5 Commits (d47126875b2297725aeb2bf433c0b538c17a3b16)

Author	SHA1	Message	Date
Peter Dillinger	9f7801c5f1	Major Cache refactoring, CPU efficiency improvement (#10975) ... Summary: This is several refactorings bundled into one to avoid having to incrementally re-modify uses of Cache several times. Overall, there are breaking changes to Cache class, and it becomes more of low-level interface for implementing caches, especially block cache. New internal APIs make using Cache cleaner than before, and more insulated from block cache evolution. Hopefully, this is the last really big block cache refactoring, because of rather effectively decoupling the implementations from the uses. This change also removes the EXPERIMENTAL designation on the SecondaryCache support in Cache. It seems reasonably mature at this point but still subject to change/evolution (as I warn in the API docs for Cache). The high-level motivation for this refactoring is to minimize code duplication / compounding complexity in adding SecondaryCache support to HyperClockCache (in a later PR). Other benefits listed below. * static_cast lines of code +29 -35 (net removed 6) * reinterpret_cast lines of code +6 -32 (net removed 26) ## cache.h and secondary_cache.h * Always use CacheItemHelper with entries instead of just a Deleter. There are several motivations / justifications: * Simpler for implementations to deal with just one Insert and one Lookup. * Simpler and more efficient implementation because we don't have to track which entries are using helpers and which are using deleters * Gets rid of hack to classify cache entries by their deleter. Instead, the CacheItemHelper includes a CacheEntryRole. This simplifies a lot of code (cache_entry_roles.h almost eliminated). Fixes https://github.com/facebook/rocksdb/issues/9428. * Makes it trivial to adjust SecondaryCache behavior based on kind of block (e.g. don't re-compress filter blocks). * It is arguably less convenient for many direct users of Cache, but direct users of Cache are now rare with introduction of typed_cache.h (below). * I considered and rejected an alternative approach in which we reduce customizability by assuming each secondary cache compatible value starts with a Slice referencing the uncompressed block contents (already true or mostly true), but we apparently intend to stack secondary caches. Saving an entry from a compressed secondary to a lower tier requires custom handling offered by SaveToCallback, etc. * Make CreateCallback part of the helper and introduce CreateContext to work with it (alternative to https://github.com/facebook/rocksdb/issues/10562). This cleans up the interface while still allowing context to be provided for loading/parsing values into primary cache. This model works for async lookup in BlockBasedTable reader (reader owns a CreateContext) under the assumption that it always waits on secondary cache operations to finish. (Otherwise, the CreateContext could be destroyed while async operation depending on it continues.) This likely contributes most to the observed performance improvement because it saves an std::function backed by a heap allocation. * Use char* for serialized data, e.g. in SaveToCallback, where void* was confusingly used. (We use `char*` for serialized byte data all over RocksDB, with many advantages over `void*`. `memcpy` etc. are legacy APIs that should not be mimicked.) * Add a type alias Cache::ObjectPtr = void*, so that we can better indicate the intent of the void* when it is to be the object associated with a Cache entry. Related: started (but did not complete) a refactoring to move away from "value" of a cache entry toward "object" or "obj". (It is confusing to call Cache a key-value store (like DB) when it is really storing arbitrary in-memory objects, not byte strings.) * Remove unnecessary key param from