Summary:
Allow applications to implement a custom compaction filter and pass it to BlobDB.
The compaction filter's custom logic can operate on blobs.
To do so, application needs to subclass `CompactionFilter` abstract class and implement `FilterV2()` method.
Optionally, a method called `ShouldFilterBlobByKey()` can be implemented if application's custom logic rely solely
on the key to make a decision without reading the blob, thus saving extra IO. Examples can be found in
db/blob/db_blob_compaction_test.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7974
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D26509280
Pulled By: riversand963
fbshipit-source-id: 59f9ae5614c4359de32f4f2b16684193cc537b39
Summary:
In the adapter class `WritableFileStringStreamAdapter`, which wraps WritableFile to be used for std::ostream, previouly only `std::endl` is considered a special case because `endl` is written by `os.put()` directly without going through `xsputn()`. `os.put()` will call `sputc()` and if we further check the internal implementation of `sputc()`, we will see it is
```
int_type __CLR_OR_THIS_CALL sputc(_Elem _Ch) { // put a character
return 0 < _Pnavail() ? _Traits::to_int_type(*_Pninc() = _Ch) : overflow(_Traits::to_int_type(_Ch));
```
As we explicitly disabled buffering, _Pnavail() is always 0. Thus every write, not captured by xsputn, becomes an overflow.
When I run tests on Windows, I found not only `std::endl` will drop into this case, writing an unsigned long long will also call `os.put()` then followed by `sputc()` and eventually call `overflow()`. Therefore, instead of only checking `std::endl`, we should try to append other characters as well unless the appending operation fails.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7991
Reviewed By: jay-zhuang
Differential Revision: D26615692
Pulled By: ajkr
fbshipit-source-id: 4c0003de1645b9531545b23df69b000e07014468
Summary:
RocksDB does auto-readahead for iterators on noticing more
than two reads for a table file. The readahead starts at 8KB and doubles on every
additional read upto BlockBasedTable::kMaxAutoReadAheadSize which is
256*1024.
This PR adds a new option BlockBasedTableOptions::max_auto_readahead_size which
replaces BlockBasedTable::kMaxAutoReadAheadSize and the new option can be
configured.
If max_auto_readahead_size is set 0 then no implicit auto prefetching will
be done. If max_auto_readahead_size provided is less than
8KB (which is initial readahead size used by rocksdb in case of
auto-readahead), readahead size will remain same as max_auto_readahead_size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7951
Test Plan: Add new unit test case.
Reviewed By: anand1976
Differential Revision: D26568085
Pulled By: akankshamahajan15
fbshipit-source-id: b6543520fc74e97d859f2002328d4c5254d417af
Summary:
For dictionary compression, we need to collect some representative samples of the data to be compressed, which we use to either generate or train (when `CompressionOptions::zstd_max_train_bytes > 0`) a dictionary. Previously, the strategy was to buffer all the data blocks during flush, and up to the target file size during compaction. That strategy allowed us to randomly pick samples from as wide a range as possible that'd be guaranteed to land in a single output file.
However, some users try to make huge files in memory-constrained environments, where this strategy can cause OOM. This PR introduces an option, `CompressionOptions::max_dict_buffer_bytes`, that limits how much data blocks are buffered before we switch to unbuffered mode (which means creating the per-SST dictionary, writing out the buffered data, and compressing/writing new blocks as soon as they are built). It is not strict as we currently buffer more than just data blocks -- also keys are buffered. But it does make a step towards giving users predictable memory usage.
Related changes include:
- Changed sampling for dictionary compression to select unique data blocks when there is limited availability of data blocks
- Made use of `BlockBuilder::SwapAndReset()` to save an allocation+memcpy when buffering data blocks for building a dictionary
- Changed `ParseBoolean()` to accept an input containing characters after the boolean. This is necessary since, with this PR, a value for `CompressionOptions::enabled` is no longer necessarily the final component in the `CompressionOptions` string.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7970
Test Plan:
- updated `CompressionOptions` unit tests to verify limit is respected (to the extent expected in the current implementation) in various scenarios of flush/compaction to bottommost/non-bottommost level
- looked at jemalloc heap profiles right before and after switching to unbuffered mode during flush/compaction. Verified memory usage in buffering is proportional to the limit set.
Reviewed By: pdillinger
Differential Revision: D26467994
Pulled By: ajkr
fbshipit-source-id: 3da4ef9fba59974e4ef40e40c01611002c861465
Summary:
Added a "only_mutable_options" flag to the ConfigOptions. When set, the Configurable methods will only look at/update options that are marked as kMutable.
