Summary:
Enhancement to MultiGet batching to read data blocks required for keys in a batch in parallel from disk. It uses Env::MultiRead() API to read multiple blocks and reduce latency.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5464
Test Plan:
1. make check
2. make asan_check
3. make asan_crash
Differential Revision: D15911771
Pulled By: anand1976
fbshipit-source-id: 605036b9af0f90ca0020dc87c3a86b4da6e83394
Summary:
Add C binding for secondary instance as well as unit test.
Test plan (on devserver)
```
$make clean && COMPILE_WITH_ASAN=1 make -j20 all
$./c_test
$make check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5505
Differential Revision: D16000043
Pulled By: riversand963
fbshipit-source-id: 3361ef6bfdf4ce12438cee7290a0ac203b5250bd
Summary:
The first key is used to defer reading the data block until this file gets to the top of merging iterator's heap. For short range scans, most files never make it to the top of the heap, so this change can reduce read amplification by a lot sometimes.
Consider the following workload. There are a few data streams (we'll be calling them "logs"), each stream consisting of a sequence of blobs (we'll be calling them "records"). Each record is identified by log ID and a sequence number within the log. RocksDB key is concatenation of log ID and sequence number (big endian). Reads are mostly relatively short range scans, each within a single log. Writes are mostly sequential for each log, but writes to different logs are randomly interleaved. Compactions are disabled; instead, when we accumulate a few tens of sst files, we create a new column family and start writing to it.
So, a typical sst file consists of a few ranges of blocks, each range corresponding to one log ID (we use FlushBlockPolicy to cut blocks at log boundaries). A typical read would go like this. First, iterator Seek() reads one block from each sst file. Then a series of Next()s move through one sst file (since writes to each log are mostly sequential) until the subiterator reaches the end of this log in this sst file; then Next() switches to the next sst file and reads sequentially from that, and so on. Often a range scan will only return records from a small number of blocks in small number of sst files; in this case, the cost of initial Seek() reading one block from each file may be bigger than the cost of reading the actually useful blocks.
Neither iterate_upper_bound nor bloom filters can prevent reading one block from each file in Seek(). But this PR can: if the index contains first key from each block, we don't have to read the block until this block actually makes it to the top of merging iterator's heap, so for short range scans we won't read any blocks from most of the sst files.
This PR does the deferred block loading inside value() call. This is not ideal: there's no good way to report an IO error from inside value(). As discussed with siying offline, it would probably be better to change InternalIterator's interface to explicitly fetch deferred value and get status. I'll do it in a separate PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5289
Differential Revision: D15256423
Pulled By: al13n321
fbshipit-source-id: 750e4c39ce88e8d41662f701cf6275d9388ba46a
Summary:
It it not safe to assume application had sync the SST file before ingest it into DB. Also the directory to put the ingested file needs to be fsync, otherwise the file can be lost. For integrity of RocksDB we need to sync the ingested file and directory before apply the change to manifest.
Also syncing after writing global sequence when write_global_seqno=true was removed in https://github.com/facebook/rocksdb/issues/4172. Adding it back.
Fixes https://github.com/facebook/rocksdb/issues/5287.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5435
Test Plan:
Test ingest file with ldb command and observe fsync/fdatasync in strace output. Tried both move_files=true and move_files=false.
https://gist.github.com/yiwu-arbug/650a4023f57979056d83485fa863bef9
More test suggestions are welcome.
Differential Revision: D15941675
Pulled By: riversand963
fbshipit-source-id: 389533f3923065a96df2cdde23ff4724a1810d78
Summary:
This PR adds more callers for table readers. These information are only used for block cache analysis so that we can know which caller accesses a block.
1. It renames the BlockCacheLookupCaller to TableReaderCaller as passing the caller from upstream requires changes to table_reader.h and TableReaderCaller is a more appropriate name.
2. It adds more table reader callers in table/table_reader_caller.h, e.g., kCompactionRefill, kExternalSSTIngestion, and kBuildTable.
This PR is long as it requires modification of interfaces in table_reader.h, e.g., NewIterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5454
Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32.
Differential Revision: D15819451
Pulled By: HaoyuHuang
fbshipit-source-id: b6caa704c8fb96ddd15b9a934b7e7ea87f88092d
Summary:
`Block::restart_index_`, `Block::restarts_`, and `Block::current_` are defined as uint32_t but `BlockBasedTableOptions::block_size` is defined as a size_t so user might see corruption as in https://github.com/facebook/rocksdb/issues/5486.
