::cache_entry_roles_detail::RegisteredDeleter<rocksdb::Block, (rocksdb::CacheEntryRole)0>::Delete(rocksdb::Slice const&, void*) cache/cache_entry_roles.h:99 https://github.com/facebook/rocksdb/issues/4 0x719348 in rocksdb::LRUHandle::Free() cache/lru_cache.h:205 https://github.com/facebook/rocksdb/issues/5 0x71047f in rocksdb::LRUCacheShard::Release(rocksdb::Cache::Handle*, bool) cache/lru_cache.cc:547 https://github.com/facebook/rocksdb/issues/6 0xa78f0a in rocksdb::Cleanable::DoCleanup() include/rocksdb/cleanable.h:60 https://github.com/facebook/rocksdb/issues/7 0xa78f0a in rocksdb::Cleanable::Reset() include/rocksdb/cleanable.h:38 https://github.com/facebook/rocksdb/issues/8 0xa78f0a in rocksdb::PinnedIteratorsManager::ReleasePinnedData() db/pinned_iterators_manager.h:71 https://github.com/facebook/rocksdb/issues/9 0xd0c21b in rocksdb::PinnedIteratorsManager::~PinnedIteratorsManager() db/pinned_iterators_manager.h:24 https://github.com/facebook/rocksdb/issues/10 0xd0c21b in rocksdb::Version::Get(rocksdb::ReadOptions const&, rocksdb::LookupKey const&, rocksdb::PinnableSlice*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, rocksdb::Status*, rocksdb::MergeContext*, unsigned long*, bool*, bool*, unsigned long*, rocksdb::ReadCallback*, bool*, bool) db/pinned_iterators_manager.h:22 https://github.com/facebook/rocksdb/issues/11 0x7f0fdf in rocksdb::DBImpl::GetImpl(rocksdb::ReadOptions const&, rocksdb::Slice const&, rocksdb::DBImpl::GetImplOptions&) db/db_impl/db_impl.cc:1886 https://github.com/facebook/rocksdb/issues/12 0x540d63 in rocksdb::DBImpl::GetMergeOperands(rocksdb::ReadOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::PinnableSlice*, rocksdb::GetMergeOperandsOptions*, int*) db/db_impl/db_impl.h:203 previously allocated by thread T0 here: https://github.com/facebook/rocksdb/issues/1 0x1239896 in rocksdb::AllocateBlock(unsigned long, **rocksdb::MemoryAllocator*)** memory/memory_allocator.h:35 https://github.com/facebook/rocksdb/issues/2 0x1239896 in rocksdb::BlockFetcher::CopyBufferToHeapBuf() table/block_fetcher.cc:171 https://github.com/facebook/rocksdb/issues/3 0x1239896 in rocksdb::BlockFetcher::GetBlockContents() table/block_fetcher.cc:206 https://github.com/facebook/rocksdb/issues/4 0x122eae5 in rocksdb::BlockFetcher::ReadBlockContents() table/block_fetcher.cc:325 https://github.com/facebook/rocksdb/issues/5 0x11b1f45 in rocksdb::Status rocksdb::BlockBasedTable::MaybeReadBlockAndLoadToCache<rocksdb::Block>(rocksdb::FilePrefetchBuffer*, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::UncompressionDict const&, bool, rocksdb::CachableEntry<rocksdb::Block>*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, rocksdb::BlockContents*) const table/block_based/block_based_table_reader.cc:1503 ``` Here is the analysis: - We have [PinnedIteratorsManager](https://github.com/facebook/rocksdb/blob/6.28.fb/db/version_set.cc#L1980) with `Cleanable` capability in our `Version::Get()` path. It's responsible for managing the life-time of pinned iterator and invoking registered cleanup functions during its own destruction. - For example in case above, the merge operands's clean-up gets associated with this manger in [GetContext::push_operand](https://github.com/facebook/rocksdb/blob/6.28.fb/table/get_context.cc#L405). During PinnedIteratorsManager's [destruction](https://github.com/facebook/rocksdb/blob/6.28.fb/db/pinned_iterators_manager.h#L67), the release function associated with those merge operand data is invoked. **And that's what we see in "freed by thread T955 here" in ASAN.** - Bug 🐛: `PinnedIteratorsManager` is local to `Version::Get()` while the data of merge operands need to outlive `Version::Get` and stay till they get [PinSelf()](https://github.com/facebook/rocksdb/blob/6.28.fb/db/db_impl/db_impl.cc#L1905), **which is the read-after-free in ASAN.** - This bug is likely to be an overlook of `PinnedIteratorsManager` when developing the API `DB::GetMergeOperands` cuz the current logic works fine with the existing case of getting the *merged value* where the operands do not need to live that long. - This bug was not surfaced much (even in its unit test) due to the release function associated with the merge operands (which are actually blocks put in cache as you can see in `BlockBasedTable::MaybeReadBlockAndLoadToCache` **in "previously allocated by" in ASAN report**) is a cache entry deleter. The deleter will call `Cache::Release()` which, for LRU cache, won't immediately deallocate the block based on LRU policy [unless the cache is full or being instructed to force erase](https://github.com/facebook/rocksdb/blob/6.28.fb/cache/lru_cache.cc#L521-L531) - `DBMergeOperandTest.MergeOperandReadAfterFreeBug` makes the cache extremely small to force cache full. **Summary:** - Fix the bug by align `PinnedIteratorsManager`'s lifetime with the merge operands Pull Request resolved: https://github.com/facebook/rocksdb/pull/9507 Test Plan: - New test `DBMergeOperandTest.MergeOperandReadAfterFreeBug` - db bench on read path - Setup (LSM tree with several levels, cache the whole db to avoid read IO, warm cache with readseq to avoid read IO): `TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks="fillrandom,readseq -num=1000000 -cache_size=100000000 -write_buffer_size=10000 -statistics=1 -max_bytes_for_level_base=10000 -level0_file_num_compaction_trigger=1``TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks="readrandom" -num=1000000 -cache_size=100000000 ` - Actual command run (run 20-run for 20 times and then average the 20-run's average micros/op) - `for j in {1..20}; do (for i in {1..20}; do rm -rf /dev/shm/rocksdb/ && TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks="fillrandom,readseq,readrandom" -num=1000000 -cache_size=100000000 -write_buffer_size=10000 -statistics=1 -max_bytes_for_level_base=10000 -level0_file_num_compaction_trigger=1 | egrep 'readrandom'; done > rr_output_pre.txt && (awk '{sum+=$3; sum_sqrt+=$3^2}END{print sum/20, sqrt(sum_sqrt/20-(sum/20)^2)}' rr_output_pre.txt) >> rr_output_pre_2.txt); done` - **Result: Pre-change: 3.79193 micros/op; Post-change: 3.79528 micros/op (+0.09%)** (pre-change)sorted avg micros/op of each 20-run | std of micros/op of each 20-run | (post-change) sorted avg micros/op of each 20-run | std of micros/op of each 20-run -- | -- | -- | -- 3.58355 | 0.265209 | 3.48715 | 0.382076 3.58845 | 0.519927 | 3.5832 | 0.382726 3.66415 | 0.452097 | 3.677 | 0.563831 3.68495 | 0.430897 | 3.68405 | 0.495355 3.70295 | 0.482893 | 3.68465 | 0.431438 3.719 | 0.463806 | 3.71945 | 0.457157 3.7393 | 0.453423 | 3.72795 | 0.538604 3.7806 | 0.527613 | 3.75075 | 0.444509 3.7817 | 0.426704 | 3.7683 | 0.468065 3.809 | 0.381033 | 3.8086 | 0.557378 3.80985 | 0.466011 | 3.81805 | 0.524833 3.8165 | 0.500351 | 3.83405 | 0.529339 3.8479 | 0.430326 | 3.86285 | 0.44831 3.85125 | 0.434108 | 3.8717 | 0.544098 3.8556 | 0.524602 | 3.895 | 0.411679 3.8656 | 0.476383 | 3.90965 | 0.566636 3.8911 | 0.488477 | 3.92735 | 0.608038 3.898 | 0.493978 | 3.9439 | 0.524511 3.97235 | 0.515008 | 3.9623 | 0.477416 3.9768 | 0.519993 | 3.98965 | 0.521481 - CI Reviewed By: ajkr Differential Revision: D34030519 Pulled By: hx235 fbshipit-source-id: a99ac585c11704c5ed93af033cb29ba0a7b16ae8	3 years ago
Ezgi Çiçek	95d9cb8357	Avoid unnecessary copy of sample_slice map (#9551) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9551 Reviewed By: riversand963 Differential Revision: D34169574 Pulled By: ezgicicek fbshipit-source-id: 2e88db59b65bda269917a9b0bed17181a4afd281	3 years ago
