Commit Graph

877 Commits

Author SHA1 Message Date
Zhichao Cao d1c510baec Handoff checksum Implementation (#7523)
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
2021-02-10 22:20:32 -08:00
Peter Dillinger e4f1e64c30 Add prefetching (batched MultiGet) for experimental Ribbon filter (#7889)
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
2021-02-10 21:04:56 -08:00
Andrew Kryczka c16d5a4fda Makefile support to statically link external plugin code (#7918)
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
2021-02-10 08:35:34 -08:00
Jay Zhuang cf160b98e1 Add full_history_ts_low option to compaction (#7884)
Summary:
The full_history_ts_low is used for user-defined timestamp GC
compaction, which is introduced in https://github.com/facebook/rocksdb/issues/7740, https://github.com/facebook/rocksdb/issues/7657 and https://github.com/facebook/rocksdb/issues/7655.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7884

Reviewed By: ltamasi

Differential Revision: D25982553

Pulled By: jay-zhuang

fbshipit-source-id: 36303d412d65b5d8166b6da24fa21ad85adbabee
2021-02-08 13:45:48 -08:00
Levi Tamasi 974458891c Revert "Turn on memtable bloom filter by default. (#6584)" (#7939)
Summary:
This reverts commit ee79a28963.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7939

Reviewed By: siying

Differential Revision: D26298564

Pulled By: ltamasi

fbshipit-source-id: 6d663516e82e6de436f8d5317932ca9a98e152bd
2021-02-06 22:34:30 -08:00
Andrew Kryczka 8d2bbdd04f Allow range deletions in `*TransactionDB` only when safe (#7929)
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
2021-02-05 15:57:26 -08:00
sdong ee79a28963 Turn on memtable bloom filter by default. (#6584)
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
2021-02-05 12:59:46 -08:00
Andrew Kryczka 78ee8564ad Integrity protection for live updates to WriteBatch (#7748)
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
2021-01-29 12:18:58 -08:00
mrambacher 0a9a05ae12 Make builds reproducible (#7866)
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
2021-01-28 17:42:16 -08:00
Zhichao Cao 95013df278 Do not set bg error for compaction in retryable IO Error case (#7899)
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
2021-01-27 17:58:12 -08:00
mrambacher 12f1137355 Add a SystemClock class to capture the time functions of an Env (#7858)
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
2021-01-25 22:09:11 -08:00
Levi Tamasi 19076c95aa Update HISTORY.md for PR 7888 (#7890)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/7890

Reviewed By: ajkr

Differential Revision: D26005509

Pulled By: ltamasi

fbshipit-source-id: e7eb732180d447900788d0e3a17dfd1c3f1e708a
2021-01-21 14:20:10 -08:00
Andrew Kryczka e18a4df62a workaround race conditions during `PeriodicWorkScheduler` registration (#7888)
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
2021-01-21 08:50:38 -08:00
Cheng Chang b0c43e7081 Update HISTORY.md (#7887)
Summary:
Mention the forward compatibility fix for WAL related version edits.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7887

Reviewed By: ltamasi

Differential Revision: D25982494

Pulled By: cheng-chang

fbshipit-source-id: 4be292aa4bf7fbc8a27c0bef1e7a98ad3ea8e1fa
2021-01-20 14:33:59 -08:00
Cheng Chang 928dea0e32 Update HISTORY.md (#7874)
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
2021-01-19 16:10:13 -08:00
Levi Tamasi ffe4906192 Update version to 6.17 (#7871)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/7871

Test Plan: `make check`

Reviewed By: jay-zhuang

Differential Revision: D25932233

Pulled By: ltamasi

fbshipit-source-id: 8b80b0638a4f34f21a27ba80b3eda7d75410b2e8
2021-01-15 18:53:00 -08:00
anand76 8e7b068ecc Make ldb load column family options from OPTIONS file (#7847)
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
2021-01-11 20:56:34 -08:00
Cheng Chang fdbebdf484 Add note for PR 7789 in history (#7855)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/7855

