Summary:
In buffered IO mode, without checksum calculation for buffered data enabled, try to align writes to the file system on a power of two. This can improve performance, especially on a distributed file system like Warm Storage that does erasure coding and benefits from full stripe writes. We do this by filling up the writable buffer, with a partial append if necessary, before flushing. When checksum calculation for buffered data is enabled, we don't do this since its preferable to not split the data, especially if the caller provides the checksum. We don't guarantee alignment if the caller manually flushes before finishing the file.
Tests:
Add unit tests in file_reader_writer_test and external_sst_file_basic_test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13158
Reviewed By: pdillinger
Differential Revision: D66669367
Pulled By: anand1976
fbshipit-source-id: 6df1b4538bda696e2170515420ee4c3766c83bb8
Summary:
Fix a longstanding race condition in SetOptions for `block_based_table_factory` options. The fix is mostly described in new, unified `TableFactoryParseFn()` in `cf_options.cc`. Also in this PR:
* Adds a virtual `Clone()` function to TableFactory
* To avoid behavioral hiccups with `SetOptions`, make the "hidden state" of `BlockBasedTableFactory` shared between an original and a clone. For example, `TailPrefetchStats`
* `Configurable` was allowed to be copied but was not safe to do so, because the copy would have and use pointers into object it was copied from (!!!). This has been fixed using relative instead of absolute pointers, though it's still technically relying on undefined behavior (consistent object layout for non-standard-layout types).
For future follow-up:
* Deny SetOptions on block cache options (dubious and not yet made safe with proper shared_ptr handling)
Fixes https://github.com/facebook/rocksdb/issues/10079
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13082
Test Plan:
added to unit tests and crash test
Ran TSAN blackbox crashtest for hours with options to amplify potential race (see https://github.com/facebook/rocksdb/issues/10079)
Reviewed By: cbi42
Differential Revision: D64947243
Pulled By: pdillinger
fbshipit-source-id: 8390299149f50e2a2b39a5247680f2637edb23c8
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13015
`Close()`ing a database now releases tracked files in `SstFileManager`. Previously this space would be leaked until the database was later reopened.
Reviewed By: jowlyzhang
Differential Revision: D62590773
fbshipit-source-id: 5461bd253d974ac4967ad52fee92e2650f8a9a28
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13010
The OnAddFile cur_compactions_reserved_size_ accounting causes wraparound when re-opening a database with an unowned SstFileManager and during recovery. It was introduced in #4164 which addresses out of space recovery with an unclear purpose. Compaction jobs do this accounting via EnoughRoomForCompaction/OnCompactionCompletion and to my understanding would never reuse a sst file name.
Reviewed By: anand1976
Differential Revision: D62535775
fbshipit-source-id: a7c44d6e0a4b5ff74bc47abfe57c32ca6770243d
Summary:
We have a request to use the cold tier as primary source of truth for the DB, and to best support such use cases and to complement the existing options controlling SST file temperatures, we add two new DB options:
* `metadata_write_temperature` for DB "small" files that don't contain much user data
* `wal_write_temperature` for WALs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12957
Test Plan: Unit test included, though it's hard to be sure we've covered all the places
Reviewed By: jowlyzhang
Differential Revision: D61664815
Pulled By: pdillinger
fbshipit-source-id: 8e19c9dd8fd2db059bb15f74938d6bc12002e82b
Summary:
Make `DestroyDB` slowly delete files if it's configured and enabled via `SstFileManager`.
It's currently not available mainly because of DeleteScheduler's logic related to tracked total_size_ and total_trash_size_. These accounting and logic should not be applied to `DestroyDB`. This PR adds a `DeleteUnaccountedDBFile` util for this purpose which deletes files without accounting it. This util also supports assigning a file to a specified trash bucket so that user can later wait for a specific trash bucket to be empty. For `DestroyDB`, files with more than 1 hard links will be deleted immediately.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12891
Test Plan: Added unit tests, existing tests.
Reviewed By: anand1976
Differential Revision: D60300220
Pulled By: jowlyzhang
fbshipit-source-id: 8b18109a177a3a9532f6dc2e40e08310c08ca3c7
Summary:
**Context/Summary:**
We discovered the following false positive in our crash test lately:
(1) PUT() writes k/v to WAL but fails in `ApplyWALToManifest()`. The k/v is in the WAL
(2) Current stress test logic will rollback the expected state of such k/v since PUT() fails
(3) If the DB crashes before recovery finishes and reopens, the WAL will be replayed and the k/v is in the DB while the expected state have been roll-backed.
We decided to leave those expected state to be pending until the loop-write of the same key succeeds.
Bonus: Now that I realized write to manifest can also fail the write which faces the similar problem as https://github.com/facebook/rocksdb/pull/12797, I decided to disable fault injection on user write per thread (instead of globally) when tracing is needed for prefix recovery; some refactory
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12838
Test Plan:
Rehearsal CI
Run below command (varies on sync_fault_injection=1,0 to verify ExpectedState behavior) for a while to ensure crash recovery validation works fine
```
python3 tools/db_crashtest.py --simple blackbox --interval=30 --WAL_size_limit_MB=0 --WAL_ttl_seconds=0 --acquire_snapshot_one_in=10000 --adaptive_readahead=1 --adm_policy=1 --advise_random_on_open=0 --allow_concurrent_memtable_write=0 --allow_data_in_errors=True --allow_fallocate=0 --async_io=0 --auto_readahead_size=0 --avoid_flush_during_recovery=0 --avoid_flush_during_shutdown=0 --avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=0 --batch_protection_bytes_per_key=0 --bgerror_resume_retry_interval=1000000 --block_align=1 --block_protection_bytes_per_key=4 --block_size=16384 --bloom_before_level=4 --bloom_bits=56.810257702625165 --bottommost_compression_type=none --bottommost_file_compaction_delay=0 --bytes_per_sync=262144 --cache_index_and_filter_blocks=1 --cache_index_and_filter_blocks_with_high_priority=1 --cache_size=8388608 --cache_type=auto_hyper_clock_cache --charge_compression_dictionary_building_buffer=1 --charge_file_metadata=1 --charge_filter_construction=1 --charge_table_reader=0 --check_multiget_consistency=0 --check_multiget_entity_consistency=1 --checkpoint_one_in=10000 --checksum_type=kxxHash --clear_column_family_one_in=0 --column_families=1 --compact_files_one_in=1000 --compact_range_one_in=1000 --compaction_pri=4 --compaction_readahead_size=1048576 --compaction_ttl=10 --compress_format_version=1 --compressed_secondary_cache_ratio=0.0 --compressed_secondary_cache_size=0 --compression_checksum=0 --compression_max_dict_buffer_bytes=0 --compression_max_dict_bytes=0 --compression_parallel_threads=1 --compression_type=none --compression_use_zstd_dict_trainer=0 --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --daily_offpeak_time_utc=04:00-08:00 --data_block_index_type=1 --db_write_buffer_size=0 --default_temperature=kWarm --default_write_temperature=kCold --delete_obsolete_files_period_micros=30000000 --delpercent=20 --delrangepercent=20 --destroy_db_initially=0 --detect_filter_construct_corruption=0 --disable_file_deletions_one_in=10000 --disable_manual_compaction_one_in=1000000 --disable_wal=0 --dump_malloc_stats=0 --enable_checksum_handoff=1 --enable_compaction_filter=0 --enable_custom_split_merge=0 --enable_do_not_compress_roles=0 --enable_index_compression=1 --enable_memtable_insert_with_hint_prefix_extractor=0 --enable_pipelined_write=0 --enable_sst_partitioner_factory=0 --enable_thread_tracking=0 --enable_write_thread_adaptive_yield=0 --error_recovery_with_no_fault_injection=1 --exclude_wal_from_write_fault_injection=0 --fail_if_options_file_error=1 --fifo_allow_compaction=0 --file_checksum_impl=crc32c --fill_cache=1 --flush_one_in=1000000 --format_version=3 --get_all_column_family_metadata_one_in=1000000 --get_current_wal_file_one_in=0 --get_live_files_apis_one_in=1000000 --get_properties_of_all_tables_one_in=1000000 --get_property_one_in=100000 --get_sorted_wal_files_one_in=0 --hard_pending_compaction_bytes_limit=274877906944 --high_pri_pool_ratio=0.5 --index_block_restart_interval=4 --index_shortening=2 --index_type=0 --ingest_external_file_one_in=0 --initial_auto_readahead_size=16384 --inplace_update_support=0 --iterpercent=10 --key_len_percent_dist=1,30,69 --key_may_exist_one_in=100 --last_level_temperature=kWarm --level_compaction_dynamic_level_bytes=1 --lock_wal_one_in=10000 --log_file_time_to_roll=60 --log_readahead_size=16777216 --long_running_snapshots=1 --low_pri_pool_ratio=0 --lowest_used_cache_tier=0 --manifest_preallocation_size=0 --manual_wal_flush_one_in=0 --mark_for_compaction_one_file_in=10 --max_auto_readahead_size=16384 --max_background_compactions=1 --max_bytes_for_level_base=67108864 --max_key=100000 --max_key_len=3 --max_log_file_size=1048576 --max_manifest_file_size=32768 --max_sequential_skip_in_iterations=1 --max_total_wal_size=0 --max_write_batch_group_size_bytes=16 --max_write_buffer_number=10 --max_write_buffer_size_to_maintain=8388608 --memtable_insert_hint_per_batch=1 --memtable_max_range_deletions=0 --memtable_prefix_bloom_size_ratio=0.01 --memtable_protection_bytes_per_key=1 --memtable_whole_key_filtering=1 --memtablerep=skip_list --metadata_charge_policy=1 --metadata_read_fault_one_in=0 --metadata_write_fault_one_in=8 --min_write_buffer_number_to_merge=1 --mmap_read=1 --mock_direct_io=False --nooverwritepercent=1 --num_file_reads_for_auto_readahead=1 --open_files=-1 --open_metadata_read_fault_one_in=0 --open_metadata_write_fault_one_in=8 --open_read_fault_one_in=0 --open_write_fault_one_in=8 --ops_per_thread=100000000 --optimize_filters_for_hits=1 --optimize_filters_for_memory=1 --optimize_multiget_for_io=1 --paranoid_file_checks=0 --partition_filters=0 --partition_pinning=3 --pause_background_one_in=1000000 --periodic_compaction_seconds=2 --prefix_size=7 --prefixpercent=0 --prepopulate_block_cache=0 --preserve_internal_time_seconds=0 --progress_reports=0 --promote_l0_one_in=0 --read_amp_bytes_per_bit=0 --read_fault_one_in=1000 --readahead_size=524288 --readpercent=10 --recycle_log_file_num=1 --reopen=0 --report_bg_io_stats=0 --reset_stats_one_in=1000000 --sample_for_compression=0 --secondary_cache_fault_one_in=0 --set_options_one_in=0 --skip_stats_update_on_db_open=1 --snapshot_hold_ops=100000 --soft_pending_compaction_bytes_limit=68719476736 --sqfc_name=foo --sqfc_version=0 --sst_file_manager_bytes_per_sec=104857600 --sst_file_manager_bytes_per_truncate=0 --stats_dump_period_sec=10 --stats_history_buffer_size=0 --strict_bytes_per_sync=1 --subcompactions=4 --sync=1 --sync_fault_injection=0 --table_cache_numshardbits=6 --target_file_size_base=16777216 --target_file_size_multiplier=1 --test_batches_snapshots=0 --top_level_index_pinning=2 --uncache_aggressiveness=239 --universal_max_read_amp=-1 --unpartitioned_pinning=1 --use_adaptive_mutex=1 --use_adaptive_mutex_lru=1 --use_attribute_group=0 --use_delta_encoding=0 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --use_full_merge_v1=0 --use_get_entity=0 --use_merge=0 --use_multi_cf_iterator=0 --use_multi_get_entity=0 --use_multiget=0 --use_put_entity_one_in=0 --use_sqfc_for_range_queries=1 --use_timed_put_one_in=0 --use_write_buffer_manager=0 --user_timestamp_size=0 --value_size_mult=32 --verification_only=0 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_compression=0 --verify_db_one_in=100000 --verify_file_checksums_one_in=1000000 --verify_iterator_with_expected_state_one_in=5 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=0 --wal_compression=none --write_buffer_size=33554432 --write_dbid_to_manifest=0 --write_fault_one_in=8 --writepercent=40
```
Reviewed By: cbi42
Differential Revision: D59377075
Pulled By: hx235
fbshipit-source-id: 91f602fd67e2d339d378cd28b982095fd073dcb6
Summary:
Unit tests `DBTest.ThreadStatusFlush` and `DBTestWithParam.ThreadStatusSingleCompaction` have been flaky and fail with error message
```
[ RUN ] DBTest.ThreadStatusFlush
op_count: 0, expected_count 1
thread id: 718113, thread status: , cf_name
thread id: 718114, thread status: , cf_name pikachu
/__w/rocksdb/rocksdb/db/db_test.cc:4817: Failure
Value of: VerifyOperationCount(env_, ThreadStatus::OP_FLUSH, 1)
Actual: false
Expected: true
[ FAILED ] DBTest.ThreadStatusFlush (106 ms)
[ RUN ] DBTestWithParam/DBTestWithParam.ThreadStatusSingleCompaction/0
db/db_test.cc:4673: Failure
Expected equality of these values:
op_count
Which is: 0
expected_count
Which is: 1
[ FAILED ] DBTestWithParam/DBTestWithParam.ThreadStatusSingleCompaction/0, where GetParam() = (1, false)
```
One cause for this is that before flush/compaction finishes, we will go through `~WritableFileWriter()`, either for WAL or SST file, and temporarily set thread_operation to UNKNOWN. This UNKNOWN thread operation seem to be there for some stress test verification. This PR fixes these tests by setting the IOActivity in ~WritableFileWriter() for debug build.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12858
Test Plan: monitor future test failure.
Reviewed By: hx235
Differential Revision: D59691564
Pulled By: cbi42
fbshipit-source-id: 3f96998bba9d42aba50d1830c2b51bef2dd6705f
Summary:
**Context/Summary** : as titled as seen_injected_error_ is a subcategory of seen_error_
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12830
Test Plan: existing CI as it only affects crash test code
Reviewed By: jaykorean
Differential Revision: D59249018
Pulled By: hx235
fbshipit-source-id: 20e4c22cade57e12a104a03999e4c841a3648b11
Summary:
a pre-existing flaw revealed by crash test with uncache behavior. Easy fix.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12782
Test Plan: Modified unit test PrefetchTest.Basic (fails without fix)
Reviewed By: hx235
Differential Revision: D58757916
Pulled By: pdillinger
fbshipit-source-id: 23c0240c7cf0cb0b69a372f9531c07af920e09da
Summary:
**Context:**
We currently have partial error injection:
- DB operation: all read, SST write
- DB open: all read, SST write, all metadata write.