Levi Tamasi	320d9a8e8a	Use a sorted vector instead of a map to store blob file metadata (#9526) ... Summary: The patch replaces `std::map` with a sorted `std::vector` for `VersionStorageInfo::blob_files_` and preallocates the space for the `vector` before saving the `BlobFileMetaData` into the new `VersionStorageInfo` in `VersionBuilder::Rep::SaveBlobFilesTo`. These changes reduce the time the DB mutex is held while saving new `Version`s, and using a sorted `vector` also makes lookups faster thanks to better memory locality. In addition, the patch introduces helper methods `VersionStorageInfo::GetBlobFileMetaData` and `VersionStorageInfo::GetBlobFileMetaDataLB` that can be used by clients to perform lookups in the `vector`, and does some general cleanup in the parts of code where blob file metadata are used. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9526 Test Plan: Ran `make check` and the crash test script for a while. Performance was tested using a load-optimized benchmark (`fillseq` with vector memtable, no WAL) and small file sizes so that a significant number of files are produced: ``` numactl --interleave=all ./db_bench --benchmarks=fillseq --allow_concurrent_memtable_write=false --level0_file_num_compaction_trigger=4 --level0_slowdown_writes_trigger=20 --level0_stop_writes_trigger=30 --max_background_jobs=8 --max_write_buffer_number=8 --db=/data/ltamasi-dbbench --wal_dir=/data/ltamasi-dbbench --num=800000000 --num_levels=8 --key_size=20 --value_size=400 --block_size=8192 --cache_size=51539607552 --cache_numshardbits=6 --compression_max_dict_bytes=0 --compression_ratio=0.5 --compression_type=lz4 --bytes_per_sync=8388608 --cache_index_and_filter_blocks=1 --cache_high_pri_pool_ratio=0.5 --benchmark_write_rate_limit=0 --write_buffer_size=16777216 --target_file_size_base=16777216 --max_bytes_for_level_base=67108864 --verify_checksum=1 --delete_obsolete_files_period_micros=62914560 --max_bytes_for_level_multiplier=8 --statistics=0 --stats_per_interval=1 --stats_interval_seconds=20 --histogram=1 --memtablerep=skip_list --bloom_bits=10 --open_files=-1 --subcompactions=1 --compaction_style=0 --min_level_to_compress=3 --level_compaction_dynamic_level_bytes=true --pin_l0_filter_and_index_blocks_in_cache=1 --soft_pending_compaction_bytes_limit=167503724544 --hard_pending_compaction_bytes_limit=335007449088 --min_level_to_compress=0 --use_existing_db=0 --sync=0 --threads=1 --memtablerep=vector --allow_concurrent_memtable_write=false --disable_wal=1 --enable_blob_files=1 --blob_file_size=16777216 --min_blob_size=0 --blob_compression_type=lz4 --enable_blob_garbage_collection=1 --seed=<some value> ``` Final statistics before the patch: ``` Cumulative writes: 0 writes, 700M keys, 0 commit groups, 0.0 writes per commit group, ingest: 284.62 GB, 121.27 MB/s Interval writes: 0 writes, 334K keys, 0 commit groups, 0.0 writes per commit group, ingest: 139.28 MB, 72.46 MB/s ``` With the patch: ``` Cumulative writes: 0 writes, 760M keys, 0 commit groups, 0.0 writes per commit group, ingest: 308.66 GB, 131.52 MB/s Interval writes: 0 writes, 445K keys, 0 commit groups, 0.0 writes per commit group, ingest: 185.35 MB, 93.15 MB/s ``` Total time to complete the benchmark is 2611 seconds with the patch, down from 2986 secs. Reviewed By: riversand963 Differential Revision: D34082728 Pulled By: ltamasi fbshipit-source-id: fc598abf676dce436734d06bb9d2d99a26a004fc	3 years ago
Yanqin Jin	629e3e1d77	Fix spelling in public API (#9490) ... Summary: I feel it would be nice if we can fix this spelling error. In `SizeApproximationOptions`, the `include_memtabtles` should be `include_memtables`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9490 Test Plan: make check Reviewed By: hx235 Differential Revision: D33949862 Pulled By: riversand963 fbshipit-source-id: b2be67501b65d4aabb6b8df1bf25eb8d54cc1466	3 years ago
Yanqin Jin	3122cb4358	Revise APIs related to user-defined timestamp (#8946) ... Summary: ajkr reminded me that we have a rule of not including per-kv related data in `WriteOptions`. Namely, `WriteOptions` should not include information about "what-to-write", but should just include information about "how-to-write". According to this rule, `WriteOptions::timestamp` (experimental) is clearly a violation. Therefore, this PR removes `WriteOptions::timestamp` for compliance. After the removal, we need to pass timestamp info via another set of APIs. This PR proposes a set of overloaded functions `Put(write_opts, key, value, ts)`, `Delete(write_opts, key, ts)`, and `SingleDelete(write_opts, key, ts)`. Planned to add `Write(write_opts, batch, ts)`, but its complexity made me reconsider doing it in another PR (maybe). For better checking and returning error early, we also add a new set of APIs to `WriteBatch` that take extra `timestamp` information when writing to `WriteBatch`es. These set of APIs in `WriteBatchWithIndex` are currently not supported, and are on our TODO list. Removed `WriteBatch::AssignTimestamps()` and renamed `WriteBatch::AssignTimestamp()` to `WriteBatch::UpdateTimestamps()` since this method require that all keys have space for timestamps allocated already and multiple timestamps can be updated. The constructor of `WriteBatch` now takes a fourth argument `default_cf_ts_sz` which is the timestamp size of the default column family. This will be used to allocate space when calling APIs that do not specify a column family handle. Also, updated `DB::Get()`, `DB::MultiGet()`, `DB::NewIterator()`, `DB::NewIterators()` methods, replacing some assertions about timestamp to returning Status code. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8946 Test Plan: make check ./db_bench -benchmarks=fillseq,fillrandom,readrandom,readseq,deleterandom -user_timestamp_size=8 ./db_stress --user_timestamp_size=8 -nooverwritepercent=0 -test_secondary=0 -secondary_catch_up_one_in=0 -continuous_verification_interval=0 Make sure there is no perf regression by running the following ``` ./db_bench_opt -db=/dev/shm/rocksdb -use_existing_db=0 -level0_stop_writes_trigger=256 -level0_slowdown_writes_trigger=256 -level0_file_num_compaction_trigger=256 -disable_wal=1 -duration=10 -benchmarks=fillrandom ``` Before this PR ``` DB path: [/dev/shm/rocksdb] fillrandom : 1.831 micros/op 546235 ops/sec; 60.4 MB/s ``` After this PR ``` DB path: [/dev/shm/rocksdb] fillrandom : 1.820 micros/op 549404 ops/sec; 60.8 MB/s ``` Reviewed By: ltamasi Differential Revision: D33721359 Pulled By: riversand963 fbshipit-source-id: c131561534272c120ffb80711d42748d21badf09	3 years ago
Yanqin Jin	d10c5c08d3	Remove iter_start_seqnum and preserve_deletes (#9430) ... Summary: According to https://github.com/facebook/rocksdb/blob/6.27.fb/db/db_impl/db_impl.cc#L2896:L2911 and https://github.com/facebook/rocksdb/blob/6.27.fb/db/db_impl/db_impl_open.cc#L203:L208, we are going to remove `iter_start_seqnum` and `preserve_deletes` starting from RocksDB 7.0 Pull Request resolved: https://github.com/facebook/rocksdb/pull/9430 Test Plan: make check and CI Reviewed By: ajkr Differential Revision: D33753639 Pulled By: riversand963 fbshipit-source-id: c80aab8e8d8fc33e52472fed524ed703d0ffc8b6	3 years ago