Reviewed By: ajkr

Differential Revision: D25872797

Pulled By: cheng-chang

fbshipit-source-id: 82159a13f897aaaad5f3c70c7dfa822e073bc623
2021-01-11 13:34:15 -08:00
Adam Retter 4926b33742 Improvements to Env::GetChildren (#7819)
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
2021-01-09 09:44:34 -08:00
Akanksha Mahajan 8ed680bdb0 Add new API to report dummy entries size in cache in WriteBufferManager (#7837)
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
2021-01-08 13:26:24 -08:00
Zhichao Cao 48c0843e69 Treat File Scope Write IO Error the same as Retryable IO Error (#7840)
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
2021-01-07 16:31:33 -08:00
Adam Retter 6e0f62f2b6 Add more tests to ASSERT_STATUS_CHECKED (3), API change (#7715)
Summary:
Third batch of adding more tests to ASSERT_STATUS_CHECKED.

* db_compaction_filter_test
* db_compaction_test
* db_dynamic_level_test
* db_inplace_update_test
* db_sst_test
* db_tailing_iter_test
* db_io_failure_test

Also update GetApproximateSizes APIs to all return Status.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7715

Reviewed By: jay-zhuang

Differential Revision: D25806896

Pulled By: pdillinger

fbshipit-source-id: 6cb9d62ba5a756c645812754c596ad3995d7c262
2021-01-06 14:15:02 -08:00
Andrew Kryczka 225abffd8f Verify file checksum generator name (#7824)
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
2021-01-04 11:51:50 -08:00
Jay Zhuang a8aeefd0fd Update release version to 6.16 (#7782)
Summary:
Update release version to 6.8

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7782

Reviewed By: siying

Differential Revision: D25648579

Pulled By: jay-zhuang

fbshipit-source-id: c536d606868b95c5fb2ae8f19c17eb259d67bc51
2020-12-19 12:39:21 -08:00
Peter Dillinger 4d1ac19e3d aggregated-table-properties with GetMapProperty (#7779)
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
2020-12-19 08:00:14 -08:00
Peter Dillinger 239d17a19c Support optimize_filters_for_memory for Ribbon filter (#7774)
Summary:
Primarily this change refactors the optimize_filters_for_memory
code for Bloom filters, based on malloc_usable_size, to also work for
Ribbon filters.

This change also replaces the somewhat slow but general
BuiltinFilterBitsBuilder::ApproximateNumEntries with
implementation-specific versions for Ribbon (new) and Legacy Bloom
(based on a recently deleted version). The reason is to emphasize
speed in ApproximateNumEntries rather than 100% accuracy.

Justification: ApproximateNumEntries (formerly CalculateNumEntry) is
only used by RocksDB for range-partitioned filters, called each time we
start to construct one. (In theory, it should be possible to reuse the
estimate, but the abstractions provided by FilterPolicy don't really
make that workable.) But this is only used as a heuristic estimate for
hitting a desired partitioned filter size because of alignment to data
blocks, which have various numbers of unique keys or prefixes. The two
factors lead us to prioritize reasonable speed over 100% accuracy.

optimize_filters_for_memory adds extra complication, because precisely
calculating num_entries for some allowed number of bytes depends on state
with optimize_filters_for_memory enabled. And the allocator-agnostic
implementation of optimize_filters_for_memory, using malloc_usable_size,
means we would have to actually allocate memory, many times, just to
precisely determine how many entries (keys) could be added and stay below
some size budget, for the current state. (In a draft, I got this
working, and then realized the balance of speed vs. accuracy was all
wrong.)

So related to that, I have made CalculateSpace, an internal-only API
only used for testing, non-authoritative also if
optimize_filters_for_memory is enabled. This simplifies some code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7774

Test Plan:
unit test updated, and for FilterSize test, range of tested
values is greatly expanded (still super fast)

Also tested `db_bench -benchmarks=fillrandom,stats -bloom_bits=10 -num=1000000 -partition_index_and_filters -format_version=5 [-optimize_filters_for_memory] [-use_ribbon_filter]` with temporary debug output of generated filter sizes.