This PR completes the error injection (with some limitations below):
- DB operation & open: all read, all write, all metadata write, all metadata read
**Summary:**
- Inject retryable metadata read, metadata write error concerning directory (e.g, dir sync, ) or file metadata (e.g, name, size, file creation/deletion...)
- Inject retryable errors to all major file types: random access file, sequential file, writable file
- Allow db stress test operations to handle above injected errors gracefully without crashing
- Change all error injection to thread-local implementation for easier disabling and enabling in the same thread. For example, we can control error handling thread to have no error injection. It's also cleaner in code.
- Limitation: compared to before, we now don't have write fault injection for backup/restore CopyOrCreateFiles work threads since they use anonymous background threads as well as read injection for db open bg thread
- Add a new flag to test error recovery without error injection so we can test the path where error recovery actually succeeds
- Some Refactory & fix to db stress test framework (see PR review comments)
- Fix some minor bugs surfaced (see PR review comments)
- Limitation: had to disable backup restore with metadata read/write injection since it surfaces too many testing issues. Will add it back later to focus on surfacing actual code/internal bugs first.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12713
Test Plan:
- Existing UT
- CI with no trivial error failure
Reviewed By: pdillinger
Differential Revision: D58326608
Pulled By: hx235
fbshipit-source-id: 011b5195aaeb6011641ae0a9194f7f2a0e325ad7
Summary:
POSIX semantics for LinkFile (hard links) allow linking a file
that is still being written two, with both the source and destination
showing any subsequent writes to the source. This may not be practical
semantics for some FileSystem implementations such as remote storage.
They might only link the flushed or sync-ed file contents at time of
LinkFile, or might even have undefined behavior if LinkFile is called on
a file still open for write (not yet "sealed"). This change builds on https://github.com/facebook/rocksdb/issues/12731
to bring more hygiene to our handling of WAL files in Checkpoint.
Specifically, we now Close WAL files as soon as they are either
(a) inactive and fully synced, or (b) inactive and obsolete (so maybe
never fully synced), rather than letting Close() happen in handling
obsolete files (maybe a background thread). This should not be a
performance issue as Close() should be trivial cost relative to other
IO ops, but just in case:
* We don't Close() while holding a mutex, to avoid blocking, and
* The old behavior is available with a new kill switch option
`background_close_inactive_wals`.
Stacked on https://github.com/facebook/rocksdb/issues/12731
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12734
Test Plan:
Extended existing unit test, especially adding a hygiene
check to FaultInjectionTestFS to detect LinkFile() on a file still open
for writes. FaultInjectionTestFS already has relevant tracking data, and
tests can opt out of the new check, as in a smoke test I have left for
the old, deprecated functionality `background_close_inactive_wals=true`.
Also ran lengthy blackbox_crash_test to ensure the hygiene check is OK
with the crash test. (The only place I can find we use LinkFile in
production is Checkpoint.)
Reviewed By: cbi42
Differential Revision: D58295284
Pulled By: pdillinger
fbshipit-source-id: 64d90ed8477e2366c19eaf9c4c5ad60b82cac5c6
Summary:
Background: there is one active WAL file but there can be
several more WAL files in various states. Those other WALs are always
in a "flushed" state but could be on the `logs_` list not yet fully
synced. We currently allow any WAL that is not the active WAL to be
hard-linked when creating a Checkpoint, as although it might still be
open for write, we are not appending any more data to it.
The problem is that a created Checkpoint is supposed to be fully synced
on return of that function, and a hard-linked WAL in the state described
above might not be fully synced. (Through some prudence in https://github.com/facebook/rocksdb/issues/10083,
it would synced if using track_and_verify_wals_in_manifest=true.)
The fix is a step toward a long term goal of removing the need to query
the filesystem to determine WAL files and their state. (I consider it
dubious any time we independently read from or query metadata from a
file we have open for writing, as this makes us more susceptible to
FileSystem deficiencies or races.) More specifically:
* Detect which WALs might not be fully synced, according to our DBImpl
metadata, and prevent hard linking those (with `trim_to_size=true`
from `GetLiveFilesStorageInfo()`. And while we're at it, use our known
flushed sizes for those WALs.
* To avoid a race between that and GetSortedWalFiles(), track a maximum
needed WAL number for the Checkpoint/GetLiveFilesStorageInfo.
* Because of the level of consistency provided by those two, we no
longer need to consider syncing as part of the FlushWAL in
GetLiveFilesStorageInfo. (We determine the max WAL number consistent
with the manifest file size, while holding DB mutex. Should make
track_and_verify_wals_in_manifest happy.) This makes the premise of
test PutRaceWithCheckpointTrackedWalSync obsolete (sync point callback
no longer hit) so the test is removed, with crash test as backstop for
related issues. See https://github.com/facebook/rocksdb/issues/10185
Stacked on https://github.com/facebook/rocksdb/issues/12729
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12731
Test Plan:
Expanded an existing test, which now fails before fix.
Also long runs of blackbox_crash_test with amplified checkpoint frequency.
Reviewed By: cbi42
Differential Revision: D58199629
Pulled By: pdillinger
fbshipit-source-id: 376e55f4a2b082cd2adb6408a41209de14422382
Summary:
In places (e.g. GetSortedWals()) RocksDB relies on querying the file size or even reading the contents of files currently open for writing, and as in POSIX semantics, expects to see the flushed size and contents regardless of what has been synced. FaultInjectionTestFS historically did not emulate this behavior, only showing synced data from such read operations. (Different from FaultInjectionTestEnv--sigh.)
This change makes the "proper" behavior the default behavior, at least for GetFileSize and FSSequentialFile. However, this new functionality is disabled in db_stress because of undiagnosed, unresolved issues.
Also removes unused and confusing field `pos_at_last_flush_`
This change is needed to support testing a relevant bug fix (in a follow-up diff). Other suggested follow-up:
* Fix db_stress not to rely on the old behavior, and fix a related FIXME in db_stress_test_base.cc in LockWAL testing.
* Fill in some corner cases in the FileSystem API for reading unsynced data (see new TODO items).
* Consider deprecating and removing Flush() API functions from FileSystem APIs. It is not clear to me that there is a supported scenario in which they do anything but confuse API users and developers. If there is a use for them, it doesn't appear to be tested.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12729
Test Plan: applies to all unit tests successfully, just updating the unit test from https://github.com/facebook/rocksdb/issues/12556 due to relying on the errant behavior. Also added a specific unit test
Reviewed By: hx235
Differential Revision: D58091835
Pulled By: pdillinger
fbshipit-source-id: f47a63b2b000f5875b6293a98577bff663d7fd33
Summary:
This PR fix the issue that deletion of obsolete files during DB::Open are not rate limited.
