Commit graph

203 commits

Author SHA1 Message Date
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
Yu Zhang 39a4ff2cab Track full_history_ts_low per SuperVersion (#11784)
Summary:
As discussed in https://github.com/facebook/rocksdb/issues/11730 , this PR tracks the effective `full_history_ts_low` per SuperVersion and update existing sanity checks for `ReadOptions.timestamp >= full_history_ts_low` to use this per SuperVersion `full_history_ts_low` instead. This also means the check is moved to happen after acquiring SuperVersion.

There are two motivations for this: 1) Each time `full_history_ts_low` really come into effect to collapse history, a new SuperVersion is always installed, because it would involve either a Flush or Compaction, both of which change the LSM tree shape. We can take advantage of this to ensure that as long as this sanity check is passed, even if `full_history_ts_low` can be concurrently increased and collapse some history above the requested `ReadOptions.timestamp`, a read request won’t have visibility to that part of history through this SuperVersion that it already acquired.  2) the existing sanity check uses `ColumnFamilyData::GetFullHistoryTsLow` without locking the db mutex, which is the mutex all `IncreaseFullHistoryTsLow` operation is using when mutating this field. So there is a race condition. This also solve the race condition on the read path.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11784

Test Plan:
`make all check`

// Checks success scenario really provide the read consistency attribute as mentioned above.
`./db_with_timestamp_basic_test --gtest_filter=*FullHistoryTsLowSanityCheckPassReadIsConsistent*`

// Checks failure scenario cleans up SuperVersion properly.
`./db_with_timestamp_basic_test --gtest_filter=*FullHistoryTsLowSanityCheckFail*`
`./db_secondary_test --gtest_filter=*FullHistoryTsLowSanityCheckFail*`
`./db_readonly_with_timestamp_test --gtest_filter=*FullHistoryTsLowSanitchCheckFail*`

Reviewed By: ltamasi

Differential Revision: D48894795

Pulled By: jowlyzhang

fbshipit-source-id: 1f801fe8e1bc8e63ca76c03cbdbd0974e5ff5bf6
2023-09-13 16:34:18 -07:00
Changyu Bi d1ff401472 Delay bottommost level single file compactions (#11701)
Summary:
For leveled compaction, RocksDB has a special kind of compaction with reason "kBottommmostFiles" that compacts bottommost level files to clear data held by snapshots (more detail in https://github.com/facebook/rocksdb/issues/3009). Such compactions can happen soon after a relevant snapshot is released. For some use cases, a bottommost file may contain only a small amount of keys that can be cleared, so compacting such a file has a high write amp. In addition, these bottommost files may be compacted in compactions with reason other than "kBottommmostFiles" if we wait for some time (so that enough data is ingested to trigger such a compaction). This PR introduces an option `bottommost_file_compaction_delay` to specify the delay of these bottommost level single file compactions.

* The main change is in `VersionStorageInfo::ComputeBottommostFilesMarkedForCompaction()` where we only add a file to `bottommost_files_marked_for_compaction_` if it oldest_snapshot is larger than its non-zero largest_seqno **and** the file is old enough. Note that if a file is not old enough but its largest_seqno is less than oldest_snapshot, we exclude it from the calculation of `bottommost_files_mark_threshold_`. This makes the change simpler, but such a file's eligibility for compaction will only be checked the next time `ComputeBottommostFilesMarkedForCompaction()` is called. This happens when a new Version is created (compaction, flush, SetOptions()...), a new enough snapshot is released (`VersionStorageInfo::UpdateOldestSnapshot()`) or when a compaction is picked and compaction score has to be re-calculated.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11701

Test Plan:
* Add two unit tests to test when bottommost_file_compaction_delay > 0.
* Ran crash test with the new option.

Reviewed By: jaykorean, ajkr

Differential Revision: D48331564

Pulled By: cbi42

fbshipit-source-id: c584f3dc5f6354fce3ed65f4c6366dc450b15ba8
2023-08-16 17:45:44 -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
Hui Xiao 9a034801ce Group rocksdb.sst.read.micros stat by different user read IOActivity + misc (#11444)
Summary:
**Context/Summary:**
- Similar to https://github.com/facebook/rocksdb/pull/11288 but for user read such as `Get(), MultiGet(), DBIterator::XXX(), Verify(File)Checksum()`.
   - For this, I refactored some user-facing `MultiGet` calls in `TransactionBase` and various types of `DB` so that it does not call a user-facing `Get()` but `GetImpl()` for passing the `ReadOptions::io_activity` check (see PR conversation)
   - New user read stats breakdown are guarded by `kExceptDetailedTimers` since measurement shows they have 4-5% regression to the upstream/main.

- Misc
   - More refactoring: with https://github.com/facebook/rocksdb/pull/11288, we complete passing `ReadOptions/IOOptions` to FS level. So we can now replace the previously [added](https://github.com/facebook/rocksdb/pull/9424) `rate_limiter_priority` parameter in `RandomAccessFileReader`'s `Read/MultiRead/Prefetch()` with `IOOptions::rate_limiter_priority`
   - Also, `ReadAsync()` call time is measured in `SST_READ_MICRO` now

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11444

Test Plan:
- CI fake db crash/stress test
- Microbenchmarking

**Build** `make clean && ROCKSDB_NO_FBCODE=1 DEBUG_LEVEL=0 make -jN db_basic_bench`
- google benchmark version: 604f6fd3f4
- db_basic_bench_base: upstream
- db_basic_bench_pr: db_basic_bench_base + this PR
- asyncread_db_basic_bench_base: upstream + [db basic bench patch for IteratorNext](https://github.com/facebook/rocksdb/compare/main...hx235:rocksdb:micro_bench_async_read)
- asyncread_db_basic_bench_pr: asyncread_db_basic_bench_base + this PR

**Test**

Get
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_{null_stat|base|pr} --benchmark_filter=DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1/negative_query:0/enable_filter:0/mmap:1/threads:1 --benchmark_repetitions=1000
```

Result
```
Coming soon
```

AsyncRead
```
TEST_TMPDIR=/dev/shm ./asyncread_db_basic_bench_{base|pr} --benchmark_filter=IteratorNext/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1/async_io:1/include_detailed_timers:0 --benchmark_repetitions=1000 > syncread_db_basic_bench_{base|pr}.out
```

Result
```
Base:
1956,1956,1968,1977,1979,1986,1988,1988,1988,1990,1991,1991,1993,1993,1993,1993,1994,1996,1997,1997,1997,1998,1999,2001,2001,2002,2004,2007,2007,2008,

