Commit Graph

180 Commits

Author SHA1 Message Date
Peter Dillinger 98c33cb8e3 Steps toward making IDENTITY file obsolete (#13019)
Summary:
* Set write_dbid_to_manifest=true by default
* Add new option write_identity_file (default true) that allows us to opt-in to future behavior without identity file
* Refactor related DB open code to minimize code duplication

_Recommend hiding whitespace changes for review_

Intended follow-up: add support to ldb for reading and even replacing the DB identity in the manifest. Could be a variant of `update_manifest` command or based on it.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13019

Test Plan: unit tests and stress test updated for new functionality

Reviewed By: anand1976

Differential Revision: D62898229

Pulled By: pdillinger

fbshipit-source-id: c08b25cf790610b034e51a9de0dc78b921abbcf0
2024-09-19 14:05:21 -07:00
Yu Zhang 295326b6ee Best efforts recovery recover seqno prefix (#12938)
Summary:
This PR make best efforts recovery more permissive by allowing it to recover incomplete Version that presents a valid point in time view from the user's perspective. Currently, a Version is only valid and saved if all files consisting that Version can be found. With this change, if only a suffix of L0 files (and their associated blob files) are missing,  a valid Version is also available to be saved and recover to. Note that we don't do this if the column family was atomically flushed. Because atomic flush also need a consistent view across the column families, we cannot guarantee that if we are recovering to incomplete version.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12938

Test Plan: Existing tests and added unit tests.

Reviewed By: anand1976

Differential Revision: D61414381

Pulled By: jowlyzhang

fbshipit-source-id: f9b73deb34d35ad696ab42315928b656d586262a
2024-08-16 17:18:54 -07:00
Changyu Bi 5c1334f763 DeleteRange() return NotSupported if row_cache is configured (#12512)
Summary:
...since this feature combination is not supported yet (https://github.com/facebook/rocksdb/issues/4122).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12512

Test Plan: new unit test.

Reviewed By: jaykorean, jowlyzhang

Differential Revision: D55820323

Pulled By: cbi42

fbshipit-source-id: eeb5e97d15c9bdc388793a2fb8e52cfa47e34bcf
2024-04-29 16:33:13 -07:00
Jay Huh 1fca175eec MultiCFSnapshot for NewIterators() API (#12573)
Summary:
As mentioned in https://github.com/facebook/rocksdb/issues/12561 and https://github.com/facebook/rocksdb/issues/12566 , `NewIterators()` API has not been providing consistent view of the db across multiple column families. This PR addresses it by utilizing `MultiCFSnapshot()` function which has been used for `MultiGet()` APIs. To be able to obtain the thread-local super version with ref, `sv_exclusive_access` parameter has been added to `MultiCFSnapshot()` so that we could call `GetReferencedSuperVersion()` or `GetAndRefSuperVersion()` depending on the param and support `Refresh()` API for MultiCfIterators

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12573

Test Plan:
**Unit Tests Added**

```
./db_iterator_test --gtest_filter="*IteratorsConsistentView*"
```
```
./multi_cf_iterator_test -- --gtest_filter="*ConsistentView*"
```

**Performance Check**

Setup
```
make -j64 release
TEST_TMPDIR=/dev/shm/db_bench ./db_bench -benchmarks="filluniquerandom" -key_size=32 -value_size=512 -num=10000000 -compression_type=none
```

Run
```
TEST_TMPDIR=/dev/shm/db_bench ./db_bench -use_existing_db=1 -benchmarks="multireadrandom" -cache_size=10485760000
```
Before the change
```
DB path: [/dev/shm/db_bench/dbbench]
multireadrandom :       6.374 micros/op 156892 ops/sec 6.374 seconds 1000000 operations; (0 of 1000000 found)
```
After the change
```
DB path: [/dev/shm/db_bench/dbbench]
multireadrandom :       6.265 micros/op 159627 ops/sec 6.265 seconds 1000000 operations; (0 of 1000000 found)
```

Reviewed By: jowlyzhang

Differential Revision: D56444066

Pulled By: jaykorean

fbshipit-source-id: 327ce73c072da30c221e18d4f3389f49115b8f99
2024-04-24 15:28:55 -07:00
Yu Zhang 1104eaa35e Add initial support for TimedPut API (#12419)
Summary:
This PR adds support for `TimedPut` API. We introduced a new type `kTypeValuePreferredSeqno` for entries added to the DB via the `TimedPut` API.

The life cycle of such an entry on the write/flush/compaction paths are:

1) It is initially added to memtable as:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, write_unix_time}`

2) When it's flushed to L0 sst files, it's converted to:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, preferred_seqno}`
 when we have easy access to the seqno to time mapping.

3) During compaction, if certain conditions are met, we swap in the `preferred_seqno` and the entry will become:
`<user_key, preferred_seqno, kTypeValue>: value`. This step helps fast track these entries to the cold tier if they are eligible after the sequence number swap.

On the read path:
A `kTypeValuePreferredSeqno` entry acts the same as a `kTypeValue` entry, the unix_write_time/preferred seqno part packed in value is completely ignored.

Needed follow ups:
1) The seqno to time mapping accessible in flush needs to be extended to cover the `write_unix_time` for possible `kTypeValuePreferredSeqno` entries. This also means we need to track these `write_unix_time` in memtable.

2) Compaction filter support for the new `kTypeValuePreferredSeqno` type for feature parity with other `kTypeValue` and equivalent types.

3) Stress test coverage for the feature

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12419

Test Plan: Added unit tests

Reviewed By: pdillinger

Differential Revision: D54920296

Pulled By: jowlyzhang

fbshipit-source-id: c8b43f7a7c465e569141770e93c748371ff1da9e
2024-03-14 15:44:55 -07:00
yuzhangyu@fb.com 1cfdece85d Run internal cpp modernizer on RocksDB repo (#12398)
Summary:
When internal cpp modernizer attempts to format rocksdb code, it will replace macro `ROCKSDB_NAMESPACE`  with its default definition `rocksdb` when collapsing nested namespace. We filed a feedback for the tool T180254030 and the team filed a bug for this: https://github.com/llvm/llvm-project/issues/83452. At the same time, they suggested us to run the modernizer tool ourselves so future auto codemod attempts will be smaller. This diff contains:

Running
`xplat/scripts/codemod_service/cpp_modernizer.sh`
in fbcode/internal_repo_rocksdb/repo (excluding some directories in utilities/transactions/lock/range/range_tree/lib that has a non meta copyright comment)
without swapping out the namespace macro `ROCKSDB_NAMESPACE`

Followed by RocksDB's own
`make format`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12398

Test Plan: Auto tests

Reviewed By: hx235

Differential Revision: D54382532

Pulled By: jowlyzhang

fbshipit-source-id: e7d5b40f9b113b60e5a503558c181f080b9d02fa
2024-03-04 10:08:32 -08:00
anand76 d227276147 Deprecate some variants of Get and MultiGet (#12327)
Summary:
A lot of variants of Get and MultiGet have been added to `include/rocksdb/db.h` over the years. Try to consolidate them by marking variants that don't return timestamps as deprecated. The underlying DB implementation will check and return Status::NotSupported() if it doesn't support returning timestamps and the caller asks for it.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12327

Reviewed By: pdillinger

Differential Revision: D53828151

Pulled By: anand1976

fbshipit-source-id: e0b5ca42d32daa2739d5f439a729815a2d4ff050
2024-02-16 09:21:06 -08:00
Akanksha Mahajan 956f1dfde3 Change ReadAsync callback API to remove const from FSReadRequest (#11649)
Summary:
Modify ReadAsync callback API to remove const from FSReadRequest as const doesn't let to fs_scratch to move the ownership.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11649

Test Plan: CircleCI jobs

Reviewed By: anand1976

Differential Revision: D53585309

Pulled By: akankshamahajan15

fbshipit-source-id: 3bff9035db0e6fbbe34721a5963443355807420d
2024-02-16 09:14:55 -08:00
Peter Dillinger 54cb9c77d9 Prefer static_cast in place of most reinterpret_cast (#12308)
Summary:
The following are risks associated with pointer-to-pointer reinterpret_cast:
* Can produce the "wrong result" (crash or memory corruption). IIRC, in theory this can happen for any up-cast or down-cast for a non-standard-layout type, though in practice would only happen for multiple inheritance cases (where the base class pointer might be "inside" the derived object). We don't use multiple inheritance a lot, but we do.
* Can mask useful compiler errors upon code change, including converting between unrelated pointer types that you are expecting to be related, and converting between pointer and scalar types unintentionally.

I can only think of some obscure cases where static_cast could be troublesome when it compiles as a replacement:
* Going through `void*` could plausibly cause unnecessary or broken pointer arithmetic. Suppose we have
`struct Derived: public Base1, public Base2`.  If we have `Derived*` -> `void*` -> `Base2*` -> `Derived*` through reinterpret casts, this could plausibly work (though technical UB) assuming the `Base2*` is not dereferenced. Changing to static cast could introduce breaking pointer arithmetic.
* Unnecessary (but safe) pointer arithmetic could arise in a case like `Derived*` -> `Base2*` -> `Derived*` where before the Base2 pointer might not have been dereferenced. This could potentially affect performance.

With some light scripting, I tried replacing pointer-to-pointer reinterpret_casts with static_cast and kept the cases that still compile. Most occurrences of reinterpret_cast have successfully been changed (except for java/ and third-party/). 294 changed, 257 remain.