Fixed DB::SetOptions to allow for the update of any mutable TableFactory options. Fixes https://github.com/facebook/rocksdb/issues/7385.
Added tests for the new flag. Updated HISTORY.md
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7936
Reviewed By: akankshamahajan15
Differential Revision: D26389646
Pulled By: mrambacher
fbshipit-source-id: 6dc247f6e999fa2814059ebbd0af8face109fea0
Summary:
The trace file record and payload encode is fixed, which requires complex backward compatibility resolving. This PR introduce a new trace file format, which makes it easier to add new entries to the payload and does not have backward compatible issues. V 0.1 is still supported in this PR. Added the tracing for lower_bound and upper_bound for iterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7977
Test Plan: make check. tested with old trace file in replay and analyzing.
Reviewed By: anand1976
Differential Revision: D26529948
Pulled By: zhichao-cao
fbshipit-source-id: ebb75a127ce3c07c25a1ccc194c551f917896a76
Summary:
TransactionDB uses read callback to filter out un-committed data before
a snapshot. But `MultiGet()` API doesn't use that at all, which causes
returning unwanted data.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7963
Test Plan: Added unittest to reproduce
Reviewed By: anand1976
Differential Revision: D26455851
Pulled By: jay-zhuang
fbshipit-source-id: 265276698cf9d8c4cd79e3250ef10d14375bac55
Summary:
in PR https://github.com/facebook/rocksdb/issues/7419 , we introduce the new Append and PositionedAppend APIs to WritableFile at File System, which enable RocksDB to pass the data verification information (e.g., checksum of the data) to the lower layer. In this PR, we use the new API in WritableFileWriter, such that the file created via WritableFileWrite can pass the checksum to the storage layer. To control which types file should apply the checksum handoff, we add checksum_handoff_file_types to DBOptions. User can use this option to control which file types (Currently supported file tyes: kLogFile, kTableFile, kDescriptorFile.) should use the new Append and PositionedAppend APIs to handoff the verification information.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7523
Test Plan: add new unit test, pass make check/ make asan_check
Reviewed By: pdillinger
Differential Revision: D24313271
Pulled By: zhichao-cao
fbshipit-source-id: aafd69091ae85c3318e3e17cbb96fe7338da11d0
Summary:
Adds support for prefetching data in Ribbon queries,
which especially optimizes batched Ribbon queries for MultiGet
(~222ns/key to ~97ns/key) but also single key queries on cold memory
(~333ns to ~226ns) because many queries span more than one cache line.
This required some refactoring of the query algorithm, and there
does not appear to be a noticeable regression in "hot memory" query
times (perhaps from 48ns to 50ns).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7889
Test Plan:
existing unit tests, plus performance validation with
filter_bench:
Each data point is the best of two runs. I saturated the machine
CPUs with other filter_bench runs in the background.
Before:
$ ./filter_bench -impl=3 -m_keys_total_max=200 -average_keys_per_filter=100000 -m_queries=50
WARNING: Assertions are enabled; benchmarks unnecessarily slow
Building...
Build avg ns/key: 125.86
Number of filters: 1993
Total size (MB): 168.166
Reported total allocated memory (MB): 183.211
Reported internal fragmentation: 8.94626%
Bits/key stored: 7.05341
Prelim FP rate %: 0.951827
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 48.0111
Batched, prepared net ns/op: 222.384
Batched, unprepared net ns/op: 343.908
Skewed 50% in 1% net ns/op: 252.916
Skewed 80% in 20% net ns/op: 320.579
Random filter net ns/op: 332.957
After:
$ ./filter_bench -impl=3 -m_keys_total_max=200 -average_keys_per_filter=100000 -m_queries=50
WARNING: Assertions are enabled; benchmarks unnecessarily slow
Building...
Build avg ns/key: 128.117
Number of filters: 1993
Total size (MB): 168.166
Reported total allocated memory (MB): 183.211
Reported internal fragmentation: 8.94626%
Bits/key stored: 7.05341
Prelim FP rate %: 0.951827
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 49.8812
Batched, prepared net ns/op: 97.1514
Batched, unprepared net ns/op: 222.025
Skewed 50% in 1% net ns/op: 197.48
Skewed 80% in 20% net ns/op: 212.457
Random filter net ns/op: 226.464
Bloom comparison, for reference:
$ ./filter_bench -impl=2 -m_keys_total_max=200 -average_keys_per_filter=100000 -m_queries=50
WARNING: Assertions are enabled; benchmarks unnecessarily slow
Building...
