Summary:
In preparation for factoring secondary cache support out of individual Cache implementations, we can get rid of the "in secondary cache" flag on entries through a workable hack: when an entry is promoted from secondary, it is inserted in primary using a helper that lacks secondary cache support, thus preventing re-insertion into secondary cache through existing logic.
This adds to the complexity of building CacheItemHelpers, because you always have to be able to get to an equivalent helper without secondary cache support, but that complexity is reasonably isolated within RocksDB typed_cache.h and test code.
gcc-7 seems to have problems with constexpr constructor referencing `this` so removed constexpr support on CacheItemHelper.
Also refactored some related test code to share common code / functionality.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11299
Test Plan: existing tests
Reviewed By: anand1976
Differential Revision: D44101453
Pulled By: pdillinger
fbshipit-source-id: 7a59d0a3938ee40159c90c3e65d7004f6a272345
Summary:
... ahead of a larger change.
* Rename confusingly named `is_in_sec_cache` to `kept_in_sec_cache`
* Unify naming of "standalone" block cache entries (was "detached" in clock_cache)
* Remove some unused definitions in clock_cache.h (leftover from a previous revision)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11291
Test Plan: usual tests and CI, no behavior changes
Reviewed By: anand1976
Differential Revision: D43984642
Pulled By: pdillinger
fbshipit-source-id: b8bf0c5b90a932a88bcbdb413b2f256834aedf97
Summary:
In rare cases seeing failures like this
```
[ RUN ] DBWriteTestInstance/DBWriteTest.LockWALInEffect/2
db/db_write_test.cc:653: Failure
Put("key3", "value")
Corruption: Not active
```
in a test with no explicit threading. This is likely because of the unpredictability of background auto-resume. I didn't really know this feature, in part because DB::Resume() was undocumented. So I believe I have fixed the test and documented the API function.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11290
Test Plan: 1000s of stress runs of the test with gtest-parallel
Reviewed By: anand1976
Differential Revision: D43984583
Pulled By: pdillinger
fbshipit-source-id: d30dec120b4864e193751b2e33ff16834d313db3
Summary:
CreateColumnFamilyWithImport() did not support range tombstones for two reasons:
1. it uses point keys of a input file to determine its boundary (smallest and largest internal key), which means range tombstones outside of the point key range will be effectively dropped.
2. it does not handle files with no point keys.
Also included a fix in external_sst_file_ingestion_job.cc where the blocks read in `GetIngestedFileInfo()` can be added to block cache now (issue fixed in https://github.com/facebook/rocksdb/pull/6429).
This PR adds support for exporting and importing column family with range tombstones. The main change is to add smallest internal key and largest internal key to `SstFileMetaData` that will be part of the output of `ExportColumnFamily()`. Then during `CreateColumnFamilyWithImport(...,const ExportImportFilesMetaData& metadata,...)`, file boundaries can be set from `metadata` directly. This is needed since when file boundaries are extended by range tombstones, sometimes they cannot be deduced from a file's content alone.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11252
Test Plan:
- added unit tests that fails before this change
Closes https://github.com/facebook/rocksdb/issues/11245
Reviewed By: ajkr
Differential Revision: D43577443
Pulled By: cbi42
fbshipit-source-id: 6bff78e583cc50c44854994dea0a8dd519398f2f
Summary:
The existing PerfContext counter `internal_merge_count` only tracks the
Merge operands applied during range scans. The patch adds a new counter
called `internal_merge_count_point_lookups` to track the same metric
for point lookups (`Get` / `MultiGet` / `GetEntity` / `MultiGetEntity`), and
also fixes a couple of cases in the iterator where the existing counter wasn't
updated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11284
Test Plan: `make check`
Reviewed By: jowlyzhang
Differential Revision: D43926082
Pulled By: ltamasi
fbshipit-source-id: 321566d8b4cf0a3b6c9b73b7a5c984fb9bb492e9
Summary:
The patch makes the following changes to the API comments:
* Some general comments about snapshots, thread safety, and user-defined timestamps are moved to a more prominent place at the top of the file.