A couple of related interventions included here:
* Previously Cache::Handle was not actually derived from in the implementations and just used as a `void*` stand-in with reinterpret_cast. Now there is a relationship to allow static_cast. In theory, this could introduce pointer arithmetic (as described above) but is unlikely without multiple inheritance AND non-empty Cache::Handle.
* Remove some unnecessary casts to void* as this is allowed to be implicit (for better or worse).

Most of the remaining reinterpret_casts are for converting to/from raw bytes of objects. We could consider better idioms for these patterns in follow-up work.

I wish there were a way to implement a template variant of static_cast that would only compile if no pointer arithmetic is generated, but best I can tell, this is not possible. AFAIK the best you could do is a dynamic check that the void* conversion after the static cast is unchanged.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12308

Test Plan: existing tests, CI

Reviewed By: ltamasi

Differential Revision: D53204947

Pulled By: pdillinger

fbshipit-source-id: 9de23e618263b0d5b9820f4e15966876888a16e2
2024-02-07 10:44:11 -08:00
anand76 95b41eec6d Fix potential incorrect result for duplicate key in MultiGet (#12295)
Summary:
The RocksDB correctness testing has recently discovered a possible, but very unlikely, correctness issue with MultiGet. The issue happens when all of the below conditions are met -
1. Duplicate keys in a MultiGet batch
2. Key matches the last key in a non-zero, non-bottommost level file
3. Final value is not in the file (merge operand, not snapshot visible etc)
4. Multiple entries exist for the key in the file spanning more than 1 data block. This can happen due to snapshots, which would force multiple versions of the key in the file, and they may spill over to another data block
5. Lookup attempt in the SST for the first of the duplicates fails with IO error on a data block (NOT the first data block, but the second or subsequent uncached block), but no errors for the other duplicates
6. Value or merge operand for the key is present in the very next level

The problem is, in FilePickerMultiGet, when looking up keys in a level we use FileIndexer and the overlapping file in the current level to determine the search bounds for that key in the file list in the next level. If the next level is empty, the search bounds are reset and we do a full binary search in the next non-empty level's LevelFilesBrief. However, under the  conditions https://github.com/facebook/rocksdb/issues/1 and https://github.com/facebook/rocksdb/issues/2 listed above, only the first of the duplicates has its next-level search bounds updated, and the remaining duplicates are skipped.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12295

Test Plan: Add unit tests that fail an assertion or return wrong result without the fix

Reviewed By: hx235

Differential Revision: D53187634

Pulled By: anand1976

fbshipit-source-id: a5eadf4fede9bbdec784cd993b15e3341436d1ea
2024-02-02 11:48:35 -08:00
Peter Dillinger 76c834e441 Remove 'virtual' when implied by 'override' (#12319)
Summary:
... to follow modern C++ style / idioms.

Used this hack:
```
for FILE in `cat my_list_of_files`; do perl -pi -e 'BEGIN{undef $/;} s/ virtual( [^;{]* override)/$1/smg' $FILE; done
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12319

Test Plan: existing tests, CI

Reviewed By: jaykorean

Differential Revision: D53275303

Pulled By: pdillinger

fbshipit-source-id: bc0881af270aa8ef4d0ae4f44c5a6614b6407377
2024-01-31 13:14:42 -08:00
anand76 65e162bf09 Add some asserts in FilePickerMultiGet for debugging (#12241)
Summary:
Add asserts to help debug a crash test failure. The test fails as wollows -
```rocksdb::FilePickerMultiGet::PrepareNextLevel(): Assertion `fp_ctx.search_right_bound == -1 || fp_ctx.search_right_bound == FileIndexer::kLevelMaxIndex' failed```

Also add a unit test to verify an edge case.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12241

Reviewed By: cbi42

Differential Revision: D52819029

Pulled By: anand1976

fbshipit-source-id: 33316985c8ace1aed9ecc2400da8b777aec488ff
2024-01-16 17:08:58 -08:00
Hui Xiao 06e593376c Group SST write in flush, compaction and db open with new stats (#11910)
Summary:
## Context/Summary
Similar to https://github.com/facebook/rocksdb/pull/11288, https://github.com/facebook/rocksdb/pull/11444, categorizing SST/blob file write according to different io activities allows more insight into the activity.

For that, this PR does the following:
- Tag different write IOs by passing down and converting WriteOptions to IOOptions
- Add new SST_WRITE_MICROS histogram in WritableFileWriter::Append() and breakdown FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS

Some related code refactory to make implementation cleaner:
- Blob stats
   - Replace high-level write measurement with low-level WritableFileWriter::Append() measurement for BLOB_DB_BLOB_FILE_WRITE_MICROS. This is to make FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS  include blob file. As a consequence, this introduces some behavioral changes on it, see HISTORY and db bench test plan below for more info.
   - Fix bugs where BLOB_DB_BLOB_FILE_SYNCED/BLOB_DB_BLOB_FILE_BYTES_WRITTEN include file failed to sync and bytes failed to write.
- Refactor WriteOptions constructor for easier construction with io_activity and rate_limiter_priority
- Refactor DBImpl::~DBImpl()/BlobDBImpl::Close() to bypass thread op verification
- Build table
   - TableBuilderOptions now includes Read/WriteOpitons so BuildTable() do not need to take these two variables
   - Replace the io_priority passed into BuildTable() with TableBuilderOptions::WriteOpitons::rate_limiter_priority. Similar for BlobFileBuilder.
This parameter is used for dynamically changing file io priority for flush, see  https://github.com/facebook/rocksdb/pull/9988?fbclid=IwAR1DtKel6c-bRJAdesGo0jsbztRtciByNlvokbxkV6h_L-AE9MACzqRTT5s for more
   - Update ThreadStatus::FLUSH_BYTES_WRITTEN to use io_activity to track flush IO in flush job and db open instead of io_priority

## Test
### db bench

Flush
```
./db_bench --statistics=1 --benchmarks=fillseq --num=100000 --write_buffer_size=100

rocksdb.sst.write.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.flush.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.compaction.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.db.open.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
```

compaction, db oopen
```
Setup: ./db_bench --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

Run:./db_bench --statistics=1 --benchmarks=compact  --db=../db_bench --use_existing_db=1

rocksdb.sst.write.micros P50 : 2.675325 P95 : 9.578788 P99 : 18.780000 P100 : 314.000000 COUNT : 638 SUM : 3279
rocksdb.file.write.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.compaction.micros P50 : 2.757353 P95 : 9.610687 P99 : 19.316667 P100 : 314.000000 COUNT : 615 SUM : 3213
rocksdb.file.write.db.open.micros P50 : 2.055556 P95 : 3.925000 P99 : 9.000000 P100 : 9.000000 COUNT : 23 SUM : 66
```

blob stats - just to make sure they aren't broken by this PR
```
Integrated Blob DB

Setup: ./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

Run:./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=compact  --db=../db_bench --use_existing_db=1

pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 7.298246 P95 : 9.771930 P99 : 9.991813 P100 : 16.000000 COUNT : 235 SUM : 1600
rocksdb.blobdb.blob.file.synced COUNT : 1
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842

post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 2.000000 P95 : 2.829360 P99 : 2.993779 P100 : 9.000000 COUNT : 707 SUM : 1614
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164

rocksdb.blobdb.blob.file.synced COUNT : 1 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 (stay the same)
```

```
Stacked Blob DB

Run: ./db_bench --use_blob_db=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 12.808042 P95 : 19.674497 P99 : 28.539683 P100 : 51.000000 COUNT : 10000 SUM : 140876
rocksdb.blobdb.blob.file.synced COUNT : 8
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445

post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 1.657370 P95 : 2.952175 P99 : 3.877519 P100 : 24.000000 COUNT : 30001 SUM : 67924
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164

rocksdb.blobdb.blob.file.synced COUNT : 8 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 (stay the same)
```

###  Rehearsal CI stress test
Trigger 3 full runs of all our CI stress tests

###  Performance

Flush
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=ManualFlush/key_num:524288/per_key_size:256 --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark; enable_statistics = true

Pre-pr: avg 507515519.3 ns
497686074,499444327,500862543,501389862,502994471,503744435,504142123,504224056,505724198,506610393,506837742,506955122,507695561,507929036,508307733,508312691,508999120,509963561,510142147,510698091,510743096,510769317,510957074,511053311,511371367,511409911,511432960,511642385,511691964,511730908,

Post-pr: avg 511971266.5 ns, regressed 0.88%
502744835,506502498,507735420,507929724,508313335,509548582,509994942,510107257,510715603,511046955,511352639,511458478,512117521,512317380,512766303,512972652,513059586,513804934,513808980,514059409,514187369,514389494,514447762,514616464,514622882,514641763,514666265,514716377,514990179,515502408,
```

Compaction
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_{pre|post}_pr --benchmark_filter=ManualCompaction/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1  --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark

Pre-pr: avg 495346098.30 ns
492118301,493203526,494201411,494336607,495269217,495404950,496402598,497012157,497358370,498153846

Post-pr: avg 504528077.20, regressed 1.85%. "ManualCompaction" include flush so the isolated regression for compaction should be around 1.85-0.88 = 0.97%
502465338,502485945,502541789,502909283,503438601,504143885,506113087,506629423,507160414,507393007
```

Put with WAL (in case passing WriteOptions slows down this path even without collecting SST write stats)
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=DBPut/comp_style:0/max_data:107374182400/per_key_size:256/enable_statistics:1/wal:1  --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark

Pre-pr: avg 3848.10 ns
3814,3838,3839,3848,3854,3854,3854,3860,3860,3860

Post-pr: avg 3874.20 ns, regressed 0.68%
3863,3867,3871,3874,3875,3877,3877,3877,3880,3881
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11910

Reviewed By: ajkr

Differential Revision: D49788060

Pulled By: hx235

fbshipit-source-id: 79e73699cda5be3b66461687e5147c2484fc5eff
2023-12-29 15:29:23 -08:00
Yu Zhang 509947ce2c Quarantine files in a limbo state after a manifest error (#12030)
Summary:
Part of the procedures to handle manifest IO error is to disable file deletion in case some files in limbo state get deleted prematurely. This is not ideal because: 1) not all the VersionEdits whose commit encounter such an error contain updates for files, disabling file deletion sometimes are not necessary. 2) `EnableFileDeletion` has a force mode that could make other threads accidentally disrupt this procedure in recovery.  3) Disabling file deletion as a whole is also not as efficient as more precisely tracking impacted files from being prematurely deleted.  This PR replaces this mechanism with tracking such files and quarantine them from being deleted in `ErrorHandler`.