Build avg ns/key: 35.3042
Number of filters: 1993
Total size (MB): 238.488
Reported total allocated memory (MB): 262.875
Reported internal fragmentation: 10.2255%
Bits/key stored: 10.0029
Prelim FP rate %: 0.965327
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 9.09931
Batched, prepared net ns/op: 34.21
Batched, unprepared net ns/op: 88.8564
Skewed 50% in 1% net ns/op: 139.75
Skewed 80% in 20% net ns/op: 181.264
Random filter net ns/op: 173.88
Reviewed By: jay-zhuang
Differential Revision: D26378710
Pulled By: pdillinger
fbshipit-source-id: 058428967c55ed763698284cd3b4bbe3351b6e69
Summary:
Added support for detecting plugins linked in the "plugin/" directory and building them from our Makefile in a standardized way. See "plugin/README.md" for details. An example of a plugin that can be built in this way can be found in https://github.com/ajkr/dedupfs.
There will be more to do in terms of making this process more convenient and adding support for CMake.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7918
Test Plan: my own plugin (https://github.com/ajkr/dedupfs) and also heard this patch worked with ZenFS.
Reviewed By: pdillinger
Differential Revision: D26189969
Pulled By: ajkr
fbshipit-source-id: 6624d4357d0ffbaedb42f0d12a3fcb737c78f758
Summary:
Explicitly reject all range deletions on `TransactionDB` or `OptimisticTransactionDB`, except when the user provides sufficient promises that allow us to proceed safely. The necessary promises are described in the API doc for `TransactionDB::DeleteRange()`. There is currently no way to provide enough promises to make it safe in `OptimisticTransactionDB`.
Fixes https://github.com/facebook/rocksdb/issues/7913.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7929
Test Plan: unit tests covering the cases it's permitted/rejected
Reviewed By: ltamasi
Differential Revision: D26240254
Pulled By: ajkr
fbshipit-source-id: 2834a0ce64cc3e4c3799e35b885a5e79c2f4f6d9
Summary:
Memtable bloom filter is useful in many use cases. A default value on with conservative 1.5% memory can benefit more use cases than use cases impacted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6584
Test Plan: Run all existing tests.
Reviewed By: pdillinger
Differential Revision: D20626739
fbshipit-source-id: 1dd45532b932139552519b8c2682bd954550c2f9
Summary:
This PR adds the foundation classes for key-value integrity protection and the first use case: protecting live updates from the source buffers added to `WriteBatch` through the destination buffer in `MemTable`. The width of the protection info is not yet configurable -- only eight bytes per key is supported. This PR allows users to enable protection by constructing `WriteBatch` with `protection_bytes_per_key == 8`. It does not yet expose a way for users to get integrity protection via other write APIs (e.g., `Put()`, `Merge()`, `Delete()`, etc.).
The foundation classes (`ProtectionInfo.*`) embed the coverage info in their type, and provide `Protect.*()` and `Strip.*()` functions to navigate between types with different coverage. For making bytes per key configurable (for powers of two up to eight) in the future, these classes are templated on the unsigned integer type used to store the protection info. That integer contains the XOR'd result of hashes with independent seeds for all covered fields. For integer fields, the hash is computed on the raw unadjusted bytes, so the result is endian-dependent. The most significant bytes are truncated when the hash value (8 bytes) is wider than the protection integer.
When `WriteBatch` is constructed with `protection_bytes_per_key == 8`, we hold a `ProtectionInfoKVOTC` (i.e., one that covers key, value, optype aka `ValueType`, timestamp, and CF ID) for each entry added to the batch. The protection info is generated from the original buffers passed by the user, as well as the original metadata generated internally. When writing to memtable, each entry is transformed to a `ProtectionInfoKVOTS` (i.e., dropping coverage of CF ID and adding coverage of sequence number), since at that point we know the sequence number, and have already selected a memtable corresponding to a particular CF. This protection info is verified once the entry is encoded in the `MemTable` buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7748
Test Plan:
- an integration test to verify a wide variety of single-byte changes to the encoded `MemTable` buffer are caught
- add to stress/crash test to verify it works in variety of configs/operations without intentional corruption
- [deferred] unit tests for `ProtectionInfo.*` classes for edge cases like KV swap, `SliceParts` and `Slice` APIs are interchangeable, etc.
Reviewed By: pdillinger
Differential Revision: D25754492
Pulled By: ajkr
fbshipit-source-id: e481bac6c03c2ab268be41359730f1ceb9964866
Summary:
Closes https://github.com/facebook/rocksdb/issues/7035
Changed how build_version.cc was generated:
- Included the GIT tag/branch in the build_version file
- Changed the "Build Date" to be:
- If the GIT branch is "clean" (no changes), the date of the last git commit
- If the branch is not clean, the current date
- Added APIs to access the "build information", rather than accessing the strings directly.