* Detailed descriptions are added for each `ValueType` and `Decision`, fixing and extending some existing comments (e.g. that of `kRemove`, which suggested that key-values are simply removed from the output, while in reality base values are converted to tombstones) and adding detailed comments that were missing (e.g. `kPurge` and `kChangeWideColumnEntity`).
* Updated/extended the comments of `FilterV2/V3` and `FilterBlobByKey`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11261
Reviewed By: akankshamahajan15
Differential Revision: D43714314
Pulled By: ltamasi
fbshipit-source-id: 835f4b1bdac1ce0e291155186095211303260729
Summary:
Add more stats for better visibility into the usefulness of the secondary cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11246
Test Plan: Add a new unit test
Reviewed By: akankshamahajan15
Differential Revision: D43521364
Pulled By: anand1976
fbshipit-source-id: a92f04884e738a9bf40ad4047acaaaea343838a7
Summary:
This makes it possible to eliminate some copies in `GetEntity` / `MultiGetEntity`,
in particular when `Merge`s or blobs are involved.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11248
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D43544215
Pulled By: ltamasi
fbshipit-source-id: bc4c8955a24bbd8bc4ab098e72133ead757f9707
Summary:
8.0.fb branch is cut so changes going forward will be part of 8.1. Updated version.h and HISTORY.md accordingly
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11238
Reviewed By: cbi42
Differential Revision: D43428345
Pulled By: ajkr
fbshipit-source-id: d344b6e504c81a85563ae9d3705b11c533b1cd43
Summary:
the comment for option `periodic_compaction_seconds` only mentions support for Leveled and FIFO compaction, while the implementation supports all compaction styles after https://github.com/facebook/rocksdb/issues/5970. This PR updates comment to reflect this.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11227
Reviewed By: ajkr
Differential Revision: D43325046
Pulled By: cbi42
fbshipit-source-id: 2364dcb5a01cd098ad52c818fe10d621445e2188
Summary:
This PR adds support to the c-api bindings for calling `Flush()` with multiple column families, which is useful for performing atomic flushes (assuming also that the db has been opened with `atomic_flush = true`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11112
Reviewed By: cbi42
Differential Revision: D42666382
Pulled By: ajkr
fbshipit-source-id: 82f05bf32d28452d85c79ea42411c8fea961fd87
Summary:
The primary purpose of the FactoryFunc was to support LITE mode where the ObjectRegistry was not available. With the removal of LITE mode, the function was no longer required.
Note that the MergeOperator had some private classes defined in header files. To gain access to their constructors (and name methods), the class definitions were moved into header files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11203
Reviewed By: cbi42
Differential Revision: D43160255
Pulled By: pdillinger
fbshipit-source-id: f3a465fd5d1a7049b73ecf31e4b8c3762f6dae6c
Summary:
From HISTORY.md: Added a subcode of `Status::Corruption`, `Status::SubCode::kMergeOperatorFailed`, for users to identify corruption failures originating in the merge operator, as opposed to RocksDB's internally identified data corruptions.
This is a followup to https://github.com/facebook/rocksdb/issues/11092, where we gave users the ability to keep running a DB despite merge operator failing. Now that the DB keeps running despite such failures, they want to be able to distinguish such failures from real corruptions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11231
Test Plan: updated unit test
Reviewed By: akankshamahajan15
Differential Revision: D43396607
Pulled By: ajkr
fbshipit-source-id: 17fbcc779ad724dafada8abd73efd38e1c5208b9
Summary:
Added `do_not_compress_roles` to `CompressedSecondaryCacheOptions` to disable compression on certain kinds of block. Filter blocks are now not compressed by CompressedSecondaryCache by default.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11204
Test Plan: unit test added
Reviewed By: anand1976
Differential Revision: D43147698
Pulled By: pdillinger
fbshipit-source-id: db496975ae975fa18f157f93fe131a16315ac875
Summary:
Enough users of NewJemallocNodumpAllocator() with cache.h to justify keeping it. (Reverting one little part of https://github.com/facebook/rocksdb/issues/11192)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11229
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D43337140
Pulled By: pdillinger
fbshipit-source-id: 886b27b96b395619a4209f51b9b7787f4fe89e57
Summary:
The new `MultiGetEntity` API can be used to get a consistent view of
a batch of keys, with the results presented as wide-column entities.