DeleterFn. This is good for efficiency in HyperClockCache, which does not directly store the cache key in memory. (Alternative to https://github.com/facebook/rocksdb/issues/10774) * Add allocator to Cache DeleterFn. This is a kind of future-proofing change in case we get more serious about using the Cache allocator for memory tracked by the Cache. Right now, only the uncompressed block contents are allocated using the allocator, and a pointer to that allocator is saved as part of the cached object so that the deleter can use it. (See CacheAllocationPtr.) If in the future we are able to "flatten out" our Cache objects some more, it would be good not to have to track the allocator as part of each object. * Removes legacy `ApplyToAllCacheEntries` and changes `ApplyToAllEntries` signature for Deleter->CacheItemHelper change. ## typed_cache.h Adds various "typed" interfaces to the Cache as internal APIs, so that most uses of Cache can use simple type safe code without casting and without explicit deleters, etc. Almost all of the non-test, non-glue code uses of Cache have been migrated. (Follow-up work: CompressedSecondaryCache deserves deeper attention to migrate.) This change expands RocksDB's internal usage of metaprogramming and SFINAE (https://en.cppreference.com/w/cpp/language/sfinae). The existing usages of Cache are divided up at a high level into these new interfaces. See updated existing uses of Cache for examples of how these are used. * PlaceholderCacheInterface - Used for making cache reservations, with entries that have a charge but no value. * BasicTypedCacheInterface<TValue> - Used for primary cache storage of objects of type TValue, which can be cleaned up with std::default_delete<TValue>. The role is provided by TValue::kCacheEntryRole or given in an optional template parameter. * FullTypedCacheInterface<TValue, TCreateContext> - Used for secondary cache compatible storage of objects of type TValue. In addition to BasicTypedCacheInterface constraints, we require TValue::ContentSlice() to return persistable data. This simplifies usage for the normal case of simple secondary cache compatibility (can give you a Slice to the data already in memory). In addition to TCreateContext performing the role of Cache::CreateContext, it is also expected to provide a factory function for creating TValue. * For each of these, there's a "Shared" version (e.g. FullTypedSharedCacheInterface) that holds a shared_ptr to the Cache, rather than assuming external ownership by holding only a raw `Cache*`. These interfaces introduce specific handle types for each interface instantiation, so that it's easy to see what kind of object is controlled by a handle. (Ultimately, this might not be worth the extra complexity, but it seems OK so far.) Note: I attempted to make the cache 'charge' automatically inferred from the cache object type, such as by expecting an ApproximateMemoryUsage() function, but this is not so clean because there are cases where we need to compute the charge ahead of time and don't want to re-compute it. ## block_cache.h This header is essentially the replacement for the old block_like_traits.h. It includes various things to support block cache access with typed_cache.h for block-based table. ## block_based_table_reader.cc Before this change, accessing the block cache here was an awkward mix of static polymorphism (template TBlocklike) and switch-case on a dynamic BlockType value. This change mostly unifies on static polymorphism, relying on minor hacks in block_cache.h to distinguish variants of Block. We still check BlockType in some places (especially for stats, which could be improved in follow-up work) but at least the BlockType is a static constant from the template parameter. (No more awkward partial redundancy between static and dynamic info.) This likely contributes to the overall