Yanqin Jin	b2e53ab2d8	Add checking for `DB::DestroyColumnFamilyHandle()` (#9347) ... Summary: Closing https://github.com/facebook/rocksdb/issues/5006 Calling `DB::DestroyColumnFamilyHandle(column_family)` with `column_family` being the return value of `DB::DefaultColumnFamily()` will return `Status::InvalidArgument()`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9347 Test Plan: make check Reviewed By: akankshamahajan15 Differential Revision: D33369675 Pulled By: riversand963 fbshipit-source-id: a8266a4daddf2b7a773c2dc7f3eb9a4adfb6b6dd	3 years ago
slk	2e5f764294	Make IncreaseFullHistoryTsLow to a public API (#9221) ... Summary: As (https://github.com/facebook/rocksdb/issues/9210) discussed, the **full_history_ts_low** is a member of CompactRangeOptions currently, which means a CF's fullHistoryTsLow is advanced only when users submit a CompactRange request. However, users may want to advance the fllHistoryTsLow without an immediate compact. This merge make IncreaseFullHistoryTsLow to a public API so users can advance each CF's fullHistoryTsLow seperately. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9221 Reviewed By: akankshamahajan15 Differential Revision: D33201106 Pulled By: riversand963 fbshipit-source-id: 9cb1d013ba93260f72e16353e693ffee167b47ee	3 years ago
Peter Dillinger	0050a73a4f	New stable, fixed-length cache keys (#9126) ... Summary: This change standardizes on a new 16-byte cache key format for block cache (incl compressed and secondary) and persistent cache (but not table cache and row cache). The goal is a really fast cache key with practically ideal stability and uniqueness properties without external dependencies (e.g. from FileSystem). A fixed key size of 16 bytes should enable future optimizations to the concurrent hash table for block cache, which is a heavy CPU user / bottleneck, but there appears to be measurable performance improvement even with no changes to LRUCache. This change replaces a lot of disjointed and ugly code handling cache keys with calls to a simple, clean new internal API (cache_key.h). (Preserving the old cache key logic under an option would be very ugly and likely negate the performance gain of the new approach. Complete replacement carries some inherent risk, but I think that's acceptable with sufficient analysis and testing.) The scheme for encoding new cache keys is complicated but explained in cache_key.cc. Also: EndianSwapValue is moved to math.h to be next to other bit operations. (Explains some new include "math.h".) ReverseBits operation added and unit tests added to hash_test for both. Fixes https://github.com/facebook/rocksdb/issues/7405 (presuming a root cause) Pull Request resolved: https://github.com/facebook/rocksdb/pull/9126 Test Plan: ### Basic correctness Several tests needed updates to work with the new functionality, mostly because we are no longer relying on filesystem for stable cache keys so table builders & readers need more context info to agree on cache keys. This functionality is so core, a huge number of existing tests exercise the cache key functionality. ### Performance Create db with `TEST_TMPDIR=/dev/shm ./db_bench -bloom_bits=10 -benchmarks=fillrandom -num=3000000 -partition_index_and_filters` And test performance with `TEST_TMPDIR=/dev/shm ./db_bench -readonly -use_existing_db -bloom_bits=10 -benchmarks=readrandom -num=3000000 -duration=30 -cache_index_and_filter_blocks -cache_size=250000 -threads=4` using DEBUG_LEVEL=0 and simultaneous before & after runs. Before ops/sec, avg over 100 runs: 121924 After ops/sec, avg over 100 runs: 125385 (+2.8%) ### Collision probability I have built a tool, ./cache_bench -stress_cache_key to broadly simulate host-wide cache activity over many months, by making some pessimistic simplifying assumptions: * Every generated file has a cache entry for every byte offset in the file (contiguous range of cache keys) * All of every file is cached for its entire lifetime We use a simple table with skewed address assignment and replacement on address collision to simulate files coming & going, with quite a variance (super-Poisson) in ages. Some output with `./cache_bench -stress_cache_key -sck_keep_bits=40`: ``` Total cache or DBs size: 32TiB Writing 925.926 MiB/s or 76.2939TiB/day Multiply by 9.22337e+18 to correct for simulation losses (but still assume whole file cached) ``` These come from default settings of 2.5M files per day of 32 MB each, and `-sck_keep_bits=40` means that to represent a single file, we are only keeping 40 bits of the 128-bit cache key. With file size of 2\*\*25 contiguous keys (pessimistic), our simulation is about 2\*\*(128-40-25) or about 9 billion billion times more prone to collision than reality. More default assumptions, relatively pessimistic: * 100 DBs in same process (doesn't matter much) * Re-open DB in same process (new session ID related to old session ID) on average every 100 files generated * Restart process (all new session IDs unrelated to old) 24 times per day After enough data, we get a result at the end: ``` (keep 40 bits) 17 collisions after 2 x 90 days, est 10.5882 days between (9.76592e+19 corrected) ``` If we believe the (pessimistic) simulation and the mathematical generalization, we would need to run a billion machines all for 97 billion days to expect a cache key collision. To help verify that our generalization ("corrected") is robust, we can make our simulation more precise with `-sck_keep_bits=41` and `42`, which takes more running time to get enough data: ``` (keep 41 bits) 16 collisions after 4 x 90 days, est 22.5 days between (1.03763e+20 corrected) (keep 42 bits) 19 collisions after 10 x 90 days, est 47.3684 days between (1.09224e+20 corrected) ``` The generalized prediction still holds. With the `-sck_randomize` option, we can see that we are beating "random" cache keys (except offsets still non-randomized) by a modest amount (roughly 20x less collision prone than random), which should make us reasonably comfortable even in "degenerate" cases: ``` 197 collisions after 1 x 90 days, est 0.456853 days between (4.21372e+18 corrected) ``` I've run other tests to validate other conditions behave as expected, never behaving "worse than random" unless we start chopping off structured data. Reviewed By: zhichao-cao Differential Revision: D33171746 Pulled By: pdillinger fbshipit-source-id: f16a57e369ed37be5e7e33525ace848d0537c88f	3 years ago
Peter Dillinger	2a67d475f1	Fix bug affecting GetSortedWalFiles, Backups, Checkpoint (#9208) ... Summary: Saw error like this: `Backup failed -- IO error: No such file or directory: While opening a file for sequentially reading: /dev/shm/rocksdb/rocksdb_crashtest_blackbox/004426.log: No such file or directory` Unfortunately, GetSortedWalFiles (used by Backups, Checkpoint, etc.) relies on no file deletions happening while its operating, which means not only disabling (more) deletions, but ensuring any pending deletions are completed. Two fixes related to this: * There was a gap in several places between decrementing pending_purge_obsolete_files_ and incrementing bg_purge_scheduled_ where the db mutex would be released and GetSortedWalFiles (and others) could get false information that no deletions are pending. * The fix to https://github.com/facebook/rocksdb/issues/8591 (disabling deletions in GetSortedWalFiles) seems incomplete because it doesn't prevent pending deletions from occuring during the operation (if deletions not already disabled, the case that was to be fixed by the change). Pull Request resolved: https://github.com/facebook/rocksdb/pull/9208 Test Plan: existing tests (it's hard to write a test for interleavings that are now excluded - this is what stress test is for) Reviewed By: ajkr Differential Revision: D32630675 Pulled By: pdillinger fbshipit-source-id: a121e3da648de130cd24d44c524232f4eb22f178	3 years ago