This PR adds a check in `BlockBasedTableFactory::SanitizeOptions` to disallow such configurations.
yiwu-arbug
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5492
Differential Revision: D15914047
Pulled By: miasantreble
fbshipit-source-id: c943f153d967e15aee7f2795730ab8259e2be201
Summary:
Currently the read-ahead logic for user reads and compaction reads go through different code paths where compaction reads create new table readers and use `ReadaheadRandomAccessFile`. This change is to unify read-ahead logic to use read-ahead in BlockBasedTableReader::InitDataBlock(). As a result of the change `ReadAheadRandomAccessFile` class and `new_table_reader_for_compaction_inputs` option will no longer be used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5431
Test Plan:
make check
Here is the benchmarking - https://gist.github.com/vjnadimpalli/083cf423f7b6aa12dcdb14c858bc18a5
Differential Revision: D15772533
Pulled By: vjnadimpalli
fbshipit-source-id: b71dca710590471ede6fb37553388654e2e479b9
Summary:
When tailing the WAL with TransactionLogIterator, it used to return Corruption status to indicate that the WAL has new tail that is not visible to the iterator, which is a misleading status. The patch replaces it with TryAgain which is more descriptive of a status, indicating that the user needs to create a new iterator to fetch the recent tail.
Fixes https://github.com/facebook/rocksdb/issues/5455
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5474
Differential Revision: D15898953
Pulled By: maysamyabandeh
fbshipit-source-id: 40966f6457cb539e1aeb104daeada6b0e46059fc
Summary:
While the secondary is replaying after the primary, the primary may switch to a new MANIFEST. The secondary is already able to detect and follow the primary to the new MANIFEST. However, the current implementation has a bug, described as follows.
The new MANIFEST's first records have been generated by VersionSet::WriteSnapshot to describe the current state of the column families and the db as of the MANIFEST creation. Since the secondary instance has already finished recovering upon start, there is no need for the secondary to process these records. Actually, if the secondary were to replay these records, the secondary may end up adding the same SST files **again** to each column family, causing consistency checks done by VersionBuilder to fail. Therefore, we record the number of records to skip at the beginning of the new MANIFEST and ignore them.
Test plan (on dev server)
```
$make clean && make -j32 all
$./db_secondary_test
```
All existing unit tests must pass as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5472
Differential Revision: D15866771
Pulled By: riversand963
fbshipit-source-id: a1eec4837fb2ad13059398efb0f437e74fd53bed
Summary:
recent commit 671d15cbdd introduced some test failures:
```
===== Running stats_history_test
[==========] Running 9 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 9 tests from StatsHistoryTest
[ RUN ] StatsHistoryTest.RunStatsDumpPeriodSec
monitoring/stats_history_test.cc:63: Failure
dbfull()->SetDBOptions({{"stats_dump_period_sec", "0"}})
Not implemented: Not supported in ROCKSDB LITE
db/db_options_test.cc:28:11: error: unused variable 'kMicrosInSec' [-Werror,-Wunused-const-variable]
const int kMicrosInSec = 1000000;
```
This PR fixes these failures
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5477
Differential Revision: D15871814
Pulled By: miasantreble
fbshipit-source-id: 0a7023914d2c1784d9d2d3f5bfb47310d4855394
Summary:
`DBImplSecondary` calls `CheckConsistency()` during open. In the past, `DBImplSecondary` did not override this function thus `DBImpl::CheckConsistency()` is called.
The following can happen. The secondary instance is performing consistency check which calls `GetFileSize(file_path)` but the file at `file_path` is deleted by the primary instance. `DBImpl::CheckConsistency` does not account for this and fails the consistency check. This is undesirable. The solution is that, we call `DBImpl::CheckConsistency()` first. If it passes, then we are good. If not, we give it a second chance and handles the case of file(s) being deleted.
Test plan (on dev server):
```
$make clean && make -j20 all
$./db_secondary_test
```
All other existing unit tests must pass as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5469
Differential Revision: D15861845
Pulled By: riversand963
fbshipit-source-id: 507d72392508caed3cd003bb2e2aa43f993dd597
Summary:
This PR continues the work in https://github.com/facebook/rocksdb/pull/4748 and https://github.com/facebook/rocksdb/pull/4535 by adding a new DBOption `persist_stats_to_disk` which instructs RocksDB to persist stats history to RocksDB itself. When statistics is enabled, and both options `stats_persist_period_sec` and `persist_stats_to_disk` are set, RocksDB will periodically write stats to a built-in column family in the following form: key -> (timestamp in microseconds)#(stats name), value -> stats value. The existing API `GetStatsHistory` will detect the current value of `persist_stats_to_disk` and either read from in-memory data structure or from the hidden column family on disk.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5046
Differential Revision: D15863138
Pulled By: miasantreble
fbshipit-source-id: bb82abdb3f2ca581aa42531734ac799f113e931b
Summary:
It seems like CF Options are not properly validated when creating a new column family with `CreateColumnFamily` API; only a selected few checks are done. Calling `ColumnFamilyData::ValidateOptions`, which is the single source for all CFOptions validations, will help fix this. (`ColumnFamilyData::ValidateOptions` is already called at the time of `DB::Open`).