These are the types of files being actively tracked in quarantine in this PR:
1) new table files and blob files from a background job
2) old manifest file whose immediately following new manifest file's CURRENT file creation gets into unclear state. Current handling is not sufficient to make sure the old manifest file is kept in case it's needed.

Note that WAL logs are not part of the quarantine because `min_log_number_to_keep` is a safe mechanism and it's only updated after successful manifest commits so it can prevent this premature deletion issue from happening.

We track these files' file numbers because they share the same file number space.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12030

Test Plan: Modified existing unit tests

Reviewed By: ajkr

Differential Revision: D51036774

Pulled By: jowlyzhang

fbshipit-source-id: 84ef26271fbbc888ef70da5c40fe843bd7038716
2023-11-11 08:11:11 -08:00
Changyu Bi d5bc30befa Enforce status checking after Valid() returns false for IteratorWrapper (#11975)
Summary:
... when compiled with ASSERT_STATUS_CHECKED = 1.

The main change is in iterator_wrapper.h. The remaining changes are just fixing existing unit tests. Adding this check to IteratorWrapper gives a good coverage as the class is used in many places, including child iterators under merging iterator, merging iterator under DB iter, file_iter under level iterator, etc. This change can catch the bug fixed in https://github.com/facebook/rocksdb/issues/11782.

Future follow up: enable `ASSERT_STATUS_CHECKED=1` for stress test and for DEBUG_LEVEL=0.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11975

Test Plan:
* `ASSERT_STATUS_CHECKED=1 DEBUG_LEVEL=2 make -j32 J=32 check`
* I tried to run stress test with `ASSERT_STATUS_CHECKED=1`, but there are a lot of existing stress code that ignore status checking, and fail without the change in this PR. So defer that to a follow up task.

Reviewed By: ajkr

Differential Revision: D50383790

Pulled By: cbi42

fbshipit-source-id: 1a28ce0f5fdf1890f93400b26b3b1b3a287624ce
2023-10-18 09:38:38 -07:00
anand76 269478ee46 Support compressed and local flash secondary cache stacking (#11812)
Summary:
This PR implements support for a three tier cache - primary block cache, compressed secondary cache, and a nvm (local flash) secondary cache. This allows more effective utilization of the nvm cache, and minimizes the number of reads from local flash by caching compressed blocks in the compressed secondary cache.

The basic design is as follows -
1. A new secondary cache implementation, ```TieredSecondaryCache```, is introduced. It keeps the compressed and nvm secondary caches and manages the movement of blocks between them and the primary block cache. To setup a three tier cache, we allocate a ```CacheWithSecondaryAdapter```, with a ```TieredSecondaryCache``` instance as the secondary cache.
2. The table reader passes both the uncompressed and compressed block to ```FullTypedCacheInterface::InsertFull```, allowing the block cache to optionally store the compressed block.
3. When there's a miss, the block object is constructed and inserted in the primary cache, and the compressed block is inserted into the nvm cache by calling ```InsertSaved```. This avoids the overhead of recompressing the block, as well as avoiding putting more memory pressure on the compressed secondary cache.
4. When there's a hit in the nvm cache, we attempt to insert the block in the compressed secondary cache and the primary cache, subject to the admission policy of those caches (i.e admit on second access). Blocks/items evicted from any tier are simply discarded.

We can easily implement additional admission policies if desired.

Todo (In a subsequent PR):
1. Add to db_bench and run benchmarks
2. Add to db_stress

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11812

Reviewed By: pdillinger

Differential Revision: D49461842

Pulled By: anand1976

fbshipit-source-id: b40ac1330ef7cd8c12efa0a3ca75128e602e3a0b
2023-09-21 20:30:53 -07:00
Yu Zhang e1fd348b92 Fix a bug in multiget for cleaning up SuperVersion (#11830)
Summary:
When `MultiGet` acquires `SuperVersion` via locking the db mutex and get the current `ColumnFamilyData::super_version_`, its corresponding cleanup logic is not correctly done.

It's currently doing this:
`MultiGetColumnFamilyData::cfd->GetSuperVersion().Unref()`

This operates on the most recent `SuperVersion` without locking db mutex , which is not thread safe by itself. And this unref operation is intended for the originally acquired `SuperVersion` instead of the current one. Because a race condition could happen where a new `SuperVersion` is installed in between this `MultiGet`'s ref and unref. When this race condition does happen, it's not sufficient to just unref the `SuperVersion`, `DBImpl::CleanupSuperVersion` should be called instead to properly clean up the `SuperVersion` had this `MultiGet` call be its last reference holder.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11830

Test Plan:
`make all check`
Added a unit test that would originally fail

Reviewed By: ltamasi

Differential Revision: D49287715

Pulled By: jowlyzhang

fbshipit-source-id: 8353636ee11b2e90d85c677a96a92360072644b0
2023-09-15 09:50:39 -07:00
Jay Huh 52816ff64d Close DB option in WaitForCompact() (#11497)
Summary:
Context:

As mentioned in https://github.com/facebook/rocksdb/issues/11436, introducing `close_db` option in `WaitForCompactOptions` to close DB after waiting for compactions to finish. Must be set to true to close the DB upon compactions finishing.
1. `bool close_db = false` added to `WaitForCompactOptions`
2. Introduced `CancelPeriodicTaskSchedulers()` and moved unregistering PeriodicTaskSchedulers to it.`CancelAllBackgroundWork()` calls it now.
3. When close_db option is on, unpersisted data (data in memtable when WAL is disabled) will be flushed in `WaitForCompact()` if flush option is not on (and `mutable_db_options_.avoid_flush_during_shutdown` is not true). The unpersisted data flush in `CancelAllBackgroundWork()` will be skipped because `shutting_down_` flag will be set true before calling `Close()`.
4. Atomic boolean `reject_new_background_jobs_` is introduced to prevent new background jobs from being added during the short period of time after waiting is done and before `shutting_down_` is set by `Close()`.
5. `WaitForCompact()` now waits for recovery in progress to complete as well. (flush operations from WAL -> L0 files)
6. Added `close_db_` cases to all existing `WaitForCompactTests`
7. Added a scenario to `DBBasicTest::DBClose`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11497

Test Plan:
- Existing DBCompactionTests
- `WaitForCompactWithOptionToFlushAndCloseDB` added
- Added a scenario to `DBBasicTest::DBClose`

Reviewed By: pdillinger, jowlyzhang

Differential Revision: D46337560

Pulled By: jaykorean

fbshipit-source-id: 0f8c7ee09394847f2af5ea4bdd331b47bcdef0b0
2023-08-11 12:30:48 -07:00
anand76 0623c5b903 Ensure VerifyFileChecksums reads don't exceed readahead_size (#11328)
Summary:
VerifyFileChecksums currently interprets the readahead_size as a payload of readahead_size for calculating the checksum, plus a prefetch of an additional readahead_size. Hence each read is readahead_size * 2. This change treats it as chunks of readahead_size for checksum calculation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11328

Test Plan: Add a unit test

Reviewed By: pdillinger

Differential Revision: D44718781

Pulled By: anand1976

fbshipit-source-id: 79bae1ebaa27de2a13bc86f5910bf09356936e63
2023-04-05 16:22:08 -07:00
Peter Dillinger 204fcff751 HyperClockCache support for SecondaryCache, with refactoring (#11301)
Summary:
Internally refactors SecondaryCache integration out of LRUCache specifically and into a wrapper/adapter class that works with various Cache implementations. Notably, this relies on separating the notion of async lookup handles from other cache handles, so that HyperClockCache doesn't have to deal with the problem of allocating handles from the hash table for lookups that might fail anyway, and might be on the same key without support for coalescing. (LRUCache's hash table can incorporate previously allocated handles thanks to its pointer indirection.) Specifically, I'm worried about the case in which hundreds of threads try to access the same block and probing in the hash table degrades to linear search on the pile of entries with the same key.

This change is a big step in the direction of supporting stacked SecondaryCaches, but there are obstacles to completing that. Especially, there is no SecondaryCache hook for evictions to pass from one to the next. It has been proposed that evictions be transmitted simply as the persisted data (as in SaveToCallback), but given the current structure provided by the CacheItemHelpers, that would require an extra copy of the block data, because there's intentionally no way to ask for a contiguous Slice of the data (to allow for flexibility in storage). `AsyncLookupHandle` and the re-worked `WaitAll()` should be essentially prepared for stacked SecondaryCaches, but several "TODO with stacked secondaries" issues remain in various places.