performance improvement, but hasn't been tested in isolation. The other key source of simplification here is a more unified system of creating block cache objects: for directly populating from primary cache and for promotion from secondary cache. Both use BlockCreateContext, for context and for factory functions. ## block_based_table_builder.cc, cache_dump_load_impl.cc Before this change, warming caches was super ugly code. Both of these source files had switch statements to basically transition from the dynamic BlockType world to the static TBlocklike world. None of that mess is needed anymore as there's a new, untyped WarmInCache function that handles all the details just as promotion from SecondaryCache would. (Fixes `TODO akanksha: Dedup below code` in block_based_table_builder.cc.) ## Everything else Mostly just updating Cache users to use new typed APIs when reasonably possible, or changed Cache APIs when not. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10975 Test Plan: tests updated Performance test setup similar to https://github.com/facebook/rocksdb/issues/10626 (by cache size, LRUCache when not "hyper" for HyperClockCache): 34MB 1thread base.hyper -> kops/s: 0.745 io_bytes/op: 2.52504e+06 miss_ratio: 0.140906 max_rss_mb: 76.4844 34MB 1thread new.hyper -> kops/s: 0.751 io_bytes/op: 2.5123e+06 miss_ratio: 0.140161 max_rss_mb: 79.3594 34MB 1thread base -> kops/s: 0.254 io_bytes/op: 1.36073e+07 miss_ratio: 0.918818 max_rss_mb: 45.9297 34MB 1thread new -> kops/s: 0.252 io_bytes/op: 1.36157e+07 miss_ratio: 0.918999 max_rss_mb: 44.1523 34MB 32thread base.hyper -> kops/s: 7.272 io_bytes/op: 2.88323e+06 miss_ratio: 0.162532 max_rss_mb: 516.602 34MB 32thread new.hyper -> kops/s: 7.214 io_bytes/op: 2.99046e+06 miss_ratio: 0.168818 max_rss_mb: 518.293 34MB 32thread base -> kops/s: 3.528 io_bytes/op: 1.35722e+07 miss_ratio: 0.914691 max_rss_mb: 264.926 34MB 32thread new -> kops/s: 3.604 io_bytes/op: 1.35744e+07 miss_ratio: 0.915054 max_rss_mb: 264.488 233MB 1thread base.hyper -> kops/s: 53.909 io_bytes/op: 2552.35 miss_ratio: 0.0440566 max_rss_mb: 241.984 233MB 1thread new.hyper -> kops/s: 62.792 io_bytes/op: 2549.79 miss_ratio: 0.044043 max_rss_mb: 241.922 233MB 1thread base -> kops/s: 1.197 io_bytes/op: 2.75173e+06 miss_ratio: 0.103093 max_rss_mb: 241.559 233MB 1thread new -> kops/s: 1.199 io_bytes/op: 2.73723e+06 miss_ratio: 0.10305 max_rss_mb: 240.93 233MB 32thread base.hyper -> kops/s: 1298.69 io_bytes/op: 2539.12 miss_ratio: 0.0440307 max_rss_mb: 371.418 233MB 32thread new.hyper -> kops/s: 1421.35 io_bytes/op: 2538.75 miss_ratio: 0.0440307 max_rss_mb: 347.273 233MB 32thread base -> kops/s: 9.693 io_bytes/op: 2.77304e+06 miss_ratio: 0.103745 max_rss_mb: 569.691 233MB 32thread new -> kops/s: 9.75 io_bytes/op: 2.77559e+06 miss_ratio: 0.103798 max_rss_mb: 552.82 1597MB 1thread base.hyper -> kops/s: 58.607 io_bytes/op: 1449.14 miss_ratio: 0.0249324 max_rss_mb: 1583.55 1597MB 1thread new.hyper -> kops/s: 69.6 io_bytes/op: 1434.89 miss_ratio: 0.0247167 max_rss_mb: 1584.02 1597MB 1thread base -> kops/s: 60.478 io_bytes/op: 1421.28 miss_ratio: 0.024452 max_rss_mb: 1589.45 1597MB 1thread new -> kops/s: 63.973 io_bytes/op: 1416.07 miss_ratio: 0.0243766 max_rss_mb: 1589.24 1597MB 32thread base.hyper -> kops/s: 1436.2 io_bytes/op: 1357.93 miss_ratio: 0.0235353 max_rss_mb: 1692.92 1597MB 32thread new.hyper -> kops/s: 1605.03 io_bytes/op: 1358.04 miss_ratio: 0.023538 max_rss_mb: 1702.78 1597MB 32thread base -> kops/s: 280.059 io_bytes/op: 1350.34 miss_ratio: 0.023289 max_rss_mb: 1675.36 1597MB 32thread new -> kops/s: 283.125 io_bytes/op: 1351.05 miss_ratio: 0.0232797 max_rss_mb: 1703.83 Almost uniformly improving over base revision, especially for hot paths with HyperClockCache, up to 12% higher throughput seen (1597MB, 32thread, hyper). The improvement for that is likely coming from much simplified code for providing context for secondary cache promotion (CreateCallback/CreateContext), and possibly from less branching in block_based_table_reader. And likely a small improvement from not reconstituting key for DeleterFn. Reviewed By: anand1976 Differential Revision: D42417818 Pulled By: pdillinger fbshipit-source-id: f86bfdd584dce27c028b151ba56818ad14f7a432	2 years ago