Jay Zhuang	6cde8d2190	Deprecating `iter_start_seqnum` and `preserve_deletes` (#9091) ... Summary: `ReadOptions::iter_start_seqnum` and `DBOptions::preserve_deletes` are deprecated, please try using user defined timestamp feature instead. The feature is used to support differential snapshots, but not well maintained (https://github.com/facebook/rocksdb/issues/6837, https://github.com/facebook/rocksdb/issues/8472) and the interface is not user friendly which returns an internal key from the iterator. The user defined timestamp feature is a more flexible feature to support similar usecase, please switch to that if you have such usecase. The deprecated feature will be removed in a future release. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9091 Test Plan: check LOG Fix https://github.com/facebook/rocksdb/issues/9090 Reviewed By: ajkr Differential Revision: D32071750 Pulled By: jay-zhuang fbshipit-source-id: b882c4668dd1bf26ce03c4c192f1bba584bf6104	3 years ago
Yanqin Jin	2035798834	Update TransactionUtil::CheckKeyForConflict to also use timestamps (#9162) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9162 Existing TransactionUtil::CheckKeyForConflict() performs only seq-based conflict checking. If user-defined timestamp is enabled, it should perform conflict checking based on timestamps too. Update TransactionUtil::CheckKey-related methods to verify the timestamp of the latest version of a key is smaller than the read timestamp. Note that CheckKeysForConflict() is not updated since it's used only by optimistic transaction, and we do not plan to update it in this upcoming batch of diffs. Existing GetLatestSequenceForKey() returns the sequence of the latest version of a specific user key. Since we support user-defined timestamp, we need to update this method to also return the timestamp (if enabled) of the latest version of the key. This will be needed for snapshot validation. Reviewed By: ltamasi Differential Revision: D31567960 fbshipit-source-id: 2e4a14aed267435a9aa91bc632d2411c01946d44	3 years ago
Jay Zhuang	29102641dd	Skip directory fsync for filesystem btrfs (#8903) ... Summary: Directory fsync might be expensive on btrfs and it may not be needed. Here are 4 directory fsync cases: 1. creating a new file: dir-fsync is not needed on btrfs, as long as the new file itself is synced. 2. renaming a file: dir-fsync is not needed if the renamed file is synced. So an API `FsyncAfterFileRename(filename, ...)` is provided to sync the file on btrfs. By default, it just calls dir-fsync. 3. deleting files: dir-fsync is forced by set `IOOptions.force_dir_fsync = true` 4. renaming multiple files (like backup and checkpoint): dir-fsync is forced, the same as above. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8903 Test Plan: run tests on btrfs and non btrfs Reviewed By: ajkr Differential Revision: D30885059 Pulled By: jay-zhuang fbshipit-source-id: dd2730b31580b0bcaedffc318a762d7dbf25de4a	3 years ago
Peter Dillinger	ad5325a736	Experimental support for SST unique IDs (#8990) ... Summary: * New public header unique_id.h and function GetUniqueIdFromTableProperties which computes a universally unique identifier based on table properties of table files from recent RocksDB versions. * Generation of DB session IDs is refactored so that they are guaranteed unique in the lifetime of a process running RocksDB. (SemiStructuredUniqueIdGen, new test included.) Along with file numbers, this enables SST unique IDs to be guaranteed unique among SSTs generated in a single process, and "better than random" between processes. See https://github.com/pdillinger/unique_id * In addition to public API producing 'external' unique IDs, there is a function for producing 'internal' unique IDs, with functions for converting between the two. In short, the external ID is "safe" for things people might do with it, and the internal ID enables more "power user" features for the future. Specifically, the external ID goes through a hashing layer so that any subset of bits in the external ID can be used as a hash of the full ID, while also preserving uniqueness guarantees in the first 128 bits (bijective both on first 128 bits and on full 192 bits). Intended follow-up: * Use the internal unique IDs in cache keys. (Avoid conflicts with https://github.com/facebook/rocksdb/issues/8912) (The file offset can be XORed into the third 64-bit value of the unique ID.) * Publish the external unique IDs in FileStorageInfo (https://github.com/facebook/rocksdb/issues/8968) Pull Request resolved: https://github.com/facebook/rocksdb/pull/8990 Test Plan: Unit tests added, and checking of unique ids in stress test. NOTE in stress test we do not generate nearly enough files to thoroughly stress uniqueness, but the test trims off pieces of the ID to check for uniqueness so that we can infer (with some assumptions) stronger properties in the aggregate. Reviewed By: zhichao-cao, mrambacher Differential Revision: D31582865 Pulled By: pdillinger fbshipit-source-id: 1f620c4c86af9abe2a8d177b9ccf2ad2b9f48243	3 years ago
Jay Zhuang	314de7e7de	Make `DB::Close()` thread-safe (#8970) ... Summary: If `DB::Close()` is called in multi-thread env, the resource could be double released, which causes exception or assert. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8970 Test Plan: Test with multi-thread benchmark, with each thread try to close the DB at the end. Reviewed By: pdillinger Differential Revision: D31242042 Pulled By: jay-zhuang fbshipit-source-id: a61276b1b61e07732e375554106946aea86a23eb	3 years ago
Peter Dillinger	3ffb3baa0b	Add (Live)FileStorageInfo API (#8968) ... Summary: New classes FileStorageInfo and LiveFileStorageInfo and 'experimental' function DB::GetLiveFilesStorageInfo, which is intended to largely replace several fragmented DB functions needed to create checkpoints and backups. This function is now used to create checkpoints and backups, because it fixes many (probably not all) of the prior complexities of checkpoint not having atomic access to DB metadata. This also ensures strong functional test coverage of the new API. Specifically, much of the old CheckpointImpl::CreateCustomCheckpoint has been migrated to and updated in DBImpl::GetLiveFilesStorageInfo, with the former now calling the latter. Also, the class FileStorageInfo in metadata.h compatibly replaces BackupFileInfo and serves as a new base class for SstFileMetaData. Some old fields of SstFileMetaData are still provided (for now) but deprecated. Although FileStorageInfo::directory is accurate when using db_paths and/or cf_paths, these have never been supported by Checkpoint nor BackupEngine and still are not. This change does now detect these cases and return NotSupported when appropriate. (More work needed for support.) Somehow this change broke ProgressCallbackDuringBackup, but the progress_callback logic was dubious to begin with because it would call the callback based on copy buffer size, not size actually copied. Logic and test updated to track size actually copied per-thread. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8968 Test Plan: tests updated. DB::GetLiveFilesStorageInfo mostly tested by use in CheckpointImpl. DBTest.SnapshotFiles updated to also test GetLiveFilesStorageInfo, including reading the data after DB close. Added CheckpointTest.CheckpointWithDbPath (NotSupported). Reviewed By: siying Differential Revision: D31242045 Pulled By: pdillinger fbshipit-source-id: b183d1ce9799e220daaefd6b3b5365d98de676c0	3 years ago