The root cause is slow deletion is disabled if trash/db size ratio exceeds the configured `max_trash_db_ratio` d610e14f93/include/rocksdb/sst_file_manager.h (L126) however, the current handling in DB::Open starts with tracking nothing but the obsolete files. This will make the ratio always look like it's 1.
In order for the deletion rate limiting logic to work properly, we should only start deleting files after `SstFileManager` has finished tracking the whole DB, so the main fix is to move these two places that attempts to delete file after the tracking are done: 1) the `DeleteScheduler::CleanupDirectory` call in `SanitizeOptions`, 2) the `DB::DeleteObsoleteFiles` call.
There are some other aesthetic changes like refactoring collecting all the DB paths into a function, rename `DBImp::DeleteUnreferencedSstFiles` to `DBImpl:: MaybeUpdateNextFileNumber` as it doesn't actually delete the files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12590
Test Plan: Added unit test and verified with manual testing
Reviewed By: anand1976
Differential Revision: D56830519
Pulled By: jowlyzhang
fbshipit-source-id: 8a38a21b1ea11c5371924f2b88663648f7a17885
Summary:
**Context/Summary:**
https://github.com/facebook/rocksdb/pull/12542 introduced a bug where wrong padded bytes used to generate file checksum if flush happens during padding. This PR fixed it along with an existing same bug for `perform_data_verification_=true`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12598
Test Plan:
- New UT that failed before this fix (`db->VerifyFileChecksums: ...Corruption: ...file checksum mismatch`) and passes after
- Benchmark
```
TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=fillseq[-X300] --num=100000 --block_align=1 --compression_type=none
```
Pre-PR:
fillseq [AVG 300 runs] : 421334 (± 4126) ops/sec; 46.6 (± 0.5) MB/sec
Post-PR: (no regression observed but a slight improvement)
fillseq [AVG 300 runs] : 425768 (± 4309) ops/sec; 47.1 (± 0.5) MB/sec
Reviewed By: ajkr, anand1976
Differential Revision: D56725688
Pulled By: hx235
fbshipit-source-id: c1a700a95def8c65c0a21e44f8c1966164925ad5
Summary:
**Context/Summary:**
When `BlockBasedTableOptions::block_align=true`, we pad bytes to align blocks d41e568b1c/table/block_based/block_based_table_builder.cc (L1415-L1421).
Those bytes are not included in generating the file checksum upon file creation. But `VerifyFileChecksums()` includes those bytes in generating the file check to compare against the checksum generating upon file creation. Therefore a file checksum mismatch is returned in `VerifyFileChecksums()`.
We decided to include those padded bytes in generating the checksum upon file creation.
Bonus: also fix surrounding code to use actual padded bytes for verification - see https://github.com/facebook/rocksdb/pull/12542#discussion_r1571429163
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12542
Test Plan:
- New UT
- Benchmark
```
TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=fillseq[-X300] --num=100000 --block_align=1 --compression_type=none
```
Pre-PR:
fillseq [AVG 300 runs] : 422857 (± 3942) ops/sec; 46.8 (± 0.4) MB/sec
Post-PR:
fillseq [AVG 300 runs] : 424707 (± 3799) ops/sec; 47.0 (± 0.4) MB/sec
Reviewed By: ajkr
Differential Revision: D56168447
Pulled By: hx235
fbshipit-source-id: 96209ef950d42943d336f11968ae3fcf9872fc2c
Summary:
This PR is a counterpart of https://github.com/facebook/rocksdb/issues/12427 . On file systems that support storage level data checksum and reconstruction, retry opening the DB if a corruption is detected when reading the MANIFEST. This could be done in `log::Reader`, but its a little complicated since the sequential file would have to be reopened in order to re-read the same data, and we may miss some subtle corruptions that don't result in checksum mismatch. The approach chosen here instead is to make the decision to retry in `DBImpl::Recover`, based on either an explicit corruption in the MANIFEST file, or missing SST files due to bad data in the MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12518
Reviewed By: ajkr
Differential Revision: D55932155
Pulled By: anand1976
fbshipit-source-id: 51755a29b3eb14b9d8e98534adb2e7d54b12ced9
Summary:
Partly following up on leftovers from https://github.com/facebook/rocksdb/issues/12388
In terms of public API:
* Make it clear that IngestExternalFileArg::file_temperature is just a hint for opening the existing file, though it was previously used for both copy-from temp hint and copy-to temp, which was bizarre.
* Specify how IngestExternalFile assigns temperature to file ingested into DB. (See details in comments.) This approach is not perfect in terms of matching how the DB assigns temperatures, but was the simplest way to get close. The key complication for matching DB temperature assignments is that ingestion files are copied (to a destination temp) before their target level is determined (in general).
* Add a temperature option to SstFileWriter::Open so that files intended for ingestion can be initially written to a chosen temperature.
* Note that "fail_if_not_bottommost_level" is obsolete/confusing use of "bottommost"
In terms of the implementation, there was a similar bit of oddness with the internal CopyFile API, which only took one temperature, ambiguously applicable to the source, destination, or both. This is also fixed.
Eventual suggested follow-up:
* Before copying files for ingestion, determine a tentative level assignment to use for destination temperature, and keep that even if final level assignment happens to be different at commit time (rare).
* More temperature handling for CreateColumnFamilyWithImport and Checkpoints.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12402
Test Plan:
Deeply revamped
ExternalSSTFileBasicTest.IngestWithTemperature to test the new changes. Previously this test was insufficient because it was only looking at temperatures according to the DB manifest. Incorporating FileTemperatureTestFS allows us to also test the temperatures in the storage layer.
Used macros instead of functions for better tracing to critical source location on test failures.
Some enhancements to FileTemperatureTestFS in the process of developing the revamped test.
Reviewed By: jowlyzhang
Differential Revision: D54442794
Pulled By: pdillinger
fbshipit-source-id: 41d9d0afdc073e6a983304c10bbc07c70cc7e995
Summary:
Currently SST files that aren't applicable to last_level_temperature nor file_temperature_age_thresholds are written with temperature kUnknown, which is a little weird and doesn't support CF-based tiering. The default_temperature option only affects how kUnknown is interpreted for stats.
This change adds a new per-CF option default_write_temperature that determines the temperature of new SST files when those other options do not apply.
Also made a change to ignore last_level_temperature with FIFO compaction, because I found that could lead to an infinite loop in compaction.
Needed follow-up: Fix temperature handling with external file ingestion
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12388
Test Plan: unit tests extended appropriately. (Ignore whitespace changes when reviewing.)
Reviewed By: jowlyzhang
Differential Revision: D54266574
Pulled By: pdillinger
fbshipit-source-id: c9ec9a74dbf22be6e986f77f9689d05fea8ef0bb
Summary:
Modify ReadAsync callback API to remove const from FSReadRequest as const doesn't let to fs_scratch to move the ownership.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11649
Test Plan: CircleCI jobs
Reviewed By: anand1976
Differential Revision: D53585309
Pulled By: akankshamahajan15
fbshipit-source-id: 3bff9035db0e6fbbe34721a5963443355807420d
Summary:
The following are risks associated with pointer-to-pointer reinterpret_cast:
* Can produce the "wrong result" (crash or memory corruption). IIRC, in theory this can happen for any up-cast or down-cast for a non-standard-layout type, though in practice would only happen for multiple inheritance cases (where the base class pointer might be "inside" the derived object). We don't use multiple inheritance a lot, but we do.