PR (2.3% regression, due to measuring `SST_READ_MICRO` that wasn't measured before):
1993,2014,2016,2022,2024,2027,2027,2028,2028,2030,2031,2031,2032,2032,2038,2039,2042,2044,2044,2047,2047,2047,2048,2049,2050,2052,2052,2052,2053,2053,
```

Reviewed By: ajkr

Differential Revision: D45918925

Pulled By: hx235

fbshipit-source-id: 58a54560d9ebeb3a59b6d807639692614dad058a
2023-08-08 17:26:50 -07:00
Changyu Bi 6a0f637633 Compare the number of input keys and processed keys for compactions (#11571)
Summary:
... to improve data integrity validation during compaction.

A new option `compaction_verify_record_count` is introduced for this verification and is enabled by default. One exception when the verification is not done is when a compaction filter returns kRemoveAndSkipUntil which can cause CompactionIterator to seek until some key and hence not able to keep track of the number of keys processed.

For expected number of input keys, we sum over the number of total keys - number of range tombstones across compaction input files (`CompactionJob::UpdateCompactionStats()`). Table properties are consulted if `FileMetaData` is not initialized for some input file. Since table properties for all input files were also constructed during `DBImpl::NotifyOnCompactionBegin()`, `Compaction::GetTableProperties()` is introduced to reduce duplicated code.

For actual number of keys processed, each subcompaction will record its number of keys processed to `sub_compact->compaction_job_stats.num_input_records` and aggregated when all subcompactions finish (`CompactionJob::AggregateCompactionStats()`). In the case when some subcompaction encountered kRemoveAndSkipUntil from compaction filter and does not have accurate count, it propagates this information through `sub_compact->compaction_job_stats.has_num_input_records`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11571

Test Plan:
* Add a new unit test `DBCompactionTest.VerifyRecordCount` for the corruption case.
* All other unit tests for non-corrupted case.
* Ran crash test for a few hours: `python3 ./tools/db_crashtest.py whitebox --simple`

Reviewed By: ajkr

Differential Revision: D47131965

Pulled By: cbi42

fbshipit-source-id: cc8e94565dd526c4347e9d3843ecf32f6727af92
2023-07-28 09:47:31 -07:00
Yu Zhang 4ea7b796b7 Respect cutoff timestamp during flush (#11599)
Summary:
Make flush respect the cutoff timestamp `full_history_ts_low` as much as possible for the user-defined timestamps in Memtables only feature. We achieve this by not proceeding with the actual flushing but instead reschedule the same `FlushRequest` so a follow up flush job can continue with the check after some interval.

This approach doesn't work well for atomic flush, so this feature currently is not supported in combination with atomic flush. Furthermore, this approach also requires a customized method to get the next immediately bigger user-defined timestamp. So currently it's limited to comparator that use uint64_t as the user-defined timestamp format. This support can be extended when we add such a customized method to `AdvancedColumnFamilyOptions`.

For non atomic flush request, at any single time, a column family can only have as many as one FlushRequest for it in the `flush_queue_`. There is deduplication done at `FlushRequest` enqueueing(`SchedulePendingFlush`) and dequeueing time (`PopFirstFromFlushQueue`). We hold the db mutex between when a `FlushRequest` is popped from the queue and the same FlushRequest get rescheduled, so no other `FlushRequest` with a higher `max_memtable_id` can be added to the `flush_queue_` blocking us from re-enqueueing the same `FlushRequest`.

Flush is continued nevertheless if there is risk of entering write stall mode had the flush being postponed, e.g. due to accumulation of write buffers, exceeding the `max_write_buffer_number` setting. When this happens, the newest user-defined timestamp in the involved Memtables need to be tracked and we use it to increase the `full_history_ts_low`, which is an inclusive cutoff timestamp for which RocksDB promises to keep all user-defined timestamps equal to and newer than it.

Tet plan:
```
./column_family_test --gtest_filter="*RetainUDT*"
./memtable_list_test --gtest_filter="*WithTimestamp*"
./flush_job_test --gtest_filter="*WithTimestamp*"
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11599

Reviewed By: ajkr

Differential Revision: D47561586

Pulled By: jowlyzhang

fbshipit-source-id: 9400445f983dd6eac489e9dd0fb5d9b99637fe89
2023-07-26 16:25:06 -07:00
mayue.fight fa878a0107 Support to create a CF by importing multiple non-overlapping CFs (#11378)
Summary:
The original Feature Request is from [https://github.com/facebook/rocksdb/issues/11317](https://github.com/facebook/rocksdb/issues/11317).
Flink uses rocksdb as the state backend,  all DB options are the same, and the keys of each DB instance are adjacent and there is no key overlap between two db instances.
In the Flink rescaling scenario, it is necessary to quickly split the DB according to a certain key range or quickly merge multiple DBs into one.

This PR is mainly used to quickly merge multiple DBs into one.

We hope to extend the function of `CreateColumnFamilyWithImports` to support creating ColumnFamily by importing multiple ColumnFamily with no overlapping keys.

The import logic is almost the same as `CreateColumnFamilyWithImport`, but it will check whether there is key overlap between CF when importing. The import will fail if there are key overlaps.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11378

Reviewed By: ajkr

Differential Revision: D46413709

Pulled By: cbi42

fbshipit-source-id: 846d0049fad11c59cf460fa846c345b26c658dfb
2023-06-15 12:25:04 -07:00
Andrew Kryczka cac3240cbf add property "rocksdb.obsolete-sst-files-size" (#11533)
Summary:
See "unreleased_history/new_features/obsolete_sst_files_size.md" for description

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11533

Test Plan: updated unit test

Reviewed By: jowlyzhang

Differential Revision: D46703152

Pulled By: ajkr

fbshipit-source-id: ea5e31cd6293eccc154130c13e66b5271f57c102
2023-06-13 15:52:45 -07:00
Jay Huh 87bc929db3 Flush option in WaitForCompact() (#11483)
Summary:
Context:

As mentioned in https://github.com/facebook/rocksdb/issues/11436, introducing `flush` option in `WaitForCompactOptions` to flush before waiting for compactions to finish. Must be set to true to ensure no immediate compactions (except perhaps periodic compactions) after closing and re-opening the DB.
1. `bool flush = false` added to `WaitForCompactOptions`
2. `DBImpl::FlushAllColumnFamilies()` is introduced and `DBImpl::FlushForGetLiveFiles()` is refactored to call it.
3. `DBImpl::FlushAllColumnFamilies()` gets called before waiting in `WaitForCompact()` if `flush` option is `true`
4. Some previous WaitForCompact tests were parameterized to include both cases for `abort_on_pause_` being true/false as well as `flush_` being true/false

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11483

Test Plan:
- `DBCompactionTest::WaitForCompactWithOptionToFlush` added
- Changed existing DBCompactionTest::WaitForCompact tests to `DBCompactionWaitForCompactTest` to include params

Reviewed By: pdillinger

Differential Revision: D46289770

Pulled By: jaykorean

fbshipit-source-id: 70d3f461d96a6e06390be60170dd7c4d0d38f8b0
2023-05-31 12:53:51 -07:00
Jay Huh 81aeb15988 Add WaitForCompact with WaitForCompactOptions to public API (#11436)
Summary:
Context:

This is the first PR for WaitForCompact() Implementation with WaitForCompactOptions. In this PR, we are introducing `Status WaitForCompact(const WaitForCompactOptions& wait_for_compact_options)` in the public API. This currently utilizes the existing internal `WaitForCompact()` implementation (with default abort_on_pause = false). `abort_on_pause` has been moved to `WaitForCompactOptions&`. In the later PRs, we will introduce the following two options in `WaitForCompactOptions`

1. `bool flush = false` by default - If true, flush before waiting for compactions to finish. Must be set to true to ensure no immediate compactions (except perhaps periodic compactions) after closing and re-opening the DB.
2. `bool close_db = false` by default - If true, will also close the DB upon compactions finishing.

1. struct `WaitForCompactOptions` added to options.h and `abort_on_pause` in the internal API moved to the option struct.
2. `Status WaitForCompact(const WaitForCompactOptions& wait_for_compact_options)` introduced in `db.h`
3. Changed the internal WaitForCompact() to `WaitForCompact(const WaitForCompactOptions& wait_for_compact_options)` and checks for the `abort_on_pause` inside the option.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11436

Test Plan:
Following tests added
- `DBCompactionTest::WaitForCompactWaitsOnCompactionToFinish`
- `DBCompactionTest::WaitForCompactAbortOnPauseAborted`
- `DBCompactionTest::WaitForCompactContinueAfterPauseNotAborted`
- `DBCompactionTest::WaitForCompactShutdownWhileWaiting`
- `TransactionTest::WaitForCompactAbortOnPause`

NOTE: `TransactionTest::WaitForCompactAbortOnPause` was added to use `StackableDB` to ensure the wrapper function is in place.

Reviewed By: pdillinger

Differential Revision: D45799659

Pulled By: jaykorean

fbshipit-source-id: b5b58f95957f2ab47d1221dee32a61d6cdc4685b
2023-05-25 17:25:51 -07:00
mayue.fight 8d8eb0e77e Support Clip DB to KeyRange (#11379)
Summary:
This PR is part of the request https://github.com/facebook/rocksdb/issues/11317.
(Another part is https://github.com/facebook/rocksdb/pull/11378)

ClipDB() will clip the entries in the CF according to the range [begin_key, end_key). All the entries outside this range will be completely deleted (including tombstones).
 This feature is mainly used to ensure that there is no overlapping Key when calling CreateColumnFamilyWithImports() to import multiple CFs.