**Test Plan:**
Added a new test: `DBTest.CreateColumnFamilyShouldFailOnIncompatibleOptions`
```
TEST_TMPDIR=/dev/shm ./db_test --gtest_filter=DBTest.CreateColumnFamilyShouldFailOnIncompatibleOptions
```
Also ran gtest-parallel to make sure the new test is not flaky.
```
TEST_TMPDIR=/dev/shm ~/gtest-parallel/gtest-parallel ./db_test --gtest_filter=DBTest.CreateColumnFamilyShouldFailOnIncompatibleOptions --repeat=10000
[10000/10000] DBTest.CreateColumnFamilyShouldFailOnIncompatibleOptions (15 ms)
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5453
Differential Revision: D15816851
Pulled By: sagar0
fbshipit-source-id: 9e702b9850f5c4a7e0ef8d39e1e6f9b81e7fe1e5
Summary:
This PR integrates the block cache tracer class into db_impl.cc.
db_impl.cc contains a member variable of AtomicBlockCacheTraceWriter class and passes its reference to the block_based_table_reader.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5433
Differential Revision: D15728016
Pulled By: HaoyuHuang
fbshipit-source-id: 23d5659e8c82d556833dcc1a5558aac8c1f7db71
Summary:
Calling PurgeObsoleteFiles with a JobContext for which HaveSomethingToDelete
is false is a precondition violation. This would trigger an assertion in debug builds;
however, in release builds with assertions disabled, this can result in the
pending_purge_obsolete_files_ counter in DBImpl underflowing, which in turn can lead
to the process hanging during database close.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5448
Differential Revision: D15792569
Pulled By: ltamasi
fbshipit-source-id: 82d92c9b4f6a9efcdc69dbb3d5a52a1ae2dd2472
Summary:
In secondary mode, it is possible that the secondary lists the primary's WAL
directory, finds a WAL and tries to open it. It is possible that the primary
deletes the WAL after secondary listing dir but before the secondary opening
it. Then the secondary will fail to open the WAL file with a PathNotFound
status. In this case, we can return OK without replaying WAL and optionally
replay more MANIFEST.
Test Plan (on my dev machine):
Without this PR, the following will fail several times out of 100 runs.
```
~/gtest-parallel/gtest-parallel -r 100 -w 16 ./db_secondary_test --gtest_filter=DBSecondaryTest.SwitchToNewManifestDuringOpen
```
With this PR, the above should always succeed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5323
Differential Revision: D15763878
Pulled By: riversand963
fbshipit-source-id: c7164fa7cb8d9001abc258b6a2dc93613e4f38ff
Summary:
If a memtable definitely covers a key, there isn't a need to check older memtables.
We can skip them by checking the earliest sequence number.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4941
Differential Revision: D13932666
fbshipit-source-id: b9d52f234b8ad9dd3bf6547645cd457175a3ca9b
Summary:
This affects our "no compression" automated tests. Since PR #5368, DBTest.DynamicMiscOptions has been failing with:
db/db_test.cc:4889: Failure
dbfull()->SetOptions({{"compression", "kSnappyCompression"}})
Invalid argument: Compression type Snappy is not linked with the binary.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5438
Differential Revision: D15752100
Pulled By: ltamasi
fbshipit-source-id: 3f19eff7cafc03b333965be0203c5853d2a9cb71
Summary:
To avoid deadlock mutex_ should never be acquired before log_write_mutex_. The patch documents that and also fixes one case in ::FlushWAL that acquires mutex_ through ::WriteStatusCheck when it already holds lock on log_write_mutex_.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5437
Differential Revision: D15749722
Pulled By: maysamyabandeh
fbshipit-source-id: f57b69c44b4b80cc6d7ddf3d3fdf4a9eb5a5a45a
Summary:
FlushScheduler's methods are instrumented with debug-time locks to check the scheduler state against a simple container definition. Since https://github.com/facebook/rocksdb/pull/2286 the scope of such locks are widened to the entire methods' body. The result is that the concurrency tested during testing (in debug mode) is stricter than the concurrency level manifested at runtime (in release mode).
The patch reverts this change to reduce the scope of such locks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5372
Differential Revision: D15545831
Pulled By: maysamyabandeh
fbshipit-source-id: 01d69191afb1dd807d4bdc990fc74813ae7b5426
Summary:
Use `CreateLoggerFromOptions` function to reduce code duplication.