Giuseppe Ottaviano	4bfd415e34	Fix sequence number bump logic in multi-CF SST ingestion (#9005) ... Summary: The code in `IngestExternalFiles()` that bumps the DB's sequence number depending on what seqnos were assigned to the files has 3 bugs: 1) There is an assertion that the sequence number is increased in all the affected column families, but this is unnecessary, it is fine if some files can stick to a lower sequence number. It is very easy to hit the assertion: it is sufficient to insert 2 files in 2 CFs, one which overlaps the CF and one that doesn't (for example the CF is empty). The line added in the `IngestFilesIntoMultipleColumnFamilies_Success` test makes the assertion fail. 2) SetLastSequence() is called with the sum of all the bumps across CFs, but we should take the maximum instead, as all CFs start with the current seqno and bump it independently. 3) The code above is accidentally under a `#ifndef NDEBUG`, so it doesn't run in optimized builds, so some files may be assigned seqnos from the future. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9005 Test Plan: Added line in `IngestFilesIntoMultipleColumnFamilies_Success` that triggers the assertion, verified that the test (and all the others) pass after the fix. Reviewed By: ajkr Differential Revision: D31597892 Pulled By: ot fbshipit-source-id: c2d3237f90290df1178736ace8653a9623f5a770	3 years ago
Zhichao Cao	bcd049cd2d	Ingest external SST files with Temperature hints (#8949) ... Summary: Add the file temperature to `IngestExternalFileArg` such that when SST files are ingested, user is able to assign the temperature to each SST file. If the temperature vector is empty or its size does not match the file name vector size, all ingested SST files will be assigned with `Temperature::unKnown`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8949 Test Plan: add the new test and make check Reviewed By: siying Differential Revision: D31127852 Pulled By: zhichao-cao fbshipit-source-id: 141a81f0f7b473d88f4ab0cb2a21a114cbc6f83c	3 years ago
anand76	532ff334d9	Don't ignore deletion rate limit if WAL dir is different (#8967) ... Summary: If WAL dir is different from the DB dir, we should still honor the SstFileManager deletion rate limit for SST files. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8967 Test Plan: Add a new unit test in db_sst_test Reviewed By: pdillinger Differential Revision: D31220116 Pulled By: anand1976 fbshipit-source-id: bcde8a53a7d728e15e597fb5d07ee86c1b38bd28	3 years ago
Yanqin Jin	b512f4bc76	Batch blob read IO for MultiGet (#8699) ... Summary: In batched `MultiGet()`, RocksDB batches blob read IO and uses `RandomAccessFileReader::MultiRead()` to read the blobs instead of issuing multiple `Read()`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8699 Test Plan: ``` make check ``` Reviewed By: ltamasi Differential Revision: D31030861 Pulled By: riversand963 fbshipit-source-id: a0df6060cbfd54cff9515a4eee08807b1dbcb0c8	3 years ago
Akanksha Mahajan	d6aa8c49f8	Expose blob file information through the EventListener interface (#8675) ... Summary: 1. Extend FlushJobInfo and CompactionJobInfo with information about the blob files generated by flush/compaction jobs. This PR add two structures BlobFileInfo and BlobFileGarbageInfo that contains the required information of blob files. 2. Notify the creation and deletion of blob files through OnBlobFileCreationStarted, OnBlobFileCreated, and OnBlobFileDeleted. 3. Test OnFile*Finish operations notifications with Blob Files. 4. Log the blob file creation/deletion events through EventLogger in Log file. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8675 Test Plan: Add new unit tests in listener_test Reviewed By: ltamasi Differential Revision: D30412613 Pulled By: akankshamahajan15 fbshipit-source-id: ca51b63c6e8c8d0485a38c503572bc5a82bd5d07	3 years ago
mrambacher	beed86473a	Make MemTableRepFactory into a Customizable class (#8419) ... 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	3 years ago
Andrew Kryczka	941543721d	Bytes read stat for `VerifyChecksum()` and `VerifyFileChecksums()` APIs (#8741) ... Summary: - Clarified some comments on compatibility for adding new ticker stats - Added read I/O stats for `VerifyChecksum()` and `VerifyFileChecksums()` APIs Pull Request resolved: https://github.com/facebook/rocksdb/pull/8741 Test Plan: new unit test Reviewed By: zhichao-cao Differential Revision: D30708578 Pulled By: ajkr fbshipit-source-id: d06b961f7e199ae92c266b683e39870aa8f63449	3 years ago
Peter Dillinger	4750421ece	Replace most typedef with using= (#8751) ... 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	3 years ago
Peter Dillinger	13ded69484	Built-in support for generating unique IDs, bug fix (#8708) ... Summary: Env::GenerateUniqueId() works fine on Windows and on POSIX where /proc/sys/kernel/random/uuid exists. Our other implementation is flawed and easily produces collision in a new multi-threaded test. As we rely more heavily on DB session ID uniqueness, this becomes a serious issue. This change combines several individually suitable entropy sources for reliable generation of random unique IDs, with goal of uniqueness and portability, not cryptographic strength nor maximum speed. Specifically: * Moves code for getting UUIDs from the OS to port::GenerateRfcUuid rather than in Env implementation details. Callers are now told whether the operation fails or succeeds. * Adds an internal API GenerateRawUniqueId for generating high-quality 128-bit unique identifiers, by combining entropy from three "tracks": * Lots of info from default Env like time, process id, and hostname. * std::random_device * port::GenerateRfcUuid (when working) * Built-in implementations of Env::GenerateUniqueId() will now always produce an RFC 4122 UUID string, either from platform-specific API or by converting the output of GenerateRawUniqueId. DB session IDs now use GenerateRawUniqueId while DB IDs (not as critical) try to use port::GenerateRfcUuid but fall back on GenerateRawUniqueId with conversion to an RFC 4122 UUID. GenerateRawUniqueId is declared and defined under env/ rather than util/ or even port/ because of the Env dependency. Likely follow-up: enhance GenerateRawUniqueId to be faster after the first call and to guarantee uniqueness within the lifetime of a single process (imparting the same property onto DB session IDs). Pull Request resolved: https://github.com/facebook/rocksdb/pull/8708 Test Plan: A new mini-stress test in env_test checks the various public and internal APIs for uniqueness, including each track of GenerateRawUniqueId individually. We can't hope to verify anywhere close to 128 bits of entropy, but it can at least detect flaws as bad as the old code. Serial execution of the new tests takes about 350 ms on my machine. Reviewed By: zhichao-cao, mrambacher Differential Revision: D30563780 Pulled By: pdillinger fbshipit-source-id: de4c9ff4b2f581cf784fcedb5f39f16e5185c364	3 years ago