When Calling ClipDB [begin, end), there are the following steps

1.  Quickly and directly delete files without overlap
 DeleteFilesInRanges(nullptr, begin) + DeleteFilesInRanges(end, nullptr)
2. Delete the Key outside the range
Delete[smallest_key, begin) + Delete[end, largest_key]
3. Delete the tombstone through Manul Compact
CompactRange(option, nullptr, nullptr)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11379

Reviewed By: ajkr

Differential Revision: D45840358

Pulled By: cbi42

fbshipit-source-id: 54152e8a45fd8ede137f99787eb252f0b51440a4
2023-05-18 13:25:01 -07:00
Jay Huh 586d78b31e Remove wait_unscheduled from waitForCompact internal API (#11443)
Summary:
Context:

In pull request https://github.com/facebook/rocksdb/issues/11436, we are introducing a new public API `waitForCompact(const WaitForCompactOptions& wait_for_compact_options)`. This API invokes the internal implementation `waitForCompact(bool wait_unscheduled=false)`. The unscheduled parameter indicates the compactions that are not yet scheduled but are required to process items in the queue.

In certain cases, we are unable to wait for compactions, such as during a shutdown or when background jobs are paused. It is important to return the appropriate status in these scenarios. For all other cases, we should wait for all compaction and flush jobs, including the unscheduled ones. The primary purpose of this new API is to wait until the system has resolved its compaction debt. Currently, the usage of `wait_unscheduled` is limited to test code.

This pull request eliminates the usage of wait_unscheduled. The internal `waitForCompact()` API now waits for unscheduled compactions unless the db is undergoing a shutdown. In the event of a shutdown, the API returns `Status::ShutdownInProgress()`.

Additionally, a new parameter, `abort_on_pause`, has been introduced with a default value of `false`. This parameter addresses the possibility of waiting indefinitely for unscheduled jobs if `PauseBackgroundWork()` was called before `waitForCompact()` is invoked. By setting `abort_on_pause` to `true`, the API will immediately return `Status::Aborted`.

Furthermore, all tests that previously called `waitForCompact(true)` have been fixed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11443

Test Plan:
Existing tests that involve a shutdown in progress:

- DBCompactionTest::CompactRangeShutdownWhileDelayed
- DBTestWithParam::PreShutdownMultipleCompaction
- DBTestWithParam::PreShutdownCompactionMiddle

Reviewed By: pdillinger

Differential Revision: D45923426

Pulled By: jaykorean

fbshipit-source-id: 7dc93fe6a6841a7d9d2d72866fa647090dba8eae
2023-05-17 18:13:50 -07:00
Changyu Bi a11f1e12ca Fix flaky test DBTestUniversalManualCompactionOutputPathId.ManualCompactionOutputPathId (#11412)
Summary:
the test is flaky when compiled with `make -j56 COERCE_CONTEXT_SWITCH=1 ./db_universal_compaction_test`. The cause is that a manual compaction `CompactRange()` can finish and return before obsolete files are deleted. One reason for this is that a manual compaction waits until `manual.done` is set here 62fc15f009/db/db_impl/db_impl_compaction_flush.cc (L1978)
and the compaction thread can set `manual.done`:
62fc15f009/db/db_impl/db_impl_compaction_flush.cc (L3672)
and then temporarily release mutex_:
62fc15f009/db/db_impl/db_impl_files.cc (L317)
before purging obsolete files:
62fc15f009/db/db_impl/db_impl_compaction_flush.cc (L3144)

With `COERCE_CONTEXT_SWITCH=1`, `bg_cv_.SignalAll()` is called during `mutex_.Lock()`, so the manual compaction thread can wake up and return before obsolete files are deleted. Updated the test to only count live SST files.

Also updated `FindObsoleteFiles()` to avoid locking a locked mutex.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11412

Test Plan: `make -j56 COERCE_CONTEXT_SWITCH=1 ./db_universal_compaction_test`

Reviewed By: ajkr

Differential Revision: D45342242

Pulled By: cbi42

fbshipit-source-id: 955c9796aa3f484e3557d300f97cffacb3ed9b0c
2023-05-03 11:12:20 -07:00
Hui Xiao 151242ce46 Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288)
Summary:
**Context:**
The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them.

**Summary**
- Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros`
   - Fixed the default histogram in `RandomAccessFileReader`
- New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader`
- Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288

Test Plan:
- **Stress test**
- **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.**  (without blob)
     - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads.
```
./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10)
```
```
// BlockBasedTable
rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805
rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116
rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689

// PlainTable
Does not apply
```
- **Db bench 2: performance**

**Read**

SETUP: db with 900 files
```
./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655  -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none
```run till convergence
```
./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3
```
Pre-change
`readrandom [AVG 60 runs] : 21568 (± 248) ops/sec`
Post-change (no regression, -0.3%)
`readrandom [AVG 60 runs] : 21486 (± 236) ops/sec`

**Compaction/Flush**run till convergence
```
./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655  -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none

rocksdb.sst.read.micros  COUNT : 33820
rocksdb.sst.read.flush.micros COUNT : 1800
rocksdb.sst.read.compaction.micros COUNT : 32020
```
Pre-change
`fillseq [AVG 46 runs] : 1391 (± 214) ops/sec;    0.7 (± 0.1) MB/sec`

Post-change (no regression, ~-0.4%)
`fillseq [AVG 46 runs] : 1385 (± 216) ops/sec;    0.7 (± 0.1) MB/sec`

Reviewed By: ajkr

Differential Revision: D44007011

Pulled By: hx235

fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 09:07:18 -07:00
Changyu Bi 43e9a60bb2 Always allow L0->L1 trivial move during manual compaction (#11375)
Summary:
during manual compaction (CompactRange()), L0->L1 trivial move is disabled when only L0 overlaps with compacting key range (introduced in https://github.com/facebook/rocksdb/issues/7368 to enforce kForce* contract). This can cause large memory usage due to compaction readahead when number of L0 files is large. This PR allows L0->L1 trivial move in this case, and will do a L1 -> L1 intra-level compaction when needed (`bottommost_level_compaction` is kForce*). In brief, consider a DB with only L0 file, and user calls CompactRange(kForce, nullptr, nullptr),
- before this PR, RocksDB does a L0 -> L1 compaction (disallow trivial move),
- after this PR, RocksDB does a L0 -> L1 compaction (allow trivial move), and a L1 -> L1 compaction.
Users can use kForceOptimized to avoid this extra L1->L1 compaction overhead when L0s are overlapping and cannot be trivial moved.

This PR also fixed a bug (see previous discussion in https://github.com/facebook/rocksdb/issues/11041) where `final_output_level` of a manual compaction can be miscalculated when `level_compaction_dynamic_level_bytes=true`. This bug could cause incorrect level being moved when CompactRangeOptions::change_level is specified.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11375

Test Plan: - Added new unit tests to test that L0 -> L1 compaction allows trivial move and L1 -> L1 compaction is done when needed.

