Commit Graph

237 Commits

Author SHA1 Message Date
Peter Dillinger 3ee4d5a11a Fix possible crash in failure to sync some WALs (#12789)
Summary:
I believe this was possible with recyclable logs before recent work like https://github.com/facebook/rocksdb/issues/12734, but this cleans up a couple of possible crashes revealed by the crash test.  A WAL with a nullptr file writer (already closed) can persist in `logs_` if a later WAL fails to sync. In case of any WAL sync failures, we don't record WAL syncs to the manifest. Thus, even if a WAL is fully synced and closed, we might need to keep it on the `logs_` list so that we know to record its sync to the manifest if there should be a successful sync next time. (However, I believe that's future-looking because currently any failure in WAL sync is considered non-recoverable.)

I don't believe this was likely enough before recent changes to warrant a release note (if it was possible).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12789

Test Plan: A unit test that would reveal the crashes, now fixed

Reviewed By: cbi42

Differential Revision: D58874154

Pulled By: pdillinger

fbshipit-source-id: bc69407cd9cbcd080af9585d502d4e33dafc3d29
2024-06-21 12:56:21 -07:00
Yu Zhang 13c758f986 Change the behavior of manual flush to not retain UDT (#12737)
Summary:
When user-defined timestamps in Memtable only feature is enabled, all scheduled flushes go through a check to see if it's eligible to be rescheduled to retain user-defined timestamps. However when the user makes a manual flush request, their intention is for all the in memory data to be persisted into SST files as soon as possible. These two sides have some conflict of interest, the user can implement some workaround like https://github.com/facebook/rocksdb/issues/12631 to explicitly mark which one takes precedence. The implementation for this can be nuanced since the user needs to be aware of all the scenarios that can trigger a manual flush and handle the concurrency well etc.

In this PR, we updated the default behavior to give manual flush precedence when it's requested. The user-defined timestamps rescheduling mechanism is turned off when a manual flush is requested. Likewise, all error recovery triggered flushes skips the rescheduling mechanism too.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12737

Test Plan: Add unit tests

Reviewed By: ajkr

Differential Revision: D58538246

Pulled By: jowlyzhang

fbshipit-source-id: 0b9b3d1af3e8d882f2d6a2406adda19324ba0694
2024-06-13 13:18:10 -07:00
Yu Zhang 44aceb88d0 Add a OnManualFlushScheduled callback in event listener (#12631)
Summary:
As titled. Also added the newest user-defined timestamp into the `MemTableInfo`. This can be a useful info in the callback.

Added some unit tests as examples for how users can use two separate approaches to allow manual flush / manual compactions to go through when the user-defined timestamps in memtable only feature is enabled. One approach relies on selectively increase cutoff timestamp in `OnMemtableSeal` callback when it's initiated by a manual flush. Another approach is to increase cutoff timestamp in `OnManualFlushScheduled` callback. The caveats of the approaches are also documented in the unit test.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12631

Reviewed By: ajkr

Differential Revision: D58260528

Pulled By: jowlyzhang

fbshipit-source-id: bf446d7140affdf124744095e0a179fa6e427532
2024-06-06 17:29:01 -07:00
Peter Dillinger 98393f0139 Fix Checkpoint hard link of inactive but unsynced WAL (#12731)
Summary:
Background: there is one active WAL file but there can be
several more WAL files in various states. Those other WALs are always
in a "flushed" state but could be on the `logs_` list not yet fully
synced. We currently allow any WAL that is not the active WAL to be
hard-linked when creating a Checkpoint, as although it might still be
open for write, we are not appending any more data to it.

The problem is that a created Checkpoint is supposed to be fully synced
on return of that function, and a hard-linked WAL in the state described
above might not be fully synced. (Through some prudence in https://github.com/facebook/rocksdb/issues/10083,
it would synced if using track_and_verify_wals_in_manifest=true.)

The fix is a step toward a long term goal of removing the need to query
the filesystem to determine WAL files and their state. (I consider it
dubious any time we independently read from or query metadata from a
file we have open for writing, as this makes us more susceptible to
FileSystem deficiencies or races.) More specifically:
* Detect which WALs might not be fully synced, according to our DBImpl
  metadata, and prevent hard linking those (with `trim_to_size=true`
  from `GetLiveFilesStorageInfo()`. And while we're at it, use our known
  flushed sizes for those WALs.
* To avoid a race between that and GetSortedWalFiles(), track a maximum
  needed WAL number for the Checkpoint/GetLiveFilesStorageInfo.
* Because of the level of consistency provided by those two, we no
  longer need to consider syncing as part of the FlushWAL in
  GetLiveFilesStorageInfo. (We determine the max WAL number consistent
  with the manifest file size, while holding DB mutex. Should make
  track_and_verify_wals_in_manifest happy.) This makes the premise of
  test PutRaceWithCheckpointTrackedWalSync obsolete (sync point callback
  no longer hit) so the test is removed, with crash test as backstop for
  related issues. See https://github.com/facebook/rocksdb/issues/10185

Stacked on https://github.com/facebook/rocksdb/issues/12729

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12731

Test Plan:
Expanded an existing test, which now fails before fix.
Also long runs of blackbox_crash_test with amplified checkpoint frequency.

Reviewed By: cbi42

Differential Revision: D58199629

Pulled By: pdillinger

fbshipit-source-id: 376e55f4a2b082cd2adb6408a41209de14422382
2024-06-05 17:40:09 -07:00
Yu Zhang fc59d8f9c6 Add public API `WriteWithCallback` to support custom callbacks (#12603)
Summary:
This PR adds a `DB::WriteWithCallback` API that does the same things as `DB::Write` while takes an argument `UserWriteCallback` to execute custom callback functions during the write.

We currently support two types of callback functions: `OnWriteEnqueued` and `OnWalWriteFinish`. The former is invoked   after the write is enqueued, and the later is invoked after WAL write finishes when applicable.

These callback functions are intended for users to use to improve synchronization between concurrent writes, their execution is on the write's critical path so it will impact the write's latency if not used properly. The documentation for the callback interface mentioned this and suggest user to keep these callback functions' implementation minimum.

Although transaction interfaces' writes doesn't yet allow user to specify such a user write callback argument, the `DBImpl::Write*` type of APIs do not differentiate between regular DB writes or writes coming from the transaction layer when it comes to supporting this `UserWriteCallback`. These callbacks works for all the write modes including: default write mode, Options.two_write_queues, Options.unordered_write, Options.enable_pipelined_write

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12603

Test Plan: Added unit test in ./write_callback_test

Reviewed By: anand1976

Differential Revision: D58044638

Pulled By: jowlyzhang

fbshipit-source-id: 87a84a0221df8f589ec8fc4d74597e72ce97e4cd
2024-05-31 19:30:19 -07:00
Peter Dillinger 7127119ae9 Refactor SyncWAL and SyncClosedLogs for code sharing (#12707)
Summary:
These functions were very similar and did not make sense for maintaining separately. This is not a pure refactor but I think bringing the behaviors closer together should reduce long term risk of unintentionally divergent behavior. This change is motivated by some forthcoming WAL handling fixes for Checkpoint and Backups.

* Sync() is always used on closed WALs, like the old SyncClosedWals. SyncWithoutFlush() is only used on the active (maybe) WAL. Perhaps SyncWithoutFlush() should be used whenever available, but I don't know which is preferred, as the previous state of the code was inconsistent.
* Syncing the WAL dir is selective based on need, like old SyncWAL, rather than done always like old SyncClosedLogs. This could be a performance improvement that was never applied to SyncClosedLogs but now is. We might still sync the dir more times than necessary in the case of parallel SyncWAL variants, but on a good FileSystem that's probably not too different performance-wise from us implementing something to have threads wait on each other.

Cosmetic changes:

* Rename internal function SyncClosedLogs to SyncClosedWals
* Merging the sync points into the common implementation between the two entry points isn't pretty, but should be fine.

Recommended follow-up:

* Clean up more confusing naming like log_dir_synced_

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12707

Test Plan: existing tests

Reviewed By: anand1976

Differential Revision: D57870856

Pulled By: pdillinger

fbshipit-source-id: 5455fba016d25dd5664fa41b253f18db2ca8919a
2024-05-30 14:53:13 -07:00
Peter Dillinger d2ef70872f Rename, deprecate `LogFile` and `VectorLogPtr` (#12695)
Summary:
These names are confusing with `Logger` etc. so moving to `WalFile` etc.