anand76	ebaa3c8a59	Fix a race condition in DumpStats() during iteration of the ColumnFamilySet (#8714) ... Summary: DumpStats() iterates through the ColumnFamilySet. There is a potential race condition because it does Ref the cfd, and the cfd could get destroyed during the iteration. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8714 Test Plan: make check Reviewed By: ltamasi Differential Revision: D30580199 Pulled By: anand1976 fbshipit-source-id: 60a3443ad0d4f7ac6a977dec780e6d2c1b70b850	3 years ago
Peter Dillinger	b6269b078a	Stable cache keys on ingested SST files (#8669) ... Summary: Extends https://github.com/facebook/rocksdb/issues/8659 to work for ingested external SST files, even the same file ingested into different DBs sharing a block cache. Note: These new cache keys are currently only enabled when FileSystem does not provide GetUniqueId. For now, they are typically larger, so slightly less efficient. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8669 Test Plan: Extended unit test Reviewed By: zhichao-cao Differential Revision: D30398532 Pulled By: pdillinger fbshipit-source-id: 1f13e2af4b8bfff5741953a69466e9589fbc23c7	3 years ago
Adam Retter	5de333fd99	Add db_test2 to to ASSERT_STATUS_CHECKED (#8640) ... Summary: This is the `db_test2` parts of https://github.com/facebook/rocksdb/pull/7737 reworked on the latest HEAD. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8640 Reviewed By: akankshamahajan15 Differential Revision: D30303684 Pulled By: mrambacher fbshipit-source-id: 263e2f82d849bde4048b60aed8b31e7deed4706a	3 years ago
Merlin Mao	f58d276764	Make TraceRecord and Replayer public (#8611) ... Summary: New public interfaces: `TraceRecord` and `TraceRecord::Handler`, available in "rocksdb/trace_record.h". `Replayer`, available in `rocksdb/utilities/replayer.h`. User can use `DB::NewDefaultReplayer()` to create a Replayer to auto/manual replay a trace file. Unit tests: - `./db_test2 --gtest_filter="DBTest2.TraceAndReplay"`: Updated with the internal API changes. - `./db_test2 --gtest_filter="DBTest2.TraceAndManualReplay"`: New for manual replay. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8611 Reviewed By: ajkr Differential Revision: D30266329 Pulled By: autopear fbshipit-source-id: 1ecb3cbbedae0f6a67c18f0cc82e002b4d81b6f8	3 years ago
Baptiste Lemaire	e3a96c4823	Memtable sampling for mempurge heuristic. (#8628) ... 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	3 years ago
Levi Tamasi	87882736ef	Fix the sorting of KeyContexts for batched MultiGet (#8633) ... Summary: `CompareKeyContext::operator()` on the trunk has a bug: when comparing column family IDs, `lhs` is used for both sides of the comparison. This results in the `KeyContext`s getting sorted solely based on key, which in turn means that keys with the same column family do not necessarily form a single range in the sorted list. This violates an assumption of the batched `MultiGet` logic, leading to the same column family showing up multiple times in the list of `MultiGetColumnFamilyData`. The end result is the code attempting to check out the thread-local `SuperVersion` for the same CF multiple times, causing an assertion violation in debug builds and memory corruption/crash in release builds. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8633 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D30169182 Pulled By: ltamasi fbshipit-source-id: a47710652df7e95b14b40fb710924c11a8478023	3 years ago
mrambacher	ab7f7c9e49	Allow WAL dir to change with db dir (#8582) ... 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	3 years ago
Peter Dillinger	1d34cd797e	Fix insecure internal API for GetImpl (#8590) ... Summary: Calling the GetImpl function could leave reference to a local callback function in a field of a parameter struct. As this is performance-critical code, I'm not going to attempt to sanitize this code too much, but make the existing hack a bit cleaner by reverting what it overwrites in the input struct. Added SaveAndRestore utility class to make that easier. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8590 Test Plan: added unit test for SaveAndRestore; existing tests for GetImpl Reviewed By: riversand963 Differential Revision: D29947983 Pulled By: pdillinger fbshipit-source-id: 2f608853f970bc06724e834cc84dcc4b8599ddeb	3 years ago
Jay Zhuang	42eaa45c1b	Avoid updating option if there's no value updated (#8518) ... 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	3 years ago
Peter Dillinger	df5dc73bec	Don't hold DB mutex for block cache entry stat scans (#8538) ... Summary: I previously didn't notice the DB mutex was being held during block cache entry stat scans, probably because I primarily checked for read performance regressions, because they require the block cache and are traditionally latency-sensitive. This change does some refactoring to avoid holding DB mutex and to avoid triggering and waiting for a scan in GetProperty("rocksdb.cfstats"). Some tests have to be updated because now the stats collector is populated in the Cache aggressively on DB startup rather than lazily. (I hope to clean up some of this added complexity in the future.) This change also ensures proper treatment of need_out_of_mutex for non-int DB properties. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8538 Test Plan: Added unit test logic that uses sync points to fail if the DB mutex is held during a scan, covering the various ways that a scan might be triggered. Performance test - the known impact to holding the DB mutex is on TransactionDB, and the easiest way to see the impact is to hack the scan code to almost always miss and take an artificially long time scanning. Here I've injected an unconditional 5s sleep at the call to ApplyToAllEntries. Before (hacked): $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op' randomtransaction : 433.219 micros/op 2308 ops/sec; 0.1 MB/s ( transactions:78999 aborts:0) rocksdb.db.write.micros P50 : 16.135883 P95 : 36.622503 P99 : 66.036115 P100 : 5000614.000000 COUNT : 149677 SUM : 8364856 $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op' randomtransaction : 448.802 micros/op 2228 ops/sec; 0.1 MB/s ( transactions:75999 aborts:0) rocksdb.db.write.micros P50 : 16.629221 P95 : 37.320607 P99 : 72.144341 P100 : 5000871.000000 COUNT : 143995 SUM : 13472323 Notice the 5s P100 write time. After (hacked): $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op' randomtransaction : 303.645 micros/op 3293 ops/sec; 0.1 MB/s ( transactions:98999 aborts:0) rocksdb.db.write.micros P50 : 16.061871 P95 : 33.978834 P99 : 60.018017 P100 : 616315.000000 COUNT : 187619 SUM : 4097407 $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op' randomtransaction : 310.383 micros/op 3221 ops/sec; 0.1 MB/s ( transactions:96999 aborts:0) rocksdb.db.write.micros P50 : 16.270026 P95 : 35.786844 P99 : 64.302878 P100 : 603088.000000 COUNT : 183819 SUM : 4095918 P100 write is now ~0.6s. Not good, but it's the same even if I completely bypass all the scanning code: $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op' randomtransaction : 311.365 micros/op 3211 ops/sec; 0.1 MB/s ( transactions:96999 aborts:0) rocksdb.db.write.micros P50 : 16.274362 P95 : 36.221184 P99 : 68.809783 P100 : 649808.000000 COUNT : 183819 SUM : 4156767 $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op' randomtransaction : 308.395 micros/op 3242 ops/sec; 0.1 MB/s ( transactions:97999 aborts:0) rocksdb.db.write.micros P50 : 16.106222 P95 : 37.202403 P99 : 67.081875 P100 : 598091.000000 COUNT : 185714 SUM : 4098832 No substantial difference. Reviewed By: siying Differential Revision: D29738847 Pulled By: pdillinger fbshipit-source-id: 1c5c155f5a1b62e4fea0fd4eeb515a8b7474027b	3 years ago