* Can mask useful compiler errors upon code change, including converting between unrelated pointer types that you are expecting to be related, and converting between pointer and scalar types unintentionally.
I can only think of some obscure cases where static_cast could be troublesome when it compiles as a replacement:
* Going through `void*` could plausibly cause unnecessary or broken pointer arithmetic. Suppose we have
`struct Derived: public Base1, public Base2`. If we have `Derived*` -> `void*` -> `Base2*` -> `Derived*` through reinterpret casts, this could plausibly work (though technical UB) assuming the `Base2*` is not dereferenced. Changing to static cast could introduce breaking pointer arithmetic.
* Unnecessary (but safe) pointer arithmetic could arise in a case like `Derived*` -> `Base2*` -> `Derived*` where before the Base2 pointer might not have been dereferenced. This could potentially affect performance.
With some light scripting, I tried replacing pointer-to-pointer reinterpret_casts with static_cast and kept the cases that still compile. Most occurrences of reinterpret_cast have successfully been changed (except for java/ and third-party/). 294 changed, 257 remain.
A couple of related interventions included here:
* Previously Cache::Handle was not actually derived from in the implementations and just used as a `void*` stand-in with reinterpret_cast. Now there is a relationship to allow static_cast. In theory, this could introduce pointer arithmetic (as described above) but is unlikely without multiple inheritance AND non-empty Cache::Handle.
* Remove some unnecessary casts to void* as this is allowed to be implicit (for better or worse).
Most of the remaining reinterpret_casts are for converting to/from raw bytes of objects. We could consider better idioms for these patterns in follow-up work.
I wish there were a way to implement a template variant of static_cast that would only compile if no pointer arithmetic is generated, but best I can tell, this is not possible. AFAIK the best you could do is a dynamic check that the void* conversion after the static cast is unchanged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12308
Test Plan: existing tests, CI
Reviewed By: ltamasi
Differential Revision: D53204947
Pulled By: pdillinger
fbshipit-source-id: 9de23e618263b0d5b9820f4e15966876888a16e2
Summary:
Provide support for FSBuffer for point lookups
It also add support for compaction and scan reads that goes through BlockFetcher when readahead/prefetching is not enabled.
Some of the compaction/Scan reads goes through FilePrefetchBuffer and some through BlockFetcher. This PR add support to use underlying file system scratch buffer for reads that go through BlockFetcher as for FilePrefetch reads, design is complicated to support this feature.
Design - In order to use underlying FileSystem provided scratch for Reads, it uses MultiRead with 1 request instead of Read API which required API change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12266
Test Plan: Stress test using underlying file system scratch buffer internally.
Reviewed By: anand1976
Differential Revision: D53019089
Pulled By: akankshamahajan15
fbshipit-source-id: 4fe3d090d77363320e4b67186fd4d51c005c0961
Summary:
In C++, `extern` is redundant in a number of cases:
* "Global" function declarations and definitions
* "Global" variable definitions when already declared `extern`
For consistency and simplicity, I've removed these in code that *we own*. In a couple of cases, I removed obsolete declarations, and for MagicNumber constants, I have consolidated the declarations into a header file (format.h)
as standard best practice would prescribe.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12300
Test Plan: no functional changes, CI
Reviewed By: ajkr
Differential Revision: D53148629
Pulled By: pdillinger
fbshipit-source-id: fb8d927959892e03af09b0c0d542b0a3b38fd886
Summary:
**Context/Summary:**
The rate_limiter_priority passed to SequentialFileReader is now passed down to underlying file system. This allows the priority associated with backup/restore SST reads to be exposed to FS.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12296
Test Plan: - Modified existing UT
Reviewed By: pdillinger
Differential Revision: D53100368
Pulled By: hx235
fbshipit-source-id: b4a28917efbb1b0d16f9d1c2b38769bffcff0f34
Summary:
After refactoring of FilePrefetchBuffer, PREFETCH_BYTES_USEFUL was miscalculated. Instead of calculating how many requested bytes are already in the buffer, it took into account alignment as well because aligned_useful_len takes into consideration alignment too.
Also refactored the naming of chunk_offset_in_buffer to make it similar to aligned_useful_len
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12251
Test Plan:
1. Validated internally through release validation benchmarks.
2. Updated unit test that fails without the fix.
Reviewed By: ajkr
Differential Revision: D52891112
Pulled By: akankshamahajan15
fbshipit-source-id: 2526a0b0572d473beaf8b841f2f9c2f6275d9779
Summary:
Fix heap use after free error in FilePrefetchBuffer
Fix heap use after free error in FilePrefetchBuffer
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12211
Test Plan:
Ran db_stress in ASAN mode
```
==652957==ERROR: AddressSanitizer: heap-use-after-free on address 0x6150006d8578 at pc 0x7f91f74ae85b bp 0x7f91c25f90c0 sp 0x7f91c25f90b8
READ of size 8 at 0x6150006d8578 thread T48
#0 0x7f91f74ae85a in void __gnu_cxx::new_allocator<rocksdb::BufferInfo*>::construct<rocksdb::BufferInfo*, rocksdb::BufferInfo*&>(rocksdb::BufferInfo**, rocksdb::BufferInfo*&) /mnt/gvfs/third-party2/libgcc/c00dcc6a3e4125c7e8b248e9a79c14b78ac9e0ca/11.x/platform010/5684a5a/include/c++/trunk/ext/new_allocator.h:163
https://github.com/facebook/rocksdb/issues/1 0x7f91f74ae85a in void std::allocator_traits<std::allocator<rocksdb::BufferInfo*> >::construct<rocksdb::BufferInfo*, rocksdb::BufferInfo*&>(std::allocator<rocksdb::BufferInfo*>&, rocksdb::BufferInfo**, rocksdb::BufferInfo*&) /mnt/gvfs/third-party2/libgcc/c00dcc6a3e4125c7e8b248e9a79c14b78ac9e0ca/11.x/platform010/5684a5a/include/c++/trunk/bits/alloc_traits.h:512
https://github.com/facebook/rocksdb/issues/2 0x7f91f74ae85a in rocksdb::BufferInfo*& std::deque<rocksdb::BufferInfo*, std::allocator<rocksdb::BufferInfo*> >::emplace_back<rocksdb::BufferInfo*&>(rocksdb::BufferInfo*&) /mnt/gvfs/third-party2/libgcc/c00dcc6a3e4125c7e8b248e9a79c14b78ac9e0ca/11.x/platform010/5684a5a/include/c++/trunk/bits/deque.tcc:170
https://github.com/facebook/rocksdb/issues/3 0x7f91f74b93d8 in rocksdb::FilePrefetchBuffer::FreeAllBuffers() file/file_prefetch_buffer.h:557
```
Reviewed By: ajkr
Differential Revision: D52575217
Pulled By: akankshamahajan15
fbshipit-source-id: 6811ec10a393f5a62fedaff0fab5fd6e823c2687
Summary:
Summary - Refactor FilePrefetchBuffer code
- Implementation:
FilePrefetchBuffer maintains a deque of free buffers (free_bufs_) of size num_buffers_ and buffers (bufs_) which contains the prefetched data. Whenever a buffer is consumed or is outdated (w.r.t. to requested offset), that buffer is cleared and returned to free_bufs_.