Similarly to `GetEntity` and the iterator's `columns` API, if the entry
corresponding to the key is a wide-column entity to start with, it is
returned as-is, and if it is a plain key-value, it is wrapped into an entity
with a single default column.
Implementation-wise, the new API shares the logic of the batched `MultiGet`
API (via the `MultiGetCommon` methods). Both single-CF and multi-CF
`MultiGetEntity` APIs are provided, and blobs are also supported.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11222
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D43256950
Pulled By: ltamasi
fbshipit-source-id: 47fb2cb7e2d0470e3580f43fdb2fe9e51f0e7005
Summary:
The files in `port/`, such as `port_posix.h`, are layering over the system libraries, so shouldn't include the DB-specific files like `options.h`. This PR remove this dependency.
# How
The reason that `port_posix.h` (or `port_win.h`) include `options.h` is to use `CpuPriority`, as there is a method `SetCpuPriority()` in `port_posix.h` that uses `CpuPriority.`
- I think `SetCpuPriority()` make sense to exist in `port_posix.h` as it provides has platform-dependent implementation
- `CpuPriority` enum is defined in `env.h`, but used in `rocksdb/include` and `port/`.
Hence, let us define `CpuPriority` enum in a common file, say `port_defs.h`, such that both directories `rocksdb/include` and `port/` can include.
When we remove this dependency, some other files have compile errors because they can't find definitions, so add header files to resolve
# Test
make all check -j
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11214
Reviewed By: pdillinger
Differential Revision: D43196910
Pulled By: guowentian
fbshipit-source-id: 70deccb72844cfb08fcc994f76c6ef6df5d55ab9
Summary:
The definition of the Cache class should not be needed by the vast majority of RocksDB users, so I think it is just distracting to include it in cache.h, which is primarily needed for configuring and creating caches. This change moves the class to a new header advanced_cache.h. It is just cut-and-paste except for modifying the class API comment.
In general, operations on shared_ptr<Cache> should continue to work when only a forward declaration of Cache is available, as long as all the Cache instances provided are already shared_ptr. See https://stackoverflow.com/a/17650101/454544
Also, the most common way to customize a Cache is by wrapping an existing implementation, so it makes sense to provide CacheWrapper in the public API. This was a cut-and-paste job except removing the implementation of Name() so that derived classes must provide it.
Intended follow-up: consolidate Release() into one function to reduce customization bugs / confusion
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11192
Test Plan: `make check`
Reviewed By: anand1976
Differential Revision: D43055487
Pulled By: pdillinger
fbshipit-source-id: 7b05492df35e0f30b581b4c24c579bc275b6d110
Summary:
In anticipation of using this to represent sets of CacheEntryRole for including or excluding kinds of blocks in block cache tiers, add significant new features to SmallEnumSet, including at least:
* List initialization
* Applicative constexpr operations
* copy/move/equality ops
* begin/end/const_iterator for iteration
* Better comments
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11178
Test Plan: unit tests added/expanded
Reviewed By: ltamasi
Differential Revision: D42973723
Pulled By: pdillinger
fbshipit-source-id: 40783486feda931c3f7c6fcc9a300acd6a4b0a0a
Summary:
The patch adds compaction filter support for wide-column entities by introducing
a new `CompactionFilter` API called `FilterV3`. This API is called for regular
key-values, merge operands, and wide-column entities as well. It is passed the
existing value/operand or wide-column structure and it can update the value or
columns or keep/delete/etc. the key-value as usual. For compatibility, the default
implementation of `FilterV3` keeps all wide-column entities and falls back to calling
`FilterV2` for plain old key-values and merge operands.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11196
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D43094147
Pulled By: ltamasi
fbshipit-source-id: 75acabe9a35254f7f404ba6173ee9c2774382ebd
Summary:
**Context/Summary:**
As instructed by convenience.h comments, a few deprecated APIs are removed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11120
Test Plan:
- make check & CI
- eyeball check on test semantics.