Bo Wang	d490bfcdb6	Avoid recompressing cold block in CompressedSecondaryCache (#10527) ... Summary: **Summary:** When a block is firstly `Lookup` from the secondary cache, we just insert a dummy block in the primary cache (charging the actual size of the block) and don’t erase the block from the secondary cache. A standalone handle is returned from `Lookup`. Only if the block is hit again, we erase it from the secondary cache and add it into the primary cache. When a block is firstly evicted from the primary cache to the secondary cache, we just insert a dummy block (size 0) in the secondary cache. When the block is evicted again, it is treated as a hot block and is inserted into the secondary cache. **Implementation Details** Add a new state of LRUHandle: The handle is never inserted into the LRUCache (both hash table and LRU list) and it doesn't experience the above three states. The entry can be freed when refs becomes 0. (refs >= 1 && in_cache == false && IS_STANDALONE == true) The behaviors of `LRUCacheShard::Lookup()` are updated if the secondary_cache is CompressedSecondaryCache: 1. If a handle is found in primary cache: 1.1. If the handle's value is not nullptr, it is returned immediately. 1.2. If the handle's value is nullptr, this means the handle is a dummy one. For a dummy handle, if it was retrieved from secondary cache, it may still exist in secondary cache. - 1.2.1. If no valid handle can be `Lookup` from secondary cache, return nullptr. - 1.2.2. If the handle from secondary cache is valid, erase it from the secondary cache and add it into the primary cache. 2. If a handle is not found in primary cache: 2.1. If no valid handle can be `Lookup` from secondary cache, return nullptr. 2.2. If the handle from secondary cache is valid, insert a dummy block in the primary cache (charging the actual size of the block) and return a standalone handle. The behaviors of `LRUCacheShard::Promote()` are updated as follows: 1. If `e->sec_handle` has value, one of the following steps can happen: 1.1. Insert a dummy handle and return a standalone handle to caller when `secondary_cache_` is `CompressedSecondaryCache` and e is a standalone handle. 1.2. Insert the item into the primary cache and return the handle to caller. 1.3. Exception handling. 3. If `e->sec_handle` has no value, mark the item as not in cache and charge the cache as its only metadata that'll shortly be released. The behavior of `CompressedSecondaryCache::Insert()` is updated: 1. If a block is evicted from the primary cache for the first time, a dummy item is inserted. 4. If a dummy item is found for a block, the block is inserted into the secondary cache. The behavior of `CompressedSecondaryCache:::Lookup()` is updated: 1. If a handle is not found or it is a dummy item, a nullptr is returned. 2. If `erase_handle` is true, the handle is erased. The behaviors of `LRUCacheShard::Release()` are adjusted for the standalone handles. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10527 Test Plan: 1. stress tests. 5. unit tests. 6. CPU profiling for db_bench. Reviewed By: siying Differential Revision: D38747613 Pulled By: gitbw95 fbshipit-source-id: 74a1eba7e1957c9affb2bd2ae3e0194584fa6eca	2 years ago