Other small, related name refactorings.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12695

Test Plan: Left most unit tests using old names as an API compatibility test. Non-test code compiles with deprecated names removed. No functional changes.

Reviewed By: ajkr

Differential Revision: D57747458

Pulled By: pdillinger

fbshipit-source-id: 7b77596b9c20d865d43b9dc66c30c8bd2b3b424f
2024-05-28 09:24:49 -07:00
Peter Dillinger d89ab23bec Disallow memtable flush and sst ingest while WAL is locked (#12652)
Summary:
We recently noticed that some memtable flushed and file
ingestions could proceed during LockWAL, in violation of its stated
contract. (Note: we aren't 100% sure its actually needed by MySQL, but
we want it to be in a clean state nonetheless.)

Despite earlier skepticism that this could be done safely (https://github.com/facebook/rocksdb/issues/12666), I
found a place to wait to wait for LockWAL to be cleared before allowing
these operations to proceed: WaitForPendingWrites()

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12652

Test Plan:
Added to unit tests. Extended how db_stress validates LockWAL
and re-enabled combination of ingestion and LockWAL in crash test, in
follow-up to https://github.com/facebook/rocksdb/issues/12642

Ran blackbox_crash_test for a long while with relevant features
amplified.

Suggested follow-up: fix FaultInjectionTestFS to report file sizes
consistent with what the user has requested to be flushed.

Reviewed By: jowlyzhang

Differential Revision: D57622142

Pulled By: pdillinger

fbshipit-source-id: aef265fce69465618974b4ec47f4636257c676ce
2024-05-21 10:17:34 -07:00
anand76 0ed93552f4 Implement obsolete file deletion (GC) in follower (#12657)
Summary:
This PR implements deletion of obsolete files in a follower RocksDB instance. The follower tails the leader's MANIFEST and creates links to newly added SST files. These links need to be deleted once those files become obsolete in order to reclaim space. There are three cases to be considered -
1. New files added and links created, but the Version could not be installed due to some missing files. Those links need to be preserved so a subsequent catch up attempt can succeed. We insert the next file number in the `VersionSet` to `pending_outputs_` to prevent their deletion.
2. Files deleted from the previous successfully installed `Version`. These are deleted as usual in `PurgeObsoleteFiles`.
3. New files added by a `VersionEdit` and deleted by a subsequent `VersionEdit`, both processed in the same catchup attempt. Links will be created for the new files when verifying a candidate `Version`. Those need to be deleted explicitly as they're never added to `VersionStorageInfo`, and thus not deleted by `PurgeObsoleteFiles`.

Test plan -
New unit tests in `db_follower_test`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12657

Reviewed By: jowlyzhang

Differential Revision: D57462697

Pulled By: anand1976

fbshipit-source-id: 898f15570638dd4930f839ffd31c560f9cb73916
2024-05-17 19:13:33 -07:00
Yu Zhang c110091d36 Support read timestamp in ldb (#12641)
Summary:
As titled. Also updated sst_dump to print out user-defined timestamp separately and in human readable format.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12641

Test Plan:
manually tested:
Example success run:
./ldb --db=$TEST_DB multi_get_entity 0x00000000000000950000000000000120 --key_hex --column_family=7  --read_timestamp=1115613683797942 --value_hex
0x00000000000000950000000000000120 ==> :0x0E0000000A0B080906070405020300011E1F1C1D1A1B181916171415121310112E2F2C2D2A2B282926272425222320213E3F3C3D3A3B383936373435323330314E4F4C4D4A4B484946474445424340415E5F5C5D5A5B58595657545552535051
Example failed run:
Failed: GetEntity failed: Invalid argument: column family enables user-defined timestamp while --read_timestamp is not a valid uint64 value.

sst_dump print out:
'000000000000015D000000000000012B000000000000013B|timestamp:1113554493256671' seq:2330405, type:1 => 010000000504070609080B0A0D0C0F0E111013121514171619181B1A1D1C1F1E212023222524272629282B2A2D2C2F2E313033323534373639383B3A3D3C3F3E

Reviewed By: ltamasi

Differential Revision: D57297006

Pulled By: jowlyzhang

fbshipit-source-id: 8486d91468e4f6c0d42dca3c9629f1c45a92bf5a
2024-05-13 15:43:12 -07:00
Levi Tamasi 97e70906fa Improve the sanity checks in (Multi)GetEntity and friends (#12630)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12630

The patch cleans up, improves, and brings into sync (to the extent possible without API signature changes) the sanity checks around the `GetEntity` / `MultiGetEntity` family of APIs, including the read-your-own-writes (`WriteBatchWithIndex`) and transaction layers. The checks are centralized in two main sets of entry points, namely in `DB(Impl)` and the "main" `GetEntityFromBatchAndDB` / `MultiGetEntityFromBatchAndDB` overloads in `WriteBatchWithIndex`. This eliminates the need to duplicate the checks in the transaction classes.

Reviewed By: jaykorean

Differential Revision: D57125741

fbshipit-source-id: 4dd059ef644a9b173fbba767538943397e4cc6cd
2024-05-09 12:25:19 -07:00
Yu Zhang 241253053a Fix delete obsolete files on recovery not rate limited (#12590)
Summary:
This PR fix the issue that deletion of obsolete files during DB::Open are not rate limited.

The root cause is slow deletion is disabled if trash/db size ratio exceeds the configured `max_trash_db_ratio` d610e14f93/include/rocksdb/sst_file_manager.h (L126) however, the current handling in DB::Open starts with tracking nothing but the obsolete files. This will make the ratio always look like it's 1.

In order for the deletion rate limiting logic to work properly, we should only start deleting files after `SstFileManager` has finished tracking the whole DB, so the main fix is to move these two places that attempts to delete file after the tracking are done: 1) the `DeleteScheduler::CleanupDirectory` call in `SanitizeOptions`, 2) the `DB::DeleteObsoleteFiles` call.

There are some other aesthetic changes like refactoring collecting all the DB paths into a function, rename `DBImp::DeleteUnreferencedSstFiles` to `DBImpl:: MaybeUpdateNextFileNumber` as it doesn't actually delete the files.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12590

Test Plan: Added unit test and verified with manual testing

Reviewed By: anand1976

Differential Revision: D56830519

Pulled By: jowlyzhang

fbshipit-source-id: 8a38a21b1ea11c5371924f2b88663648f7a17885
2024-05-01 12:26:54 -07:00
anand76 e36b0a2da4 Fix corruption bug when recycle_log_file_num changed from 0 (#12591)
Summary:
When `recycle_log_file_num` is changed from 0 to non-zero and the DB is reopened, any log files from the previous session that are still alive get reused. However, the WAL records in those files are not in the recyclable format. If one of those files is reused and is empty, a subsequent re-open, in `RecoverLogFiles`, can replay those records and insert stale data into the memtable. Another manifestation of this is an assertion failure `first_seqno_ == 0 || s >= first_seqno_` in `rocksdb::MemTable::Add`.

We could fix this by either 1) Writing a special record when reusing a log file, or 2) Implement more rigorous checking in `RecoverLogFiles` to ensure we don't replay stale records, or 3) Not reuse files created by a previous DB session. We choose option 3 as its the simplest, and flipping `recycle_log_file_num` is expected to be a rare event.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12591

Test Plan: 1. Add a unit test to verify the bug and fix

Reviewed By: jowlyzhang

Differential Revision: D56655812

Pulled By: anand1976

fbshipit-source-id: aa3a26b4a5e892d39a54b5a0658233cbebebac87
2024-04-29 12:25:00 -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
anand76 d8fb849b7e Basic RocksDB follower implementation (#12540)
Summary:
A basic implementation of RocksDB follower mode, which opens a remote database (referred to as leader) on a distributed file system by tailing its MANIFEST. It leverages the secondary instance mode, but is different in some key ways -
1. It has its own directory with links to the leader's database
2. Periodically refreshes itself
3. (Future) Snapshot support
4. (Future) Garbage collection of obsolete links
5. (Long term) Memtable replication

There are two main classes implementing this functionality - `DBImplFollower` and `OnDemandFileSystem`. The former is derived from `DBImplSecondary`. Similar to `DBImplSecondary`, it implements recovery and catch up through MANIFEST tailing using the `ReactiveVersionSet`, but does not consider logs. In a future PR, we will implement memtable replication, which will eliminate the need to catch up using logs. In addition, the recovery and catch-up tries to avoid directory listing as repeated metadata operations are expensive.