Reviewed By: pdillinger
Differential Revision: D42937507
Pulled By: hx235
fbshipit-source-id: a9e4709387da01b1d0e9148c2e210f02e9746ee1
Summary:
This option has long been intended to be set to false by default and deprecated. It might never be practical to completely remove the feature, so that we can continue to test for backward compatibility by keeping the ability to generate DBs in the old way.
Also improved API comments.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11179
Test Plan: existing tests (with one tiny update)
Reviewed By: hx235
Differential Revision: D42973927
Pulled By: pdillinger
fbshipit-source-id: e9bc161cb933266e094aea2dff8cc03753c39dab
Summary:
The previous API comments for LockWAL didn't provide much about why you might want to use it, and didn't really meet what one would infer its contract was. Also, LockWAL was not in db_stress / crash test. In this change:
* Implement a counting semantics for LockWAL()+UnlockWAL(), so that they can safely be used concurrently across threads or recursively within a thread. This should make the API much less bug-prone and easier to use.
* Make sure no UnlockWAL() is needed after non-OK LockWAL() (to match RocksDB conventions)
* Make UnlockWAL() reliably return non-OK when there's no matching LockWAL() (for debug-ability)
* Clarify API comments on LockWAL(), UnlockWAL(), FlushWAL(), and SyncWAL(). Their exact meanings are not obvious, and I don't think it's appropriate to talk about implementation mutexes in the API comments, but about what operations might block each other.
* Add LockWAL()/UnlockWAL() to db_stress and crash test, mostly to check for assertion failures, but also checks that latest seqno doesn't change while WAL is locked. This is simpler to add when LockWAL() is allowed in multiple threads.
* Remove unnecessary use of sync points in test DBWALTest::LockWal. There was a bug during development of above changes that caused this test to fail sporadically, with and without this sync point change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11143
Test Plan: unit tests added / updated, added to stress/crash test
Reviewed By: ajkr
Differential Revision: D42848627
Pulled By: pdillinger
fbshipit-source-id: 6d976c51791941a31fd8fbf28b0f82e888d9f4b4
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.
Most of changes were done through following comments:
unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'`
by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147
Test Plan: See CI
Reviewed By: pdillinger
Differential Revision: D42796341
fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
Summary:
Since compressed block cache is removed, those stats are not needed. They are removed in different PR in case there is a problem with it. The stats are removed in the same way in https://github.com/facebook/rocksdb/pull/11131/ . HISTORY.md was already updated by mistake, and it would be correct after merging this PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11135
Test Plan: Watch CI
Reviewed By: ltamasi
Differential Revision: D42757616
fbshipit-source-id: bd7cb782585c8535ce5784295225c376f3011f35
Summary:
These tickers/histograms have been obsolete (and not populated) for a long time.
The patch removes them from the API completely. Note that this means that the
numeric values of the remaining tickers change in the C++ code as they get shifted up.
This should be OK: the values of some existing tickers have changed many times
over the years as items have been added in the middle. (In contrast, the convention
in the Java bindings is to keep the ids, which are not guaranteed to be the same
as the ids on the C++ side, the same across releases.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11123
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D42727793
Pulled By: ltamasi
fbshipit-source-id: e058a155a20b05b45f53e67ee380aece1b43b6c5
Summary:
Compressed block cache is replaced by compressed secondary cache. Remove the feature.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11117
Test Plan: See CI passes
Reviewed By: pdillinger
Differential Revision: D42700164
fbshipit-source-id: 6cbb24e460da29311150865f60ecb98637f9f67d
Summary:
Capture more of the original intent at a high level, without getting bogged down in low-level details.