Test plan (on my machine)
```
$make clean && make -j32 db_secondary_test
$KEEP_DB=1 ./db_secondary_test
```
Verify all info logs of the secondary instance are properly logged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5427
Differential Revision: D15748922
Pulled By: riversand963
fbshipit-source-id: bad7261df1b8373efc504f141efc7871e375a311
Summary:
BlockCacheLookupContext only contains the caller for now.
We will trace block accesses at five places:
1. BlockBasedTable::GetFilter.
2. BlockBasedTable::GetUncompressedDict.
3. BlockBasedTable::MaybeReadAndLoadToCache. (To trace access on data, index, and range deletion block.)
4. BlockBasedTable::Get. (To trace the referenced key and whether the referenced key exists in a fetched data block.)
5. BlockBasedTable::MultiGet. (To trace the referenced key and whether the referenced key exists in a fetched data block.)
We create the context at:
1. BlockBasedTable::Get. (kUserGet)
2. BlockBasedTable::MultiGet. (kUserMGet)
3. BlockBasedTable::NewIterator. (either kUserIterator, kCompaction, or external SST ingestion calls this function.)
4. BlockBasedTable::Open. (kPrefetch)
5. Index/Filter::CacheDependencies. (kPrefetch)
6. BlockBasedTable::ApproximateOffsetOf. (kCompaction or kUserApproximateSize).
I loaded 1 million key-value pairs into the database and ran the readrandom benchmark with a single thread. I gave the block cache 10 GB to make sure all reads hit the block cache after warmup. The throughput is comparable.
Throughput of this PR: 231334 ops/s.
Throughput of the master branch: 238428 ops/s.
Experiment setup:
RocksDB: version 6.2
Date: Mon Jun 10 10:42:51 2019
CPU: 24 * Intel Core Processor (Skylake)
CPUCache: 16384 KB
Keys: 20 bytes each
Values: 100 bytes each (100 bytes after compression)
Entries: 1000000
Prefix: 20 bytes
Keys per prefix: 0
RawSize: 114.4 MB (estimated)
FileSize: 114.4 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: NoCompression
Compression sampling rate: 0
Memtablerep: skip_list
Perf Level: 1
Load command: ./db_bench --benchmarks="fillseq" --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000
Run command: ./db_bench --benchmarks="readrandom,stats" --use_existing_db --threads=1 --duration=120 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000 --duration=120
TODOs:
1. Create a caller for external SST file ingestion and differentiate the callers for iterator.
2. Integrate tracer to trace block cache accesses.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5421
Differential Revision: D15704258
Pulled By: HaoyuHuang
fbshipit-source-id: 4aa8a55f8cb1576ffb367bfa3186a91d8f06d93a
Summary:
In regular RocksDB instance, `MemTable::earliest_seqno_` is "db sequence number at the time of creation". However, we cannot use the db sequence number to set the value of `MemTable::earliest_seqno_` for secondary instance, i.e. `DBImplSecondary` due to the logic of MANIFEST and WAL replay.
When replaying the log files of the primary, the secondary instance first replays MANIFEST and updates the db sequence number if necessary. Next, the secondary replays WAL files, creates new memtables if necessary and inserts key-value pairs into memtables. The following can occur when the db has two or more column families.
Assume the db has column family "default" and "cf1". At a certain in time, both "default" and "cf1" have data in memtables.
1. Primary triggers a flush and flushes "cf1". "default" is **not** flushed.
2. Secondary replays the MANIFEST updates its db sequence number to the latest value learned from the MANIFEST.
3. Secondary starts to replay WAL that contains the writes to "default". It is possible that the write batches' sequence numbers are smaller than the db sequence number. In this case, these write batches will be skipped, and these updates will not be visible to reader until "default" is later flushed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5413
Differential Revision: D15637407
Pulled By: riversand963
fbshipit-source-id: 3de3fe35cfc6f1b9f844f3f926f0df29717b6580
Summary:
The patch reduces the contention over prepared_mutex_ using these techniques:
1) Move ::RemovePrepared() to be called from the commit callback when we have two write queues.