The second main piece is the `OnDemandFileSystem`, which plugs in as an `Env` for the follower instance and creates the illusion of the follower directory as a clone of the leader directory. It creates links to SSTs on first reference. When the follower tails the MANIFEST and attempts to create a new `Version`, it calls `VerifyFileMetadata` to verify the size of the file, and optionally the unique ID of the file. During this process, links are created which prevent the underlying files from getting deallocated even if the leader deletes the files.

TODOs: Deletion of obsolete links, snapshots, robust checking against misconfigurations, better observability etc.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12540

Reviewed By: jowlyzhang

Differential Revision: D56315718

Pulled By: anand1976

fbshipit-source-id: d19e1aca43a6af4000cb8622a718031b69ebd97b
2024-04-19 19:13:31 -07:00
Jay Huh 909ff2c208 MultiCFSnapshot Refactor - separate multiget key range info from CFD & superversion info (#12561)
Summary:
While implementing MultiCFIterators (CoalescingIterator and AttributeGroupIterator), we found that the existing `NewIterators()` API does not ensure a uniform view of the DB across all column families. The `NewIterators()` function is utilized to generate child iterators for the MultiCfIterators, and it's expected that all child iterators maintain a consistent view of the DB.

For example, within the loop where the super version for each CF is being obtained, if a CF undergoes compaction after the super versions for previous CFs have already been retrieved, we lose the consistency in the view of the CFs for the iterators due to the API not under a db mutex.

This preliminary refactoring of `MultiCFSnapshot` aims to address this issue in the `NewIterators()` API in the later PR. Currently, `MultiCFSnapshot` is used to achieve a consistent view across CFs in `MultiGet`. The `MultiGetColumnFamilyData` contains MultiGet-specific information that can be decoupled from the cfd and sv, allowing `MultiCFSnapshot` to be used in other places.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12561

Test Plan:
**Existing Unit Tests for `MultiCFSnapshot()`**

```
./db_basic_test -- --gtest_filter="*MultiGet*"
```

**Performance Test**

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 :       4.760 micros/op 210072 ops/sec 4.760 seconds 1000000 operations; (0 of 1000000 found)
```

After the change
```
DB path: [/dev/shm/db_bench/dbbench]
multireadrandom :       4.593 micros/op 217727 ops/sec 4.593 seconds 1000000 operations; (0 of 1000000 found)
```

Reviewed By: anand1976

Differential Revision: D56309422

Pulled By: jaykorean

fbshipit-source-id: 7a9164d12c810b6c2d2db062827fcc4a36cbc77b
2024-04-18 20:11:01 -07:00
anand76 97991960e9 Retry DB::Open upon a corruption detected while reading the MANIFEST (#12518)
Summary:
This PR is a counterpart of https://github.com/facebook/rocksdb/issues/12427 . On file systems that support storage level data checksum and reconstruction, retry opening the DB if a corruption is detected when reading the MANIFEST. This could be done in `log::Reader`, but its a little complicated since the sequential file would have to be reopened in order to re-read the same data, and we may miss some subtle corruptions that don't result in checksum mismatch. The approach chosen here instead is to make the decision to retry in `DBImpl::Recover`, based on either an explicit corruption in the MANIFEST file, or missing SST files due to bad data in the MANIFEST.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12518

Reviewed By: ajkr

Differential Revision: D55932155

Pulled By: anand1976

fbshipit-source-id: 51755a29b3eb14b9d8e98534adb2e7d54b12ced9
2024-04-18 17:36:33 -07:00
Jay Huh d34712e0ac MultiCfIterator - AttributeGroupIter Impl & CoalescingIter Optimization (#12534)
Summary:
Continuing from the previous MultiCfIterator Implementations - (https://github.com/facebook/rocksdb/issues/12422, https://github.com/facebook/rocksdb/issues/12480 #12465), this PR completes the `AttributeGroupIterator` by implementing `AttributeGroupIteratorImpl::AddToAttributeGroups()`. While implementing the `AttributeGroupIterator`, we had to make some changes in `MultiCfIteratorImpl` and found an opportunity to improve `Coalesce()` in `CoalescingIterator`.

Lifting `UNDER CONSTRUCTION - DO NOT USE` comment by replacing it with `EXPERIMENTAL`

Here are some implementation details:
- `IteratorAttributeGroups` is introduced to avoid having to copy all `WideColumn` objects during iteration.
- `PopulateIterator()` no longer advances non-top iterators that have the same key as the top iterator in the heap.
- `AdvanceIterator()` needs to advance the non-top iterators when they have the same key as the top iterator in the heap.
- Instead of populating one by one, `PopulateIterator()` now collects all items with the same key and calls `populate_func(items)` at once.
- This allowed optimization in `Coalesce()` such that we no longer do K-1 rounds of 2-way merge, but do one K-way merge instead.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12534

Test Plan:
Uncommented the assertions in `verifyAttributeGroupIterator()`