Bloom+optimize_filters_for_memory:

      1 Filter size: 197 (224 in memory)
    134 Filter size: 3525 (3584 in memory)
    107 Filter size: 4037 (4096 in memory)
    Total on disk: 904,506
    Total in memory: 918,752

Ribbon+optimize_filters_for_memory:

      1 Filter size: 3061 (3072 in memory)
    110 Filter size: 3573 (3584 in memory)
     58 Filter size: 4085 (4096 in memory)
    Total on disk: 633,021 (-30.0%)
    Total in memory: 634,880 (-30.9%)

Bloom (no offm):

      1 Filter size: 261 (320 in memory)
      1 Filter size: 3333 (3584 in memory)
    240 Filter size: 3717 (4096 in memory)
    Total on disk: 895,674 (-1% on disk vs. +offm; known tolerable overhead of offm)
    Total in memory: 986,944 (+7.4% vs. +offm)

Ribbon (no offm):

      1 Filter size: 2949 (3072 in memory)
      1 Filter size: 3381 (3584 in memory)
    167 Filter size: 3701 (4096 in memory)
    Total on disk: 624,397 (-30.3% vs. Bloom)
    Total in memory: 690,688 (-30.0% vs. Bloom)

Note that optimize_filters_for_memory is even more effective for Ribbon filter than for cache-local Bloom, because it can close the unused memory gap even tighter than Bloom filter, because of 16 byte increments for Ribbon vs. 64 byte increments for Bloom.

Reviewed By: jay-zhuang

Differential Revision: D25592970

Pulled By: pdillinger

fbshipit-source-id: 606fdaa025bb790d7e9c21601e8ea86e10541912
2020-12-18 14:31:03 -08:00
Burton Li 2021392e25 Do not full scan obsolete files on compaction busy (#7739)
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
2020-12-15 13:51:10 -08:00
Peter Dillinger 003e72b201 Use size_t for filter APIs, protect against overflow (#7726)
Summary:
Deprecate CalculateNumEntry and replace with
ApproximateNumEntries (better name) using size_t instead of int and
uint32_t, to minimize confusing casts and bad overflow behavior
(possible though probably not realistic). Bloom sizes are now explicitly
capped at max size supported by implementations: just under 4GiB for
fv=5 Bloom, and just under 512MiB for fv<5 Legacy Bloom. This
hardening could help to set up for fuzzing.

Also, since RocksDB only uses this information as an approximation
for trying to hit certain sizes for partitioned filters, it's more important
that the function be reasonably fast than for it to be completely
accurate. It's hard enough to be 100% accurate for Ribbon (currently
reversing CalculateSpace) that adding optimize_filters_for_memory
into the mix is just not worth trying to be 100% accurate for num
entries for bytes.

Also:
- Cleaned up filter_policy.h to remove MSVC warning handling and
potentially unsafe use of exception for "not implemented"
- Correct the number of entries limit beyond which current Ribbon
implementation falls back on Bloom instead.
- Consistently use "num_entries" rather than "num_entry"
- Remove LegacyBloomBitsBuilder::CalculateNumEntry as it's essentially
obsolete from general implementation
BuiltinFilterBitsBuilder::CalculateNumEntries.
- Fix filter_bench to skip some tests that don't make sense when only
one or a small number of filters has been generated.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7726

Test Plan:
expanded existing unit tests for CalculateSpace /
ApproximateNumEntries. Also manually used filter_bench to verify Legacy and
fv=5 Bloom size caps work (much too expensive for unit test). Note that
the actual bits per key is below requested due to space cap.

    $ ./filter_bench -impl=0 -bits_per_key=20 -average_keys_per_filter=256000000 -vary_key_count_ratio=0 -m_keys_total_max=256 -allow_bad_fp_rate
    ...
    Total size (MB): 511.992
    Bits/key stored: 16.777
    ...
    $ ./filter_bench -impl=2 -bits_per_key=20 -average_keys_per_filter=2000000000 -vary_key_count_ratio=0 -m_keys_total_max=2000
    ...
    Total size (MB): 4096
    Bits/key stored: 17.1799
    ...
    $