2) Use two separate mutex for PreparedHeap, one prepared_mutex_ needed for ::RemovePrepared, and one ::push_pop_mutex() needed for ::AddPrepared(). Given that we call ::AddPrepared only from the first write queue and ::RemovePrepared mostly from the 2nd, this will result into each the two write queues not competing with each other over a single mutex. ::RemovePrepared might occasionally need to acquire ::push_pop_mutex() if ::erase() ends up with calling ::pop()
3) Acquire ::push_pop_mutex() on the first callback of the write queue and release it on the last.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5420
Differential Revision: D15741985
Pulled By: maysamyabandeh
fbshipit-source-id: 84ce8016007e88bb6e10da5760ba1f0d26347735
Summary:
I'm not able to prove it, but the stress test failure may be caused by the following sequence of events -
1. Crash db_stress while writing the log file. This should result in a corrupted WAL.
2. Run db_stress with recycle_log_file_num=1. Crash during recovery immediately after writing manifest and updating the current file. The old log from the previous run is left behind, but the memtable would have been flushed during recovery and the CF log number will point to the newer log
3. Run db_stress with recycle_log_file_num=0. During recovery, the old log file will be processed and the corruption will be detected. Since the CF has moved ahead, we get the "SST file is ahead of WAL" error
Test -
1. stress_crash
2. make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5412
Differential Revision: D15699120
Pulled By: anand1976
fbshipit-source-id: 9092ce81e7c4a0b4b4e66560c23ea4812a4d9cbe
Summary:
PR #5111 reduced the number of key comparisons when iterating with
upper/lower bounds; however, this caused a regression for MyRocks.
Reverting to the previous behavior in BlockBasedTableIterator as a hotfix.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5428
Differential Revision: D15721038
Pulled By: ltamasi
fbshipit-source-id: 5450106442f1763bccd17f6cfd648697f2ae8b6c
Summary:
When using `PRIu64` type of printf specifier, current code base does the following:
```
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
```
However, this can be simplified to
```
#include <cinttypes>
```
as long as flag `-std=c++11` is used.
This should solve issues like https://github.com/facebook/rocksdb/issues/5159
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5402
Differential Revision: D15701195
Pulled By: miasantreble
fbshipit-source-id: 6dac0a05f52aadb55e9728038599d3d2e4b59d03
Summary:
It's useful to be able to (optionally) associate key-value pairs with user-provided timestamps. This PR is an early effort towards this goal and continues the work of facebook#4942. A suite of new unit tests exist in DBBasicTestWithTimestampWithParam. Support for timestamp requires the user to provide timestamp as a slice in `ReadOptions` and `WriteOptions`. All timestamps of the same database must share the same length, format, etc. The format of the timestamp is the same throughout the same database, and the user is responsible for providing a comparator function (Comparator) to order the <key, timestamp> tuples. Once created, the format and length of the timestamp cannot change (at least for now).
Test plan (on devserver):
```
$COMPILE_WITH_ASAN=1 make -j32 all
$./db_basic_test --gtest_filter=Timestamp/DBBasicTestWithTimestampWithParam.PutAndGet/*
$make check
```
All tests must pass.
We also run the following db_bench tests to verify whether there is regression on Get/Put while timestamp is not enabled.
```
$TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillseq,readrandom -num=1000000
$TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=1000000
```
Repeat for 6 times for both versions.
Results are as follows:
```
| | readrandom | fillrandom |
| master | 16.77 MB/s | 47.05 MB/s |
| PR5079 | 16.44 MB/s | 47.03 MB/s |
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5079
Differential Revision: D15132946
Pulled By: riversand963
fbshipit-source-id: 833a0d657eac21182f0f206c910a6438154c742c
Summary:
With this commit, RocksDB secondary instance respects atomic groups in version edits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5411
Differential Revision: D15617512
Pulled By: HaoyuHuang
fbshipit-source-id: 913f4ede391d772dcaf5649e3cd2099fa292d120
Summary:
Flush/compaction use `MergeUntil` which has a special code path to
handle a merge ending with a non-`Merge` point key. In particular if
that key is a `Put` we forgot to check whether it is covered by a range
tombstone. If it is covered then we must not include it in the following call
to `TimedFullMerge`.