```
./multi_cf_iterator_test
```

Reviewed By: ltamasi

Differential Revision: D56089019

Pulled By: jaykorean

fbshipit-source-id: 6b0b4247e221f69b40b147d41492008cc9b15054
2024-04-16 08:45:38 -07:00
Jay Huh 58a98bded9 MultiCFIterator Refactor - CoalescingIterator & AttributeGroupIterator (#12480)
Summary:
There are a couple of reasons to modify the current implementation of the MultiCfIterator, which implements the generic `Iterator` interface.
- The default behavior of `value()`/`columns()` returning data from different Column Families for different keys can be prone to errors, even though there might be valid use cases where users do not care about the origin of the value/columns.
- The `attribute_groups()` API, which is not yet implemented, will not be useful for a single-CF iterator.

In this PR, we are implementing the following changes:
- `IteratorBase` introduced, which includes all basic iterator functions except `value()` and `columns()`.
- `Iterator`, which now inherits from `IteratorBase`, includes `value()` and `columns()`.
- New public interface `AttributeGroupIterator` inherits from `IteratorBase` and additionally includes `attribute_groups()` (to be implemented).
- Renamed former `MultiCfIterator` to `CoalescingIterator` which inherits from `Iterator`
- Existing MultiCfIteratorTest has been split into two - `CoalescingIteratorTest` and `AttributeGroupIteratorTest`.
- Moved AttributeGroup related code from `wide_columns.h` to a new file, `attribute_groups.h`.

Some Implementation Details
- `MultiCfIteratorImpl` takes two functions - `populate_func` and `reset_func` and use them to populate `value_` and `columns_` in CoalescingIterator and `attribute_groups_` in AttributeGroupIterator. In CoalescingIterator, populate_func is `Coalesce()`, in AttributeGroupIterator populate_func is `AddToAttributeGroups()`. `reset_func` clears populated value_, columns_ and attribute_groups_ accordingly.
- `Coalesce()` merge sorts columns from multiple CFs when a key exists in more than on CFs. column that appears in later CF overwrites the prior ones.

For example, if CF1 has `"key_1" ==> {"col_1": "foo",  "col_2", "baz"}` and CF2 has `"key_1" ==> {"col_2": "quux", "col_3", "bla"}`, and when the iterator is at `key_1`, `columns()` will return `{"col_1": "foo", "col_2", "quux", "col_3", "bla"}`

In this example, `value()` will be empty, because none of them have values for `kDefaultColumnName`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12480

Test Plan:
## Unit Test
```
./multi_cf_iterator_test
```

## Performance Test

To make sure this change does not impact existing `Iterator` performance

**Build**
```
$> make -j64 release
```
**Setup**
```
$> TEST_TMPDIR=/dev/shm/db_bench ./db_bench -benchmarks="filluniquerandom" -key_size=32 -value_size=512 -num=1000000 -compression_type=none
```
**Run**
```
TEST_TMPDIR=/dev/shm/db_bench ./db_bench -use_existing_db=1 -benchmarks="newiterator,seekrandom" -cache_size=10485760000
```

**Before the change**
```
DB path: [/dev/shm/db_bench/dbbench]
newiterator  :       0.519 micros/op 1927904 ops/sec 0.519 seconds 1000000 operations;
DB path: [/dev/shm/db_bench/dbbench]
seekrandom   :       5.302 micros/op 188589 ops/sec 5.303 seconds 1000000 operations; (0 of 1000000 found)
```
**After the change**
```
DB path: [/dev/shm/db_bench/dbbench]
newiterator  :       0.497 micros/op 2011012 ops/sec 0.497 seconds 1000000 operations;
DB path: [/dev/shm/db_bench/dbbench]
seekrandom   :       5.252 micros/op 190405 ops/sec 5.252 seconds 1000000 operations; (0 of 1000000 found)
```

Reviewed By: ltamasi

Differential Revision: D55353909

Pulled By: jaykorean

fbshipit-source-id: 8d7786ffee09e022261ce34aa60e8633685e1946
2024-04-11 11:34:04 -07:00
Peter Dillinger b515a5db3f Replace ScopedArenaIterator with ScopedArenaPtr<InternalIterator> (#12470)
Summary:
ScopedArenaIterator is not an iterator. It is a pointer wrapper. And we don't need a custom implemented pointer wrapper when std::unique_ptr can be instantiated with what we want.

So this adds ScopedArenaPtr<T> to replace those uses.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12470

Test Plan: CI (including ASAN/UBSAN)

Reviewed By: jowlyzhang

Differential Revision: D55254362

Pulled By: pdillinger

fbshipit-source-id: cc96a0b9840df99aa807f417725e120802c0ae18
2024-03-22 13:40:42 -07:00
Yu Zhang f2546b6623 Support returning write unix time in iterator property (#12428)
Summary:
This PR adds support to return data's approximate unix write time in the iterator property API. The general implementation is:
1) If the entry comes from a SST file, the sequence number to time mapping recorded in that file's table properties will be used to deduce the entry's write time from its sequence number. If no such recording is available, `std::numeric_limits<uint64_t>::max()` is returned to indicate the write time is unknown except if the entry's sequence number is zero, in which case, 0 is returned. This also means that even if `preclude_last_level_data_seconds` and `preserve_internal_time_seconds` can be toggled off between DB reopens, as long as the SST file's table property has the mapping available, the entry's write time can be deduced and returned.

2) If the entry comes from memtable, we will use the DB's sequence number to write time mapping to do similar things. A copy of the DB's seqno to write time mapping is kept in SuperVersion to allow iterators to have lock free access. This also means a new `SuperVersion` is installed each time DB's seqno to time mapping updates, which is originally proposed by Peter in  https://github.com/facebook/rocksdb/issues/11928 . Similarly, if the feature is not enabled, `std::numeric_limits<uint64_t>::max()` is returned to indicate the write time is unknown.

Needed follow up:
1) The write time for `kTypeValuePreferredSeqno` should be special cased, where it's already specified by the user, so we can directly return it.

2) Flush job can be updated to use DB's seqno to time mapping copy in the SuperVersion.

3) Handle the case when `TimedPut` is called with a write time that is `std::numeric_limits<uint64_t>::max()`. We can make it a regular `Put`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12428

Test Plan: Added unit test

Reviewed By: pdillinger

Differential Revision: D54967067

Pulled By: jowlyzhang

fbshipit-source-id: c795b1b7ec142e09e53f2ed3461cf719833cb37a
2024-03-15 15:37:37 -07:00
Jay Huh 3412195367 Introduce MultiCfIterator (#12153)
Summary:
This PR introduces a new implementation of `Iterator` via a new public API called `NewMultiCfIterator()`. The new API takes a vector of column family handles to build a cross-column-family iterator, which internally maintains multiple `DBIter`s as child iterators from a consistent database state. When a key exists in multiple column families, the iterator selects the value (and wide columns) from the first column family containing the key, following the order provided in the `column_families` parameter. Similar to the merging iterator, a min heap is used to iterate across the child iterators. Backward iteration and direction change functionalities will be implemented in future PRs.

The comparator used to compare keys across different column families will be derived from the iterator of the first column family specified in `column_families`. This comparator will be checked against the comparators from all other column families that the iterator will traverse. If there's a mismatch with any of the comparators, the initialization of the iterator will fail.

Please note that this PR is not enough for users to start using `MultiCfIterator`. The `MultiCfIterator` and related APIs are still marked as "**DO NOT USE - UNDER CONSTRUCTION**". This PR is just the first of many PRs that will follow soon.

This PR includes the following:
- Introduction and partial implementation of the `MultiCfIterator`, which implements the generic `Iterator` interface. The implementation includes the construction of the iterator, `SeekToFirst()`, `Next()`, `Valid()`, `key()`, `value()`, and `columns()`.
- Unit tests to verify iteration across multiple column families in two distinct scenarios: (1) keys are unique across all column families, and (2) the same keys exist in multiple column families.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12153

Reviewed By: pdillinger

Differential Revision: D52308697

Pulled By: jaykorean

fbshipit-source-id: b03e69f13b40af5a8f0598d0f43a0bec01ef8294
2024-03-05 10:22:43 -08:00
Jay Huh c00c16855d Access DBImpl* and CFD* by CFHImpl* in Iterators (#12395)
Summary:
In the current implementation of iterators, `DBImpl*` and `ColumnFamilyData*` are held in `DBIter` and `ArenaWrappedDBIter` for two purposes: tracing and Refresh() API. With the introduction of a new iterator called MultiCfIterator in PR https://github.com/facebook/rocksdb/issues/12153 , which is a cross-column-family iterator that maintains multiple DBIters as child iterators from a consistent database state, we need to make some changes to the existing implementation. The new iterator will still be exposed through the generic Iterator interface with an additional capability to return AttributeGroups (via `attribute_groups()`) which is a list of wide columns grouped by column family. For more information about AttributeGroup, please refer to previous PRs:  https://github.com/facebook/rocksdb/issues/11925 #11943, and https://github.com/facebook/rocksdb/issues/11977.

To be able to return AttributeGroup in the default single CF iterator created, access to `ColumnFamilyHandle*` within `DBIter` is necessary. However, this is not currently available in `DBIter`. Since `DBImpl*` and `ColumnFamilyData*` can be easily accessed via `ColumnFamilyHandleImpl*`, we have decided to replace the pointers to `ColumnFamilyData` and `DBImpl` in `DBIter` with a pointer to `ColumnFamilyHandleImpl`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12395

Test Plan:
# Summary

In the current implementation of iterators, `DBImpl*` and `ColumnFamilyData*` are held in `DBIter` and `ArenaWrappedDBIter` for two purposes: tracing and Refresh() API. With the introduction of a new iterator called MultiCfIterator in PR #12153 , which is a cross-column-family iterator that maintains multiple DBIters as child iterators from a consistent database state, we need to make some changes to the existing implementation. The new iterator will still be exposed through the generic Iterator interface with an additional capability to return AttributeGroups (via `attribute_groups()`) which is a list of wide columns grouped by column family. For more information about AttributeGroup, please refer to previous PRs:  #11925 #11943, and #11977.

To be able to return AttributeGroup in the default single CF iterator created, access to `ColumnFamilyHandle*` within `DBIter` is necessary. However, this is not currently available in `DBIter`. Since `DBImpl*` and `ColumnFamilyData*` can be easily accessed via `ColumnFamilyHandleImpl*`, we have decided to replace the pointers to `ColumnFamilyData` and `DBImpl` in `DBIter` with a pointer to `ColumnFamilyHandleImpl`.