The build_version.cc file is now regenerated whenever the library objects are rebuilt.
Verified that the built files remain the same size across builds on a "clean build" and the same information is reported by sst_dump --version
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7866
Reviewed By: pdillinger
Differential Revision: D26086565
Pulled By: mrambacher
fbshipit-source-id: 6fcbe47f6033989d5cf26a0ccb6dfdd9dd239d7f
Summary:
When retryable IO error occurs during compaction, it is mapped to soft error and set the BG error. However, auto resume is not called to clean the soft error since compaction will reschedule by itself. In this change, When retryable IO error occurs during compaction, BG error is not set. User will be informed the error via EventHelper.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7899
Test Plan: tested with error_handler_fs_test
Reviewed By: anand1976
Differential Revision: D26094097
Pulled By: zhichao-cao
fbshipit-source-id: c53424f11d237405592cd762f43cbbdf8da8234f
Summary:
Introduces and uses a SystemClock class to RocksDB. This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.
Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead. There are likely more places that can be changed, but this is a start to show what can/should be done. Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.
There are several Env classes that implement these functions. Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR. It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).
Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858
Reviewed By: pdillinger
Differential Revision: D26006406
Pulled By: mrambacher
fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
Summary:
This provides a workaround for two race conditions that will be fixed in
a more sophisticated way later. This PR:
(1) Makes the client serialize calls to `Timer::Start()` and `Timer::Shutdown()` (see https://github.com/facebook/rocksdb/issues/7711). The long-term fix will be to make those functions thread-safe.
(2) Makes `PeriodicWorkScheduler` atomically add/cancel work together with starting/shutting down its `Timer`. The long-term fix will be for `Timer` API to offer more specialized APIs so the client will not need to synchronize.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7888
Test Plan: ran the repro provided in https://github.com/facebook/rocksdb/issues/7881
Reviewed By: jay-zhuang
Differential Revision: D25990891
Pulled By: ajkr
fbshipit-source-id: a97fdaebbda6d7db7ddb1b146738b68c16c5be38
Summary:
I find that the `track_and_verify_wals_in_manifest` option was only removed from 6.15 branch's HISTORY, but still appears under 6.15 in master branch's HISTORY. It should be moved to 6.16 since that's when the feature should be available.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7874
Reviewed By: jay-zhuang
Differential Revision: D25935971
Pulled By: cheng-chang
fbshipit-source-id: fe8bf1ec111597f9207e109aa3be65f8f919f1fd
Summary:
When the --try_load_options is used in conjunction with the
--column_family option, ldb incorrectly sets the ColumnFamilyOptions for
that column family to defaults. This PR fixes that by retaining from the
OPTIONS file and applying command line overrides.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7847
Test Plan: Add a unit test in ldb_cmd_test
Reviewed By: ajkr
Differential Revision: D25874720
Pulled By: anand1976
fbshipit-source-id: 04bcf23b55e5a30b5b6a59b0e5cb4faef3da7429
Summary:
The main improvement here is to not include `.` or `..` in the results of `Env::GetChildren`. The occurrence of `.` or `..`; it is non-portable, dependent on the Operating System and the File System. See: https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html
There were lots of duplicate checks spread through the RocksDB codebase previously to skip `.` and `..`. This new removes the need for those at the source.
Also some minor fixes to `Env::GetChildren`:
* Improve error handling in POSIX implementation
* Remove unnecessary array allocation on Windows
* Fix struct name for Windows Non-UTF-8 API
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7819
Reviewed By: ajkr
Differential Revision: D25837394
Pulled By: jay-zhuang
fbshipit-source-id: 1e137e7218d38b450af9c083f73d5357abcbba2e
Summary:
Add new API WriteBufferManager::dummy_entries_in_cache_usage() which reports the dummy entries size stored in cache to account for DataBlocks in WriteBufferManager.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7837
Test Plan: Updated test ./write_buffer_manager_test
Reviewed By: ajkr
Differential Revision: D25794312
Pulled By: akankshamahajan15
fbshipit-source-id: 197f5e8701e3dc57a7df72dab1735624f90daf4b
Summary:
In RocksDB, when IO error happens, the flags of IOStatus can be set. If the IOStatus is set as "File Scope IO Error", it indicate that the error is constrained in the file level. Since RocksDB does not continues write data to a file when any IO Error happens, File Scope IO Error can be treated the same as Retryable IO Error. Adding the logic to ErrorHandler::SetBGError to include the file scope IO Error in its error handling logic, which is the same as retryable IO Error.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7840
Test Plan: added new unit tests in error_handler_fs_test. make check
Reviewed By: anand1976
Differential Revision: D25820481
Pulled By: zhichao-cao
fbshipit-source-id: 69cabd3d010073e064d6142ce1cabf341b8a6806
Summary:
Previously we only had a debug assertion to check the right generator was being used for verification. However a user hit a problem in production where their factory was creating the wrong generator for some files, leading to checksum mismatches. It would have been easier to debug if we verified in optimized builds that the generator with the proper name is used. This PR adds such verification.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7824
Reviewed By: zhichao-cao
Differential Revision: D25740254
Pulled By: ajkr
fbshipit-source-id: a6231521747605021bad3231484b5d4f99f4044f
Summary:
So that we can more easily get aggregate live table data such
as total filter, index, and data sizes.