Fixes#5392.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5406
Differential Revision: D15611144
Pulled By: sagar0
fbshipit-source-id: ba6a7863ca2d043f591de78fd0c4f4561f0c500e
Summary:
The PR #5275 separated the column dropped and shutdown status codes. However, there were a couple of places in compaction where this change ended up treating a ShutdownInProgress() error as a real error and set bg_error. This caused MyRocks unit test to fail due to WAL writes during shutdown returning this error. Fix it by ignoring the shutdown status during compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5400
Differential Revision: D15611680
Pulled By: anand1976
fbshipit-source-id: c602e97840e3ae24eb420d61e0ce95d3e6258632
Summary:
Currently we validate options in DB::Open. However the validation step is missing when options are dynamically updated in ::SetOptions. The patch fixes that.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5368
Differential Revision: D15540101
Pulled By: maysamyabandeh
fbshipit-source-id: d27bbffd8f0252d1b50bcf59e0a70a278ed937f4
Summary:
util/ means for lower level libraries. trace_replay is highly integrated to DB and sometimes call DB. Move it out to a separate directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5376
Differential Revision: D15550938
Pulled By: siying
fbshipit-source-id: f46dce5ceffdc05a73f26379c7bb1b79ebe6c207
Summary:
Many logging related source files are under util/. It will be more structured if they are together.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387
Differential Revision: D15579036
Pulled By: siying
fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f
Summary:
In order to improve code readability, this PR moves LevelCompactionBuilder and LevelCompactionPicker to compaction_picker_level.h and .cc
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5369
Differential Revision: D15540172
Pulled By: miasantreble
fbshipit-source-id: c1a578b93f127cd63661b53f32b356e6edd349af
Summary:
The methods and fields in the private section of DBImpl were all intermingled, making it hard to figure out where the fields/methods start and where they end. I cleaned up the code a little so that all the type declaration are at the beginning, followed by methods, and all the data fields are at the end. This follows
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5385
Differential Revision: D15566978
Pulled By: sagar0
fbshipit-source-id: 4618a7d819ad4e2d7cc9ae1af2c59f400140bb1b
Summary:
1. Fix a bug in WAL replay in which write batches with old sequence numbers are mistakenly inserted into memtables.
2. Add support for benchmarking secondary instance to db_bench_tool.
With changes made in this PR, we can start benchmarking secondary instance
using two processes. It is also possible to vary the frequency at which the
secondary instance tries to catch up with the primary. The info log of the
secondary can be found in a directory whose path can be specified with
'-secondary_path'.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5170
Differential Revision: D15564608
Pulled By: riversand963
fbshipit-source-id: ce97688ed3d33f69d3a0b9266ebbbbf887aa0ec8
Summary:
Fix flaky DBTest2.PresetCompressionDict test.
This PR fixes two issues with the test:
1. Replaces `GetSstFiles` with `TotalSize`, which is based on `DB::GetColumnFamilyMetaData` so that only the size of the live SST files is taken into consideration when computing the total size of all sst files. Earlier, with `GetSstFiles`, even obsolete files were getting picked up.
1. In ZSTD compression, it is sometimes possible that using a trained dictionary is not better than using an untrained one. Using a trained dictionary performs well in 99% of the cases, but still in the remaining ~1% of the cases (out of 10000 runs) using an untrained dictionary gets better compression results.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5378
Differential Revision: D15559100
Pulled By: sagar0
fbshipit-source-id: c35adbf13871f520a2cec48f8bad9ff27ff7a0b4
Summary:
Currently, when the block cache is used for index blocks as well, it is
not really the index block that is stored in the cache but an
IndexReader object. Since this object is not pure data (it has, for
instance, pointers that might dangle), it's not really sharable. To
avoid the issues around this, the current code uses a dummy unique cache
key for each TableReader to store the IndexReader, and erases the
IndexReader entry when the TableReader is closed. Instead of doing this,
the new code moves the IndexReader out of the cache altogether. In
particular, instead of the TableReader owning, or caching/pinning the
IndexReader based on the customer's settings, the TableReader
unconditionally owns the IndexReader, which in turn owns/caches/pins
the index block (which is itself sharable and thus can be safely put in
the cache without any hacks).
Note: the change has two side effects:
1) Partitions of partitioned indexes no longer affect the read
amplification statistics.
2) Eviction statistics for index blocks are temporarily broken. We plan to fix
this in a separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5298
Differential Revision: D15303203
Pulled By: ltamasi
fbshipit-source-id: 935a69ba59d87d5e44f42e2310619b790c366e47
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377
Differential Revision: D15551366
Pulled By: siying
fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
Summary:
By increasing the ratio, we ensure that all files go through background deletion and eliminate flakiness due to timing of deletions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5366
Differential Revision: D15549992
Pulled By: anand1976
fbshipit-source-id: d137375cd791fc1a802841412755d6e2b8fd7688
Summary:
When dynamically setting options, we check the option type info and skip options that are marked deprecated. However this check is only done at top level, which results in bugs where SetOptions will corrupt option values and cause unexpected system behavior iff a deprecated second level option is set dynamically.
For exmaple, the following call:
```
dbfull()->SetOptions(
{{"compaction_options_fifo",
"{allow_compaction=true;max_table_files_size=1024;ttl=731;}"}});
```
was from pre 6.0 release when `ttl` was part of `compaction_options_fifo`. Now that it got moved out of `compaction_options_fifo`, this call will incorrectly set `compaction_options_fifo.max_table_files_size` to 731 (as `max_table_files_size` is the first one in `OptionsHelper::fifo_compaction_options_type_info` struct) and cause files to gett evicted much faster than expected.