Reviewed By: ajkr

Differential Revision: D44943518

Pulled By: cbi42

fbshipit-source-id: e9fb770d17b163c18a623e1d1bd6b81159192708
2023-04-20 11:10:48 -07:00
Hui Xiao 11cb6af6e5 Fix bug of prematurely excluded CF in atomic flush contains unflushed data that should've been included in the atomic flush (#11148)
Summary:
**Context:**
Atomic flush should guarantee recoverability of all data of seqno up to the max seqno of the flush. It achieves this by ensuring all such data are flushed by the time this atomic flush finishes through `SelectColumnFamiliesForAtomicFlush()`. However, our crash test exposed the following case where an excluded CF from an atomic flush contains unflushed data of seqno less than the max seqno of that atomic flush and loses its data with `WriteOptions::DisableWAL=true` in face of a crash right after the atomic flush finishes .
```
./db_stress --preserve_unverified_changes=1 --reopen=0 --acquire_snapshot_one_in=0 --adaptive_readahead=1 --allow_data_in_errors=True --async_io=1 --atomic_flush=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=0 --batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=15 --bottommost_compression_type=none --bytes_per_sync=262144 --cache_index_and_filter_blocks=0 --cache_size=8388608 --cache_type=lru_cache --charge_compression_dictionary_building_buffer=0 --charge_file_metadata=1 --charge_filter_construction=0 --charge_table_reader=0 --checkpoint_one_in=0 --checksum_type=kXXH3 --clear_column_family_one_in=0 --compact_files_one_in=0 --compact_range_one_in=0 --compaction_pri=1 --compaction_ttl=100 --compression_max_dict_buffer_bytes=134217727 --compression_max_dict_bytes=16384 --compression_parallel_threads=1 --compression_type=lz4hc --compression_use_zstd_dict_trainer=0 --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --data_block_index_type=0 --db=$db --db_write_buffer_size=1048576 --delpercent=4 --delrangepercent=1 --destroy_db_initially=0 --detect_filter_construct_corruption=0 --disable_wal=1 --enable_compaction_filter=0 --enable_pipelined_write=0 --expected_values_dir=$exp --fail_if_options_file_error=0 --fifo_allow_compaction=0 --file_checksum_impl=none --flush_one_in=0 --format_version=5 --get_current_wal_file_one_in=0 --get_live_files_one_in=100 --get_property_one_in=0 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=2 --index_type=0 --ingest_external_file_one_in=0 --initial_auto_readahead_size=524288 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True --long_running_snapshots=1 --manual_wal_flush_one_in=100 --mark_for_compaction_one_file_in=0 --max_auto_readahead_size=0 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=10000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=64 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=0 --memtable_prefix_bloom_size_ratio=0.01 --memtable_protection_bytes_per_key=4 --memtable_whole_key_filtering=0 --memtablerep=skip_list --min_write_buffer_number_to_merge=2 --mmap_read=1 --mock_direct_io=False --nooverwritepercent=1 --num_file_reads_for_auto_readahead=0 --open_files=-1 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=0 --open_write_fault_one_in=0 --ops_per_thread=100000000 --optimize_filters_for_memory=1 --paranoid_file_checks=1 --partition_filters=0 --partition_pinning=3 --pause_background_one_in=0 --periodic_compaction_seconds=100 --prefix_size=8 --prefixpercent=5 --prepopulate_block_cache=0 --preserve_internal_time_seconds=3600 --progress_reports=0 --read_fault_one_in=32 --readahead_size=16384 --readpercent=50 --recycle_log_file_num=0 --ribbon_starting_level=6 --secondary_cache_fault_one_in=0 --set_options_one_in=10000 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=104857600 --sst_file_manager_bytes_per_truncate=1048576 --stats_dump_period_sec=10 --subcompactions=1 --sync=0 --sync_fault_injection=0 --target_file_size_base=524288 --target_file_size_multiplier=2 --test_batches_snapshots=0 --top_level_index_pinning=0 --unpartitioned_pinning=1 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --use_full_merge_v1=0 --use_merge=0 --use_multiget=1 --use_put_entity_one_in=0 --user_timestamp_size=0 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=0 --verify_db_one_in=1000 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=524288 --wal_compression=none --write_buffer_size=524288 --write_dbid_to_manifest=1 --write_fault_one_in=0 --writepercent=30 &
    pid=$!
    sleep 0.2
    sleep 10
    kill $pid
    sleep 0.2
./db_stress --ops_per_thread=1 --preserve_unverified_changes=1 --reopen=0 --acquire_snapshot_one_in=0 --adaptive_readahead=1 --allow_data_in_errors=True --async_io=1 --atomic_flush=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=0 --batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=15 --bottommost_compression_type=none --bytes_per_sync=262144 --cache_index_and_filter_blocks=0 --cache_size=8388608 --cache_type=lru_cache --charge_compression_dictionary_building_buffer=0 --charge_file_metadata=1 --charge_filter_construction=0 --charge_table_reader=0 --checkpoint_one_in=0 --checksum_type=kXXH3 --clear_column_family_one_in=0 --compact_files_one_in=0 --compact_range_one_in=0 --compaction_pri=1 --compaction_ttl=100 --compression_max_dict_buffer_bytes=134217727 --compression_max_dict_bytes=16384 --compression_parallel_threads=1 --compression_type=lz4hc --compression_use_zstd_dict_trainer=0 --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --data_block_index_type=0 --db=$db --db_write_buffer_size=1048576 --delpercent=4 --delrangepercent=1 --destroy_db_initially=0 --detect_filter_construct_corruption=0 --disable_wal=1 --enable_compaction_filter=0 --enable_pipelined_write=0 --expected_values_dir=$exp --fail_if_options_file_error=0 --fifo_allow_compaction=0 --file_checksum_impl=none --flush_one_in=0 --format_version=5 --get_current_wal_file_one_in=0 --get_live_files_one_in=100 --get_property_one_in=0 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=2 --index_type=0 --ingest_external_file_one_in=0 --initial_auto_readahead_size=524288 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True --long_running_snapshots=1 --manual_wal_flush_one_in=100 --mark_for_compaction_one_file_in=0 --max_auto_readahead_size=0 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=10000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=64 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=0 --memtable_prefix_bloom_size_ratio=0.01 --memtable_protection_bytes_per_key=4 --memtable_whole_key_filtering=0 --memtablerep=skip_list --min_write_buffer_number_to_merge=2 --mmap_read=1 --mock_direct_io=False --nooverwritepercent=1 --num_file_reads_for_auto_readahead=0 --open_files=-1 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=0 --open_write_fault_one_in=0 --ops_per_thread=100000000 --optimize_filters_for_memory=1 --paranoid_file_checks=1 --partition_filters=0 --partition_pinning=3 --pause_background_one_in=0 --periodic_compaction_seconds=100 --prefix_size=8 --prefixpercent=5 --prepopulate_block_cache=0 --preserve_internal_time_seconds=3600 --progress_reports=0 --read_fault_one_in=32 --readahead_size=16384 --readpercent=50 --recycle_log_file_num=0 --ribbon_starting_level=6 --secondary_cache_fault_one_in=0 --set_options_one_in=10000 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=104857600 --sst_file_manager_bytes_per_truncate=1048576 --stats_dump_period_sec=10 --subcompactions=1 --sync=0 --sync_fault_injection=0 --target_file_size_base=524288 --target_file_size_multiplier=2 --test_batches_snapshots=0 --top_level_index_pinning=0 --unpartitioned_pinning=1 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --use_full_merge_v1=0 --use_merge=0 --use_multiget=1 --use_put_entity_one_in=0 --user_timestamp_size=0 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=0 --verify_db_one_in=1000 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=524288 --wal_compression=none --write_buffer_size=524288 --write_dbid_to_manifest=1 --write_fault_one_in=0 --writepercent=30 &
    pid=$!
    sleep 0.2
    sleep 40
    kill $pid
    sleep 0.2

Verification failed for column family 6 key 0000000000000239000000000000012B0000000000000138 (56622): value_from_db: , value_from_expected: 4A6331754E4F4C4D42434041464744455A5B58595E5F5C5D5253505156575455, msg: Value not found: NotFound:
Crash-recovery verification failed :(
No writes or ops?
Verification failed :(
```

The bug is due to the following:
- When atomic flush is used, an empty CF is legally [excluded](https://github.com/facebook/rocksdb/blob/7.10.fb/db/db_filesnapshot.cc#L39) in `SelectColumnFamiliesForAtomicFlush` as the first step of `DBImpl::FlushForGetLiveFiles` before [passing](https://github.com/facebook/rocksdb/blob/7.10.fb/db/db_filesnapshot.cc#L42) the included CFDs to `AtomicFlushMemTables`.
- But [later](https://github.com/facebook/rocksdb/blob/7.10.fb/db/db_impl/db_impl_compaction_flush.cc#L2133) in `AtomicFlushMemTables`, `WaitUntilFlushWouldNotStallWrites` will [release the db mutex](https://github.com/facebook/rocksdb/blob/7.10.fb/db/db_impl/db_impl_compaction_flush.cc#L2403), during which data@seqno N can be inserted into the excluded CF and data@seqno M can be inserted into one of the included CFs, where M > N.
- However, data@seqno N in an already-excluded CF is thus excluded from this atomic flush while we seqno N is less than seqno M.