Also adds ldb support for getting properties
Also fixed some missing/inaccurate related comments in db.h
For example:
$ ./ldb --db=testdb get_property rocksdb.aggregated-table-properties
rocksdb.aggregated-table-properties.data_size: 102871
rocksdb.aggregated-table-properties.filter_size: 0
rocksdb.aggregated-table-properties.index_partitions: 0
rocksdb.aggregated-table-properties.index_size: 2232
rocksdb.aggregated-table-properties.num_data_blocks: 100
rocksdb.aggregated-table-properties.num_deletions: 0
rocksdb.aggregated-table-properties.num_entries: 15000
rocksdb.aggregated-table-properties.num_merge_operands: 0
rocksdb.aggregated-table-properties.num_range_deletions: 0
rocksdb.aggregated-table-properties.raw_key_size: 288890
rocksdb.aggregated-table-properties.raw_value_size: 198890
rocksdb.aggregated-table-properties.top_level_index_size: 0
$ ./ldb --db=testdb get_property rocksdb.aggregated-table-properties-at-level1
rocksdb.aggregated-table-properties-at-level1.data_size: 80909
rocksdb.aggregated-table-properties-at-level1.filter_size: 0
rocksdb.aggregated-table-properties-at-level1.index_partitions: 0
rocksdb.aggregated-table-properties-at-level1.index_size: 1787
rocksdb.aggregated-table-properties-at-level1.num_data_blocks: 81
rocksdb.aggregated-table-properties-at-level1.num_deletions: 0
rocksdb.aggregated-table-properties-at-level1.num_entries: 12466
rocksdb.aggregated-table-properties-at-level1.num_merge_operands: 0
rocksdb.aggregated-table-properties-at-level1.num_range_deletions: 0
rocksdb.aggregated-table-properties-at-level1.raw_key_size: 238210
rocksdb.aggregated-table-properties-at-level1.raw_value_size: 163414
rocksdb.aggregated-table-properties-at-level1.top_level_index_size: 0
$
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7779
Test Plan: Added a test to ldb_test.py
Reviewed By: jay-zhuang
Differential Revision: D25653103
Pulled By: pdillinger
fbshipit-source-id: 2905469a08a64dd6b5510cbd7be2e64d3234d6d3
Summary:
Primarily this change refactors the optimize_filters_for_memory
code for Bloom filters, based on malloc_usable_size, to also work for
Ribbon filters.
This change also replaces the somewhat slow but general
BuiltinFilterBitsBuilder::ApproximateNumEntries with
implementation-specific versions for Ribbon (new) and Legacy Bloom
(based on a recently deleted version). The reason is to emphasize
speed in ApproximateNumEntries rather than 100% accuracy.
Justification: ApproximateNumEntries (formerly CalculateNumEntry) is
only used by RocksDB for range-partitioned filters, called each time we
start to construct one. (In theory, it should be possible to reuse the
estimate, but the abstractions provided by FilterPolicy don't really
make that workable.) But this is only used as a heuristic estimate for
hitting a desired partitioned filter size because of alignment to data
blocks, which have various numbers of unique keys or prefixes. The two
factors lead us to prioritize reasonable speed over 100% accuracy.
optimize_filters_for_memory adds extra complication, because precisely
calculating num_entries for some allowed number of bytes depends on state
with optimize_filters_for_memory enabled. And the allocator-agnostic
implementation of optimize_filters_for_memory, using malloc_usable_size,
means we would have to actually allocate memory, many times, just to
precisely determine how many entries (keys) could be added and stay below
some size budget, for the current state. (In a draft, I got this
working, and then realized the balance of speed vs. accuracy was all
wrong.)