It could be argued that the stacking instead be done as a SecondaryCache adapter that wraps two (or more) SecondaryCaches, but at least with the current API that would require an extra heap allocation on SecondaryCache Lookup for a wrapper SecondaryCacheResultHandle that can transfer a Lookup between secondaries. We could also consider trying to unify the Cache and SecondaryCache APIs, though that might be difficult if `AsyncLookupHandle` is kept a fixed struct.

## cache.h (public API)
Moves `secondary_cache` option from LRUCacheOptions to ShardedCacheOptions so that it is applicable to HyperClockCache.

## advanced_cache.h (advanced public API)
* Add `Cache::CreateStandalone()` so that the SecondaryCache support wrapper can use it.
* Add `SetEvictionCallback()` / `eviction_callback_` so that the SecondaryCache support wrapper can use it. Only a single callback is supported for efficiency. If there is ever a need for more than one, hopefully that can be handled with a broadcast callback wrapper.

These are essentially the two "extra" pieces of `Cache` for pulling out specific SecondaryCache support from the `Cache` implementation. I think it's a good trade-off as these are reasonable, limited, and reusable "cut points" into the `Cache` implementations.

* Remove async capability from standard `Lookup()` (getting rid of awkward restrictions on pending Handles) and add `AsyncLookupHandle` and `StartAsyncLookup()`. As noted in the comments, the full struct of `AsyncLookupHandle` is exposed so that it can be stack allocated, for efficiency, though more data is being copied around than before, which could impact performance. (Lookup info -> AsyncLookupHandle -> Handle vs. Lookup info -> Handle)

I could foresee a future in which a Cache internally saves a pointer to the AsyncLookupHandle, which means it's dangerous to allow it to be copyable or even movable. It also means it's not compatible with std::vector (which I don't like requiring as an API parameter anyway), so `WaitAll()` expects any contiguous array of AsyncLookupHandles. I believe this is best for common case efficiency, while behaving well in other cases also. For example, `WaitAll()` has no effect on default-constructed AsyncLookupHandles, which look like a completed cache miss.

## cacheable_entry.h
A couple of functions are obsolete because Cache::Handle can no longer be pending.

## cache.cc
Provides default implementations for new or revamped Cache functions, especially appropriate for non-blocking caches.

## secondary_cache_adapter.{h,cc}
The full details of the Cache wrapper adding SecondaryCache support. Essentially replicates the SecondaryCache handling that was in LRUCache, but obviously refactored. There is a bit of logic duplication, where Lookup() is essentially a manually optimized version of StartAsyncLookup() and Wait(), but it's roughly a dozen lines of code.

## sharded_cache.h, typed_cache.h, charged_cache.{h,cc}, sim_cache.cc
Simply updated for Cache API changes.

## lru_cache.{h,cc}
Carefully remove SecondaryCache logic, implement `CreateStandalone` and eviction handler functionality.

## clock_cache.{h,cc}
Expose existing `CreateStandalone` functionality, add eviction handler functionality. Light refactoring.

## block_based_table_reader*
Mostly re-worked the only usage of async Lookup, which is in BlockBasedTable::MultiGet. Used arrays in place of autovector in some places for efficiency. Simplified some logic by not trying to process some cache results before they're all ready.

Created new function `BlockBasedTable::GetCachePriority()` to reduce some pre-existing code duplication (and avoid making it worse).

Fixed at least one small bug from the prior confusing mixture of async and sync Lookups. In MaybeReadBlockAndLoadToCache(), called by RetrieveBlock(), called by MultiGet() with wait=false, is_cache_hit for the block_cache_tracer entry would not be set to true if the handle was pending after Lookup and before Wait.

## Intended follow-up work
* Figure out if there are any missing stats or block_cache_tracer work in refactored BlockBasedTable::MultiGet
* Stacked secondary caches (see above discussion)
* See if we can make up for the small MultiGet performance regression.
* Study more performance with SecondaryCache
* Items evicted from over-full LRUCache in Release were not being demoted to SecondaryCache, and still aren't to minimize unit test churn. Ideally they would be demoted, but it's an exceptional case so not a big deal.
* Use CreateStandalone for cache reservations (save unnecessary hash table operations). Not a big deal, but worthy cleanup.
* Somehow I got the contract for SecondaryCache::Insert wrong in #10945. (Doesn't take ownership!) That API comment needs to be fixed, but didn't want to mingle that in here.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11301

Test Plan:
## Unit tests
Generally updated to include HCC in SecondaryCache tests, though HyperClockCache has some different, less strict behaviors that leads to some tests not really being set up to work with it. Some of the tests remain disabled with it, but I think we have good coverage without them.

## Crash/stress test
Updated to use the new combination.

## Performance
First, let's check for regression on caches without secondary cache configured. Adding support for the eviction callback is likely to have a tiny effect, but it shouldn't be worrisome. LRUCache could benefit slightly from less logic around SecondaryCache handling. We can test with cache_bench default settings, built with DEBUG_LEVEL=0 and PORTABLE=0.

```
(while :; do base/cache_bench --cache_type=hyper_clock_cache | grep Rough; done) | awk '{ sum += $9; count++; print $0; print "Average: " int(sum / count) }'
```

**Before** this and #11299 (which could also have a small effect), running for about an hour, before & after running concurrently for each cache type:
HyperClockCache: 3168662 (average parallel ops/sec)
LRUCache: 2940127

**After** this and #11299, running for about an hour:
HyperClockCache: 3164862 (average parallel ops/sec) (0.12% slower)
LRUCache: 2940928 (0.03% faster)

This is an acceptable difference IMHO.

Next, let's consider essentially the worst case of new CPU overhead affecting overall performance. MultiGet uses the async lookup interface regardless of whether SecondaryCache or folly are used. We can configure a benchmark where all block cache queries are for data blocks, and all are hits.

Create DB and test (before and after tests running simultaneously):
```
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=30000000 -disable_wal=1 -bloom_bits=16
TEST_TMPDIR=/dev/shm base/db_bench -benchmarks=multireadrandom[-X30] -readonly -multiread_batched -batch_size=32 -num=30000000 -bloom_bits=16 -cache_size=6789000000 -duration 20 -threads=16
```

**Before**:
multireadrandom [AVG    30 runs] : 3444202 (± 57049) ops/sec;  240.9 (± 4.0) MB/sec
multireadrandom [MEDIAN 30 runs] : 3514443 ops/sec;  245.8 MB/sec
**After**:
multireadrandom [AVG    30 runs] : 3291022 (± 58851) ops/sec;  230.2 (± 4.1) MB/sec
multireadrandom [MEDIAN 30 runs] : 3366179 ops/sec;  235.4 MB/sec

So that's roughly a 3% regression, on kind of a *worst case* test of MultiGet CPU. Similar story with HyperClockCache:

**Before**:
multireadrandom [AVG    30 runs] : 3933777 (± 41840) ops/sec;  275.1 (± 2.9) MB/sec
multireadrandom [MEDIAN 30 runs] : 3970667 ops/sec;  277.7 MB/sec
**After**:
multireadrandom [AVG    30 runs] : 3755338 (± 30391) ops/sec;  262.6 (± 2.1) MB/sec
multireadrandom [MEDIAN 30 runs] : 3785696 ops/sec;  264.8 MB/sec

Roughly a 4-5% regression. Not ideal, but not the whole story, fortunately.

Let's also look at Get() in db_bench:

```
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=readrandom[-X30] -readonly -num=30000000 -bloom_bits=16 -cache_size=6789000000 -duration 20 -threads=16
```

**Before**:
readrandom [AVG    30 runs] : 2198685 (± 13412) ops/sec;  153.8 (± 0.9) MB/sec
readrandom [MEDIAN 30 runs] : 2209498 ops/sec;  154.5 MB/sec
**After**:
readrandom [AVG    30 runs] : 2292814 (± 43508) ops/sec;  160.3 (± 3.0) MB/sec
readrandom [MEDIAN 30 runs] : 2365181 ops/sec;  165.4 MB/sec

That's showing roughly a 4% improvement, perhaps because of the secondary cache code that is no longer part of LRUCache. But weirdly, HyperClockCache is also showing 2-3% improvement:

**Before**:
readrandom [AVG    30 runs] : 2272333 (± 9992) ops/sec;  158.9 (± 0.7) MB/sec
readrandom [MEDIAN 30 runs] : 2273239 ops/sec;  159.0 MB/sec
**After**:
readrandom [AVG    30 runs] : 2332407 (± 11252) ops/sec;  163.1 (± 0.8) MB/sec
readrandom [MEDIAN 30 runs] : 2335329 ops/sec;  163.3 MB/sec

Reviewed By: ltamasi

Differential Revision: D44177044

Pulled By: pdillinger

fbshipit-source-id: e808e48ff3fe2f792a79841ba617be98e48689f5
2023-03-17 20:23:49 -07:00
anand76 eac6b6d0cd Ignore async_io ReadOption if FileSystem doesn't support it (#11296)
Summary:
In PosixFileSystem, IO uring support is opt-in. If the support is not enabled by the user, then ignore the async_io ReadOption in MultiGet and iteration at the top, rather than follow the async_io codepath and transparently switch to sync IO at the FileSystem layer.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11296

Test Plan: Add new unit tests

Reviewed By: akankshamahajan15

Differential Revision: D44045776

Pulled By: anand1976

fbshipit-source-id: a0881bf763ca2fde50b84063d0068bb521edd8b9
2023-03-17 14:57:09 -07:00
anand76 63da9cfa26 Return any errors returned by ReadAsync to the MultiGet caller (#11171)
Summary:
Currently, we incorrectly return a Status::Corruption to the MultiGet caller if the file system ReadAsync cannot issue a read and returns an error for some reason, such as IOStatus::NotSupported(). In this PR, we copy the ReadAsync error to the request status so it can be returned to the user.