Reviewed By: jay-zhuang

Differential Revision: D25239800

Pulled By: pdillinger

fbshipit-source-id: f94e6d065efd31e05ec630ae1a82e6400d8390c4
2020-12-11 22:18:12 -08:00
anand76 8a1488efbf Ensure that MultiGet works properly with compressed cache (#7756)
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
2020-12-09 17:01:13 -08:00
Cheng Chang 70f2e0916a Write min_log_number_to_keep to MANIFEST during atomic flush under 2 phase commit (#7570)
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
2020-12-03 19:22:24 -08:00
Jay Zhuang 7fec715db4 Make CompactRange and GetApproximateSizes work with timestamp (#7684)
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
2020-12-02 13:00:53 -08:00
Jay Zhuang 9e1640403a Exclude timestamp from prefix extractor (#7668)
Summary:
Timestamp should not be included in prefix extractor, as we discussed here: https://github.com/facebook/rocksdb/pull/7589#discussion_r511068586

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7668

Test Plan: added unittest

Reviewed By: riversand963

Differential Revision: D24966265

Pulled By: jay-zhuang

fbshipit-source-id: 0dae618c333d4b7942a40d556535a1795e060aea
2020-12-01 14:07:15 -08:00
Andrew Kryczka eb65d673fe Fix kPointInTimeRecovery handling of truncated WAL (#7701)
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
2020-11-30 18:11:38 -08:00
Cheng Chang 5c585e1908 Ship the track WAL in MANIFEST feature (#7689)
Summary:
Updates the option description and HISTORY.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7689

Test Plan: N/A

Reviewed By: zhichao-cao

Differential Revision: D25056238

Pulled By: cheng-chang

fbshipit-source-id: 6af1ef6f8dcf2173cbc0fccadc0e06cefd92bcae
2020-11-19 14:45:54 -08:00
Cheng Chang 8a97f35619 Call out a bug in HISTORY (#7690)
Summary:
It's worth mentioning the corner case bug fixed in PR 7621.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7690

Test Plan: N/A

Reviewed By: zhichao-cao

Differential Revision: D25056678

Pulled By: cheng-chang

fbshipit-source-id: 1ab42ec080f3ffe21f5d97acf65ee0af993112ba
2020-11-18 14:54:22 -08:00
Yanqin Jin 84a700819e Fix the logic of setting read_amp_bytes_per_bit from OPTIONS file (#7680)
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
2020-11-17 00:44:30 -08:00
Andrew Kryczka 1c5f13f2a5 Fail early when `merge_operator` not configured (#7667)
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
2020-11-16 20:39:01 -08:00
Ramkumar Vadivelu 5bd1258381 Update release history to 6.15 (#7673)
Summary:
Update release history to 6.15

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7673

Test Plan: No code change

Reviewed By: ajkr

Differential Revision: D24971069

Pulled By: ramvadiv

fbshipit-source-id: 5cb3f5cbc1b19beb580ea8095acdef72cc092905
2020-11-15 12:37:24 -08:00
Peter Dillinger 60af964372 Experimental (production candidate) SST schema for Ribbon filter (#7658)
Summary:
Added experimental public API for Ribbon filter:
NewExperimentalRibbonFilterPolicy(). This experimental API will
take a "Bloom equivalent" bits per key, and configure the Ribbon
filter for the same FP rate as Bloom would have but ~30% space
savings. (Note: optimize_filters_for_memory is not yet implemented
for Ribbon filter. That can be added with no effect on schema.)

Internally, the Ribbon filter is configured using a "one_in_fp_rate"
value, which is 1 over desired FP rate. For example, use 100 for 1%
FP rate. I'm expecting this will be used in the future for configuring
Bloom-like filters, as I expect people to more commonly hold constant
the filter accuracy and change the space vs. time trade-off, rather than
hold constant the space (per key) and change the accuracy vs. time
trade-off, though we might make that available.