Baptiste Lemaire	837705ad80	Make mempurge a background process (equivalent to in-memory compaction). (#8505) ... Summary: In https://github.com/facebook/rocksdb/issues/8454, I introduced a new process baptized `MemPurge` (memtable garbage collection). This new PR is built upon this past mempurge prototype. In this PR, I made the `mempurge` process a background task, which provides superior performance since the mempurge process does not cling on the db_mutex anymore, and addresses severe restrictions from the past iteration (including a scenario where the past mempurge was failling, when a memtable was mempurged but was still referred to by an iterator/snapshot/...). Now the mempurge process ressembles an in-memory compaction process: the stack of immutable memtables is filtered out, and the useful payload is used to populate an output memtable. If the output memtable is filled at more than 60% capacity (arbitrary heuristic) the mempurge process is aborted and a regular flush process takes place, else the output memtable is kept in the immutable memtable stack. Note that adding this output memtable to the `imm()` memtable stack does not trigger another flush process, so that the flush thread can go to sleep at the end of a successful mempurge. MemPurge is activated by making the `experimental_allow_mempurge` flag `true`. When activated, the `MemPurge` process will always happen when the flush reason is `kWriteBufferFull`. The 3 unit tests confirm that this process supports `Put`, `Get`, `Delete`, `DeleteRange` operators and is compatible with `Iterators` and `CompactionFilters`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8505 Reviewed By: pdillinger Differential Revision: D29619283 Pulled By: bjlemaire fbshipit-source-id: 8a99bee76b63a8211bff1a00e0ae32360aaece95	3 years ago
mrambacher	be219089ad	Add BlobMetaData retrieval methods (#8273) ... Summary: Added BlobMetaData to ColumnFamilyMetaData and LiveBlobMetaData and DB API GetLiveBlobMetaData to retrieve it. First pass at struct. More tests and maybe fields to come... Pull Request resolved: https://github.com/facebook/rocksdb/pull/8273 Reviewed By: ltamasi Differential Revision: D29102400 Pulled By: mrambacher fbshipit-source-id: 8a2383a4446328be6b91dced9841fdd3dfc80b73	3 years ago
Jay Zhuang	54d73d6429	Fix DeleteFilesInRange may cause inconsistent compaction error (#8434) ... Summary: `DeleteFilesInRange()` marks deleting files to `being_compacted` before deleting, which may cause ongoing compactions report corruption exception or ASSERT for debug build. Adding the missing `ComputeCompactionScore()` when `being_compacted` is set. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8434 Test Plan: Unittest Reviewed By: ajkr Differential Revision: D29276127 Pulled By: jay-zhuang fbshipit-source-id: f5b223e3c1fc6d821e100e3f3442bc70c1d50cf7	3 years ago
Zhichao Cao	82a70e1470	Trace MultiGet Keys and CF_IDs to the trace file (#8421) ... Summary: Tracing the MultiGet information including timestamp, keys, and CF_IDs to the trace file for analyzing and replay. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8421 Test Plan: make check, add test to trace_analyzer_test Reviewed By: anand1976 Differential Revision: D29221195 Pulled By: zhichao-cao fbshipit-source-id: 30c677d6c39ab31ef4bbdf7e0d1fa1fd79f295ff	3 years ago
Peter Dillinger	b3dbeadc34	Fix double-dumping CF stats to log (#8380) ... Summary: DBImpl::DumpStats is supposed to do this: Dump DB stats to LOG For each CF, dump CFStatsNoFileHistogram to LOG For each CF, dump CFFileHistogram to LOG Instead, due to a longstanding bug from 2017 (https://github.com/facebook/rocksdb/issues/2126), it would dump CFStats, which includes both CFStatsNoFileHistogram and CFFileHistogram, in both loops, resulting in near-duplicate output. This fixes the bug. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8380 Test Plan: Manual inspection of LOG after db_bench Reviewed By: jay-zhuang Differential Revision: D29017535 Pulled By: pdillinger fbshipit-source-id: 3010604c4a629a80347f129cd746ce9b0d0cbda6	3 years ago
Zhichao Cao	f44e69c64a	Use DbSessionId as cache key prefix when secondary cache is enabled (#8360) ... Summary: Currently, we either use the file system inode or a monotonically incrementing runtime ID as the block cache key prefix. However, if we use a monotonically incrementing runtime ID (in the case that the file system does not support inode id generation), in some cases, it cannot ensure uniqueness (e.g., we have secondary cache migrated from host to host). We use DbSessionID (20 bytes) + current file number (at most 10 bytes) as the new cache block key prefix when the secondary cache is enabled. So can accommodate scenarios such as transfer of cache state across hosts. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8360 Test Plan: add the test to lru_cache_test Reviewed By: pdillinger Differential Revision: D29006215 Pulled By: zhichao-cao fbshipit-source-id: 6cff686b38d83904667a2bd39923cd030df16814	3 years ago
mrambacher	8948dc8524	Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262) ... Summary: The ImmutableCFOptions contained a bunch of fields that belonged to the ImmutableDBOptions. This change cleans that up by introducing an ImmutableOptions struct. Following the pattern of Options struct, this class inherits from the DB and CFOption structs (of the Immutable form). Only one structural change (the ImmutableCFOptions::fs was changed to a shared_ptr from a raw one) is in this PR. All of the other changes involve moving the member variables from the ImmutableCFOptions into the ImmutableOptions and changing member variables or function parameters as required for compilation purposes. Follow-on PRs may do a further clean-up of the code, such as renaming variables (such as "ImmutableOptions cf_options") and potentially eliminating un-needed function parameters (there is no longer a need to pass both an ImmutableDBOptions and an ImmutableOptions to a function). Pull Request resolved: https://github.com/facebook/rocksdb/pull/8262 Reviewed By: pdillinger Differential Revision: D28226540 Pulled By: mrambacher fbshipit-source-id: 18ae71eadc879dedbe38b1eb8e6f9ff5c7147dbf	4 years ago
mrambacher	01e460d538	Make types of Immutable/Mutable Options fields match that of the underlying Option (#8176) ... Summary: This PR is a first step at attempting to clean up some of the Mutable/Immutable Options code. With this change, a DBOption and a ColumnFamilyOption can be reconstructed from their Mutable and Immutable equivalents, respectively. readrandom tests do not show any performance degradation versus master (though both are slightly slower than the current 6.19 release). There are still fields in the ImmutableCFOptions that are not CF options but DB options. Eventually, I would like to move those into an ImmutableOptions (= ImmutableDBOptions+ImmutableCFOptions). But that will be part of a future PR to minimize changes and disruptions. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8176 Reviewed By: pdillinger Differential Revision: D27954339 Pulled By: mrambacher fbshipit-source-id: ec6b805ba9afe6e094bffdbd76246c2d99aa9fad	4 years ago