This PR adds verification to second level options like `compaction_options_fifo.ttl` or `compaction_options_fifo.max_table_files_size` when set dynamically, and filter out those marked as deprecated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5367
Differential Revision: D15530998
Pulled By: miasantreble
fbshipit-source-id: 818258be5c3abe09cd82d62f3c083572d70fecdd
Summary:
util/ means for lower level libraries, so it's a good idea to move the files which requires knowledge to DB out. Create a file/ and move some files there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5375
Differential Revision: D15550935
Pulled By: siying
fbshipit-source-id: 61a9715dcde5386eebfb43e93f847bba1ae0d3f2
Summary:
Add some comments in db_impl.h. Also reordered function order a little bit so that I can add a comment to flag the area of functions implementing DB interface.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5338
Differential Revision: D15498284
Pulled By: siying
fbshipit-source-id: 3d7c59c8303577fe44d13c74ae84c7ce05164f77
Summary:
RocksDB always tries to perform a hard link operation on the external SST file to ingest. This operation can fail if the external SST resides on a different device/FS, or the underlying FS does not support hard link. Currently RocksDB assumes that if the link fails, the user is willing to perform file copy, which is not true according to the post. This commit provides an option named 'failed_move_fall_back_to_copy' for users to choose which behavior they want.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5333
Differential Revision: D15457597
Pulled By: HaoyuHuang
fbshipit-source-id: f3626e13f845db4f7ed970a53ec8a2b1f0d62214
Summary:
Add file comment in db/db_iter.h and minor changes in other parts.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5340
Differential Revision: D15484605
Pulled By: siying
fbshipit-source-id: 173771f9d5bd51303de5410ee5afd0a4af9d6572
Summary:
Modified FindIntraL0Compaction to stop picking more files if total
amount of compensated bytes would be larger than max_compaction_bytes
option.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5329
Differential Revision: D15435728
Pulled By: ThomasFersch
fbshipit-source-id: d118a6da88d5df8ee20944422ade37cf6b15d60c
Summary:
In version_set.cc, there is a function GetCurrentManifestPath. The goal of this task is to refactor ListColumnFamilies function so that ListColumnFamilies calls GetCurrentManifestPath to search for MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5331
Differential Revision: D15444524
Pulled By: HaoyuHuang
fbshipit-source-id: 1dcbd030bc0f2e835695741f450bba150f2f2903
Summary:
Right now, in log writer, we call flush after writing each physical record. I don't see the necessarity of it. Right now, the underlying writer has a buffer, so there isn't a concern that the write request is too large either. On the other hand, in an Env where every flush is expensive, the current approach is significantly slower than only flushing after a whole record finishes, when the record is very large.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5328
Differential Revision: D15425032
Pulled By: siying
fbshipit-source-id: 440ebef002dfbb60c59d8388c9ddfc83d79700aa
Summary:
WritePrepared transactions when configured with two_write_queues=true offers higher throughput with unordered_write feature without however compromising the rocksdb guarantees. This is because it performs ordering among writes in a 2nd step that is not tied to memtable write speed. The 2nd step is naturally provided by 2PC when the commit phase does the ordering as well. Without 2PC, the 2nd step would only be provided when we use two_write_queues=true, where WritePrepared after performing the writes, in a 2nd step uses the 2nd queue to assign order to the writes.
The patch clarifies the need for two_write_queues=true in the HISTORY and inline comments of unordered_writes. Moreover it extends the stress tests of WritePrepared to unordred_write.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5313
Differential Revision: D15379977
Pulled By: maysamyabandeh
fbshipit-source-id: 5b6f05b9b59285dcbf3b0532215ba9fe7d926e00
Summary:
RocksDB secondary can replay both MANIFEST and WAL now.
On the one hand, the memory usage by memtables will grow after replaying WAL for sometime. On the other hand, replaying the MANIFEST can bring the database persistent data to a more recent point in time, giving us the opportunity to discard some memtables containing out-dated data.