**Summary:**
- Replace `SelectColumnFamiliesForAtomicFlush()`-before-`AtomicFlushMemTables()` with `SelectColumnFamiliesForAtomicFlush()`-after-wait-within-`AtomicFlushMemTables()` so we ensure no write affecting the recoverability of this atomic job (i.e, change to max seqno of this atomic flush or insertion of data with less seqno than the max seqno of the atomic flush to excluded CF) can happen after calling `SelectColumnFamiliesForAtomicFlush()`.
- For above, refactored and clarified comments on `SelectColumnFamiliesForAtomicFlush()` and `AtomicFlushMemTables()` for clearer semantics of passed-in CFDs to atomic-flush

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11148

Test Plan:
- New unit test failed before the fix and passes after
- Make check
- Rehearsal stress test

Reviewed By: ajkr

Differential Revision: D42799871

Pulled By: hx235

fbshipit-source-id: 13636b63e9c25c5895857afc36ea580d57f6d644
2023-03-14 16:53:20 -07:00
Levi Tamasi 9794acb597 Add a new MultiGetEntity API (#11222)
Summary:
The new `MultiGetEntity` API can be used to get a consistent view of
a batch of keys, with the results presented as wide-column entities.
Similarly to `GetEntity` and the iterator's `columns` API, if the entry
corresponding to the key is a wide-column entity to start with, it is
returned as-is, and if it is a plain key-value, it is wrapped into an entity
with a single default column.

Implementation-wise, the new API shares the logic of the batched `MultiGet`
API (via the `MultiGetCommon` methods). Both single-CF and multi-CF
`MultiGetEntity` APIs are provided, and blobs are also supported.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11222

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D43256950

Pulled By: ltamasi

fbshipit-source-id: 47fb2cb7e2d0470e3580f43fdb2fe9e51f0e7005
2023-02-15 09:34:17 -08:00
Peter Dillinger 390cc0b156 Ensure LockWAL() stall cleared for UnlockWAL() return (#11172)
Summary:
Fixes https://github.com/facebook/rocksdb/issues/11160

By counting the number of stalls placed on a write queue, we can check in UnlockWAL() whether the stall present at the start of UnlockWAL() has been cleared by the end, or wait until it's cleared.

More details in code comments and new unit test.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11172

Test Plan: unit test added. Yes, it uses sleep to amplify failure on buggy behavior if present, but using a sync point to only allow new behavior would fail with the old code only because it doesn't contain the new sync point. Basically, using a sync point in UnlockWAL() could easily mask a regression by artificially limiting key behaviors. The test would only check that UnlockWAL() invokes code that *should* do the right thing, without checking that it *does* the right thing.

Reviewed By: ajkr

Differential Revision: D42894341

Pulled By: pdillinger

fbshipit-source-id: 15c9da0ca383e6aec845b29f5447d76cecbf46c3
2023-02-03 12:08:37 -08:00
Peter Dillinger 94e3beec77 Cleanup, improve, stress test LockWAL() (#11143)
Summary:
The previous API comments for LockWAL didn't provide much about why you might want to use it, and didn't really meet what one would infer its contract was. Also, LockWAL was not in db_stress / crash test. In this change:

* Implement a counting semantics for LockWAL()+UnlockWAL(), so that they can safely be used concurrently across threads or recursively within a thread. This should make the API much less bug-prone and easier to use.
* Make sure no UnlockWAL() is needed after non-OK LockWAL() (to match RocksDB conventions)
* Make UnlockWAL() reliably return non-OK when there's no matching LockWAL() (for debug-ability)
* Clarify API comments on LockWAL(), UnlockWAL(), FlushWAL(), and SyncWAL(). Their exact meanings are not obvious, and I don't think it's appropriate to talk about implementation mutexes in the API comments, but about what operations might block each other.
* Add LockWAL()/UnlockWAL() to db_stress and crash test, mostly to check for assertion failures, but also checks that latest seqno doesn't change while WAL is locked. This is simpler to add when LockWAL() is allowed in multiple threads.
* Remove unnecessary use of sync points in test DBWALTest::LockWal. There was a bug during development of above changes that caused this test to fail sporadically, with and without this sync point change.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11143

Test Plan: unit tests added / updated, added to stress/crash test

Reviewed By: ajkr

Differential Revision: D42848627

Pulled By: pdillinger

fbshipit-source-id: 6d976c51791941a31fd8fbf28b0f82e888d9f4b4
2023-01-30 22:52:30 -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
Peter Dillinger 546e213c4f Fix DelayWrite() calls for two_write_queues (#11130)
Summary:
PR https://github.com/facebook/rocksdb/issues/11020 fixed a case where it was easy to deadlock the DB with LockWAL() but introduced a bug showing up as a rare assertion failure in the stress test. Specifically, `assert(w->state == STATE_INIT)` in `WriteThread::LinkOne()` called from `BeginWriteStall()`, `DelayWrite()`, `WriteImplWALOnly()`. I haven't been about to generate a unit test that reproduces this failure but I believe the root cause is that DelayWrite() was never meant to be re-entrant, only called from the DB's write_thread_ leader. https://github.com/facebook/rocksdb/issues/11020 introduced a call to DelayWrite() from the nonmem_write_thread_ group leader.

This fix is to make DelayWrite() apply to the specific write queue that it is being called from (inject a dummy write stall entry to the head of the appropriate write queue). WriteController is re-entrant, based on polling and state changes signalled with bg_cv_, so can manage stalling two queues. The only anticipated complication (called out by Andrew in previous PR) is that we don't want timed write delays being injected in parallel for the two queues, because that dimishes the intended throttling effect. Thus, we only allow timed delays for the primary write queue.

HISTORY not updated because this is intended for the same release where the bug was introduced.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11130

Test Plan:
Although I was not able to reproduce the assertion failure, I was able to reproduce a distinct flaw with what I believe is the same root cause: a kind of deadlock if both write queues need to wake up from stopped writes. Only one will be waiting on bg_cv_ (the other waiting in `LinkOne()` for the write queue to open up), so a single SignalAll() will only unblock one of the queues, with the other re-instating the stop until another signal on bg_cv_. A simple unit test is added for this case.

Will also run crash_test_with_multiops_wc_txn for a while looking for issues.

Reviewed By: ajkr

Differential Revision: D42749330

Pulled By: pdillinger

fbshipit-source-id: 4317dd899a93d57c26fd5af7143038f82d4d4d1b
2023-01-25 14:18:27 -08:00
Hui Xiao 86fa2592be Fix data race on ColumnFamilyData::flush_reason by letting FlushRequest/Job owns flush_reason instead of CFD (#11111)
Summary:
**Context:**
Concurrent flushes on the same CF can set on `ColumnFamilyData::flush_reason` before each other flush finishes. An symptom is one CF has different flush_reason with others though all of them are in an atomic flush  `db_stress: db/db_impl/db_impl_compaction_flush.cc:423: rocksdb::Status rocksdb::DBImpl::AtomicFlushMemTablesToOutputFiles(const rocksdb::autovector<rocksdb::DBImpl::BGFlushArg>&, bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::Env::Priority): Assertion cfd->GetFlushReason() == cfds[0]->GetFlushReason() failed. `

**Summary:**
Suggested by ltamasi, we now refactor and let FlushRequest/Job to own flush_reason as there is no good way to define `ColumnFamilyData::flush_reason` in face of concurrent flushes on the same CF (which wasn't the case a long time ago when `ColumnFamilyData::flush_reason ` first introduced`)

**Tets:**
- new unit test
- make check
- aggressive crash test rehearsal

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11111

Reviewed By: ajkr

Differential Revision: D42644600

Pulled By: hx235

fbshipit-source-id: 8589c8184869d3415e5b780c887f877818a5ebaf
2023-01-24 09:54:04 -08:00
Hui Xiao 9502856edd Add missing range conflict check between file ingestion and RefitLevel() (#10988)
Summary:
**Context:**
File ingestion never checks whether the key range it acts on overlaps with an ongoing RefitLevel() (used in `CompactRange()` with `change_level=true`). That's because RefitLevel() doesn't register and make its key range known to file ingestion. Though it checks overlapping with other compactions by https://github.com/facebook/rocksdb/blob/7.8.fb/db/external_sst_file_ingestion_job.cc#L998.