# Test Plan

There should be no behavior changes. Existing tests and CI for the correctness tests.

**Test for Perf Regression**
Build
```
$> make -j64 release
```
Setup
```
$> TEST_TMPDIR=/dev/shm/db_bench ./db_bench -benchmarks="filluniquerandom" -key_size=32 -value_size=512 -num=1000000 -compression_type=none
```
Run
```
TEST_TMPDIR=/dev/shm/db_bench ./db_bench -use_existing_db=1 -benchmarks="newiterator,seekrandom" -cache_size=10485760000
```

Before the change
```
DB path: [/dev/shm/db_bench/dbbench]
newiterator  :       0.552 micros/op 1810157 ops/sec 0.552 seconds 1000000 operations;
DB path: [/dev/shm/db_bench/dbbench]
seekrandom   :       4.502 micros/op 222143 ops/sec 4.502 seconds 1000000 operations; (0 of 1000000 found)
```
After the change
```
DB path: [/dev/shm/db_bench/dbbench]
newiterator  :       0.520 micros/op 1924401 ops/sec 0.520 seconds 1000000 operations;
DB path: [/dev/shm/db_bench/dbbench]
seekrandom   :       4.532 micros/op 220657 ops/sec 4.532 seconds 1000000 operations; (0 of 1000000 found)
```

Reviewed By: pdillinger

Differential Revision: D54332713

Pulled By: jaykorean

fbshipit-source-id: b28d897ad519e58b1ca82eb068a6319544a4fae5
2024-03-01 10:28:20 -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
Yu Zhang 4bea83aa44 Remove the force mode for EnableFileDeletions API (#12337)
Summary:
There is no strong reason for user to need this mode while on the other hand, its behavior is destructive.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12337

Reviewed By: hx235

Differential Revision: D53630393

Pulled By: jowlyzhang

fbshipit-source-id: ce94b537258102cd98f89aa4090025663664dd78
2024-02-13 18:36:25 -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
Peter Dillinger 4e60663b31 Remove unnecessary, confusing 'extern' (#12300)
Summary:
In C++, `extern` is redundant in a number of cases:
* "Global" function declarations and definitions
* "Global" variable definitions when already declared `extern`

For consistency and simplicity, I've removed these in code that *we own*. In a couple of cases, I removed obsolete declarations, and for MagicNumber constants, I have consolidated the declarations into a header file (format.h)
as standard best practice would prescribe.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12300

Test Plan: no functional changes, CI

Reviewed By: ajkr

Differential Revision: D53148629

Pulled By: pdillinger

fbshipit-source-id: fb8d927959892e03af09b0c0d542b0a3b38fd886
2024-01-29 10:38:08 -08:00
Peter Dillinger f046a8f617 Deflake ColumnFamilyTest.WriteStallSingleColumnFamily (#12294)
Summary:
https://github.com/facebook/rocksdb/issues/12267 apparently introduced a data race in test code where a background read of estimated_compaction_needed_bytes while holding the DB mutex could race with forground write for testing purposes. This change adds the DB mutex to those writes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12294

Test Plan: 1000 TSAN runs of test (massively fails before change, passes after)

Reviewed By: ajkr

Differential Revision: D53095483

Pulled By: pdillinger

fbshipit-source-id: 13fcb383ebad313dabe39eb8f9085c34d370b54a
2024-01-25 14:40:18 -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
Jay Huh 8b8f6c63ef ColumnFamilyHandle Nullcheck in GetEntity and MultiGetEntity (#12057)
Summary:
- Add missing null check for ColumnFamilyHandle in `GetEntity()`
- `FailIfCfHasTs()` now returns `Status::InvalidArgument()` if `column_family` is null. `MultiGetEntity()` can rely on this for cfh null check.
- Added `DeleteRange` API using Default Column Family to be consistent with other major APIs (This was also causing Java Test failure after the `FailIfCfHasTs()` change)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12057

Test Plan:
- Updated `DBWideBasicTest::GetEntityAsPinnableAttributeGroups` to include null CF case
- Updated `DBWideBasicTest::MultiCFMultiGetEntityAsPinnableAttributeGroups` to include null CF case

Reviewed By: jowlyzhang

Differential Revision: D51167445

Pulled By: jaykorean

fbshipit-source-id: 1c1e44fd7b7df4d2dc3bb2d7d251da85bad7d664
2023-11-13 14:30:04 -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
Jay Huh 2adef5367a AttributeGroups - PutEntity Implementation (#11977)
Summary:
Write Path for AttributeGroup Support. The new `PutEntity()` API uses `WriteBatch` and atomically writes WideColumns entities in multiple Column Families.

Combined the release note from PR https://github.com/facebook/rocksdb/issues/11925

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11977

Test Plan:
- `DBWideBasicTest::MultiCFMultiGetEntityAsPinnableAttributeGroups` updated
- `WriteBatchTest::AttributeGroupTest` added
- `WriteBatchTest::AttributeGroupSavePointTest` added

Reviewed By: ltamasi

Differential Revision: D50457122

Pulled By: jaykorean

fbshipit-source-id: 4997b265e415588ce077933082dcd1ac3eeae2cd
2023-11-06 16:52:51 -08:00
Jay Huh 0ecfc4fbb4 AttributeGroups - GetEntity Implementation (#11943)
Summary:
Implementation of `GetEntity()` API that returns wide-column entities as AttributeGroups from multiple column families for a single key. Regarding the definition of Attribute groups, please see the detailed example description in PR https://github.com/facebook/rocksdb/issues/11925

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11943

Test Plan:
- `DBWideBasicTest::GetEntityAsPinnableAttributeGroups` added

will enable the new API in the `db_stress` after merging

Reviewed By: ltamasi

Differential Revision: D50195794

Pulled By: jaykorean

fbshipit-source-id: 218d54841ac7e337de62e13b1233b0a99bd91af3
2023-11-06 15:04:41 -08:00
Yu Zhang 60df39e530 Rate limiting stale sst files' deletion during recovery (#12016)
Summary:
As titled. If SstFileManager is available, deleting stale sst files will be delegated to it so it can be rate limited.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12016

Reviewed By: hx235

Differential Revision: D50670482

Pulled By: jowlyzhang

fbshipit-source-id: bde5b76ea1d98e67f6b4f08bfba3db48e46aab4e
2023-10-28 09:50:52 -07:00
Peter Dillinger 4155087746 Use manifest to persist pre-allocated seqnos (#11995)
Summary:
... and other fixes for crash test after https://github.com/facebook/rocksdb/issues/11922.
* When pre-allocating sequence numbers for establishing a time history, record that last sequence number in the manifest so that it is (most likely) restored on recovery even if no user writes were made or were recovered (e.g. no WAL).
* When pre-allocating sequence numbers for establishing a time history, only do this for actually new DBs.
* Remove the feature that ensures non-zero sequence number on creating the first column family with preserve/preclude option after initial DB::Open. Until fixed in a way compatible with the crash test, this creates a gap where some data written with active preserve/preclude option won't have a known associated time.

Together, these ensure we don't upset the crash test by manipulating sequence numbers after initial DB creation (esp when re-opening with different options). (The crash test expects that the seqno after re-open corresponds to a known point in time from previous crash test operation, matching an expected DB state.)

Follow-up work:
* Re-fill the gap to ensure all data written under preserve/preclude settings have a known time estimate.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11995

Test Plan:
Added to unit test SeqnoTimeTablePropTest.PrePopulateInDB

Verified fixes two crash test scenarios:
## 1st reproducer
First apply
```
 diff --git a/db_stress_tool/expected_state.cc b/db_stress_tool/expected_state.cc
index b483e154c..ef63b8d6c 100644
 --- a/db_stress_tool/expected_state.cc
+++ b/db_stress_tool/expected_state.cc
@@ -333,6 +333,7 @@ Status FileExpectedStateManager::SaveAtAndAfter(DB* db) {
     s = NewFileTraceWriter(Env::Default(), soptions, trace_file_path,
                            &trace_writer);
   }
+  if (getenv("CRASH")) assert(false);
   if (s.ok()) {
     TraceOptions trace_opts;
     trace_opts.filter |= kTraceFilterGet;
```

Then
```
mkdir -p /dev/shm/rocksdb_test/rocksdb_crashtest_expected
mkdir -p /dev/shm/rocksdb_test/rocksdb_crashtest_whitebox
rm -rf /dev/shm/rocksdb_test/rocksdb_crashtest_*/*
CRASH=1 ./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=1 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --preserve_internal_time_seconds=36000
./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=0 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --preserve_internal_time_seconds=0
```

Without the fix you get
```
...
DB path: [/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox]
(Re-)verified 34 unique IDs
Error restoring historical expected values: Corruption: DB is older than any restorable expected state
```

## 2nd reproducer
First apply
```
 diff --git a/db_stress_tool/db_stress_test_base.cc b/db_stress_tool/db_stress_test_base.cc
index 62ddead7b..f2654980f 100644
 --- a/db_stress_tool/db_stress_test_base.cc
+++ b/db_stress_tool/db_stress_test_base.cc
@@ -1126,6 +1126,7 @@ void StressTest::OperateDb(ThreadState* thread) {
         // OPERATION write
         TestPut(thread, write_opts, read_opts, rand_column_families, rand_keys,
                 value);
+        if (getenv("CRASH")) assert(false);
       } else if (prob_op < del_bound) {
         assert(write_bound <= prob_op);
         // OPERATION delete
```

Then
```
rm -rf /dev/shm/rocksdb_test/rocksdb_crashtest_*/*
CRASH=1 ./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=1 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --disable_wal=1 --reopen=0 --preserve_internal_time_seconds=0
./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=0 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --disable_wal=1 --reopen=0 --preserve_internal_time_seconds=3600
```

Without the fix you get
```
DB path: [/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox]
(Re-)verified 34 unique IDs
db_stress: db_stress_tool/expected_state.cc:380: virtual rocksdb::{anonymous}::ExpectedStateTraceRecordHandler::~
ExpectedStateTraceRecordHandler(): Assertion `IsDone()' failed.
```

Reviewed By: jowlyzhang

Differential Revision: D50533346

Pulled By: pdillinger

fbshipit-source-id: 1056be45c5b9e537c8c601b28c4b27431a782477
2023-10-23 09:20:59 -07:00
Hui Xiao 0836a2b26d New tickers on deletion compactions grouped by reasons (#11957)
Summary:
Context/Summary: as titled

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11957

Test Plan: piggyback on existing tests; fixed a failed test due to adding new stats

Reviewed By: ajkr, cbi42

Differential Revision: D50294310

Pulled By: hx235

fbshipit-source-id: d99b97ebac41efc1bdeaf9ca7a1debd2927d54cd
2023-10-18 18:00:07 -07:00
Yu Zhang 933ee295f4 Fix a race condition between recovery and backup (#11955)
Summary:
A race condition between recovery and backup can happen with error messages like this:
```Failure in BackupEngine::CreateNewBackup with: IO error: No such file or directory: While opening a file for sequentially reading: /dev/shm/rocksdb_test/rocksdb_crashtest_whitebox/002653.log: No such file or directory```