Tests:
Update existing unit tests and add a new one for this scenario

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11171

Reviewed By: akankshamahajan15

Differential Revision: D42950057

Pulled By: anand1976

fbshipit-source-id: 85ffcb015fa6c064c311f8a28488fec78c487869
2023-02-02 16:35:27 -08:00
sdong 4720ba4391 Remove RocksDB LITE (#11147)
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
2023-01-27 13:14:19 -08:00
sdong 2800aa069a Remove compressed block cache (#11117)
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
2023-01-24 17:09:19 -08:00
Peter Dillinger 4a9185340d A better contract for best_efforts_recovery (#11085)
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
2023-01-24 12:55:03 -08:00
Peter Dillinger 9f7801c5f1 Major Cache refactoring, CPU efficiency improvement (#10975)
Summary:
This is several refactorings bundled into one to avoid having to incrementally re-modify uses of Cache several times. Overall, there are breaking changes to Cache class, and it becomes more of low-level interface for implementing caches, especially block cache. New internal APIs make using Cache cleaner than before, and more insulated from block cache evolution. Hopefully, this is the last really big block cache refactoring, because of rather effectively decoupling the implementations from the uses. This change also removes the EXPERIMENTAL designation on the SecondaryCache support in Cache. It seems reasonably mature at this point but still subject to change/evolution (as I warn in the API docs for Cache).

The high-level motivation for this refactoring is to minimize code duplication / compounding complexity in adding SecondaryCache support to HyperClockCache (in a later PR). Other benefits listed below.

* static_cast lines of code +29 -35 (net removed 6)
* reinterpret_cast lines of code +6 -32 (net removed 26)

## cache.h and secondary_cache.h
* Always use CacheItemHelper with entries instead of just a Deleter. There are several motivations / justifications:
  * Simpler for implementations to deal with just one Insert and one Lookup.
  * Simpler and more efficient implementation because we don't have to track which entries are using helpers and which are using deleters
  * Gets rid of hack to classify cache entries by their deleter. Instead, the CacheItemHelper includes a CacheEntryRole. This simplifies a lot of code (cache_entry_roles.h almost eliminated). Fixes https://github.com/facebook/rocksdb/issues/9428.
  * Makes it trivial to adjust SecondaryCache behavior based on kind of block (e.g. don't re-compress filter blocks).
  * It is arguably less convenient for many direct users of Cache, but direct users of Cache are now rare with introduction of typed_cache.h (below).
  * I considered and rejected an alternative approach in which we reduce customizability by assuming each secondary cache compatible value starts with a Slice referencing the uncompressed block contents (already true or mostly true), but we apparently intend to stack secondary caches. Saving an entry from a compressed secondary to a lower tier requires custom handling offered by SaveToCallback, etc.
* Make CreateCallback part of the helper and introduce CreateContext to work with it (alternative to https://github.com/facebook/rocksdb/issues/10562). This cleans up the interface while still allowing context to be provided for loading/parsing values into primary cache. This model works for async lookup in BlockBasedTable reader (reader owns a CreateContext) under the assumption that it always waits on secondary cache operations to finish. (Otherwise, the CreateContext could be destroyed while async operation depending on it continues.) This likely contributes most to the observed performance improvement because it saves an std::function backed by a heap allocation.
* Use char* for serialized data, e.g. in SaveToCallback, where void* was confusingly used. (We use `char*` for serialized byte data all over RocksDB, with many advantages over `void*`. `memcpy` etc. are legacy APIs that should not be mimicked.)
* Add a type alias Cache::ObjectPtr = void*, so that we can better indicate the intent of the void* when it is to be the object associated with a Cache entry. Related: started (but did not complete) a refactoring to move away from "value" of a cache entry toward "object" or "obj". (It is confusing to call Cache a key-value store (like DB) when it is really storing arbitrary in-memory objects, not byte strings.)
* Remove unnecessary key param from DeleterFn. This is good for efficiency in HyperClockCache, which does not directly store the cache key in memory. (Alternative to https://github.com/facebook/rocksdb/issues/10774)
* Add allocator to Cache DeleterFn. This is a kind of future-proofing change in case we get more serious about using the Cache allocator for memory tracked by the Cache. Right now, only the uncompressed block contents are allocated using the allocator, and a pointer to that allocator is saved as part of the cached object so that the deleter can use it. (See CacheAllocationPtr.) If in the future we are able to "flatten out" our Cache objects some more, it would be good not to have to track the allocator as part of each object.
* Removes legacy `ApplyToAllCacheEntries` and changes `ApplyToAllEntries` signature for Deleter->CacheItemHelper change.

## typed_cache.h
Adds various "typed" interfaces to the Cache as internal APIs, so that most uses of Cache can use simple type safe code without casting and without explicit deleters, etc. Almost all of the non-test, non-glue code uses of Cache have been migrated. (Follow-up work: CompressedSecondaryCache deserves deeper attention to migrate.) This change expands RocksDB's internal usage of metaprogramming and SFINAE (https://en.cppreference.com/w/cpp/language/sfinae).

The existing usages of Cache are divided up at a high level into these new interfaces. See updated existing uses of Cache for examples of how these are used.
* PlaceholderCacheInterface - Used for making cache reservations, with entries that have a charge but no value.
* BasicTypedCacheInterface<TValue> - Used for primary cache storage of objects of type TValue, which can be cleaned up with std::default_delete<TValue>. The role is provided by TValue::kCacheEntryRole or given in an optional template parameter.
* FullTypedCacheInterface<TValue, TCreateContext> - Used for secondary cache compatible storage of objects of type TValue. In addition to BasicTypedCacheInterface constraints, we require TValue::ContentSlice() to return persistable data. This simplifies usage for the normal case of simple secondary cache compatibility (can give you a Slice to the data already in memory). In addition to TCreateContext performing the role of Cache::CreateContext, it is also expected to provide a factory function for creating TValue.
* For each of these, there's a "Shared" version (e.g. FullTypedSharedCacheInterface) that holds a shared_ptr to the Cache, rather than assuming external ownership by holding only a raw `Cache*`.

These interfaces introduce specific handle types for each interface instantiation, so that it's easy to see what kind of object is controlled by a handle. (Ultimately, this might not be worth the extra complexity, but it seems OK so far.)

Note: I attempted to make the cache 'charge' automatically inferred from the cache object type, such as by expecting an ApproximateMemoryUsage() function, but this is not so clean because there are cases where we need to compute the charge ahead of time and don't want to re-compute it.

## block_cache.h
This header is essentially the replacement for the old block_like_traits.h. It includes various things to support block cache access with typed_cache.h for block-based table.

## block_based_table_reader.cc
Before this change, accessing the block cache here was an awkward mix of static polymorphism (template TBlocklike) and switch-case on a dynamic BlockType value. This change mostly unifies on static polymorphism, relying on minor hacks in block_cache.h to distinguish variants of Block. We still check BlockType in some places (especially for stats, which could be improved in follow-up work) but at least the BlockType is a static constant from the template parameter. (No more awkward partial redundancy between static and dynamic info.) This likely contributes to the overall performance improvement, but hasn't been tested in isolation.

The other key source of simplification here is a more unified system of creating block cache objects: for directly populating from primary cache and for promotion from secondary cache. Both use BlockCreateContext, for context and for factory functions.

## block_based_table_builder.cc, cache_dump_load_impl.cc
Before this change, warming caches was super ugly code. Both of these source files had switch statements to basically transition from the dynamic BlockType world to the static TBlocklike world. None of that mess is needed anymore as there's a new, untyped WarmInCache function that handles all the details just as promotion from SecondaryCache would. (Fixes `TODO akanksha: Dedup below code` in block_based_table_builder.cc.)

## Everything else
Mostly just updating Cache users to use new typed APIs when reasonably possible, or changed Cache APIs when not.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10975

Test Plan:
tests updated

Performance test setup similar to https://github.com/facebook/rocksdb/issues/10626 (by cache size, LRUCache when not "hyper" for HyperClockCache):