Jay Zhuang	f0fca2b1d5	Add internal compaction API for Secondary instance (#8171) ... Summary: Add compaction API for secondary instance, which compact the files to a secondary DB path without installing to the LSM tree. The API will be used to remote compaction. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8171 Test Plan: `make check` Reviewed By: ajkr Differential Revision: D27694545 Pulled By: jay-zhuang fbshipit-source-id: 8ff3ec1bffdb2e1becee994918850c8902caf731	4 years ago
Akanksha Mahajan	596e9008e4	Stall writes in WriteBufferManager when memory_usage exceeds buffer_size (#7898) ... Summary: When WriteBufferManager is shared across DBs and column families to maintain memory usage under a limit, OOMs have been observed when flush cannot finish but writes continuously insert to memtables. In order to avoid OOMs, when memory usage goes beyond buffer_limit_ and DBs tries to write, this change will stall incoming writers until flush is completed and memory_usage drops. Design: Stall condition: When total memory usage exceeds WriteBufferManager::buffer_size_ (memory_usage() >= buffer_size_) WriterBufferManager::ShouldStall() returns true. DBImpl first block incoming/future writers by calling write_thread_.BeginWriteStall() (which adds dummy stall object to the writer's queue). Then DB is blocked on a state State::Blocked (current write doesn't go through). WBStallInterface object maintained by every DB instance is added to the queue of WriteBufferManager. If multiple DBs tries to write during this stall, they will also be blocked when check WriteBufferManager::ShouldStall() returns true. End Stall condition: When flush is finished and memory usage goes down, stall will end only if memory waiting to be flushed is less than buffer_size/2. This lower limit will give time for flush to complete and avoid continous stalling if memory usage remains close to buffer_size. WriterBufferManager::EndWriteStall() is called, which removes all instances from its queue and signal them to continue. Their state is changed to State::Running and they are unblocked. DBImpl then signal all incoming writers of that DB to continue by calling write_thread_.EndWriteStall() (which removes dummy stall object from the queue). DB instance creates WBMStallInterface which is an interface to block and signal DBs during stall. When DB needs to be blocked or signalled by WriteBufferManager, state_for_wbm_ state is changed accordingly (RUNNING or BLOCKED). Pull Request resolved: https://github.com/facebook/rocksdb/pull/7898 Test Plan: Added a new test db/db_write_buffer_manager_test.cc Reviewed By: anand1976 Differential Revision: D26093227 Pulled By: akankshamahajan15 fbshipit-source-id: 2bbd982a3fb7033f6de6153aa92a221249861aae	4 years ago
Peter Dillinger	879357fdb0	Make backups openable as read-only DBs (#8142) ... Summary: A current limitation of backups is that you don't know the exact database state of when the backup was taken. With this new feature, you can at least inspect the backup's DB state without restoring it by opening it as a read-only DB. Rather than add something like OpenAsReadOnlyDB to the BackupEngine API, which would inhibit opening stackable DB implementations read-only (if/when their APIs support it), we instead provide a DB name and Env that can be used to open as a read-only DB. Possible follow-up work: * Add a version of GetBackupInfo for a single backup. * Let CreateNewBackup return the BackupID of the newly-created backup. Implementation details: Refactored ChrootFileSystem to split off new base class RemapFileSystem, which allows more general remapping of files. We use this base class to implement BackupEngineImpl::RemapSharedFileSystem. To minimize API impact, I decided to just add these fields `name_for_open` and `env_for_open` to those set by GetBackupInfo when include_file_details=true. Creating the RemapSharedFileSystem adds a bit to the memory consumption, perhaps unnecessarily in some cases, but this has been mitigated by (a) only initialize the RemapSharedFileSystem lazily when GetBackupInfo with include_file_details=true is called, and (b) using the existing `shared_ptr<FileInfo>` objects to hold most of the mapping data. To enhance API safety, RemapSharedFileSystem is wrapped by new ReadOnlyFileSystem which rejects any attempts to write. This uncovered a couple of places in which DB::OpenForReadOnly would write to the filesystem, so I fixed these. Added a release note because this affects logging. Additional minor refactoring in backupable_db.cc to support the new functionality. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8142 Test Plan: new test (run with ASAN and UBSAN), added to stress test and ran it for a while with amplified backup_one_in Reviewed By: ajkr Differential Revision: D27535408 Pulled By: pdillinger fbshipit-source-id: 04666d310aa0261ef6b2385c43ca793ce1dfd148	4 years ago
Akanksha Mahajan	689b13e639	Add request_id in IODebugContext. (#8045) ... Summary: Add request_id in IODebugContext which will be populated by underlying FileSystem for IOTracing purposes. Update IOTracer to trace request_id in the tracing records. Provided API IODebugContext::SetRequestId which will set the request_id and enable tracing for request_id. The API hides the implementation and underlying file system needs to call this API directly. Update DB::StartIOTrace API and remove redundant Env* from the argument as its not used and DB already has Env that is passed down to IOTracer. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8045 Test Plan: Update unit test. Differential Revision: D26899871 Pulled By: akankshamahajan15 fbshipit-source-id: 56adef52ee5af0fb3060b607c3af1ec01635fa2b	4 years ago
sherriiiliu	e6534900bd	Fix possible hang issue in ~DBImpl() when flush is scheduled in LOW pool (#8125) ... Summary: In DBImpl::CloseHelper, we wait for bg_compaction_scheduled_ and bg_flush_scheduled_ to drop to 0. Unschedule is called prior to cancel any unscheduled flushes/compactions. It is assumed that anything in the high priority is a flush, and anything in the low priority pool is a compaction. This assumption, however, is broken when the high-pri pool is full. As a result, bg_compaction_scheduled_ can go < 0 and bg_flush_scheduled_ will remain > 0 and DB can be in hang state. The fix is, we decrement the `bg_{flush,compaction,bottom_compaction}_scheduled_` inside the `Unschedule{Flush,Compaction,BottomCompaction}Callback()`s. DB `mutex_` will make the counts atomic in `Unschedule`. Related discussion: https://github.com/facebook/rocksdb/issues/7928 Pull Request resolved: https://github.com/facebook/rocksdb/pull/8125 Test Plan: Added new test case which hangs without the fix. Reviewed By: jay-zhuang Differential Revision: D27390043 Pulled By: ajkr fbshipit-source-id: 78a367fba9a59ac5607ad24bd1c46dc16d5ec110	4 years ago
Akanksha Mahajan	27d57a035e	Use SST file manager to track blob files as well (#8037) ... Summary: Extend support to track blob files in SST File manager. This PR notifies SstFileManager whenever a new blob file is created, via OnAddFile and an obsolete blob file deleted via OnDeleteFile and delete file via ScheduleFileDeletion. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8037 Test Plan: Add new unit tests Reviewed By: ltamasi Differential Revision: D26891237 Pulled By: akankshamahajan15 fbshipit-source-id: 04c69ccfda2a73782fd5c51982dae58dd11979b6	4 years ago