RefitLevel() (used in `CompactRange()` with `change_level=true`) doesn't check whether the key range it acts on overlaps with an ongoing file ingestion. That's because file ingestion does not register and make its key range known to other compactions.
- Note that non-refitlevel-compaction (e.g, manual compaction w/o RefitLevel() or general compaction) also does not check key range overlap with ongoing file ingestion for the same reason.
- But it's fine. Credited to cbi42's discovery, `WaitForIngestFile` was called by background and foreground compactions. They were introduced in 0f88160f67, 5c64fb67d2 and 87dfc1d23e.
- Regardless, this PR registers file ingestion like a compaction is a general approach that will also add range conflict check between file ingestion and non-refitlevel-compaction, though it has not been the issue motivated this PR.

Above are bugs resulting in two bad consequences:
- If file ingestion and RefitLevel() creates files in the same level, then range-overlapped files will be created at that level and caught as corruption by `force_consistency_checks=true`
- If file ingestion and RefitLevel() creates file in different levels, then with one further compaction on the ingested file, it can result in two same keys both with seqno 0 in two different levels. Then with iterator's [optimization](c62f322169/db/db_iter.cc (L342-L343)) that assumes no two same keys both with seqno 0, it will either break this assertion in debug build or, even worst, return value of this same key for the key after it, which is the wrong value to return, in release build.

Therefore we decide to introduce range conflict check for file ingestion and RefitLevel() inspired from the existing range conflict check among compactions.

**Summary:**
- Treat file ingestion job and RefitLevel() as `Compaction` of new compaction reasons: `CompactionReason::kExternalSstIngestion` and `CompactionReason::kRefitLevel` and register/unregister them.  File ingestion is treated as compaction from L0 to different levels and RefitLevel() as compaction from source level to target level.
- Check for `RangeOverlapWithCompaction` with other ongoing compactions, `RegisterCompaction()` on this "compaction" before changing the LSM state in `VersionStorageInfo`, and `UnregisterCompaction()` after changing.
- Replace scattered fixes (0f88160f67, 5c64fb67d2 and 87dfc1d23e.) that prevents overlapping between file ingestion and non-refit-level compaction with this fix cuz those practices are easy to overlook.
- Misc: logic cleanup, see PR comments

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10988

Test Plan:
- New unit test `DBCompactionTestWithOngoingFileIngestionParam*` that failed pre-fix and passed afterwards.
- Made compatible with existing tests, see PR comments
- make check
- [Ongoing] Stress test rehearsal with normal value and aggressive CI value https://github.com/facebook/rocksdb/pull/10761

Reviewed By: cbi42

Differential Revision: D41535685

Pulled By: hx235

fbshipit-source-id: 549833a577ba1496d20a870583d4caa737da1258
2022-12-29 15:05:36 -08:00
Yanqin Jin c93ba7db5d Revise LockWAL/UnlockWAL implementation (#11020)
Summary:
RocksDB has two public APIs: `DB::LockWAL()`/`DB::UnlockWAL()`. The current implementation acquires and
releases the internal `DBImpl::log_write_mutex_`.

According to the comment on `DBImpl::log_write_mutex_`: https://github.com/facebook/rocksdb/blob/7.8.fb/db/db_impl/db_impl.h#L2287:L2288
> Note: to avoid dealock, if needed to acquire both log_write_mutex_ and mutex_, the order should be first mutex_ and then log_write_mutex_.

This puts limitations on how applications can use the `LockWAL()` API. After `LockWAL()` returns ok, then application
should not perform any operation that acquires `mutex_`. Currently, the use case of `LockWAL()` is MyRocks implementing
the MySQL storage engine handlerton `lock_hton_log` interface. The operation that MyRocks performs after `LockWAL()`
is `GetSortedWalFiless()` which not only acquires mutex_, but also `log_write_mutex_`.

There are two issues:
1. Applications using these two APIs may hang if one thread calls `GetSortedWalFiles()` after
calling `LockWAL()` because log_write_mutex is not recursive.
2. Two threads may dead lock due to lock order inversion.

To fix these issues, we can modify the implementation of LockWAL so that it does not keep
`log_write_mutex_` held until UnlockWAL. To achieve the goal of locking the WAL, we can
instead manually inject a write stall so that all future writes will be stopped.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11020

Test Plan: make check

Reviewed By: ajkr

Differential Revision: D41785203

Pulled By: riversand963

fbshipit-source-id: 5ccb7a9c6eb9a2c3fa80fd2c399cc2568b8f89ce
2022-12-13 21:45:00 -08:00
Jay Zhuang 1078d860a9 Add an unittest for Periodic compaction conflict with ongoing compaction (#10908)
Summary:
Add a tiered storage migration test which would conflict with
an ongoing penultimate level compaction.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10908

Test Plan: Test only change

Reviewed By: anand1976

Differential Revision: D40864509

Pulled By: ajkr

fbshipit-source-id: e316e849a01a6c71a41be130101f909b6c0498cb
2022-12-12 10:37:55 -08:00
Yanqin Jin 7d26e4c5a3 Basic Support for Merge with user-defined timestamp (#10819)
Summary:
This PR implements the originally disabled `Merge()` APIs when user-defined timestamp is enabled.

Simplest usage:
```cpp
// assume string append merge op is used with '.' as delimiter.
// ts1 < ts2
db->Put(WriteOptions(), "key", ts1, "v0");
db->Merge(WriteOptions(), "key", ts2, "1");
ReadOptions ro;
ro.timestamp = &ts2;
db->Get(ro, "key", &value);
ASSERT_EQ("v0.1", value);
```

Some code comments are added for clarity.

Note: support for timestamp in `DB::GetMergeOperands()` will be done in a follow-up PR.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10819

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D40603195

Pulled By: riversand963

fbshipit-source-id: f96d6f183258f3392d80377025529f7660503013
2022-10-31 22:28:58 -07:00
akankshamahajan 0e7b27bfcf Refactor block cache tracing APIs (#10811)
Summary:
Refactor the classes, APIs and data structures for block cache tracing to allow a user provided trace writer to be used. Currently, only a TraceWriter is supported, with a default built-in implementation of FileTraceWriter. The TraceWriter, however, takes a flat trace record and is thus only suitable for file tracing. This PR introduces an abstract BlockCacheTraceWriter class that takes a structured BlockCacheTraceRecord. The BlockCacheTraceWriter implementation can then format and log the record in whatever way it sees fit. The default BlockCacheTraceWriterImpl does file tracing using a user provided TraceWriter.

`DB::StartBlockTrace` will internally redirect to changed `BlockCacheTrace::StartBlockCacheTrace`.
New API `DB::StartBlockTrace` is also added that directly takes `BlockCacheTraceWriter` pointer.