If a buffer is available in free_bufs_, it's moved to bufs_ and is sent for prefetching. num_buffers_ defines how many buffers are maintained that contains prefetched data.
If num_buffers_ == 1, it's a sequential read flow. Read API will be called on that one buffer whenever the data is requested and is not in the buffer.
If num_buffers_ > 1, then the data is prefetched asynchronosuly in the buffers whenever the data is consumed from the buffers and that buffer is freed.
If num_buffers > 1, then requested data can be overlapping between 2 buffers. To return the continuous buffer overlap_bufs_ is used. The requested data is copied from 2 buffers to the overlap_bufs_ and overlap_bufs_ is returned to
the caller.
- Merged Sync and Async code flow into one in FilePrefetchBuffer.
Test Plan -
- Crash test passed
- Unit tests
- Pending - Benchmarks
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12097
Reviewed By: ajkr
Differential Revision: D51759552
Pulled By: akankshamahajan15
fbshipit-source-id: 69a352945affac2ed22be96048d55863e0168ad5
Summary:
FilePrefetchBuffer makes an unchecked assumption about the behavior of RandomAccessFileReader::Read: that it will write to the provided buffer rather than returning the data in an alternate buffer. FilePrefetchBuffer has been quietly incompatible with mmap reads (e.g. allow_mmap_reads / use_mmap_reads) because in that case an alternate buffer is returned (mmapped memory). This incompatibility currently leads to quiet data corruption, as seen in amplified crash test failure in https://github.com/facebook/rocksdb/issues/12200.
In this change,
* Check whether RandomAccessFileReader::Read has the expected behavior, and fail if not. (Assertion failure in debug build, return Corruption in release build.) This will detect future regressions synchronously and precisely, rather than relying on debugging downstream data corruption.
* Why not recover? My understanding is that FilePrefetchBuffer is not intended for use when RandomAccessFileReader::Read uses an alternate buffer, so quietly recovering could lead to undesirable (inefficient) behavior.
* Mention incompatibility with mmap-based readers in the internal API comments for FilePrefetchBuffer
* Fix two cases where FilePrefetchBuffer could be used with mmap, both stemming from SstFileDumper, though one fix is in BlockBasedTableReader. There is currently no way to ask a RandomAccessFileReader whether it's using mmap, so we currently have to rely on other options as clues.
Keeping separate from https://github.com/facebook/rocksdb/issues/12200 in part because this change is more appropriate for backport than that one.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12206
Test Plan:
* Manually verified that the new check aids in debugging.
* Unit test added, that fails if either fix is missed.
* Ran blackbox_crash_test for hours, with and without https://github.com/facebook/rocksdb/issues/12200
Reviewed By: akankshamahajan15
Differential Revision: D52551701
Pulled By: pdillinger
fbshipit-source-id: dea87c5782b7c484a6c6e424585c8832dfc580dc
Summary:
## Context/Summary
Similar to https://github.com/facebook/rocksdb/pull/11288, https://github.com/facebook/rocksdb/pull/11444, categorizing SST/blob file write according to different io activities allows more insight into the activity.
For that, this PR does the following:
- Tag different write IOs by passing down and converting WriteOptions to IOOptions
- Add new SST_WRITE_MICROS histogram in WritableFileWriter::Append() and breakdown FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS
Some related code refactory to make implementation cleaner:
- Blob stats
- Replace high-level write measurement with low-level WritableFileWriter::Append() measurement for BLOB_DB_BLOB_FILE_WRITE_MICROS. This is to make FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS include blob file. As a consequence, this introduces some behavioral changes on it, see HISTORY and db bench test plan below for more info.
- Fix bugs where BLOB_DB_BLOB_FILE_SYNCED/BLOB_DB_BLOB_FILE_BYTES_WRITTEN include file failed to sync and bytes failed to write.
- Refactor WriteOptions constructor for easier construction with io_activity and rate_limiter_priority
- Refactor DBImpl::~DBImpl()/BlobDBImpl::Close() to bypass thread op verification
- Build table
- TableBuilderOptions now includes Read/WriteOpitons so BuildTable() do not need to take these two variables
- Replace the io_priority passed into BuildTable() with TableBuilderOptions::WriteOpitons::rate_limiter_priority. Similar for BlobFileBuilder.
This parameter is used for dynamically changing file io priority for flush, see https://github.com/facebook/rocksdb/pull/9988?fbclid=IwAR1DtKel6c-bRJAdesGo0jsbztRtciByNlvokbxkV6h_L-AE9MACzqRTT5s for more
- Update ThreadStatus::FLUSH_BYTES_WRITTEN to use io_activity to track flush IO in flush job and db open instead of io_priority
## Test
### db bench
Flush
```
./db_bench --statistics=1 --benchmarks=fillseq --num=100000 --write_buffer_size=100
rocksdb.sst.write.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.flush.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.compaction.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.db.open.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
```
compaction, db oopen
```
Setup: ./db_bench --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench
Run:./db_bench --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1
rocksdb.sst.write.micros P50 : 2.675325 P95 : 9.578788 P99 : 18.780000 P100 : 314.000000 COUNT : 638 SUM : 3279
rocksdb.file.write.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.compaction.micros P50 : 2.757353 P95 : 9.610687 P99 : 19.316667 P100 : 314.000000 COUNT : 615 SUM : 3213
rocksdb.file.write.db.open.micros P50 : 2.055556 P95 : 3.925000 P99 : 9.000000 P100 : 9.000000 COUNT : 23 SUM : 66
```
blob stats - just to make sure they aren't broken by this PR
```
Integrated Blob DB
Setup: ./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench
Run:./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1
pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 7.298246 P95 : 9.771930 P99 : 9.991813 P100 : 16.000000 COUNT : 235 SUM : 1600
rocksdb.blobdb.blob.file.synced COUNT : 1
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842
post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 2.000000 P95 : 2.829360 P99 : 2.993779 P100 : 9.000000 COUNT : 707 SUM : 1614
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164
rocksdb.blobdb.blob.file.synced COUNT : 1 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 (stay the same)
```
```
Stacked Blob DB
Run: ./db_bench --use_blob_db=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench
pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 12.808042 P95 : 19.674497 P99 : 28.539683 P100 : 51.000000 COUNT : 10000 SUM : 140876
rocksdb.blobdb.blob.file.synced COUNT : 8
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445
post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 1.657370 P95 : 2.952175 P99 : 3.877519 P100 : 24.000000 COUNT : 30001 SUM : 67924
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164
rocksdb.blobdb.blob.file.synced COUNT : 8 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 (stay the same)
```
### Rehearsal CI stress test
Trigger 3 full runs of all our CI stress tests
### Performance
Flush
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=ManualFlush/key_num:524288/per_key_size:256 --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark; enable_statistics = true
Pre-pr: avg 507515519.3 ns
497686074,499444327,500862543,501389862,502994471,503744435,504142123,504224056,505724198,506610393,506837742,506955122,507695561,507929036,508307733,508312691,508999120,509963561,510142147,510698091,510743096,510769317,510957074,511053311,511371367,511409911,511432960,511642385,511691964,511730908,
Post-pr: avg 511971266.5 ns, regressed 0.88%
502744835,506502498,507735420,507929724,508313335,509548582,509994942,510107257,510715603,511046955,511352639,511458478,512117521,512317380,512766303,512972652,513059586,513804934,513808980,514059409,514187369,514389494,514447762,514616464,514622882,514641763,514666265,514716377,514990179,515502408,
```
Compaction
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_{pre|post}_pr --benchmark_filter=ManualCompaction/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1 --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark
Pre-pr: avg 495346098.30 ns
492118301,493203526,494201411,494336607,495269217,495404950,496402598,497012157,497358370,498153846
Post-pr: avg 504528077.20, regressed 1.85%. "ManualCompaction" include flush so the isolated regression for compaction should be around 1.85-0.88 = 0.97%
502465338,502485945,502541789,502909283,503438601,504143885,506113087,506629423,507160414,507393007
```
Put with WAL (in case passing WriteOptions slows down this path even without collecting SST write stats)
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=DBPut/comp_style:0/max_data:107374182400/per_key_size:256/enable_statistics:1/wal:1 --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark
Pre-pr: avg 3848.10 ns
3814,3838,3839,3848,3854,3854,3854,3860,3860,3860
Post-pr: avg 3874.20 ns, regressed 0.68%
3863,3867,3871,3874,3875,3877,3877,3877,3880,3881
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11910
Reviewed By: ajkr
Differential Revision: D49788060
Pulled By: hx235
fbshipit-source-id: 79e73699cda5be3b66461687e5147c2484fc5eff
Summary:
Add support for tuning of readahead_size by block cache lookup for async_io.