34MB 1thread base.hyper -> kops/s: 0.745 io_bytes/op: 2.52504e+06 miss_ratio: 0.140906 max_rss_mb: 76.4844
34MB 1thread new.hyper -> kops/s: 0.751 io_bytes/op: 2.5123e+06 miss_ratio: 0.140161 max_rss_mb: 79.3594
34MB 1thread base -> kops/s: 0.254 io_bytes/op: 1.36073e+07 miss_ratio: 0.918818 max_rss_mb: 45.9297
34MB 1thread new -> kops/s: 0.252 io_bytes/op: 1.36157e+07 miss_ratio: 0.918999 max_rss_mb: 44.1523
34MB 32thread base.hyper -> kops/s: 7.272 io_bytes/op: 2.88323e+06 miss_ratio: 0.162532 max_rss_mb: 516.602
34MB 32thread new.hyper -> kops/s: 7.214 io_bytes/op: 2.99046e+06 miss_ratio: 0.168818 max_rss_mb: 518.293
34MB 32thread base -> kops/s: 3.528 io_bytes/op: 1.35722e+07 miss_ratio: 0.914691 max_rss_mb: 264.926
34MB 32thread new -> kops/s: 3.604 io_bytes/op: 1.35744e+07 miss_ratio: 0.915054 max_rss_mb: 264.488
233MB 1thread base.hyper -> kops/s: 53.909 io_bytes/op: 2552.35 miss_ratio: 0.0440566 max_rss_mb: 241.984
233MB 1thread new.hyper -> kops/s: 62.792 io_bytes/op: 2549.79 miss_ratio: 0.044043 max_rss_mb: 241.922
233MB 1thread base -> kops/s: 1.197 io_bytes/op: 2.75173e+06 miss_ratio: 0.103093 max_rss_mb: 241.559
233MB 1thread new -> kops/s: 1.199 io_bytes/op: 2.73723e+06 miss_ratio: 0.10305 max_rss_mb: 240.93
233MB 32thread base.hyper -> kops/s: 1298.69 io_bytes/op: 2539.12 miss_ratio: 0.0440307 max_rss_mb: 371.418
233MB 32thread new.hyper -> kops/s: 1421.35 io_bytes/op: 2538.75 miss_ratio: 0.0440307 max_rss_mb: 347.273
233MB 32thread base -> kops/s: 9.693 io_bytes/op: 2.77304e+06 miss_ratio: 0.103745 max_rss_mb: 569.691
233MB 32thread new -> kops/s: 9.75 io_bytes/op: 2.77559e+06 miss_ratio: 0.103798 max_rss_mb: 552.82
1597MB 1thread base.hyper -> kops/s: 58.607 io_bytes/op: 1449.14 miss_ratio: 0.0249324 max_rss_mb: 1583.55
1597MB 1thread new.hyper -> kops/s: 69.6 io_bytes/op: 1434.89 miss_ratio: 0.0247167 max_rss_mb: 1584.02
1597MB 1thread base -> kops/s: 60.478 io_bytes/op: 1421.28 miss_ratio: 0.024452 max_rss_mb: 1589.45
1597MB 1thread new -> kops/s: 63.973 io_bytes/op: 1416.07 miss_ratio: 0.0243766 max_rss_mb: 1589.24
1597MB 32thread base.hyper -> kops/s: 1436.2 io_bytes/op: 1357.93 miss_ratio: 0.0235353 max_rss_mb: 1692.92
1597MB 32thread new.hyper -> kops/s: 1605.03 io_bytes/op: 1358.04 miss_ratio: 0.023538 max_rss_mb: 1702.78
1597MB 32thread base -> kops/s: 280.059 io_bytes/op: 1350.34 miss_ratio: 0.023289 max_rss_mb: 1675.36
1597MB 32thread new -> kops/s: 283.125 io_bytes/op: 1351.05 miss_ratio: 0.0232797 max_rss_mb: 1703.83

Almost uniformly improving over base revision, especially for hot paths with HyperClockCache, up to 12% higher throughput seen (1597MB, 32thread, hyper). The improvement for that is likely coming from much simplified code for providing context for secondary cache promotion (CreateCallback/CreateContext), and possibly from less branching in block_based_table_reader. And likely a small improvement from not reconstituting key for DeleterFn.

Reviewed By: anand1976

Differential Revision: D42417818

Pulled By: pdillinger

fbshipit-source-id: f86bfdd584dce27c028b151ba56818ad14f7a432
2023-01-11 14:20:40 -08:00
anand76 8ffabdc226 Fix table cache leak in MultiGet with async_io (#10997)
Summary:
When MultiGet with the async_io option encounters an IO error in TableCache::GetTableReader, it may result in leakage of table cache handles due to queued coroutines being abandoned. This PR fixes it by ensuring any queued coroutines are run before aborting the MultiGet.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10997

Test Plan:
1. New unit test in db_basic_test
2. asan_crash

Reviewed By: pdillinger

Differential Revision: D41587244

Pulled By: anand1976

fbshipit-source-id: 900920cd3fba47cb0fc744a62facc5ffe2eccb64
2022-12-04 22:58:25 -08:00
Andrew Kryczka 5cf6ab6f31 Ran clang-format on db/ directory (#10910)
Summary:
Ran `find ./db/ -type f | xargs clang-format -i`. Excluded minor changes it tried to make on db/db_impl/. Everything else it changed was directly under db/ directory. Included minor manual touchups mentioned in PR commit history.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10910

Reviewed By: riversand963

Differential Revision: D40880683

Pulled By: ajkr

fbshipit-source-id: cfe26cda05b3fb9a72e3cb82c286e21d8c5c4174
2022-11-02 14:34:24 -07:00
anand76 bb9a6d4e4b Bypass a MultiGet test when async_io is used (#10669)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10669

Reviewed By: akankshamahajan15

Differential Revision: D39492658

Pulled By: anand1976

fbshipit-source-id: abef79808e30762654680f7dd7e46487c631febc
2022-09-14 09:59:54 -07:00
anand76 5fbcc8c54d Update MULTIGET_IO_BATCH_SIZE for non-async MultiGet (#10622)
Summary:
This stat was only getting updated in the async (coroutine) version of MultiGet.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10622

Reviewed By: akankshamahajan15

Differential Revision: D39188790

Pulled By: anand1976

fbshipit-source-id: 7e231507f65fc94c8a006c38f79dfba182a2c24a
2022-08-31 21:03:52 -07:00
Peter Dillinger c5afbbfe4b Don't wait for indirect flush in read-only DB (#10569)
Summary:
Some APIs for getting live files, which are used by Checkpoint
and BackupEngine, can optionally trigger and wait for a flush. These
would deadlock when used on a read-only DB. Here we fix that by assuming
the user wants the overall operation to succeed and is OK without
flushing (because the DB is read-only).

Follow-up work: the same or other issues can be hit by directly invoking
some DB functions that are clearly not appropriate for read-only
instance, but are not covered by overrides in DBImplReadOnly and
CompactedDBImpl. These should be fixed to avoid similar problems on
accidental misuse. (Long term, it would be nice to have a DBReadOnly
class without those members, like BackupEngineReadOnly.)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10569

Test Plan: tests updated to catch regression (hang before the fix)

Reviewed By: riversand963

Differential Revision: D38995759

Pulled By: pdillinger

fbshipit-source-id: f5f8bc7123e13cb45bd393dd974d7d6eda20bc68
2022-08-29 13:36:23 -07:00
anand76 35cdd3e71e MultiGet async IO across multiple levels (#10535)
Summary:
This PR exploits parallelism in MultiGet across levels. It applies only to the coroutine version of MultiGet. Previously, MultiGet file reads from SST files in the same level were parallelized. With this PR, MultiGet batches with keys distributed across multiple levels are read in parallel. This is accomplished by splitting the keys not present in a level (determined by bloom filtering) into a separate batch, and processing the new batch in parallel with the original batch.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10535

Test Plan:
1. Ensure existing MultiGet unit tests pass, updating them as necessary
2. New unit tests - TODO
3. Run stress test - TODO

No noticeable regression (<1%) without async IO -
Without PR: `multireadrandom :       7.261 micros/op 1101724 ops/sec 60.007 seconds 66110936 operations;  571.6 MB/s (8168992 of 8168992 found)`
With PR: `multireadrandom :       7.305 micros/op 1095167 ops/sec 60.007 seconds 65717936 operations;  568.2 MB/s (8271992 of 8271992 found)`

For a fully cached DB, but with async IO option on, no regression observed (<1%) -
Without PR: `multireadrandom :       5.201 micros/op 1538027 ops/sec 60.005 seconds 92288936 operations;  797.9 MB/s (11540992 of 11540992 found) `
With PR: `multireadrandom :       5.249 micros/op 1524097 ops/sec 60.005 seconds 91452936 operations;  790.7 MB/s (11649992 of 11649992 found) `

Reviewed By: akankshamahajan15

Differential Revision: D38774009

Pulled By: anand1976

fbshipit-source-id: c955e259749f1c091590ade73105b3ee46cd0007
2022-08-19 16:52:52 -07:00
anand76 65814a4ae6 Fix range deletion handling in async MultiGet (#10534)
Summary:
The fix in https://github.com/facebook/rocksdb/issues/10513 was not complete w.r.t range deletion handling. It didn't handle the case where a file with a range tombstone covering a key also overlapped another key in the batch. In that case, ```mget_range``` would be non-empty. However, ```mget_range``` would only have the second key and, therefore, the first key would be skipped when iterating through the range tombstones in ```TableCache::MultiGet```.

Test plan -
1. Add a unit test
2. Run stress tests

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10534

Reviewed By: akankshamahajan15

Differential Revision: D38773880

Pulled By: anand1976

fbshipit-source-id: dae491dbe52e18bbce5179b77b63f20771a66c00
2022-08-17 13:51:39 -07:00
anand76 0b02960d8c Fix MultiGet range deletion handling and a memory leak (#10513)
Summary:
This PR fixes 2 bugs introduced in https://github.com/facebook/rocksdb/issues/10432 -
1. If the bloom filter returned a negative result for all MultiGet keys in a file, the range tombstones in that file were being ignored, resulting in incorrect results if those tombstones covered a key in a higher level.
2. If all the keys in a file were filtered out in `TableCache::MultiGetFilter`, the table cache handle was not being released.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10513

Test Plan: Add a new unit test that fails without this fix

Reviewed By: akankshamahajan15

Differential Revision: D38548739

Pulled By: anand1976

fbshipit-source-id: a741a1e25d2e991d63f038100f126c2dc404a87c
2022-08-09 14:44:47 -07:00
anand76 bf4532eb5c Break TableReader MultiGet into filter and lookup stages (#10432)
Summary:
This PR is the first step in enhancing the coroutines MultiGet to be able to lookup a batch in parallel across levels. By having a separate TableReader function for probing the bloom filters, we can quickly figure out which overlapping keys from a batch are definitely not in the file and can move on to the next level.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10432

Reviewed By: akankshamahajan15

Differential Revision: D38245910

Pulled By: anand1976

fbshipit-source-id: 3d20db2350378c3fe6f086f0c7ba5ff01d7f04de
2022-08-04 12:51:57 -07:00
Peter Dillinger 27f3af5966 Fix serious FSDirectory use-after-Close bug (missing fsync) (#10460)
Summary:
TL;DR: due to a recent change, if you drop a column family,
often that DB will no longer fsync after writing new SST files
to remaining or new column families, which could lead to data
loss on power loss.