This same philosophy can be applied to KV and IO tracing as well.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10811

Test Plan:
existing unit tests
Old API DB::StartBlockTrace checked with db_bench tool
create database
```
./db_bench --benchmarks="fillseq" \
--key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 \
--cache_index_and_filter_blocks --cache_size=1048576 \
--disable_auto_compactions=1 --disable_wal=1 --compression_type=none \
--min_level_to_compress=-1 --compression_ratio=1 --num=10000000
```

To trace block cache accesses when running readrandom benchmark:
```
./db_bench --benchmarks="readrandom" --use_existing_db --duration=60 \
--key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 \
--cache_index_and_filter_blocks --cache_size=1048576 \
--disable_auto_compactions=1 --disable_wal=1 --compression_type=none \
--min_level_to_compress=-1 --compression_ratio=1 --num=10000000 \
--threads=16 \
-block_cache_trace_file="/tmp/binary_trace_test_example" \
-block_cache_trace_max_trace_file_size_in_bytes=1073741824 \
-block_cache_trace_sampling_frequency=1

```

Reviewed By: anand1976

Differential Revision: D40435289

Pulled By: akankshamahajan15

fbshipit-source-id: fa2755f4788185e19f4605e731641cfd21ab3282
2022-10-21 12:15:35 -07:00
Yanqin Jin edda219fc3 Manual flush with wait=false should not stall when writes stopped (#10001)
Summary:
When `FlushOptions::wait` is set to false, manual flush should not stall forever.

If the database has already stopped writes, then the thread calling `DB::Flush()` with
`FlushOptions::wait=false` should not enter the `DBImpl::write_thread_`.

To prevent this, we should do a check at the beginning and return `TryAgain()`

Resolves: https://github.com/facebook/rocksdb/issues/9892

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10001

Reviewed By: siying

Differential Revision: D36422303

Pulled By: siying

fbshipit-source-id: 723bd3065e8edc4f17c82449d0d6b95a2381ac0a
2022-10-04 16:43:01 -07:00
Changyu Bi 9f2363f4c4 User-defined timestamp support for DeleteRange() (#10661)
Summary:
Add user-defined timestamp support for range deletion. The new API is `DeleteRange(opt, cf, begin_key, end_key, ts)`. Most of the change is to update the comparator to compare without timestamp. Other than that, major changes are
- internal range tombstone data structures (`FragmentedRangeTombstoneList`, `RangeTombstone`, etc.) to store timestamps.
- Garbage collection of range tombstones and range tombstone covered keys during compaction.
- Get()/MultiGet() to return the timestamp of a range tombstone when needed.
- Get/Iterator with range tombstones bounded by readoptions.timestamp.
- timestamp crash test now issues DeleteRange by default.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10661

Test Plan:
- Added unit test: `make check`
- Stress test: `python3 tools/db_crashtest.py --enable_ts whitebox --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4`
- Ran `db_bench` to measure regression when timestamp is not enabled. The tests are for write (with some range deletion) and iterate with DB fitting in memory: `./db_bench--benchmarks=fillrandom,seekrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=500000 --seek_nexts=10 --disable_auto_compactions -disable_wal=true --max_num_range_tombstones=1000`.  Did not see consistent regression in no timestamp case.

| micros/op | fillrandom | seekrandom |
| --- | --- | --- |
|main| 2.58 |10.96|
|PR 10661| 2.68 |10.63|

Reviewed By: riversand963

Differential Revision: D39441192

Pulled By: cbi42

fbshipit-source-id: f05aca3c41605caf110daf0ff405919f300ddec2
2022-09-30 16:13:03 -07:00
Hui Xiao 3b8164912e Add manual_wal_flush, FlushWAL() to stress/crash test (#10698)
Summary:
**Context/Summary:**
Introduce `manual_wal_flush_one_in` as titled.
- When `manual_wal_flush_one_in  > 0`, we also need tracing to correctly verify recovery because WAL data can be lost in this case when `FlushWAL()` is not explicitly called by users of RocksDB (in our case, db stress) and the recovery from such potential WAL data loss is a prefix recovery that requires tracing to verify. As another consequence, we need to disable features can't run under unsync data loss with `manual_wal_flush_one_in`

Incompatibilities fixed along the way:
```
db_stress: db/db_impl/db_impl_open.cc:2063: static rocksdb::Status rocksdb::DBImpl::Open(const rocksdb::DBOptions&, const string&, const std::vector<rocksdb::ColumnFamilyDescriptor>&, std::vector<rocksdb::ColumnFamilyHandle*>*, rocksdb::DB**, bool, bool): Assertion `impl->TEST_WALBufferIsEmpty()' failed.
```
 - It turns out that `Writer::AddCompressionTypeRecord` before this assertion `EmitPhysicalRecord(kSetCompressionType, encode.data(), encode.size());` but do not trigger flush if `manual_wal_flush` is set . This leads to `impl->TEST_WALBufferIsEmpty()' is false.
    - As suggested, assertion is removed and violation case is handled by `FlushWAL(sync=true)` along with refactoring `TEST_WALBufferIsEmpty()` to be `WALBufferIsEmpty()` since it is used in prod code now.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10698

Test Plan:
- Locally running `python3 tools/db_crashtest.py blackbox --manual_wal_flush_one_in=1 --manual_wal_flush=1 --sync_wal_one_in=100 --atomic_flush=1 --flush_one_in=100 --column_families=3`
- Joined https://github.com/facebook/rocksdb/pull/10624 in auto CI testings with all RocksDB stress/crash test jobs

Reviewed By: ajkr

Differential Revision: D39593752

Pulled By: ajkr

fbshipit-source-id: 3a2135bb792c52d2ffa60257d4fbc557fb04d2ce
2022-09-30 15:48:33 -07:00
Peter Dillinger 6de7081cf3 Always verify SST unique IDs on SST file open (#10532)
Summary:
Although we've been tracking SST unique IDs in the DB manifest
unconditionally, checking has been opt-in and with an extra pass at DB::Open
time. This changes the behavior of `verify_sst_unique_id_in_manifest` to
check unique ID against manifest every time an SST file is opened through
table cache (normal DB operations), replacing the explicit pass over files
at DB::Open time. This change also enables the option by default and
removes the "EXPERIMENTAL" designation.

One possible criticism is that the option no longer ensures the integrity
of a DB at Open time. This is far from an all-or-nothing issue. Verifying
the IDs of all SST files hardly ensures all the data in the DB is readable.
(VerifyChecksum is supposed to do that.) Also, with
max_open_files=-1 (default, extremely common), all SST files are
opened at DB::Open time anyway.

Implementation details:
* `VerifySstUniqueIdInManifest()` functions are the extra/explicit pass
that is now removed.
* Unit tests that manipulate/corrupt table properties have to opt out of
this check, because that corrupts the "actual" unique id. (And even for
testing we don't currently have a mechanism to set "no unique id"
in the in-memory file metadata for new files.)
* A lot of other unit test churn relates to (a) default checking on, and
(b) checking on SST open even without DB::Open (e.g. on flush)
* Use `FileMetaData` for more `TableCache` operations (in place of
`FileDescriptor`) so that we have access to the unique_id whenever
we might need to open an SST file. **There is the possibility of
performance impact because we can no longer use the more
localized `fd` part of an `FdWithKeyRange` but instead follow the
`file_metadata` pointer. However, this change (possible regression)
is only done for `GetMemoryUsageByTableReaders`.**
* Removed a completely unnecessary constructor overload of
`TableReaderOptions`

Possible follow-up:
* Verification only happens when opening through table cache. Are there
more places where this should happen?
* Improve error message when there is a file size mismatch vs. manifest
(FIXME added in the appropriate place).
* I'm not sure there's a justification for `FileDescriptor` to be distinct from
`FileMetaData`.
* I'm skeptical that `FdWithKeyRange` really still makes sense for
optimizing some data locality by duplicating some data in memory, but I
could be wrong.
* An unnecessary overload of NewTableReader was recently added, in
the public API nonetheless (though unusable there). It should be cleaned
up to put most things under `TableReaderOptions`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10532

Test Plan:
updated unit tests

Performance test showing no significant difference (just noise I think):
`./db_bench -benchmarks=readwhilewriting[-X10] -num=3000000 -disable_wal=1 -bloom_bits=8 -write_buffer_size=1000000 -target_file_size_base=1000000`
Before: readwhilewriting [AVG 10 runs] : 68702 (± 6932) ops/sec
After: readwhilewriting [AVG 10 runs] : 68239 (± 7198) ops/sec

Reviewed By: jay-zhuang

Differential Revision: D38765551

Pulled By: pdillinger

fbshipit-source-id: a827a708155f12344ab2a5c16e7701c7636da4c2
2022-09-07 22:52:42 -07:00
Changyu Bi 30bc495c03 Skip swaths of range tombstone covered keys in merging iterator (2022 edition) (#10449)
Summary:
Delete range logic is moved from `DBIter` to `MergingIterator`, and `MergingIterator` will seek to the end of a range deletion if possible instead of scanning through each key and check with `RangeDelAggregator`.