The old text made some weak promises about handling of LOCK files. There should be no specific concern for LOCK files, because we already rely on LockFile() to create the file if it's not present already. And the lock file is generally size 0, so don't have to worry about truncation. Added a unit test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11085
Test Plan: existing tests, and a new one.
Reviewed By: siying
Differential Revision: D42713233
Pulled By: pdillinger
fbshipit-source-id: 2fce7c974d35fac065037c9c4c7326a59c9fe340
Summary:
Prior to this PR, `FullMergeV2()` can only return `false` to indicate failure, which causes any operation invoking it to fail. During a compaction, such a failure causes the compaction to fail and causes the DB to irreversibly enter read-only mode. Some users asked for a way to allow the merge operator to fail without such widespread damage.
To limit the blast radius of merge operator failures, this PR introduces the `MergeOperationOutput::op_failure_scope` API. When unpopulated (`kDefault`) or set to `kTryMerge`, the merge operator failure handling is the same as before. When set to `kMustMerge`, merge operator failure still causes failure to operations that must merge (`Get()`, iterator, `MultiGet()`, etc.). However, under `kMustMerge`, flushes/compactions can survive merge operator failures by outputting the unmerged input operands.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11092
Reviewed By: siying
Differential Revision: D42525673
Pulled By: ajkr
fbshipit-source-id: 951dc3bf190f86347dccf3381be967565cda52ee
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
Summary:
**Context:**
File ingestion never checks whether the key range it acts on overlaps with an ongoing RefitLevel() (used in `CompactRange()` with `change_level=true`). That's because RefitLevel() doesn't register and make its key range known to file ingestion. Though it checks overlapping with other compactions by https://github.com/facebook/rocksdb/blob/7.8.fb/db/external_sst_file_ingestion_job.cc#L998.
RefitLevel() (used in `CompactRange()` with `change_level=true`) doesn't check whether the key range it acts on overlaps with an ongoing file ingestion. That's because file ingestion does not register and make its key range known to other compactions.
- Note that non-refitlevel-compaction (e.g, manual compaction w/o RefitLevel() or general compaction) also does not check key range overlap with ongoing file ingestion for the same reason.
- But it's fine. Credited to cbi42's discovery, `WaitForIngestFile` was called by background and foreground compactions. They were introduced in 0f88160f67, 5c64fb67d2 and 87dfc1d23e.
- Regardless, this PR registers file ingestion like a compaction is a general approach that will also add range conflict check between file ingestion and non-refitlevel-compaction, though it has not been the issue motivated this PR.
Above are bugs resulting in two bad consequences:
- If file ingestion and RefitLevel() creates files in the same level, then range-overlapped files will be created at that level and caught as corruption by `force_consistency_checks=true`
- If file ingestion and RefitLevel() creates file in different levels, then with one further compaction on the ingested file, it can result in two same keys both with seqno 0 in two different levels. Then with iterator's [optimization](c62f322169/db/db_iter.cc (L342-L343)) that assumes no two same keys both with seqno 0, it will either break this assertion in debug build or, even worst, return value of this same key for the key after it, which is the wrong value to return, in release build.
Therefore we decide to introduce range conflict check for file ingestion and RefitLevel() inspired from the existing range conflict check among compactions.
**Summary:**
- Treat file ingestion job and RefitLevel() as `Compaction` of new compaction reasons: `CompactionReason::kExternalSstIngestion` and `CompactionReason::kRefitLevel` and register/unregister them. File ingestion is treated as compaction from L0 to different levels and RefitLevel() as compaction from source level to target level.
- Check for `RangeOverlapWithCompaction` with other ongoing compactions, `RegisterCompaction()` on this "compaction" before changing the LSM state in `VersionStorageInfo`, and `UnregisterCompaction()` after changing.
- Replace scattered fixes (0f88160f67, 5c64fb67d2 and 87dfc1d23e.) that prevents overlapping between file ingestion and non-refit-level compaction with this fix cuz those practices are easy to overlook.