**Design/ Implementation** -
**BlockBasedTableIterator.cc** -
`BlockCacheLookupForReadAheadSize` callback API lookups in the block cache and tries to reduce the start
and end offset passed. This function looks into the block cache for the blocks between `start_offset`
and `end_offset` and add all the handles in the queue.
It then iterates from the end in the handles to find first miss block and update the end offset to that block.
It also iterates from the start and find first miss block and update the start offset to that block.
```
_read_curr_block_ argument : True if this call was due to miss in the cache and caller wants to read that block
synchronously.
False if current call is to prefetch additional data in extra buffers
(due to ReadAsync call in FilePrefetchBuffer)
```
In case there is no data to be read in that callback (because of upper_bound or all blocks are in cache),
it updates start and end offset to be equal and that `FilePrefetchBuffer` interprets that as 0 length to be read.
**FilePrefetchBuffer.cc** -
FilePrefetchBuffer calls the callback - `ReadAheadSizeTuning` and pass the start and end offset to that
callback to get updated start and end offset to read based on cache hits/misses.
1. In case of Read calls (when offset passed to FilePrefetchBuffer is on cache miss and that data needs to be read), _read_curr_block_ is passed true.
2. In case of ReadAsync calls, when buffer is all consumed and can go for additional prefetching, the start offset passed is the initial end offset of prev buffer (without any updated offset based on cache hit/miss).
Foreg. if following are the data blocks with cache hit/miss and start offset
and Read API found miss on DB1 and based on readahead_size (50) it passes end offset to be 50.
[DB1 - miss- 0 ] [DB2 - hit -10] [DB3 - miss -20] [DB4 - miss-30] [DB5 - hit-40]
[DB6 - hit-50] [DB7 - miss-60] [DB8 - miss - 70] [DB9 - hit - 80] [DB6 - hit 90]
- For Read call - updated start offset remains 0 but end offset updates to DB4, as DB5 is in cache.
- Read calls saves initial end offset 50 as that was meant to be prefetched.
- Now for next ReadAsync call - the start offset will be 50 (previous buffer initial end offset) and based on readahead_size, end offset will be 100
- On callback, because of cache hits - callback will update the start offset to 60 and end offset to 80 to read only 2 data blocks (DB7 and DB8).
- And for that ReadAsync call - initial end offset will be set to 100 which will again used by next ReadAsync call as start offset.
- `initial_end_offset_` in `BufferInfo` is used to save the initial end offset of that buffer.
- If let's say DB5 and DB6 overlaps in 2 buffers (because of alignment), `prev_buf_end_offset` is passed to make sure already prefetched data is not prefetched again in second buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11936
Test Plan:
- Ran crash_test several times.
- New unit tests added.
Reviewed By: anand1976
Differential Revision: D50906217
Pulled By: akankshamahajan15
fbshipit-source-id: 0d75d3c98274e98aa34901b201b8fb05232139cf
Summary:
Add stats for better observability of scan prefetching. Its only implemented for sync scan right now. These stats can help inform future improvements in scan prefetching.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11981
Test Plan: Add a new unit test
Reviewed By: akankshamahajan15
Differential Revision: D50516505
Pulled By: anand1976
fbshipit-source-id: cb1cc6cf02df8295930a49c62b11870020df3f97
Summary:
... when compiled with ASSERT_STATUS_CHECKED = 1.
The main change is in iterator_wrapper.h. The remaining changes are just fixing existing unit tests. Adding this check to IteratorWrapper gives a good coverage as the class is used in many places, including child iterators under merging iterator, merging iterator under DB iter, file_iter under level iterator, etc. This change can catch the bug fixed in https://github.com/facebook/rocksdb/issues/11782.
Future follow up: enable `ASSERT_STATUS_CHECKED=1` for stress test and for DEBUG_LEVEL=0.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11975
Test Plan:
* `ASSERT_STATUS_CHECKED=1 DEBUG_LEVEL=2 make -j32 J=32 check`
* I tried to run stress test with `ASSERT_STATUS_CHECKED=1`, but there are a lot of existing stress code that ignore status checking, and fail without the change in this PR. So defer that to a follow up task.
Reviewed By: ajkr
Differential Revision: D50383790
Pulled By: cbi42
fbshipit-source-id: 1a28ce0f5fdf1890f93400b26b3b1b3a287624ce
Summary:
Remove assertion from PrefetchAsync (roundup_len2 >= alignment) as for non direct_io, buffer size can be less than alignment resulting in assertion.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11965
Test Plan: Ran the issue causing db_stress without this assertion and the verification completes successfully.
Reviewed By: anand1976
Differential Revision: D50328955
Pulled By: akankshamahajan15
fbshipit-source-id: 65f55ca230d2bbc63f4e2cc34c7273b22b515879
Summary:
1. **Error** in TestIterateAgainstExpected API - `Assertion index < pre_read_expected_values.size() && index < post_read_expected_values.size() failed.`
**Fix** - `Prev` op is not supported with `auto_readahead_size`. So added support to Reseek in db_iter, if Prev is called. In BlockBasedTableIterator, index_iter_ already moves forward. So there is no way to do Prev from BlockBasedTableIterator.
2. **Error** - `void rocksdb::BlockBasedTableIterator::BlockCacheLookupForReadAheadSize(uint64_t, size_t, size_t&): Assertion index_iter_->value().handle.offset() == offset`
**Fix** - Remove prefetch_buffer to be used when uncompressed dict is read.
3. ** Error in TestPrefixScan API - `db_stress: db/db_iter.cc:369: bool rocksdb::DBIter::FindNextUserEntryInternal(bool, const rocksdb::Slice*): Assertion !skipping_saved_key || CompareKeyForSkip(ikey_.user_key, saved_key_.GetUserKey()) > 0 failed.