So related to that, I have made CalculateSpace, an internal-only API
only used for testing, non-authoritative also if
optimize_filters_for_memory is enabled. This simplifies some code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7774
Test Plan:
unit test updated, and for FilterSize test, range of tested
values is greatly expanded (still super fast)
Also tested `db_bench -benchmarks=fillrandom,stats -bloom_bits=10 -num=1000000 -partition_index_and_filters -format_version=5 [-optimize_filters_for_memory] [-use_ribbon_filter]` with temporary debug output of generated filter sizes.
Bloom+optimize_filters_for_memory:
1 Filter size: 197 (224 in memory)
134 Filter size: 3525 (3584 in memory)
107 Filter size: 4037 (4096 in memory)
Total on disk: 904,506
Total in memory: 918,752
Ribbon+optimize_filters_for_memory:
1 Filter size: 3061 (3072 in memory)
110 Filter size: 3573 (3584 in memory)
58 Filter size: 4085 (4096 in memory)
Total on disk: 633,021 (-30.0%)
Total in memory: 634,880 (-30.9%)
Bloom (no offm):
1 Filter size: 261 (320 in memory)
1 Filter size: 3333 (3584 in memory)
240 Filter size: 3717 (4096 in memory)
Total on disk: 895,674 (-1% on disk vs. +offm; known tolerable overhead of offm)
Total in memory: 986,944 (+7.4% vs. +offm)
Ribbon (no offm):
1 Filter size: 2949 (3072 in memory)
1 Filter size: 3381 (3584 in memory)
167 Filter size: 3701 (4096 in memory)
Total on disk: 624,397 (-30.3% vs. Bloom)
Total in memory: 690,688 (-30.0% vs. Bloom)
Note that optimize_filters_for_memory is even more effective for Ribbon filter than for cache-local Bloom, because it can close the unused memory gap even tighter than Bloom filter, because of 16 byte increments for Ribbon vs. 64 byte increments for Bloom.
Reviewed By: jay-zhuang
Differential Revision: D25592970
Pulled By: pdillinger
fbshipit-source-id: 606fdaa025bb790d7e9c21601e8ea86e10541912
Summary:
When ConcurrentTaskLimiter is enabled and there are too many outstanding compactions, BackgroundCompaction returns Status::Busy(), which shouldn't be treat as compaction failure.
This caused performance issue when outstanding compactions reached the limit.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7739
Reviewed By: cheng-chang
Differential Revision: D25508319
Pulled By: ltamasi
fbshipit-source-id: 3b181b16ada0ca3393cfa3a7412985764e79c719
Summary:
Deprecate CalculateNumEntry and replace with
ApproximateNumEntries (better name) using size_t instead of int and
uint32_t, to minimize confusing casts and bad overflow behavior
(possible though probably not realistic). Bloom sizes are now explicitly
capped at max size supported by implementations: just under 4GiB for
fv=5 Bloom, and just under 512MiB for fv<5 Legacy Bloom. This
hardening could help to set up for fuzzing.
Also, since RocksDB only uses this information as an approximation
for trying to hit certain sizes for partitioned filters, it's more important
that the function be reasonably fast than for it to be completely
accurate. It's hard enough to be 100% accurate for Ribbon (currently
reversing CalculateSpace) that adding optimize_filters_for_memory
into the mix is just not worth trying to be 100% accurate for num
entries for bytes.
Also:
- Cleaned up filter_policy.h to remove MSVC warning handling and
potentially unsafe use of exception for "not implemented"
- Correct the number of entries limit beyond which current Ribbon
implementation falls back on Bloom instead.
- Consistently use "num_entries" rather than "num_entry"
- Remove LegacyBloomBitsBuilder::CalculateNumEntry as it's essentially
obsolete from general implementation
BuiltinFilterBitsBuilder::CalculateNumEntries.
- Fix filter_bench to skip some tests that don't make sense when only
one or a small number of filters has been generated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7726
Test Plan:
expanded existing unit tests for CalculateSpace /
ApproximateNumEntries. Also manually used filter_bench to verify Legacy and
fv=5 Bloom size caps work (much too expensive for unit test). Note that
the actual bits per key is below requested due to space cap.
$ ./filter_bench -impl=0 -bits_per_key=20 -average_keys_per_filter=256000000 -vary_key_count_ratio=0 -m_keys_total_max=256 -allow_bad_fp_rate
...
Total size (MB): 511.992
Bits/key stored: 16.777
...