- Misc: logic cleanup, see PR comments
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10988
Test Plan:
- New unit test `DBCompactionTestWithOngoingFileIngestionParam*` that failed pre-fix and passed afterwards.
- Made compatible with existing tests, see PR comments
- make check
- [Ongoing] Stress test rehearsal with normal value and aggressive CI value https://github.com/facebook/rocksdb/pull/10761
Reviewed By: cbi42
Differential Revision: D41535685
Pulled By: hx235
fbshipit-source-id: 549833a577ba1496d20a870583d4caa737da1258
Summary:
We have a request for RocksDB to essentially support
disconnected incremental backup. In other words, if there is limited
or no connectivity to the primary backup dir, we should still be able to
take an incremental backup relative to that primary backup dir,
assuming some metadata about that primary dir is available (and
obviously anticipating primary backup dir will be fully available if
restore is needed).
To support that, this feature allows the API user to "exclude" DB
files from backup. This only applies to files that can be shared
between backups (sst and blob files), and excluded files are
tracked in the backup metadata sufficiently to ensure they are
restored at restore time. At restore time, the user provides
a set of alternate backup directories (as open BackupEngines, which
can be read-only), and excluded files must be found in one of the
backup directories ("included" in some backup).
This feature depends on backup schema version 2 features, though
schema version 2.0 support is not sufficient to read / restore a
backup with exclusions. This change updates the schema version to
2.1 because of this feature, so that it's easy to recognize whether
a RocksDB release supports this feature, while backups not using the
feature are fully compatible with 2.0.
Also in this PR:
* Stacked on https://github.com/facebook/rocksdb/pull/11029
* Allow progress_callback to be empty, not just no-op function, and
recover from exceptions thrown by BackupEngine callbacks.
* The internal-only `AsBackupEngine()` function is working around the
diamond hierarchy of `BackupEngineImplThreadSafe` to get to the
internals, without using confusing features like virtual inheritance.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11030
Test Plan: unit tests added / updated
Reviewed By: ajkr
Differential Revision: D42004388
Pulled By: pdillinger
fbshipit-source-id: 31b6e533d308a5462e528d9012d650482d974077
Summary:
RocksDB has two public APIs: `DB::LockWAL()`/`DB::UnlockWAL()`. The current implementation acquires and
releases the internal `DBImpl::log_write_mutex_`.
According to the comment on `DBImpl::log_write_mutex_`: https://github.com/facebook/rocksdb/blob/7.8.fb/db/db_impl/db_impl.h#L2287:L2288
> Note: to avoid dealock, if needed to acquire both log_write_mutex_ and mutex_, the order should be first mutex_ and then log_write_mutex_.
This puts limitations on how applications can use the `LockWAL()` API. After `LockWAL()` returns ok, then application
should not perform any operation that acquires `mutex_`. Currently, the use case of `LockWAL()` is MyRocks implementing
the MySQL storage engine handlerton `lock_hton_log` interface. The operation that MyRocks performs after `LockWAL()`
is `GetSortedWalFiless()` which not only acquires mutex_, but also `log_write_mutex_`.
There are two issues:
1. Applications using these two APIs may hang if one thread calls `GetSortedWalFiles()` after
calling `LockWAL()` because log_write_mutex is not recursive.
2. Two threads may dead lock due to lock order inversion.
To fix these issues, we can modify the implementation of LockWAL so that it does not keep
`log_write_mutex_` held until UnlockWAL. To achieve the goal of locking the WAL, we can
instead manually inject a write stall so that all future writes will be stopped.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11020
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D41785203
Pulled By: riversand963
fbshipit-source-id: 5ccb7a9c6eb9a2c3fa80fd2c399cc2568b8f89ce
Summary:
**Context:**
Sorting L0 files by `largest_seqno` has at least two inconvenience:
- File ingestion and compaction involving ingested files can create files of overlapping seqno range with the existing files. `force_consistency_check=true` will catch such overlap seqno range even those harmless overlap.