With the invariant that a key in level L (consider memtable as the first level, each immutable and L0 as a separate level) has a larger sequence number than all keys in any level >L, a range tombstone `[start, end)` from level L covers all keys in its range in any level >L. This property motivates optimizations in iterator:
- in `Seek(target)`, if level L has a range tombstone `[start, end)` that covers `target.UserKey`, then for all levels > L, we can do Seek() on `end` instead of `target` to skip some range tombstone covered keys.
- in `Next()/Prev()`, if the current key is covered by a range tombstone `[start, end)` from level L, we can do `Seek` to `end` for all levels > L.

This PR implements the above optimizations in `MergingIterator`. As all range tombstone covered keys are now skipped in `MergingIterator`, the range tombstone logic is removed from `DBIter`. The idea in this PR is similar to https://github.com/facebook/rocksdb/issues/7317, but this PR leaves `InternalIterator` interface mostly unchanged. **Credit**: the cascading seek optimization and the sentinel key (discussed below) are inspired by [Pebble](https://github.com/cockroachdb/pebble/blob/master/merging_iter.go) and suggested by ajkr in https://github.com/facebook/rocksdb/issues/7317. The two optimizations are mostly implemented in `SeekImpl()/SeekForPrevImpl()` and `IsNextDeleted()/IsPrevDeleted()` in `merging_iterator.cc`. See comments for each method for more detail.

One notable change is that the minHeap/maxHeap used by `MergingIterator` now contains range tombstone end keys besides point key iterators. This helps to reduce the number of key comparisons. For example, for a range tombstone `[start, end)`, a `start` and an `end` `HeapItem` are inserted into the heap. When a `HeapItem` for range tombstone start key is popped from the minHeap, we know this range tombstone becomes "active" in the sense that, before the range tombstone's end key is popped from the minHeap, all the keys popped from this heap is covered by the range tombstone's internal key range `[start, end)`.

Another major change, *delete range sentinel key*, is made to `LevelIterator`. Before this PR, when all point keys in an SST file are iterated through in `MergingIterator`, a level iterator would advance to the next SST file in its level. In the case when an SST file has a range tombstone that covers keys beyond the SST file's last point key, advancing to the next SST file would lose this range tombstone. Consequently, `MergingIterator` could return keys that should have been deleted by some range tombstone. We prevent this by pretending that file boundaries in each SST file are sentinel keys. A `LevelIterator` now only advance the file iterator once the sentinel key is processed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10449

Test Plan:
- Added many unit tests in db_range_del_test
- Stress test: `./db_stress --readpercent=5 --prefixpercent=19 --writepercent=20 -delpercent=10 --iterpercent=44 --delrangepercent=2`
- Additional iterator stress test is added to verify against iterators against expected state: https://github.com/facebook/rocksdb/issues/10538. This is based on ajkr's previous attempt https://github.com/facebook/rocksdb/pull/5506#issuecomment-506021913.

```
python3 ./tools/db_crashtest.py blackbox --simple --write_buffer_size=524288 --target_file_size_base=524288 --max_bytes_for_level_base=2097152 --compression_type=none --max_background_compactions=8 --value_size_mult=33 --max_key=5000000 --interval=10 --duration=7200 --delrangepercent=3 --delpercent=9 --iterpercent=25 --writepercent=60 --readpercent=3 --prefixpercent=0 --num_iterations=1000 --range_deletion_width=100 --verify_iterator_with_expected_state_one_in=1
```

- Performance benchmark: I used a similar setup as in the blog [post](http://rocksdb.org/blog/2018/11/21/delete-range.html) that introduced DeleteRange, "a database with 5 million data keys, and 10000 range tombstones (ignoring those dropped during compaction) that were written in regular intervals after 4.5 million data keys were written".  As expected, the performance with this PR depends on the range tombstone width.
```
# Setup:
TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=fillrandom --writes=4500000 --num=5000000
TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=overwrite --writes=500000 --num=5000000 --use_existing_db=true --writes_per_range_tombstone=50

# Scan entire DB
TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=readseq[-X5] --use_existing_db=true --num=5000000 --disable_auto_compactions=true

# Short range scan (10 Next())
TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=100000 --seek_nexts=10 --disable_auto_compactions=true

# Long range scan(1000 Next())
TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=2500 --seek_nexts=1000 --disable_auto_compactions=true
```
Avg over of 10 runs (some slower tests had fews runs):

For the first column (tombstone), 0 means no range tombstone, 100-10000 means width of the 10k range tombstones, and 1 means there is a single range tombstone in the entire DB (width is 1000). The 1 tombstone case is to test regression when there's very few range tombstones in the DB, as no range tombstone is likely to take a different code path than with range tombstones.

- Scan entire DB

| tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% |
| ------------- | ------------- | ------------- |  ------------- |
| 0 range tombstone    |2525600 (± 43564)    |2486917 (± 33698)    |-1.53%               |
| 100   |1853835 (± 24736)    |2073884 (± 32176)    |+11.87%              |
| 1000  |422415 (± 7466)      |1115801 (± 22781)    |+164.15%             |
| 10000 |22384 (± 227)        |227919 (± 6647)      |+918.22%             |
| 1 range tombstone      |2176540 (± 39050)    |2434954 (± 24563)    |+11.87%              |
- Short range scan

| tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% |
| ------------- | ------------- | ------------- |  ------------- |
| 0  range tombstone   |35398 (± 533)        |35338 (± 569)        |-0.17%               |
| 100   |28276 (± 664)        |31684 (± 331)        |+12.05%              |
| 1000  |7637 (± 77)          |25422 (± 277)        |+232.88%             |
| 10000 |1367                 |28667                |+1997.07%            |
| 1 range tombstone      |32618 (± 581)        |32748 (± 506)        |+0.4%                |

- Long range scan

| tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% |
| ------------- | ------------- | ------------- |  ------------- |
| 0 range tombstone     |2262 (± 33)          |2353 (± 20)          |+4.02%               |
| 100   |1696 (± 26)          |1926 (± 18)          |+13.56%              |
| 1000  |410 (± 6)            |1255 (± 29)          |+206.1%              |
| 10000 |25                   |414                  |+1556.0%             |
| 1 range tombstone   |1957 (± 30)          |2185 (± 44)          |+11.65%              |

- Microbench does not show significant regression: https://gist.github.com/cbi42/59f280f85a59b678e7e5d8561e693b61

Reviewed By: ajkr

Differential Revision: D38450331

Pulled By: cbi42

fbshipit-source-id: b5ef12e8d8c289ed2e163ccdf277f5039b511fca
2022-09-02 09:51:19 -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
Jay Zhuang d9e71fb2c5 Fix periodic_task unable to re-register the same task type (#10379)
Summary:
Timer has a limitation that it cannot re-register a task with the same name,
because the cancel only mark the task as invalid and wait for the Timer thread
to clean it up later, before the task is cleaned up, the same task name cannot
be added. Which makes the task option update likely to fail, which basically
cancel and re-register the same task name. Change the periodic task name to a
random unique id and store it in periodic_task_scheduler.

Also refactor the `periodic_work` to `periodic_task` to make each job function
as a `task`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10379

Test Plan: unittests

Reviewed By: ajkr

Differential Revision: D38000615

Pulled By: jay-zhuang

fbshipit-source-id: e4135f9422e3b53aaec8eda54f4e18ce633a279e
2022-08-25 18:52:37 -07:00