### Benchmarking

```
$ ./filter_bench -impl=2 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 34.1341
Number of filters: 1993
Total size (MB): 238.488
Reported total allocated memory (MB): 262.875
Reported internal fragmentation: 10.2255%
Bits/key stored: 10.0029
----------------------------
Mixed inside/outside queries...
  Single filter net ns/op: 18.7508
  Random filter net ns/op: 258.246
    Average FP rate %: 0.968672
----------------------------
Done. (For more info, run with -legend or -help.)
$ ./filter_bench -impl=3 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 130.851
Number of filters: 1993
Total size (MB): 168.166
Reported total allocated memory (MB): 183.211
Reported internal fragmentation: 8.94626%
Bits/key stored: 7.05341
----------------------------
Mixed inside/outside queries...
  Single filter net ns/op: 58.4523
  Random filter net ns/op: 363.717
    Average FP rate %: 0.952978
----------------------------
Done. (For more info, run with -legend or -help.)
```

168.166 / 238.488 = 0.705  -> 29.5% space reduction

130.851 / 34.1341 = 3.83x construction time for this Ribbon filter vs. lastest Bloom filter (could make that as little as about 2.5x for less space reduction)

### Working around a hashing "flaw"

bloom_test discovered a flaw in the simple hashing applied in
StandardHasher when num_starts == 1 (num_slots == 128), showing an
excessively high FP rate.  The problem is that when many entries, on the
order of number of hash bits or kCoeffBits, are associated with the same
start location, the correlation between the CoeffRow and ResultRow (for
efficiency) can lead to a solution that is "universal," or nearly so, for
entries mapping to that start location. (Normally, variance in start
location breaks the effective association between CoeffRow and
ResultRow; the same value for CoeffRow is effectively different if start
locations are different.) Without kUseSmash and with num_starts > 1 (thus
num_starts ~= num_slots), this flaw should be completely irrelevant.  Even
with 10M slots, the chances of a single slot having just 16 (or more)
entries map to it--not enough to cause an FP problem, which would be local
to that slot if it happened--is 1 in millions. This spreadsheet formula
shows that: =1/(10000000*(1 - POISSON(15, 1, TRUE)))

As kUseSmash==false (the setting for Standard128RibbonBitsBuilder) is
intended for CPU efficiency of filters with many more entries/slots than
kCoeffBits, a very reasonable work-around is to disallow num_starts==1
when !kUseSmash, by making the minimum non-zero number of slots
2*kCoeffBits. This is the work-around I've applied. This also means that
the new Ribbon filter schema (Standard128RibbonBitsBuilder) is not
space-efficient for less than a few hundred entries. Because of this, I
have made it fall back on constructing a Bloom filter, under existing
schema, when that is more space efficient for small filters. (We can
change this in the future if we want.)

TODO: better unit tests for this case in ribbon_test, and probably
update StandardHasher for kUseSmash case so that it can scale nicely to
small filters.

### Other related changes

* Add Ribbon filter to stress/crash test
* Add Ribbon filter to filter_bench as -impl=3
* Add option string support, as in "filter_policy=experimental_ribbon:5.678;"
where 5.678 is the Bloom equivalent bits per key.
* Rename internal mode BloomFilterPolicy::kAuto to kAutoBloom
* Add a general BuiltinFilterBitsBuilder::CalculateNumEntry based on
binary searching CalculateSpace (inefficient), so that subclasses
(especially experimental ones) don't have to provide an efficient
implementation inverting CalculateSpace.
* Minor refactor FastLocalBloomBitsBuilder for new base class
XXH3pFilterBitsBuilder shared with new Standard128RibbonBitsBuilder,
which allows the latter to fall back on Bloom construction in some
extreme cases.
* Mostly updated bloom_test for Ribbon filter, though a test like
FullBloomTest::Schema is a next TODO to ensure schema stability
(in case this becomes production-ready schema as it is).
* Add some APIs to ribbon_impl.h for configuring Ribbon filters.
Although these are reasonably covered by bloom_test, TODO more unit
tests in ribbon_test
* Added a "tool" FindOccupancyForSuccessRate to ribbon_test to get data
for constructing the linear approximations in GetNumSlotsFor95PctSuccess.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7658

Test Plan:
Some unit tests updated but other testing is left TODO. This
is considered experimental but laying down schema compatibility as early
as possible in case it proves production-quality. Also tested in
stress/crash test.