More bug detail:
The intent of https://github.com/facebook/rocksdb/issues/10049 was to Close FSDirectory objects at
DB::Close time rather than waiting for DB object destruction.
Unfortunately, it also closes shared FSDirectory objects on
DropColumnFamily (& destroy remaining handles), which can lead
to use-after-Close on FSDirectory shared with remaining column
families. Those "uses" are only Fsyncs (or redundant Closes). In
the default Posix filesystem, an Fsync on a closed FSDirectory is a
quiet no-op. Consequently (under most configurations), if you drop
a column family, that DB will no longer fsync after writing new SST
files to column families sharing the same directory (true under most
configurations).

More fix detail:
Basically, this removes unnecessary Close ops on destroying
ColumnFamilyData. We let `shared_ptr` take care of calling the
destructor at the right time. If the intent was to require Close be
called before destroying FSDirectory, that was not made clear by the
author of FileSystem and was not at all enforced by https://github.com/facebook/rocksdb/issues/10049, which
could have added `assert(fd_ == -1)` to `~PosixDirectory()` but did
not. To keep this fix simple, we relax the unit test for https://github.com/facebook/rocksdb/issues/10049 to allow
timely destruction of FSDirectory to suffice as Close (in
CountedFileSystem). Added a TODO to revisit that.

Also in this PR:
* Added a TODO to share FSDirectory instances between DB and its column
families. (Already shared among column families.)
* Made DB::Close attempt to close all its open FSDirectory objects even
if there is a failure in closing one. Also code clean-up around this
logic.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10460

Test Plan:
add an assert to check for use-after-Close. With that
existing tests can detect the misuse. With fix, tests pass (except noted
relaxing of unit test for https://github.com/facebook/rocksdb/issues/10049)

Reviewed By: ajkr

Differential Revision: D38357922

Pulled By: pdillinger

fbshipit-source-id: d42079cadbedf0a969f03389bf586b3b4e1f9137
2022-08-02 10:54:32 -07:00
Jay Zhuang dcb6a3be4e Add helper function to get debug type name (#10243)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10243

Reviewed By: riversand963

Differential Revision: D37370236

Pulled By: jay-zhuang

fbshipit-source-id: 6e7a6fadf45fdfb5afe97b3f6fe4acf1260d4a86
2022-07-15 14:42:00 -07:00
Yanqin Jin b283f041f5 Stop tracking syncing live WAL for performance (#10330)
Summary:
With https://github.com/facebook/rocksdb/issues/10087, applications calling `SyncWAL()` or writing with `WriteOptions::sync=true` can suffer
from performance regression. This PR reverts to original behavior of tracking the syncing of closed WALs.
After we revert back to old behavior, recovery, whether kPointInTime or kAbsoluteConsistency, may fail to
detect corruption in synced WALs if the corruption is in the live WAL.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10330

Test Plan:
make check

Before https://github.com/facebook/rocksdb/issues/10087
```bash
fillsync     :     750.269 micros/op 1332 ops/sec 75.027 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync     :     776.492 micros/op 1287 ops/sec 77.649 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 2 runs] : 1310 (± 44) ops/sec;    0.1 (± 0.0) MB/sec
fillsync     :     805.625 micros/op 1241 ops/sec 80.563 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 3 runs] : 1287 (± 51) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [AVG    3 runs] : 1287 (± 51) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [MEDIAN 3 runs] : 1287 ops/sec;    0.1 MB/sec
```

Before this PR and after https://github.com/facebook/rocksdb/issues/10087
```bash
fillsync     :    1479.601 micros/op 675 ops/sec 147.960 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync     :    1626.080 micros/op 614 ops/sec 162.608 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 2 runs] : 645 (± 59) ops/sec;    0.1 (± 0.0) MB/sec
fillsync     :    1588.402 micros/op 629 ops/sec 158.840 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 3 runs] : 640 (± 35) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [AVG    3 runs] : 640 (± 35) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [MEDIAN 3 runs] : 629 ops/sec;    0.1 MB/sec
```

After this PR
```bash
fillsync     :     749.621 micros/op 1334 ops/sec 74.962 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync     :     865.577 micros/op 1155 ops/sec 86.558 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 2 runs] : 1244 (± 175) ops/sec;    0.1 (± 0.0) MB/sec
fillsync     :     845.837 micros/op 1182 ops/sec 84.584 seconds 100000 operations;    0.1 MB/s (100 ops)
fillsync [AVG 3 runs] : 1223 (± 109) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [AVG    3 runs] : 1223 (± 109) ops/sec;    0.1 (± 0.0) MB/sec
fillsync [MEDIAN 3 runs] : 1182 ops/sec;    0.1 MB/sec
```

Reviewed By: ajkr

Differential Revision: D37725212

Pulled By: riversand963

fbshipit-source-id: 8fa7d13b3c7662be5d56351c42caf3266af937ae
2022-07-12 17:16:57 -07:00
Peter Dillinger f81ea75df7 Don't count no prefix as Bloom hit (#10244)
Summary:
When a key is "out of domain" for the prefix_extractor (no
prefix assigned) then the Bloom filter is not queried. PerfContext
was counting this as a Bloom "hit" while Statistics doesn't count this
as a prefix Bloom checked. I think it's more accurate to call it neither
hit nor miss, so changing the counting to make it PerfContext coounting
more like Statistics.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10244

Test Plan:
tests updates and expanded (Get and MultiGet). Iterator test
coverage of the change will come in next PR

Reviewed By: bjlemaire

Differential Revision: D37371297

Pulled By: pdillinger

fbshipit-source-id: fed132fba6a92b2314ab898d449fce2d1586c157
2022-06-23 11:00:27 -07:00
Yanqin Jin 9586dcf1ce Expose the initial logger creation error (#10223)
Summary:
https://github.com/facebook/rocksdb/issues/9984 changes the behavior of RocksDB: if logger creation failed during `SanitizeOptions()`,
`DB::Open()` will fail. However, since `SanitizeOptions()` is called in `DBImpl::DBImpl()`, we cannot
directly expose the error to caller without some additional work.
This is a first version proposal which:
- Adds a new member `init_logger_creation_s` to `DBImpl` to store the result of init logger creation
- Checks the error during `DB::Open()` and return it to caller if non-ok

This is not very ideal. We can alternatively move the logger creation logic out of the `SanitizeOptions()`.
Since `SanitizeOptions()` is used in other places, we need to check whether this change breaks anything
in case other callers of `SanitizeOptions()` assumes that a logger should be created.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10223

Test Plan: make check

Reviewed By: pdillinger

Differential Revision: D37321717

Pulled By: riversand963

fbshipit-source-id: 58042358a86369d606549dd9938933dd47591c4b
2022-06-22 08:26:38 -07:00
anand76 a6691d0f65 Update stats to help users estimate MultiGet async IO impact (#10182)
Summary:
Add a couple of stats to help users estimate the impact of potential MultiGet perf improvements -
1. NUM_LEVEL_READ_PER_MULTIGET - A histogram stat for number of levels that required MultiGet to read from a file
2. MULTIGET_COROUTINE_COUNT - A ticker stat to count the number of times the coroutine version of MultiGetFromSST was used

The NUM_DATA_BLOCKS_READ_PER_LEVEL stat is obsoleted as it doesn't provide useful information for MultiGet optimization.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10182

Reviewed By: akankshamahajan15

Differential Revision: D37213296

Pulled By: anand1976

fbshipit-source-id: 5d2b7708017c0e278578ae4bffac3926f6530efb
2022-06-16 12:12:43 -07:00
Peter Dillinger 3d358a7e25 Fix handling of accidental truncation of IDENTITY file (#10173)
Summary:
A consequence of https://github.com/facebook/rocksdb/issues/9990 was requiring a non-empty DB ID to generate
new SST files. But if the DB ID is not tracked in the manifest and the IDENTITY file
is somehow truncated to 0 bytes, then an empty DB ID would be assigned, leading
to crash. This change ensures a non-empty DB ID is assigned and set in the
IDENTITY file.