$ ./filter_bench -impl=2 -bits_per_key=20 -average_keys_per_filter=2000000000 -vary_key_count_ratio=0 -m_keys_total_max=2000
...
Total size (MB): 4096
Bits/key stored: 17.1799
...
$
Reviewed By: jay-zhuang
Differential Revision: D25239800
Pulled By: pdillinger
fbshipit-source-id: f94e6d065efd31e05ec630ae1a82e6400d8390c4
Summary:
Ensure that when direct IO is enabled and a compressed block cache is
configured, MultiGet inserts compressed data blocks into the compressed
block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7756
Test Plan: Add unit test to db_basic_test
Reviewed By: cheng-chang
Differential Revision: D25416240
Pulled By: anand1976
fbshipit-source-id: 75d57526370c9c0a45ff72651f3278dbd8a9086f
Summary:
When 2 phase commit is enabled, if there are prepared data in a WAL, the WAL should be kept, the minimum log number for such a WAL is written to MANIFEST during flush. In atomic flush, such information is not written to MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7570
Test Plan: Added a new unit test `DBAtomicFlushTest.ManualFlushUnder2PC`, this test fails in atomic flush without this PR, after this PR, it succeeds.
Reviewed By: riversand963
Differential Revision: D24394222
Pulled By: cheng-chang
fbshipit-source-id: 60ce74b21b704804943be40c8de01b41269cf116
Summary:
Add timestamp to the `CompactRange()` and `GetApproximateSizes` range keys if needed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7684
Test Plan: make check
Reviewed By: riversand963
Differential Revision: D25015421
Pulled By: jay-zhuang
fbshipit-source-id: 51ca0756087eb053a3b11801e5c7ce1c6e2d38a9
Summary:
WAL may be truncated to an incomplete record due to crash while writing
the last record or corruption. In the former case, no hole will be
produced since no ACK'd data was lost. In the latter case, a hole could
be produced without this PR since we proceeded to recover the next WAL
as if nothing happened. This PR changes the record reading code to
always report a corruption for incomplete records in
`kPointInTimeRecovery` mode, and the upper layer will only ignore them
if the next WAL has consecutive seqnum (i.e., we are guaranteed no
hole).
While this solves the hole problem for the case of incomplete
records, the possibility is still there if the WAL is corrupted by
truncation to an exact record boundary. This PR also regresses how much data
can be recovered when writes are mixed with/without
`WriteOptions::disableWAL`, as then we can not distinguish between a
seqnum gap caused by corruption and a seqnum gap caused by a `disableWAL` write.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7701
Test Plan:
Interestingly there already was a test for this case
(`DBWALTestWithParams.kPointInTimeRecovery`); it just had a typo bug in
the verification that prevented it from noticing holes in recovery.
Reviewed By: anand1976
Differential Revision: D25111765
Pulled By: ajkr
fbshipit-source-id: 5e330b13b1ee2b5be096cea9d0ff6075843e57b6
Summary:
Instead of using `EncodeFixed32` which always serialize a integer to
little endian, we should use the local machine's endianness when
populating a native data structure during options parsing.
Without this fix, `read_amp_bytes_per_bit` may be populated incorrectly
on big-endian machines.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7680
Test Plan: make check
Reviewed By: pdillinger
Differential Revision: D24999166
Pulled By: riversand963
fbshipit-source-id: dc603cff6e17f8fa32479ce6df93b93082e6b0c4
Summary:
An application may accidentally write merge operands without properly configuring `merge_operator`. We should alert them as early as possible that there's an API misuse. Previously RocksDB only notified them when a query or background operation needed to merge but couldn't. With this PR, RocksDB notifies them of the problem before applying the merge operand to the memtable (although it may already be in WAL, which seems it'd cause a crash loop until they enable `merge_operator`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7667
Reviewed By: riversand963
Differential Revision: D24933360
Pulled By: ajkr
fbshipit-source-id: 3a4a2ceb0b7aed184113dd03b8efd735a8332f7f
Summary:
Added experimental public API for Ribbon filter:
NewExperimentalRibbonFilterPolicy(). This experimental API will
take a "Bloom equivalent" bits per key, and configure the Ribbon
filter for the same FP rate as Bloom would have but ~30% space
savings. (Note: optimize_filters_for_memory is not yet implemented
for Ribbon filter. That can be added with no effect on schema.)
Internally, the Ribbon filter is configured using a "one_in_fp_rate"
value, which is 1 over desired FP rate. For example, use 100 for 1%
FP rate. I'm expecting this will be used in the future for configuring
Bloom-like filters, as I expect people to more commonly hold constant
the filter accuracy and change the space vs. time trade-off, rather than
hold constant the space (per key) and change the accuracy vs. time
trade-off, though we might make that available.