Reviewed By: jay-zhuang

Differential Revision: D24899349

Pulled By: pdillinger

fbshipit-source-id: 9715f3e6371c959d923aea8077c9423c7a9f82b8
2020-11-12 20:46:14 -08:00
Yanqin Jin 2400cd69e3 Update HISTORY.md for PR6069 (#7663)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/7663

Reviewed By: ajkr

Differential Revision: D24913081

Pulled By: riversand963

fbshipit-source-id: 704f427812f2b4f92e16d6cbc93be64d730d1cf9
2020-11-12 08:38:41 -08:00
Andrew Kryczka ec346da98c Always apply bottommost_compression_opts when enabled (#7633)
Summary:
Previously, even when `bottommost_compression_opts`'s `enabled` flag was set, it only took effect when
`bottommost_compression` was also set to something other than `kDisableCompressionOption`.
This wasn't documented and, if we kept the old behavior, it'd make
things complicated like the migration instructions in https://github.com/facebook/rocksdb/issues/7619. We can
simplify the API by making `bottommost_compression_opts` always take
effect when its `enabled` flag is set.

Fixes https://github.com/facebook/rocksdb/issues/7631.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7633

Reviewed By: ltamasi

Differential Revision: D24710358

Pulled By: ajkr

fbshipit-source-id: bbbdf9c1b53c63a4239d902cc3f5a11da1874647
2020-11-11 20:32:28 -08:00
mrambacher c442f6809f Create a Customizable class to load classes and configurations (#6590)
Summary:
The Customizable class is an extension of the Configurable class and allows instances to be created by a name/ID.  Classes that extend customizable can define their Type (e.g. "TableFactory", "Cache") and  a method to instantiate them (TableFactory::CreateFromString).  Customizable objects can be registered with the ObjectRegistry and created dynamically.

Future PRs will make more types of objects extend Customizable.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/6590

Reviewed By: cheng-chang

Differential Revision: D24841553

Pulled By: zhichao-cao

fbshipit-source-id: d0c2132bd932e971cbfe2c908ca2e5db30c5e155
2020-11-11 15:10:41 -08:00
Jay Zhuang 18aee7db7e Fix a seek issue with prefix extractor and timestamp (#7644)
Summary:
During seek, prefix compare should not include timestamp.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7644

Test Plan: added unittest

Reviewed By: riversand963

Differential Revision: D24772066

Pulled By: jay-zhuang

fbshipit-source-id: 3982655a8bf8da256a738e8497b73b3d9bdac92e
2020-11-10 14:53:13 -08:00
Yanqin Jin b6d8e36741 Compute NeedCompact() after table builder Finish() (#7627)
Summary:
In `BuildTable()`, we call `builder->Finish()` before evaluating `builder->NeedCompact()`.
However, we call `builder->NeedCompact()` before `builder->Finish()` in compaction job. This can be wrong because the table properties collectors may rely on the success of `Finish()` to provide correct result for `NeedCompact()`.