PR https://github.com/facebook/rocksdb/issues/6949  introduced disabling file deletion during error handling of manifest IO errors. Aformentioned race condition is caused by this chain of event:

[Backup engine]     disable file deletion
[Recovery]              disable file deletion <= this is optional for the race condition, it may or may not get called
[Backup engine]     get list of file to copy/link
[Recovery]              force enable file deletion
....                            some files refered by backup engine get deleted
[Backup engine]    copy/link file <= error no file found

This PR fixes this with:
1) Recovery thread is currently forcing enabling file deletion as long as file deletion is disabled. Regardless of whether the previous error handling is for manifest IO error and that disabled it in the first place. This means it could incorrectly enabling file deletions intended by other threads like backup threads, file snapshotting threads. This PR does this check explicitly before making the call.

2) `disable_delete_obsolete_files_` is designed as a counter to allow different threads to enable and disable file deletion separately. The recovery thread currently does a force enable file deletion, because `ErrorHandler::SetBGError()` can be called multiple times by different threads when they receive a manifest IO error(details per PR https://github.com/facebook/rocksdb/issues/6949), resulting in `DBImpl::DisableFileDeletions` to be called multiple times too. Making a force enable file deletion call that resets the counter `disable_delete_obsolete_files_` to zero is a workaround for this. However, as it shows in the race condition, it can incorrectly suppress other threads like a backup thread's intention to keep the file deletion disabled. <strike>This PR adds a `std::atomic<int> disable_file_deletion_count_` to the error handler to track the needed counter decrease more precisely</strike>. This PR tracks and caps file deletion enabling/disabling in error handler.

3) for recovery, the section to find obsolete files and purge them was moved to be done after the attempt to enable file deletion. The actual finding and purging is more likely to happen if file deletion was previously disabled and get re-enabled now. An internal function `DBImpl::EnableFileDeletionsWithLock` was added to support change 2) and 3). Some useful logging was explicitly added to keep those log messages around.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11955

Test Plan: existing unit tests

Reviewed By: anand1976

Differential Revision: D50290592

Pulled By: jowlyzhang

fbshipit-source-id: 73aa8331ca4d636955a5b0324b1e104a26e00c9b
2023-10-17 13:18:04 -07:00
Peter Dillinger 2fd850c7eb Remove write queue synchronization from WriteOptionsFile (#11951)
Summary:
This has become obsolete with the new `options_mutex_` in https://github.com/facebook/rocksdb/pull/11929

* Remove now-unnecessary parameter from WriteOptionsFile
* Rename (and negate) other parameter for better clarity (the caller shouldn't tell the callee what the callee needs, just what the caller knows, provides, and requests)
* Move a ROCKS_LOG_WARN (I/O) in WriteOptionsFile to outside of holding DB mutex.
* Also *avoid* (but not always eliminate) write queue synchronization in SetDBOptions. Still needed if there was a change to WAL size limit or other configuration.
* Improve some comments

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11951

Test Plan: existing unit tests and TSAN crash test local run

Reviewed By: ajkr

Differential Revision: D50247904

Pulled By: pdillinger

fbshipit-source-id: 7dfe445c705ec013886a2adb7c50abe50d83af69
2023-10-16 08:58:47 -07:00
Jay Huh c9d8e6a5bf AttributeGroups - MultiGetEntity Implementation (#11925)
Summary:
Introducing the notion of AttributeGroup by adding the `MultiGetEntity()` API retrieving `PinnableAttributeGroups`.
An "attribute group" refers to a logical grouping of wide-column entities within RocksDB. These attribute groups are implemented using column families.

Users can store WideColumns in different CFs for various reasons (e.g. similar access patterns, same types, etc.). This new API `MultiGetEntity()` takes keys and `PinnableAttributeGroups` per key. `PinnableAttributeGroups` is just a list of `PinnableAttributeGroup`s in which we have `ColumnFamilyHandle*`, `Status`, and `PinnableWideColumns`.

Let's say a user stored "hot" wide columns in column family "hot_data_cf" and "cold" wide columns in column family "cold_data_cf" and all other columns in "common_cf".

Prior to this PR, if the user wants to query for two keys, "key_1" and "key_2" and but only interested in "common_cf" and "hot_data_cf" for "key_1", and "common_cf" and "cold_data_cf" for "key_2", the user would have to construct input like `keys = ["key_1", "key_1", "key_2", "key_2"]`, `column_families = ["common_cf", "hot_data_cf", "common_cf", "cold_data_cf"]` and get the flat list of `PinnableWideColumns` to find the corresponding <key,CF> combo.

With the new `MultiGetEntity()` introduced in this PR, users can now query only `["common_cf", "hot_data_cf"]` for `"key_1"`, and only `["common_cf", "cold_data_cf"]` for `"key_2"`. The user will get `PinnableAttributeGroups` for each key, and `PinnableAttributeGroups` gives a list of `PinnableAttributeGroup`s where the user can find column family and corresponding `PinnableWideColumns` and the `Status`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11925

Test Plan:
- `DBWideBasicTest::MultiCFMultiGetEntityAsPinnableAttributeGroups` added

will enable this new API in the `db_stress` in a separate PR

Reviewed By: ltamasi

Differential Revision: D50017414

Pulled By: jaykorean

fbshipit-source-id: 643611d1273c574bc81b94c6f5aeea24b40c4586
2023-10-13 15:58:03 -07:00
Changyu Bi 6e3429b8a6 Fix data race in accessing `recovery_in_prog_` (#11950)
Summary:
We saw the following TSAN stress test failure:
```
WARNING: ThreadSanitizer: data race (pid=17523)
  Write of size 1 at 0x7b8c000008b9 by thread T4243 (mutexes: write M0):
    #0 rocksdb::ErrorHandler::RecoverFromRetryableBGIOError() fbcode/internal_repo_rocksdb/repo/db/error_handler.cc:742 (db_stress+0x95f954) (BuildId: 35795dfb86ddc9c4f20ddf08a491f24d)
    https://github.com/facebook/rocksdb/issues/1 std:🧵:_State_impl<std:🧵:_Invoker<std::tuple<void (rocksdb::ErrorHandler::*)(), rocksdb::ErrorHandler*>>>::_M_run() fbcode/third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/invoke.h:74 (db_stress+0x95fc2b) (BuildId: 35795dfb86ddc9c4f20ddf08a491f24d)
    https://github.com/facebook/rocksdb/issues/2 execute_native_thread_routine /home/engshare/third-party2/libgcc/11.x/src/gcc-11.x/x86_64-facebook-linux/libstdc++-v3/src/c++11/../../../.././libstdc++-v3/src/c++11/thread.cc:82:18 (libstdc++.so.6+0xdf4e4) (BuildId: 452d1cdae868baeeb2fdf1ab140f1c219bf50c6e)

  Previous read of size 1 at 0x7b8c000008b9 by thread T22:
    #0 rocksdb::DBImpl::SyncClosedLogs(rocksdb::JobContext*, rocksdb::VersionEdit*) fbcode/internal_repo_rocksdb/repo/db/error_handler.h:76 (db_stress+0x84f69c) (BuildId: 35795dfb86ddc9c4f20ddf08a491f24d)
```

This is due to a data race in accessing `recovery_in_prog_`. This PR fixes it by accessing `recovery_in_prog_` under db mutex before calling `SyncClosedLogs()`. I think the original PR https://github.com/facebook/rocksdb/pull/10489 intended to clear the error if it's a recovery flush. So ideally we can also just check flush reason. I plan to keep a safer change in this PR and make that change in the future if needed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11950

Test Plan: check future TSAN stress test results.