Also,
* Some light refactoring to clean up the logic
* (I/O efficiency) If the ID is tracked in the manifest and already matches the
IDENTITY file, don't needlessly overwrite the file.
* (Debugging) Log the DB ID to info log on open, because sometimes IDENTITY
can change if DB is moved around (though it would be unusual for info log to
be copied/moved without IDENTITY file)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10173

Test Plan: unit tests expanded/updated

Reviewed By: ajkr

Differential Revision: D37176545

Pulled By: pdillinger

fbshipit-source-id: a9b414cd35bfa33de48af322a36c24538d50bef1
2022-06-15 15:39:49 -07:00
Yanqin Jin d739de63e5 Fix a bug in WAL tracking (#10087)
Summary:
Closing https://github.com/facebook/rocksdb/issues/10080

When `SyncWAL()` calls `MarkLogsSynced()`, even if there is only one active WAL file,
this event should still be added to the MANIFEST.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10087

Test Plan: make check

Reviewed By: ajkr

Differential Revision: D36797580

Pulled By: riversand963

fbshipit-source-id: 24184c9dd606b3939a454ed41de6e868d1519999
2022-06-03 16:33:00 -07:00
Zichen Zhu 65893ad959 Explicitly closing all directory file descriptors (#10049)
Summary:
Currently, the DB directory file descriptor is left open until the deconstruction process (`DB::Close()` does not close the file descriptor). To verify this, comment out the lines between `db_ = nullptr` and `db_->Close()` (line 512, 513, 514, 515 in ldb_cmd.cc) to leak the ``db_'' object, build `ldb` tool and run
```
strace --trace=open,openat,close ./ldb --db=$TEST_TMPDIR --ignore_unknown_options put K1 V1 --create_if_missing
```
There is one directory file descriptor that is not closed in the strace log.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10049

Test Plan: Add a new unit test DBBasicTest.DBCloseAllDirectoryFDs: Open a database with different WAL directory and three different data directories, and all directory file descriptors should be closed after calling Close(). Explicitly call Close() after a directory file descriptor is not used so that the counter of directory open and close should be equivalent.

Reviewed By: ajkr, hx235

Differential Revision: D36722135

Pulled By: littlepig2013

fbshipit-source-id: 07bdc2abc417c6b30997b9bbef1f79aa757b21ff
2022-06-01 18:03:34 -07:00
Jay Zhuang 151dc0038a Bypass tests instead of skipping (#10076)
Summary:
Make fb test infra happy, more details: https://github.com/facebook/rocksdb/issues/8048

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10076

Test Plan: CI

Reviewed By: ajkr

Differential Revision: D36768766

Pulled By: jay-zhuang

fbshipit-source-id: 4f039a5c623abb6d4a7d09bbf97077618e7ec2c8
2022-05-31 13:02:50 -07:00
Yanqin Jin 514f0b0937 Fail DB::Open() if logger cannot be created (#9984)
Summary:
For regular db instance and secondary instance, we return error and refuse to open DB if Logger creation fails.

Our current code allows it, but it is really difficult to debug because
there will be no LOG files. The same for OPTIONS file, which will be explored in another PR.

Furthermore, Arena::AllocateAligned(size_t bytes, size_t huge_page_size, Logger* logger) has an
assertion as the following:

```cpp
#ifdef MAP_HUGETLB
if (huge_page_size > 0 && bytes > 0) {
  assert(logger != nullptr);
}
#endif
```

It can be removed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9984

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D36347754

Pulled By: riversand963

fbshipit-source-id: 529798c0511d2eaa2f0fd40cf7e61c4cbc6bc57e
2022-05-27 07:23:31 -07:00
anand76 57997ddaaf Multi file concurrency in MultiGet using coroutines and async IO (#9968)
Summary:
This PR implements a coroutine version of batched MultiGet in order to concurrently read from multiple SST files in a level using async IO, thus reducing the latency of the MultiGet. The API from the user perspective is still synchronous and single threaded, with the RocksDB part of the processing happening in the context of the caller's thread. In Version::MultiGet, the decision is made whether to call synchronous or coroutine code.

A good way to review this PR is to review the first 4 commits in order - de773b3, 70c2f70, 10b50e1, and 377a597 - before reviewing the rest.

TODO:
1. Figure out how to build it in CircleCI (requires some dependencies to be installed)
2. Do some stress testing with coroutines enabled

No regression in synchronous MultiGet between this branch and main -
```
./db_bench -use_existing_db=true --db=/data/mysql/rocksdb/prefix_scan -benchmarks="readseq,multireadrandom" -key_size=32 -value_size=512 -num=5000000 -batch_size=64 -multiread_batched=true -use_direct_reads=false -duration=60 -ops_between_duration_checks=1 -readonly=true -adaptive_readahead=true -threads=16 -cache_size=10485760000 -async_io=false -multiread_stride=40000 -statistics
```
Branch - ```multireadrandom :       4.025 micros/op 3975111 ops/sec 60.001 seconds 238509056 operations; 2062.3 MB/s (14767808 of 14767808 found)```

Main - ```multireadrandom :       3.987 micros/op 4013216 ops/sec 60.001 seconds 240795392 operations; 2082.1 MB/s (15231040 of 15231040 found)```

More benchmarks in various scenarios are given below. The measurements were taken with ```async_io=false``` (no coroutines) and ```async_io=true``` (use coroutines). For an IO bound workload (with every key requiring an IO), the coroutines version shows a clear benefit, being ~2.6X faster. For CPU bound workloads, the coroutines version has ~6-15% higher CPU utilization, depending on how many keys overlap an SST file.

1. Single thread IO bound workload on remote storage with sparse MultiGet batch keys (~1 key overlap/file) -
No coroutines - ```multireadrandom :     831.774 micros/op 1202 ops/sec 60.001 seconds 72136 operations;    0.6 MB/s (72136 of 72136 found)```
Using coroutines - ```multireadrandom :     318.742 micros/op 3137 ops/sec 60.003 seconds 188248 operations;    1.6 MB/s (188248 of 188248 found)```

2. Single thread CPU bound workload (all data cached) with ~1 key overlap/file -
No coroutines - ```multireadrandom :       4.127 micros/op 242322 ops/sec 60.000 seconds 14539384 operations;  125.7 MB/s (14539384 of 14539384 found)```
Using coroutines - ```multireadrandom :       4.741 micros/op 210935 ops/sec 60.000 seconds 12656176 operations;  109.4 MB/s (12656176 of 12656176 found)```

3. Single thread CPU bound workload with ~2 key overlap/file -
No coroutines - ```multireadrandom :       3.717 micros/op 269000 ops/sec 60.000 seconds 16140024 operations;  139.6 MB/s (16140024 of 16140024 found)```
Using coroutines - ```multireadrandom :       4.146 micros/op 241204 ops/sec 60.000 seconds 14472296 operations;  125.1 MB/s (14472296 of 14472296 found)```

4. CPU bound multi-threaded (16 threads) with ~4 key overlap/file -
No coroutines - ```multireadrandom :       4.534 micros/op 3528792 ops/sec 60.000 seconds 211728728 operations; 1830.7 MB/s (12737024 of 12737024 found) ```
Using coroutines - ```multireadrandom :       4.872 micros/op 3283812 ops/sec 60.000 seconds 197030096 operations; 1703.6 MB/s (12548032 of 12548032 found) ```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9968

Reviewed By: akankshamahajan15

Differential Revision: D36348563

Pulled By: anand1976

fbshipit-source-id: c0ce85a505fd26ebfbb09786cbd7f25202038696
2022-05-19 15:36:27 -07:00
sdong 736a7b5433 Remove own ToString() (#9955)
Summary:
ToString() is created as some platform doesn't support std::to_string(). However, we've already used std::to_string() by mistake for 16 months (in db/db_info_dumper.cc). This commit just remove ToString().

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9955

Test Plan: Watch CI tests

Reviewed By: riversand963

Differential Revision: D36176799

fbshipit-source-id: bdb6dcd0e3a3ab96a1ac810f5d0188f684064471
2022-05-06 13:03:58 -07:00
Akanksha Mahajan ae82d91492 Remove corrupted WAL files in kPointRecoveryMode with avoid_flush_duing_recovery set true (#9634)
Summary:
1) In case of non-TransactionDB and avoid_flush_during_recovery = true, RocksDB won't
flush the data from WAL to L0 for all column families if possible. As a
result, not all column families can increase their log_numbers, and
min_log_number_to_keep won't change.
2) For transaction DB (.allow_2pc), even with the flush, there may be old WAL files that it must not delete because they can contain data of uncommitted transactions and min_log_number_to_keep won't change.

If we persist a new MANIFEST with
advanced log_numbers for some column families, then during a second
crash after persisting the MANIFEST, RocksDB will see some column
families' log_numbers larger than the corrupted wal, and the "column family inconsistency" error will be hit, causing recovery to fail.

As a solution,
1. the corrupted WALs whose numbers are larger than the
corrupted wal and smaller than the new WAL will be moved to archive folder.
2. Currently, RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. This PR buffers the edits in a structure and writes to a new MANIFEST after recovery is successful

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9634

Test Plan:
1. Added new unit tests
                2. make crast_test -j

Reviewed By: riversand963

Differential Revision: D34463666

Pulled By: akankshamahajan15

fbshipit-source-id: e233d3af0ed4e2028ca0cf051e5a334a0fdc9d19
2022-04-11 15:39:31 -07:00
anand76 627deb7ceb Fix some MultiGet batching stats (#9583)
Summary:
The NUM_INDEX_AND_FILTER_BLOCKS_READ_PER_LEVEL, NUM_DATA_BLOCKS_READ_PER_LEVEL, and NUM_SST_READ_PER_LEVEL stats were being recorded only when the last file in a level happened to have hits. They are supposed to be updated for every level. Also, there was some overcounting of GetContextStats. This PR fixes both the problems.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9583

Test Plan: Update the unit test in db_basic_test

Reviewed By: akankshamahajan15

Differential Revision: D34308044

Pulled By: anand1976

fbshipit-source-id: b3b36020fda26ba91bc6e0e47d52d58f4d7f656e
2022-02-17 16:31:41 -08:00