Received signal 6 (Aborted)
Invoking GDB for stack trace...
db_stress: table/merging_iterator.cc:1036: bool rocksdb::MergingIterator::SkipNextDeleted(): Assertion comparator_->Compare(range_tombstone_iters_[i]->start_key(), pik) <= 0 failed`
**Fix** - SeekPrev also calls 1) SeekPrev , 2)Seek and then 3)Prev in some cases in db_iter.cc leading to failure of Prev operation. These backward operations also call Seek. Added direction to disable lookup once direction is backwards in BlockBasedTableIterator.cc
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11884
Test Plan: Ran various flavors of crash tests locally for the whole duration
Reviewed By: anand1976
Differential Revision: D49834201
Pulled By: akankshamahajan15
fbshipit-source-id: 9a007b4d46a48002c43dc4623a400ecf47d997fe
Summary:
Implement block cache lookup to determine readahead_size during scans. It's enabled if auto_readahead_size, block_cache and iterate_upper_bound - all three are set.
Design -
1. Whenever there is a cache miss and FilePrefetchBuffer is called, a callback is made to determine readahead_size for that prefetching.
2. The callback iterates over index and do block cache lookup for each data block handle until existing readahead_size is reached. Then It removes the cache hit data blocks from end to calculate optimized readahead_size.
3. Since index_iter_ is moved, it stores block handles in a queue, and use that queue to get block handle instead of doing index_iter_->Next().
4. This is for Sync scans. Async scans support is in progress.
NOTE:
The issue right now is after Seek and Next, if Prev is called, there is no way to do Prev operation. index_iter_ is already pointing to a different block. So it returns "Not supported" in that case with error message - "auto tuning of readahead size is not supported with Prev op"
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11860
Test Plan:
- Added new unit test
- crash_tests
- Running scans locally to check for any regression
Reviewed By: anand1976
Differential Revision: D49548118
Pulled By: akankshamahajan15
fbshipit-source-id: f1aee409a71b4ad9e5bf3610f43edf30c6630c78
Summary:
When auto_readahead_size is enabled in async_io, during seek, first buffer will prefetch the data - (current block + readahead till upper_bound). There can be cases where
1. first buffer prefetched all the data till upper bound, or
2. first buffer already has the data from prev seek call
and second buffer prefetch further leading to alignment issues.
This PR fixes that assertion and second buffer won't go for prefetching if first buffer has already prefetched till upper_bound.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11852
Test Plan:
- Added new unit test that failed without this fix.
- crash tests passed locally
Reviewed By: pdillinger
Differential Revision: D49384138
Pulled By: akankshamahajan15
fbshipit-source-id: 54417e909e4d986f1e5a17dbaea059cd4962fd4d
Summary:
With the async_io option, the Seek happens in 2 phases. Phase 1 starts an asynchronous read on a block cache miss, and phase 2 waits for it to complete and finishes the seek. In both phases, BlockBasedTable::NewDataBlockIterator is called, which tries to lookup the block cache for the data block first before looking in the prefetch buffer. It's optimized by doing the block cache lookup only in the first phase and save some CPU.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11616
Test Plan: Added unit test
Reviewed By: jaykorean
Differential Revision: D47477887
Pulled By: akankshamahajan15
fbshipit-source-id: 0355e0a68fc0ea2eb92340ae42735afcdbcbfd79
Summary:
Update the logic in FilePrefetchBuffer to update `upper_bound_offset_` during reseek. During Reseek, `iterate_upper_bound` can be changed dynamically. So added an API to update that in FilePrefetchBuffer.
Added unit test to confirm the behavior.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11775
Test Plan:
- Check stress tests in case there is any failure after this diff.
- make crash_test -j32 with auto_readahead_size=1 passed locally
Reviewed By: anand1976
Differential Revision: D48815177
Pulled By: akankshamahajan15
fbshipit-source-id: 5f44fbb3af06c86a1c38f139c5fa4543891837f4
Summary:
During Seek, the iterator seeks every file on L0. In async_io, it submit the requests to seek on every file on L0 asynchronously using RocksDB FilePrefetchBuffer.
However, FilePrefetchBuffer does alignment and reads extra bytes then needed that can increase the throughput.
In case of non direct io, the alignment can be avoided.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11793
Test Plan:
- Added a unit test that fails without this PR.
- make crash_test -j32 completed successfully
Reviewed By: anand1976
Differential Revision: D48985051
Pulled By: akankshamahajan15
fbshipit-source-id: 2d130a9e7c3df9c4fcd0408406e6277ab75a4389
Summary:
Some repro unit tests for the bug fixed in https://github.com/facebook/rocksdb/pull/11782.
Ran on main without https://github.com/facebook/rocksdb/pull/11782:
```
./db_compaction_test --gtest_filter='*ErrorWhenReadFileHead'
Note: Google Test filter = *ErrorWhenReadFileHead
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from DBCompactionTest
[ RUN ] DBCompactionTest.ErrorWhenReadFileHead
db/db_compaction_test.cc:10105: Failure
Value of: s.IsIOError()
Actual: false
Expected: true
[ FAILED ] DBCompactionTest.ErrorWhenReadFileHead (3960 ms)
./db_iterator_test --gtest_filter="*ErrorWhenReadFile*"
Note: Google Test filter = *ErrorWhenReadFile*
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from DBIteratorTest
[ RUN ] DBIteratorTest.ErrorWhenReadFile
db/db_iterator_test.cc:3399: Failure
Value of: (iter->status()).ok()
Actual: true
Expected: false
[ FAILED ] DBIteratorTest.ErrorWhenReadFile (280 ms)
[----------] 1 test from DBIteratorTest (280 ms total)
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11788
Reviewed By: ajkr
Differential Revision: D48940284
Pulled By: cbi42
fbshipit-source-id: 06f3c5963f576db3f85d305ffb2745ee13d209bb
Summary:
Fix seg fault in auto_readahead_size with async_io when readahead_size = 0. If readahead_size is trimmed and is 0, it's not eligible for further prefetching and should return.
Error occured when the first buffer already contains data and it goes for prefetching in second buffer leading to assertion failure -
`assert(roundup_len1 >= alignment);
`
because roundup_len1 = length + readahead_size.
length is 0 and readahead_size is also 0.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11769
Test Plan: Reproducible with db_stress with async_io enabled.
Reviewed By: anand1976
Differential Revision: D48743031
Pulled By: akankshamahajan15
fbshipit-source-id: 0e08c41f862f6287ca223fbfaf6cd42fc97b3c87
Summary:
**Context/Summary:** as title, should be harmless. And it's a guessed fix to https://github.com/facebook/rocksdb/issues/11717 while no repro has obtained on my end yet.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11720
Test Plan: existing tests
Reviewed By: cbi42
Differential Revision: D48475661
Pulled By: hx235
fbshipit-source-id: 7c7390319f094c540e703fe2e78a8d601b7a894b
Summary:
Implement trimming of readahead_size under a new option ReadOptions.auto_readahead_size. It'll trim the readahead_size during prefetching upto iterate_upper_bound offset only when ReadOptions.iterate_upper_bound is set, therefore reducing the prefetching of data beyond upper_bound.
It's enabled for both implicit auto readahead size and when ReadOptions.readahead_size is specified and for sync and async_io.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11684
Test Plan: Added new unit test
Reviewed By: anand1976
Differential Revision: D48479723
Pulled By: akankshamahajan15
fbshipit-source-id: 2b1703579caf779105e836b580866ffd7db076fc