Reviewed By: anand1976

Differential Revision: D50242255

Pulled By: cbi42

fbshipit-source-id: 0d487948ef9546b038a34460f3bb037f6e5bfc58
2023-10-12 16:55:25 -07:00
Peter Dillinger d010b02e86 Fix race in options taking effect (#11929)
Summary:
In follow-up to https://github.com/facebook/rocksdb/issues/11922, fix a race in functions like CreateColumnFamily and SetDBOptions where the DB reports one option setting but a different one is left in effect.

To fix, we can add an extra mutex around these rare operations. We don't want to hold the DB mutex during I/O or other slow things because of the many purposes it serves, but a mutex more limited to these cases should be fine.

I believe this would fix a write-write race in https://github.com/facebook/rocksdb/issues/10079 but not the read-write race.

Intended follow-up to this:
* Should be able to remove write thread synchronization from DBImpl::WriteOptionsFile

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11929

Test Plan:
Added two mini-stress style regression tests that fail with >1% probability before this change:
DBOptionsTest::SetStatsDumpPeriodSecRace
ColumnFamilyTest::CreateAndDropPeriodicRace

I haven't reproduced such an inconsistency between in-memory options and on disk latest options, but this change at least improves safety and adds a test anyway:
DBOptionsTest::SetStatsDumpPeriodSecRace

Reviewed By: ajkr

Differential Revision: D50024506

Pulled By: pdillinger

fbshipit-source-id: 1e99a9ed4d96fdcf3ac5061ec6b3cee78aecdda4
2023-10-12 10:05:23 -07:00
Peter Dillinger 1d5bddbc58 Bootstrap, pre-populate seqno_to_time_mapping (#11922)
Summary:
This change has two primary goals (follow-up to https://github.com/facebook/rocksdb/issues/11917, https://github.com/facebook/rocksdb/issues/11920):
* Ensure the DB seqno_to_time_mapping has entries that allow us to put a good time lower bound on any writes that happen after setting up preserve/preclude options (either in a new DB, new CF, SetOptions, etc.) and haven't yet aged out of that time window. This allows us to remove a bunch of work-arounds in tests.
* For new DBs using preserve/preclude options, automatically reserve some sequence numbers and pre-map them to cover the time span back to the preserve/preclude cut-off time. In the future, this will allow us to import data from another DB by key, value, and write time by assigning an appropriate seqno in this DB for that write time.

Note that the pre-population (historical mappings) does not happen if the original options at DB Open time do not have preserve/preclude, so it is recommended to create initial column families at that time with create_missing_column_families, to take advantage of this (future) feature. (Adding these historical mappings after DB Open would risk non-monotonic seqno_to_time_mapping, which is dubious if not dangerous.)

Recommended follow-up:
* Solve existing race conditions (not memory safety) where parallel operations like CreateColumnFamily or SetDBOptions could leave the wrong setting in effect.
* Make SeqnoToTimeMapping more gracefully handle a possible case in which too many mappings are added for the time range of concern. It seems like there could be cases where data is massively excluded from the cold tier because of entries falling off the front of the mapping list (causing GetProximalSeqnoBeforeTime() to return 0). (More investigation needed.)

No release note for the minor bug fix because this is still an experimental feature with limited usage.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11922

Test Plan: tests added / updated

Reviewed By: jowlyzhang

Differential Revision: D49956563

Pulled By: pdillinger

fbshipit-source-id: 92beb918c3a298fae9ca8e509717b1067caa1519
2023-10-06 08:21:21 -07:00
Peter Dillinger 141b872bd4 Improve efficiency of create_missing_column_families, light refactor (#11920)
Summary:
In preparing some seqno_to_time_mapping improvements, I found that some of the wrap-up work for creating column families was unnecessarily repeated in the case of DB::Open with create_missing_column_families. This change fixes that (`CreateColumnFamily()` -> `CreateColumnFamilyImpl()` in `DBImpl::Open()`), motivated by avoiding repeated calls to `RegisterRecordSeqnoTimeWorker()` but with the side benefit of avoiding repeated calls to `WriteOptionsFile()` for each CF.

Also in this change:
* Add a `Status::UpdateIfOk()` function for combining statuses in a common pattern
* Rename `max_time_duration` -> `min_preserve_seconds` (include units as much as possible)
* Improved comments in several places

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11920

Test Plan: tests added / updated

Reviewed By: jaykorean

Differential Revision: D49919147

Pulled By: pdillinger

fbshipit-source-id: 3d0318c1d070c842c5331da0a5b415caedc104f1
2023-10-04 14:14:22 -07:00
Andrew Kryczka 10fd05e394 Give retry flushes their own functions (#11903)
Summary:
Recovery triggers flushes for very different scenarios:

(1) `FlushReason::kErrorRecoveryRetryFlush`: a flush failed
(2) `FlushReason::kErrorRecovery`: a WAL may be corrupted
(3) `FlushReason::kCatchUpAfterErrorRecovery`: immutable memtables may have accumulated

The old code called called `FlushAllColumnFamilies()` in all cases, which uses manual flush functions: `AtomicFlushMemTables()` and `FlushMemTable()`. Forcing flushing the latest data on all CFs was useful for (2) because it ensures all CFs move past the corrupted WAL.

However, those code paths were overkill for (1) and (3), where only already-immutable memtables need to be flushed. There were conditionals to exclude some of the extraneous logic but I found there was still too much happening. For example, both of the manual flush functions enter the write thread. Entering the write thread is inconvenient because then we can't allow stalled writes to wait on a retrying flush to finish.

Instead of continuing down the path of adding more conditionals to the manual flush functions, this PR introduces a dedicated function for cases (1) and (3): `RetryFlushesForErrorRecovery()`. Also I cleaned up the manual flush functions to remove existing conditionals for these cases as they're no longer needed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11903

Reviewed By: cbi42

Differential Revision: D49693812

Pulled By: ajkr

fbshipit-source-id: 7630ac539b9d6c92052c13a3cdce53256134d990
2023-10-02 16:26:24 -07:00
Jay Huh 63ed868840 Offpeak in db option (#11893)
Summary:
RocksDB's primary function is to facilitate read and write operations. Compactions, while essential for minimizing read amplifications and optimizing storage, can sometimes compete with these primary tasks. Especially during periods of high read/write traffic, it's vital to ensure that primary operations receive priority, avoiding any potential disruptions or slowdowns. Conversely, during off-peak times when traffic is minimal, it's an opportune moment to tackle low-priority tasks like TTL based compactions, optimizing resource usage.

In this PR, we are incorporating the concept of off-peak time into RocksDB by introducing `daily_offpeak_time_utc` within the DBOptions. This setting is formatted as "HH:mm-HH:mm" where the first one before "-" is the start time and the second one is the end time, inclusive. It will be later used for resource optimization in subsequent PRs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11893

Test Plan:
- New Unit Test Added - `DBOptionsTest::OffPeakTimes`
- Existing Unit Test Updated - `OptionsTest`, `OptionsSettableTest`

Reviewed By: pdillinger

Differential Revision: D49714553

Pulled By: jaykorean

fbshipit-source-id: fef51ea7c0fede6431c715bff116ddbb567c8752
2023-09-29 13:03:39 -07:00
Peter Dillinger 02443dd93f Refactor, clean up, fixes, and more testing for SeqnoToTimeMapping (#11905)
Summary:
This change is before a planned DBImpl change to ensure all sufficiently recent sequence numbers since Open are covered by SeqnoToTimeMapping (bug fix with existing test work-arounds). **Intended follow-up**

However, I found enough issues with SeqnoToTimeMapping to warrant this PR first, including very small fixes in DB implementation related to API contract of SeqnoToTimeMapping.