Test plan (on devserver):
make check

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7627

Reviewed By: ajkr

Differential Revision: D24728741

Pulled By: riversand963

fbshipit-source-id: 5a0dce244e14eb1106c4f87021e6bebca82b486e
2020-11-04 10:44:56 -08:00
Yanqin Jin fde0cd7ced Add API to verify whole sst file checksum (#7578)
Summary:
Existing API `VerifyChecksum()` allows application to verify sst files' block checksums.
Since whole file, user-specified checksum is tracked in MANIFEST, we can expose a new
API to verify sst files' file checksums.

```
// Compute table file checksums if applicable and compare with MANIFEST.
// Returns OK if no file has mismatching whole-file checksum.
Status DB::VerifyFileChecksums(const ReadOptions& /*read_options*/);
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7578

Test Plan: make check

Reviewed By: pdillinger

Differential Revision: D24436783

Pulled By: riversand963

fbshipit-source-id: 52b51519b842f2b3c4e3351998a97c86cbec85b3
2020-11-03 20:34:56 -08:00
Jay Zhuang 881e0dcc09 Fix MultiGet unable to query timestamp data issue (#7589)
Summary:
The filter query key should not contain timestamp. The timestamp is
stripped for Get(), but not MultiGet().

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7589

Reviewed By: riversand963

Differential Revision: D24494661

Pulled By: jay-zhuang

fbshipit-source-id: fc5ff40f9d683a89a760c6ff0ab3aed05a70c317
2020-11-03 09:45:41 -08:00
Andrew Kryczka 1adbceb581 Expand effect of dictionary settings in `ColumnFamilyOptions::compression_opts` (#7619)
Summary:
In dictionary compression's initial implementation, in order to save CPU overhead, we only enabled it
for bottom level under the assumption that the vast majority of data is
stored there. At that time, there was no
such thing as `ColumnFamilyOptions::bottommost_compression_opts`, so we just
hardcoded disabling dictionary compression in flush and compactions to
non-bottommost level. Now, we have users who generate all their files
through flush and are considering using dictionary compression.

To support such a use case, this PR expands the scope of `ColumnFamilyOptions::compression_opts` to
additionally include flushed files and files generated by compaction to
a non-bottommost level. Users can still get the old behavior by moving
their dictionary settings to `ColumnFamilyOptions::bottommost_compression_opts`
and explicitly enabling both that and `ColumnFamilyOptions::bottommost_compression`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7619

Reviewed By: ltamasi

Differential Revision: D24665610

Pulled By: ajkr

fbshipit-source-id: 656b90bce1033fe21c71e09af931ef5bde3e464c
2020-11-02 19:21:11 -08:00
Andrew Kryczka a388c8cc6b Add recent fixes to HISTORY.md (#7617)
Summary:
The recently reverted behavior changes were released to at least one
place internally, so we should mention the reverts in release notes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7617

Reviewed By: akankshamahajan15

Differential Revision: D24654343

Pulled By: ajkr

fbshipit-source-id: eb64b2797d8508cd95a2dc2698122c1be29ce817
2020-10-30 14:03:35 -07:00
Yanqin Jin 6134ce6444 Perform post-flush updates of memtable list in a callback (#6069)
Summary:
Currently, the following interleaving of events can lead to SuperVersion containing both immutable memtables as well as the resulting L0. This can cause Get to return incorrect result if there are merge operands. This may also affect other operations such as single deletes.

```
  time  main_thr  bg_flush_thr  bg_compact_thr  compact_thr  set_opts_thr
0  |                                                         WriteManifest:0
1  |                                           issue compact
2  |                                 wait
3  |   Merge(counter)
4  |   issue flush
5  |                   wait
6  |                                                         WriteManifest:1
7  |                                 wake up
8  |                                 write manifest
9  |                  wake up
10 |  Get(counter)
11 |                  remove imm
   V
```

The reason behind is that: one bg flush thread's installing new `Version` can be batched and performed by another thread that is the "leader" MANIFEST writer. This bg thread removes the memtables from current super version only after `LogAndApply` returns. After the leader MANIFEST writer signals (releasing mutex) this bg flush thread, it is possible that another thread sees this cf with both memtables (whose data have been flushed to the newest L0) and the L0 before this bg flush thread removes the memtables.

To address this issue, each bg flush thread can pass a callback function to `LogAndApply`. The callback is responsible for removing the memtables. Therefore, the leader MANIFEST writer can call this callback and remove the memtables before releasing the mutex.

Test plan (devserver)
```
$make merge_test
$./merge_test --gtest_filter=MergeTest.MergeWithCompactionAndFlush
$make check
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/6069

Reviewed By: cheng-chang

Differential Revision: D18790894

Pulled By: riversand963

fbshipit-source-id: e41bd600c0448b4f4b2deb3f7677f95e3076b4ed
2020-10-26 18:23:01 -07:00
Akanksha Mahajan eef27d0048 Bug fix to remove function calling in assert statement (#7581)
Summary:
Remove function calling in assert statement as assert is a no
op in opt build and that function might not be called. This causes hang
in closing RocksDB when refit level is set.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7581

Test Plan: make check -j64

Reviewed By: riversand963

Differential Revision: D24466420

Pulled By: akankshamahajan15

fbshipit-source-id: 97db4ec5a95ae693c3290e176a3c12a9b1ad2f6d
2020-10-21 20:18:06 -07:00