- For example, consider the following sequence of events ("key@n" indicates key at seqno "n")
- insert k1@1 to memtable m1
- ingest file s1 with k2@2, ingest file s2 with k3@3
- insert k4@4 to m1
- compact files s1, s2 and result in new file s3 of seqno range [2, 3]
- flush m1 and result in new file s4 of seqno range [1, 4]. And `force_consistency_check=true` will think s4 and s3 has file reordering corruption that might cause retuning an old value of k1
- However such caught corruption is a false positive since s1, s2 will not have overlapped keys with k1 or whatever inserted into m1 before ingest file s1 by the requirement of file ingestion (otherwise the m1 will be flushed first before any of the file ingestion completes). Therefore there in fact isn't any file reordering corruption.
- Single delete can decrease a file's largest seqno and ordering by `largest_seqno` can introduce a wrong ordering hence file reordering corruption
- For example, consider the following sequence of events ("key@n" indicates key at seqno "n", Credit to ajkr for this example)
- an existing SST s1 contains only k1@1
- insert k1@2 to memtable m1
- ingest file s2 with k3@3, ingest file s3 with k4@4
- insert single delete k5@5 in m1
- flush m1 and result in new file s4 of seqno range [2, 5]
- compact s1, s2, s3 and result in new file s5 of seqno range [1, 4]
- compact s4 and result in new file s6 of seqno range [2] due to single delete
- By the last step, we have file ordering by largest seqno (">" means "newer") : s5 > s6 while s6 contains a newer version of the k1's value (i.e, k1@2) than s5, which is a real reordering corruption. While this can be caught by `force_consistency_check=true`, there isn't a good way to prevent this from happening if ordering by `largest_seqno`
Therefore, we are redesigning the sorting criteria of L0 files and avoid above inconvenience. Credit to ajkr , we now introduce `epoch_num` which describes the order of a file being flushed or ingested/imported (compaction output file will has the minimum `epoch_num` among input files'). This will avoid the above inconvenience in the following ways:
- In the first case above, there will no longer be overlap seqno range check in `force_consistency_check=true` but `epoch_number` ordering check. This will result in file ordering s1 < s2 < s4 (pre-compaction) and s3 < s4 (post-compaction) which won't trigger false positive corruption. See test class `DBCompactionTestL0FilesMisorderCorruption*` for more.
- In the second case above, this will result in file ordering s1 < s2 < s3 < s4 (pre-compacting s1, s2, s3), s5 < s4 (post-compacting s1, s2, s3), s5 < s6 (post-compacting s4), which are correct file ordering without causing any corruption.
**Summary:**
- Introduce `epoch_number` stored per `ColumnFamilyData` and sort CF's L0 files by their assigned `epoch_number` instead of `largest_seqno`.
- `epoch_number` is increased and assigned upon `VersionEdit::AddFile()` for flush (or similarly for WriteLevel0TableForRecovery) and file ingestion (except for allow_behind_true, which will always get assigned as the `kReservedEpochNumberForFileIngestedBehind`)
- Compaction output file is assigned with the minimum `epoch_number` among input files'
- Refit level: reuse refitted file's epoch_number
- Other paths needing `epoch_number` treatment:
- Import column families: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`
- Repair: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`.
- Assigning new epoch_number to a file and adding this file to LSM tree should be atomic. This is guaranteed by us assigning epoch_number right upon `VersionEdit::AddFile()` where this version edit will be apply to LSM tree shape right after by holding the db mutex (e.g, flush, file ingestion, import column family) or by there is only 1 ongoing edit per CF (e.g, WriteLevel0TableForRecovery, Repair).
- Assigning the minimum input epoch number to compaction output file won't misorder L0 files (even through later `Refit(target_level=0)`). It's due to for every key "k" in the input range, a legit compaction will cover a continuous epoch number range of that key. As long as we assign the key "k" the minimum input epoch number, it won't become newer or older than the versions of this key that aren't included in this compaction hence no misorder.