Bo Wang	13cb7a84b6	Fix the memory leak in db_stress tests that are caused by `FaultInjectionSecondaryCache` and add `CompressedSecondaryCache` into stress tests. (#10523) ... Summary: 1. Fix the memory leak in db_stress tests that are caused by `FaultInjectionSecondaryCache`. To address the test requirements for both CompressedSecondaryCache and CachlibWrapper, a new class variable `base_is_compressed_sec_cache_` is added to determine the different behaviors in `Lookup()` and `WaitAll()`. 2. Add `CompressedSecondaryCache` into stress tests. Before this PR, memory leak is reported during crash tests if `CompressedSecondaryCache` is in stress tests. One example is shown as follows: ``` ==70722==ERROR: LeakSanitizer: detected memory leaks Direct leak of 6648240 byte(s) in 83103 object(s) allocated from: #0 0x13de9d7 in operator new(unsigned long) (/data/sandcastle/boxes/eden-trunk-hg-fbcode-fbsource/fbcode/buck-out/dbgo/gen/aab7ed39/internal_repo_rocksdb/repo/db_stress+0x13de9d7) https://github.com/facebook/rocksdb/issues/1 0x9084c7 in rocksdb::BlocklikeTraits<rocksdb::Block>::Create(rocksdb::BlockContents&&, unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*) internal_repo_rocksdb/repo/table/block_based/block_like_traits.h:128 https://github.com/facebook/rocksdb/issues/2 0x9084c7 in std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)::operator()(void const*, unsigned long, void**, unsigned long*) const internal_repo_rocksdb/repo/table/block_based/block_like_traits.h:34 https://github.com/facebook/rocksdb/issues/3 0x9082c9 in rocksdb::Block std::__invoke_impl<rocksdb::Status, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*, unsigned long, void**, unsigned long*>(std::__invoke_other, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*&&, unsigned long&&, void**&&, unsigned long*&&) third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/invoke.h:61 https://github.com/facebook/rocksdb/issues/4 0x90825d in std::enable_if<is_invocable_r_v<rocksdb::Block, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*, unsigned long, void**, unsigned long*>, rocksdb::Block>::type std::__invoke_r<rocksdb::Status, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*, unsigned long, void**, unsigned long*>(std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*&&, unsigned long&&, void**&&, unsigned long*&&) third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/invoke.h:114 https://github.com/facebook/rocksdb/issues/5 0x9081b0 in std::_Function_handler<rocksdb::Status (void const*, unsigned long, void**, unsigned long*), std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)>::_M_invoke(std::_Any_data const&, void const*&&, unsigned long&&, void**&&, unsigned long*&&) third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/std_function.h:291 https://github.com/facebook/rocksdb/issues/6 0x991f2c in std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)>::operator()(void const*, unsigned long, void**, unsigned long*) const third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/std_function.h:560 https://github.com/facebook/rocksdb/issues/7 0x990277 in rocksdb::CompressedSecondaryCache::Lookup(rocksdb::Slice const&, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, bool, bool&) internal_repo_rocksdb/repo/cache/compressed_secondary_cache.cc:77 https://github.com/facebook/rocksdb/issues/8 0xd3aa4d in rocksdb::FaultInjectionSecondaryCache::Lookup(rocksdb::Slice const&, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, bool, bool&) internal_repo_rocksdb/repo/utilities/fault_injection_secondary_cache.cc:92 https://github.com/facebook/rocksdb/issues/9 0xeadaab in rocksdb::lru_cache::LRUCacheShard::Lookup(rocksdb::Slice const&, unsigned int, rocksdb::Cache::CacheItemHelper const*, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, rocksdb::Cache::Priority, bool, rocksdb::Statistics*) internal_repo_rocksdb/repo/cache/lru_cache.cc:445 https://github.com/facebook/rocksdb/issues/10 0x1064573 in rocksdb::ShardedCache::Lookup(rocksdb::Slice const&, rocksdb::Cache::CacheItemHelper