### Benchmarking
```
$ ./filter_bench -impl=2 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 34.1341
Number of filters: 1993
Total size (MB): 238.488
Reported total allocated memory (MB): 262.875
Reported internal fragmentation: 10.2255%
Bits/key stored: 10.0029
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 18.7508
Random filter net ns/op: 258.246
Average FP rate %: 0.968672
----------------------------
Done. (For more info, run with -legend or -help.)
$ ./filter_bench -impl=3 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 130.851
Number of filters: 1993
Total size (MB): 168.166
Reported total allocated memory (MB): 183.211
Reported internal fragmentation: 8.94626%
Bits/key stored: 7.05341
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 58.4523
Random filter net ns/op: 363.717
Average FP rate %: 0.952978
----------------------------
Done. (For more info, run with -legend or -help.)
```
168.166 / 238.488 = 0.705 -> 29.5% space reduction
130.851 / 34.1341 = 3.83x construction time for this Ribbon filter vs. lastest Bloom filter (could make that as little as about 2.5x for less space reduction)
### Working around a hashing "flaw"
bloom_test discovered a flaw in the simple hashing applied in
StandardHasher when num_starts == 1 (num_slots == 128), showing an
excessively high FP rate. The problem is that when many entries, on the
order of number of hash bits or kCoeffBits, are associated with the same
start location, the correlation between the CoeffRow and ResultRow (for
efficiency) can lead to a solution that is "universal," or nearly so, for
entries mapping to that start location. (Normally, variance in start
location breaks the effective association between CoeffRow and
ResultRow; the same value for CoeffRow is effectively different if start
locations are different.) Without kUseSmash and with num_starts > 1 (thus
num_starts ~= num_slots), this flaw should be completely irrelevant. Even
with 10M slots, the chances of a single slot having just 16 (or more)
entries map to it--not enough to cause an FP problem, which would be local
to that slot if it happened--is 1 in millions. This spreadsheet formula
shows that: =1/(10000000*(1 - POISSON(15, 1, TRUE)))
As kUseSmash==false (the setting for Standard128RibbonBitsBuilder) is
intended for CPU efficiency of filters with many more entries/slots than
kCoeffBits, a very reasonable work-around is to disallow num_starts==1
when !kUseSmash, by making the minimum non-zero number of slots
2*kCoeffBits. This is the work-around I've applied. This also means that
the new Ribbon filter schema (Standard128RibbonBitsBuilder) is not
space-efficient for less than a few hundred entries. Because of this, I
have made it fall back on constructing a Bloom filter, under existing
schema, when that is more space efficient for small filters. (We can
change this in the future if we want.)
TODO: better unit tests for this case in ribbon_test, and probably
update StandardHasher for kUseSmash case so that it can scale nicely to
small filters.
### Other related changes
* Add Ribbon filter to stress/crash test
* Add Ribbon filter to filter_bench as -impl=3
* Add option string support, as in "filter_policy=experimental_ribbon:5.678;"
where 5.678 is the Bloom equivalent bits per key.
* Rename internal mode BloomFilterPolicy::kAuto to kAutoBloom
* Add a general BuiltinFilterBitsBuilder::CalculateNumEntry based on
binary searching CalculateSpace (inefficient), so that subclasses
(especially experimental ones) don't have to provide an efficient
implementation inverting CalculateSpace.
* Minor refactor FastLocalBloomBitsBuilder for new base class
XXH3pFilterBitsBuilder shared with new Standard128RibbonBitsBuilder,
which allows the latter to fall back on Bloom construction in some
extreme cases.
* Mostly updated bloom_test for Ribbon filter, though a test like
FullBloomTest::Schema is a next TODO to ensure schema stability
(in case this becomes production-ready schema as it is).
* Add some APIs to ribbon_impl.h for configuring Ribbon filters.
Although these are reasonably covered by bloom_test, TODO more unit
tests in ribbon_test
* Added a "tool" FindOccupancyForSuccessRate to ribbon_test to get data
for constructing the linear approximations in GetNumSlotsFor95PctSuccess.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7658
Test Plan:
Some unit tests updated but other testing is left TODO. This
is considered experimental but laying down schema compatibility as early
as possible in case it proves production-quality. Also tested in
stress/crash test.
Reviewed By: jay-zhuang
Differential Revision: D24899349
Pulled By: pdillinger
fbshipit-source-id: 9715f3e6371c959d923aea8077c9423c7a9f82b8