- Persist `epoch_number` of each file in manifest and recover `epoch_number` on db recovery
- Backward compatibility with old db without `epoch_number` support is guaranteed by assigning `epoch_number` to recovered files by `NewestFirstBySeqno` order. See `VersionStorageInfo::RecoverEpochNumbers()` for more
- Forward compatibility with manifest is guaranteed by flexibility of `NewFileCustomTag`
- Replace `force_consistent_check` on L0 with `epoch_number` and remove false positive check like case 1 with `largest_seqno` above
- Due to backward compatibility issue, we might encounter files with missing epoch number at the beginning of db recovery. We will still use old L0 sorting mechanism (`NewestFirstBySeqno`) to check/sort them till we infer their epoch number. See usages of `EpochNumberRequirement`.
- Remove fix https://github.com/facebook/rocksdb/pull/5958#issue-511150930 and their outdated tests to file reordering corruption because such fix can be replaced by this PR.
- Misc:
- update existing tests with `epoch_number` so make check will pass
- update https://github.com/facebook/rocksdb/pull/5958#issue-511150930 tests to verify corruption is fixed using `epoch_number` and cover universal/fifo compaction/CompactRange/CompactFile cases
- assert db_mutex is held for a few places before calling ColumnFamilyData::NewEpochNumber()
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10922
Test Plan:
- `make check`
- New unit tests under `db/db_compaction_test.cc`, `db/db_test2.cc`, `db/version_builder_test.cc`, `db/repair_test.cc`
- Updated tests (i.e, `DBCompactionTestL0FilesMisorderCorruption*`) under https://github.com/facebook/rocksdb/pull/5958#issue-511150930
- [Ongoing] Compatibility test: manually run 36a5686ec0 (with file ingestion off for running the `.orig` binary to prevent this bug affecting upgrade/downgrade formality checking) for 1 hour on `simple black/white box`, `cf_consistency/txn/enable_ts with whitebox + test_best_efforts_recovery with blackbox`
- [Ongoing] normal db stress test
- [Ongoing] db stress test with aggressive value https://github.com/facebook/rocksdb/pull/10761
Reviewed By: ajkr
Differential Revision: D41063187
Pulled By: hx235
fbshipit-source-id: 826cb23455de7beaabe2d16c57682a82733a32a9
Summary:
Previously, you could get a format_version error if SST file size was too small in manifest, or a weird "too short" error if too big in manifest. Now we ensure:
* Magic number error is reported first if we attempt to open an SST file and the footer is completely bad.
* Footer errors are reported with affected file.
* If manifest file size doesn't match actual, then the error includes expected and actual sizes (if an error is reported; in some cases we allow the file to be too big)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11009
Test Plan:
unit tests added, some manual
Previously, the code for "file too short" in footer processing was only covered by some tests attempting to verify SST checksums on non-SST files (fixed).
Reviewed By: siying
Differential Revision: D41656272
Pulled By: pdillinger
fbshipit-source-id: 3da32702eb5aaedbea0e5e74742ad57edd7ad3df
Summary:
Currently, `iterate_upper_bound` is not checked for range tombstone keys in MergingIterator. This may impact performance when there is a large number of range tombstones right after `iterate_upper_bound`. This PR fixes this issue by checking `iterate_upper_bound` in MergingIterator for range tombstone keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10966
Test Plan:
- added unit test
- stress test: `python3 tools/db_crashtest.py whitebox --simple --verify_iterator_with_expected_state_one_in=5 --delrangepercent=5 --prefixpercent=18 --writepercent=48 --readpercen=15 --duration=36000 --range_deletion_width=100`
- ran different stress tests over sandcastle
- Falcon team ran some test traffic and saw reduced CPU usage on processing range tombstones.
Reviewed By: ajkr
Differential Revision: D41414172
Pulled By: cbi42
fbshipit-source-id: 9b2c29eb3abb99327c6a649bdc412e70d863f981
hackingthekernel