const*, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, rocksdb::Cache::Priority, bool, rocksdb::Statistics*) internal_repo_rocksdb/repo/cache/sharded_cache.cc:89 https://github.com/facebook/rocksdb/issues/11 0x8be0df in rocksdb::BlockBasedTable::GetEntryFromCache(rocksdb::CacheTier const&, rocksdb::Cache*, rocksdb::Slice const&, rocksdb::BlockType, bool, rocksdb::GetContext*, rocksdb::Cache::CacheItemHelper const*, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, rocksdb::Cache::Priority) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:389 https://github.com/facebook/rocksdb/issues/12 0x905790 in rocksdb::Status rocksdb::BlockBasedTable::GetDataBlockFromCache<rocksdb::Block>(rocksdb::Slice const&, rocksdb::Cache*, rocksdb::Cache*, rocksdb::ReadOptions const&, rocksdb::CachableEntry<rocksdb::Block>*, rocksdb::UncompressionDict const&, rocksdb::BlockType, bool, rocksdb::GetContext*) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:1263 https://github.com/facebook/rocksdb/issues/13 0x8b9259 in rocksdb::Status rocksdb::BlockBasedTable::MaybeReadBlockAndLoadToCache<rocksdb::Block>(rocksdb::FilePrefetchBuffer*, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::UncompressionDict const&, bool, bool, rocksdb::CachableEntry<rocksdb::Block>*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, rocksdb::BlockContents*, bool) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:1559 https://github.com/facebook/rocksdb/issues/14 0x8b710c in rocksdb::Status rocksdb::BlockBasedTable::RetrieveBlock<rocksdb::Block>(rocksdb::FilePrefetchBuffer*, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::UncompressionDict const&, rocksdb::CachableEntry<rocksdb::Block>*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, bool, bool, bool, bool) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:1726 https://github.com/facebook/rocksdb/issues/15 0x8c329f in rocksdb::DataBlockIter* rocksdb::BlockBasedTable::NewDataBlockIterator<rocksdb::DataBlockIter>(rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::DataBlockIter*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, rocksdb::FilePrefetchBuffer*, bool, bool, rocksdb::Status&) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader_impl.h:58 https://github.com/facebook/rocksdb/issues/16 0x920117 in rocksdb::BlockBasedTableIterator::InitDataBlock() internal_repo_rocksdb/repo/table/block_based/block_based_table_iterator.cc:262 https://github.com/facebook/rocksdb/issues/17 0x920d42 in rocksdb::BlockBasedTableIterator::MaterializeCurrentBlock() internal_repo_rocksdb/repo/table/block_based/block_based_table_iterator.cc:332 https://github.com/facebook/rocksdb/issues/18 0xc6a201 in rocksdb::IteratorWrapperBase<rocksdb::Slice>::PrepareValue() internal_repo_rocksdb/repo/table/iterator_wrapper.h:78 https://github.com/facebook/rocksdb/issues/19 0xc6a201 in rocksdb::IteratorWrapperBase<rocksdb::Slice>::PrepareValue() internal_repo_rocksdb/repo/table/iterator_wrapper.h:78 https://github.com/facebook/rocksdb/issues/20 0xef9f6c in rocksdb::MergingIterator::PrepareValue() internal_repo_rocksdb/repo/table/merging_iterator.cc:260 https://github.com/facebook/rocksdb/issues/21 0xc6a201 in rocksdb::IteratorWrapperBase<rocksdb::Slice>::PrepareValue() internal_repo_rocksdb/repo/table/iterator_wrapper.h:78 https://github.com/facebook/rocksdb/issues/22 0xc67bcd in rocksdb::DBIter::FindNextUserEntryInternal(bool, rocksdb::Slice const*) internal_repo_rocksdb/repo/db/db_iter.cc:326 https://github.com/facebook/rocksdb/issues/23 0xc66d36 in rocksdb::DBIter::FindNextUserEntry(bool, rocksdb::Slice const*) internal_repo_rocksdb/repo/db/db_iter.cc:234 https://github.com/facebook/rocksdb/issues/24 0xc7ab47 in rocksdb::DBIter::Next() internal_repo_rocksdb/repo/db/db_iter.cc:161 https://github.com/facebook/rocksdb/issues/25 0x70d938 in rocksdb::BatchedOpsStressTest::TestPrefixScan(rocksdb::ThreadState*, rocksdb::ReadOptions