Functional fixes / changes:
* This fixes some mishandling of boundary cases. For example, if the user decides to stop writing to DB, the last written sequence number would perpetually have its write time updated to "now" and would always be ineligible for migration to cold tier. Part of the problem is that the SeqnoToTimeMapping would return a seqno known to have been written before (immediately or otherwise) the requested time, but compaction_job.cc would include that seqno in the preserve/exclude set. That is fixed (in part) by adding one in compaction_job.cc
* That problem was worse because a whole range of seqnos could be updated perpetually with new times in SeqnoToTimeMapping::Append (if no writes to DB). That logic was apparently optimized for GetOldestApproximateTime (now GetProximalTimeBeforeSeqno), which is not used in production, to the detriment of GetOldestSequenceNum (now GetProximalSeqnoBeforeTime), which is used in production. (Perhaps plans changed during development?) This is fixed in Append to optimize for accuracy of GetProximalSeqnoBeforeTime. (Unit tests added and updated.)
* Related: SeqnoToTimeMapping did not have a clear contract about the relationships between seqnos and times, just the idea of a rough correspondence. Now the class description makes it clear that the write time of each recorded seqno comes before or at the associated time, to support getting best results for GetProximalSeqnoBeforeTime. And this makes it easier to make clear the contract of each API function.
  * Update `DBImpl::RecordSeqnoToTimeMapping()` to follow this ordering in gathering samples.

Some part of these changes has required an expanded test work-around for the problem (see intended follow-up above) that the DB does not immediately ensure recent seqnos are covered by its mapping. These work-arounds will be removed with that planned work.

An apparent compaction bug is revealed in
PrecludeLastLevelTest::RangeDelsCauseFileEndpointsToOverlap, so that test is disabled. Filed GitHub issue #11909

Cosmetic / code safety things (not exhaustive):
* Fix some confusing names.
  * `seqno_time_mapping` was used inconsistently in places. Now just `seqno_to_time_mapping` to correspond to class name.
  * Rename confusing `GetOldestSequenceNum` -> `GetProximalSeqnoBeforeTime` and `GetOldestApproximateTime` -> `GetProximalTimeBeforeSeqno`. Part of the motivation is that our times and seqnos here have the same underlying type, so we want to be clear about which is expected where to avoid mixing.
  * Rename `kUnknownSeqnoTime` to `kUnknownTimeBeforeAll` because the value is a bad choice for unknown if we ever add ProximalAfterBlah functions.
  * Arithmetic on SeqnoTimePair doesn't make sense except for delta encoding, so use better names / APIs with that in mind.
  * (OMG) Don't allow direct comparison between SeqnoTimePair and SequenceNumber. (There is no checking that it isn't compared against time by accident.)
  * A field name essentially matching the containing class name is a confusing pattern (`seqno_time_mapping_`).
  * Wrap calls to confusing (but useful) upper_bound and lower_bound functions to have clearer names and more code reuse.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11905

Test Plan: GetOldestSequenceNum (now GetProximalSeqnoBeforeTime) and TruncateOldEntries were lacking unit tests, despite both being used in production (experimental feature). Added those and expanded others.

Reviewed By: jowlyzhang

Differential Revision: D49755592

Pulled By: pdillinger

fbshipit-source-id: f72a3baac74d24b963c77e538bba89a7fc8dce51
2023-09-29 11:21:59 -07:00
Jay Huh cff6490bc4 Add IOActivity.kMultiGetEntity (#11842)
Summary:
- As a follow up from https://github.com/facebook/rocksdb/issues/11799, adding `Env::IOActivity::kMultiGetEntity` support to `DBImpl::MultiGetEntity()`.

## Minor Refactor
- Because both `DBImpl::MultiGet()` and `DBImpl::MultiGetEntity()` call `DBImpl::MultiGetCommon()` which later calls `DBImpl::MultiGetWithCallback()` where we check `Env::IOActivity::kMultiGet`, minor refactor was needed so that we don't check `Env::IOActivity::kMultiGet` for  `DBImpl::MultiGetEntity()`.
- I still see more areas for refactoring to avoid duplicate code of checking IOActivity and setting it when Unknown, but this will be addressed separately.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11842

Test Plan:
- Added the `ThreadStatus::OperationType::OP_MULTIGETENTITY` in `db_stress` to verify the pass-down IOActivity in a thread aligns with the actual activity the thread is doing.
```
python3 tools/db_crashtest.py blackbox --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 --duration=60 --interval=10
python3 tools/db_crashtest.py blackbox --simple --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 --duration=60 --interval=10
python3 tools/db_crashtest.py blackbox --cf_consistency --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 --duration=60 --interval=10
```

Reviewed By: ltamasi

Differential Revision: D49329575

Pulled By: jaykorean

fbshipit-source-id: 05198f1d3f92e6be3d42a3d184bacb3ab2ce6923
2023-09-15 15:34:04 -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 f2b623bcc1 GetEntity Support for ReadOnlyDB and SecondaryDB (#11799)
Summary:
`GetEntity` API support for ReadOnly DB and Secondary DB.
- Introduced `GetImpl()` with `GetImplOptions` in `db_impl_readonly` and refactored current `Get()` logic into `GetImpl()` so that look up logic can be reused for `GetEntity()` (Following the same pattern as `DBImpl::Get()` and `DBImpl::GetEntity()`)
- Introduced `GetImpl()` with `GetImplOptions` in `db_impl_secondary` and refactored current `GetImpl()` logic. This is to make `DBImplSecondary::Get/GetEntity` consistent with `DBImpl::Get/GetEntity` and `DBImplReadOnly::Get/GetEntity`
- `GetImpl()` in `db_impl` is now virtual. both `db_impl_readonly` and `db_impl_secondary`'s `Get()` override are no longer needed since all three dbs now have the same `Get()` which calls `GetImpl()` internally.
- `GetImpl()` in `DBImplReadOnly` and `DBImplSecondary` now pass in `columns` instead of `nullptr` in lookup functions like `memtable->get()`
- Introduced `GetEntity()` API in `DBImplReadOnly` and `DBImplSecondary` which simply calls `GetImpl()` with `columns` set in `GetImplOptions`.
- Introduced `Env::IOActivity::kGetEntity` and set read_options.io_activity to `Env::IOActivity::kGetEntity` for `GetEntity()` operations (in db_impl)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11799

Test Plan:
**Unit Tests**
- Added verification in `DBWideBasicTest::PutEntity` by Reopening DB as ReadOnly with the same setup.
- Added verification in `DBSecondaryTest::ReopenAsSecondary` by calling `PutEntity()` and `GetEntity()` on top of existing `Put()` and `Get()`
- `make -j64 check`

**Crash Tests**
- `python3 tools/db_crashtest.py blackbox --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 --duration=60 --inter
val=10`
- `python3 tools/db_crashtest.py blackbox --simple --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 `
- `python3 tools/db_crashtest.py blackbox --cf_consistency --max_key=25000000 --write_buffer_size=4194304 --max_bytes_for_level_base=2097152 --target_file_size_base=2097152 --periodic_compaction_seconds=0 --use_put_entity_one_in=10 --use_get_entity=1 --duration=60 --inter
val=10`

Reviewed By: ltamasi

Differential Revision: D49037040

Pulled By: jaykorean

fbshipit-source-id: a0648253ded6e91af7953de364ed3c6bf163626b
2023-09-15 08:30:44 -07:00
Jonah Gao 84d335b619 Remove an unused variable: `last_stats_dump_time_microsec_` (#11824)
Summary:
`last_stats_dump_time_microsec_`  is not used after initialization.

I guess that it was previously used to implement periodically dumping stats,
but this functionality has now been delegated to the `PeriodicTaskScheduler`.
4b79e8c003/db/db_impl/db_impl.cc (L770-L778)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11824

Reviewed By: cbi42

Differential Revision: D49278311

Pulled By: jowlyzhang

fbshipit-source-id: 5856245580afc026e6b490755a45c5436a2375c9
2023-09-14 11:25:33 -07:00