const&, std::vector<int, std::allocator<int> > const&, std::vector<long, std::allocator<long> > const&) internal_repo_rocksdb/repo/db_stress_tool/batched_ops_stress.cc:320 https://github.com/facebook/rocksdb/issues/26 0x6dc6a8 in rocksdb::StressTest::OperateDb(rocksdb::ThreadState*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:907 https://github.com/facebook/rocksdb/issues/27 0x6867de in rocksdb::ThreadBody(void*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_driver.cc:33 https://github.com/facebook/rocksdb/issues/28 0xce4cc2 in rocksdb::(anonymous namespace)::StartThreadWrapper(void*) internal_repo_rocksdb/repo/env/env_posix.cc:461 https://github.com/facebook/rocksdb/issues/29 0x7f23f9068c0e in start_thread /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/nptl/pthread_create.c:434:8 ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10523 Test Plan: ``` $COMPILE_WITH_ASAN=1 make -j 24 $db_stress J=40 crash_test_with_txn ``` Reviewed By: anand1976 Differential Revision: D38646839 Pulled By: gitbw95 fbshipit-source-id: 9452895c7dc95481a9d7afe83b15193cf5b1c43e	2 years ago
gitbw95	f241d082b6	Prevent double caching in the compressed secondary cache (#9747) ... Summary: ### **Summary:** When both LRU Cache and CompressedSecondaryCache are configured together, there possibly are some data blocks double cached. **Changes include:** 1. Update IS_PROMOTED to IS_IN_SECONDARY_CACHE to prevent confusions. 2. This PR updates SecondaryCacheResultHandle and use IsErasedFromSecondaryCache to determine whether the handle is erased in the secondary cache. Then, the caller can determine whether to SetIsInSecondaryCache(). 3. Rename LRUSecondaryCache to CompressedSecondaryCache. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9747 Test Plan: **Test Scripts:** 1. Populate a DB. The on disk footprint is 482 MB. The data is set to be 50% compressible, so the total decompressed size is expected to be 964 MB. ./db_bench --benchmarks=fillrandom --num=10000000 -db=/db_bench_1 2. overwrite it to a stable state: ./db_bench --benchmarks=overwrite,stats --num=10000000 -use_existing_db -duration=10 --benchmark_write_rate_limit=2000000 -db=/db_bench_1 4. Run read tests with diffeernt cache setting: T1: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=520000000 --statistics -db=/db_bench_1 T2: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=320000000 -compressed_secondary_cache_size=400000000 --statistics -use_compressed_secondary_cache -db=/db_bench_1 T3: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=520000000 -compressed_secondary_cache_size=400000000 --statistics -use_compressed_secondary_cache -db=/db_bench_1 T4: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=20000000 -compressed_secondary_cache_size=500000000 --statistics -use_compressed_secondary_cache -db=/db_bench_1 **Before this PR** | Cache Size | Compressed Secondary Cache Size | Cache Hit Rate | |------------|-------------------------------------|----------------| |520 MB | 0 MB | 85.5% | |320 MB | 400 MB | 96.2% | |520 MB | 400 MB | 98.3% | |20 MB | 500 MB | 98.8% | **Before this PR** | Cache Size | Compressed Secondary Cache Size | Cache Hit Rate | |------------|-------------------------------------|----------------| |520 MB | 0 MB | 85.5% | |320 MB | 400 MB | 99.9% | |520 MB | 400 MB | 99.9% | |20 MB | 500 MB | 99.2% | Reviewed By: anand1976 Differential Revision: D35117499 Pulled By: gitbw95 fbshipit-source-id: ea2657749fc13efebe91a8a1b56bc61d6a224a12	3 years ago
anand76	78556c14dd	Secondary cache error injection (#9002) ... Summary: Implement secondary cache error injection in db_stress. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9002 Reviewed By: zhichao-cao Differential Revision: D31874896 Pulled By: anand1976 fbshipit-source-id: 8cf04c061a4a44efa0fe88423d05cade67b85f73	3 years ago