This PR coordinates the MANIFEST and WAL replay, using the updates from MANIFEST replay to update the active memtable and immutable memtable list of each column family.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5305
Differential Revision: D15386512
Pulled By: riversand963
fbshipit-source-id: a3ea6fc415f8382d8cf624f52a71ebdcffa3e355
Summary:
Previously if iterator upper/lower bound presents, `DBIter` will check the bound for every key. This patch turns the check into per-file or per-data block check when applicable, by checking against either file largest/smallest key or block index key.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5111
Differential Revision: D15330061
Pulled By: siying
fbshipit-source-id: 8a653fe3cd50d94d81eb2d13b087326c58ee2024
Summary:
RangeDelAggregator::StripeRep::Invalidate() clears up several vectors. If we know there isn't anything to there, we can safe these small CPUs. Profiling shows that it sometimes take non-negligible amount of CPU. Worth a small optimization.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5312
Differential Revision: D15380511
Pulled By: siying
fbshipit-source-id: 53c5f34c33b4cb1e743643c6086ac56d0b84ec2e
Summary:
If DB is opened with `avoid_unnecessary_blocking_io` being true, then `~ColumnFamilyHandleImpl` enqueues a purge request and schedules a background thread to perform the deletion. Without test sync point, whether the SST file is purged or not at a later point in time is not deterministic. If the SST does not exist, it will cause an assertion failure.
How to reproduce:
```
$git checkout 6492430eaf
$make -j20 deletefile_test
$gtest-parallel --repeat 1000 --worker 16 ./deletefile_test --gtest_filter=DeleteFileTest.BackgroundPurgeCFDropTest
```
The test may fail a few times.
With changes made in this PR, repeat the above commands, and the test should not fail.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5310
Differential Revision: D15361136
Pulled By: riversand963
fbshipit-source-id: c4308d5f8da83472c893bf7f8ceed347fbfa850f
Summary:
The recent improvement in https://github.com/facebook/rocksdb/pull/3661 could cause a deadlock: When writing recoverable state, we also commit its sequence number to commit table, which could result into evicting existing commit entry, which could result into advancing max_evicted_seq_, which would need to get snapshots from database, which requires obtaining db mutex. The patch releases db_mutex before calling the callback in WriteRecoverableState to avoid the potential deadlock. It also improves the stress tests to let the issue be manifested in the tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5306
Differential Revision: D15341458
Pulled By: maysamyabandeh
fbshipit-source-id: 05dcbed7e21b789fd1e5fd5ee8eea08077162323
Summary:
The test was not using separate MemTablePostProcessInfo per memetable insert thread and thus tsan was complaining about data race.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5308
Differential Revision: D15356420
Pulled By: maysamyabandeh
fbshipit-source-id: 46c2f2d19fb02c3c775b587aa09ca9c0dae6ed04
Summary:
This PR has two fixes for crash test failures -
1. Fix a bug in TestMultiGet() in db_stress that was passing list of key to MultiGet() in the wrong order, thus ensuring that actual values don't match expected values
2. Remove an incorrect assertion in FilePickerMultiGet::GetNextFileInLevelWithKeys() that checks that files in a level are in sorted order. This is not true with MultiGet(), especially if there are duplicate keys and we may have to go back one file for the next key. Furthermore, this assertion makes more sense when a new version is created, rather than at lookup time
Test -
asan_crash and ubsan_crash tests
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5301
Differential Revision: D15337383
Pulled By: anand1976
fbshipit-source-id: 35092cb15bbc1700e5e823cbe07bfa62f1e9e6c6
Summary:
Performing unordered writes in rocksdb when unordered_write option is set to true. When enabled the writes to memtable are done without joining any write thread. This offers much higher write throughput since the upcoming writes would not have to wait for the slowest memtable write to finish. The tradeoff is that the writes visible to a snapshot might change over time. If the application cannot tolerate that, it should implement its own mechanisms to work around that. Using TransactionDB with WRITE_PREPARED write policy is one way to achieve that. Doing so increases the max throughput by 2.2x without however compromising the snapshot guarantees.
The patch is prepared based on an original by siying
Existing unit tests are extended to include unordered_write option.
Benchmark Results:
```
TEST_TMPDIR=/dev/shm/ ./db_bench_unordered --benchmarks=fillrandom --threads=32 --num=10000000 -max_write_buffer_number=16 --max_background_jobs=64 --batch_size=8 --writes=3000000 -level0_file_num_compaction_trigger=99999 --level0_slowdown_writes_trigger=99999 --level0_stop_writes_trigger=99999 -enable_pipelined_write=false -disable_auto_compactions --unordered_write=1
```
With WAL
- Vanilla RocksDB: 78.6 MB/s
- WRITER_PREPARED with unordered_write: 177.8 MB/s (2.2x)
- unordered_write: 368.9 MB/s (4.7x with relaxed snapshot guarantees)
Without WAL
- Vanilla RocksDB: 111.3 MB/s
- WRITER_PREPARED with unordered_write: 259.3 MB/s MB/s (2.3x)
- unordered_write: 645.6 MB/s (5.8x with relaxed snapshot guarantees)
- WRITER_PREPARED with unordered_write disable concurrency control: 185.3 MB/s MB/s (2.35x)
Limitations:
- The feature is not yet extended to `max_successive_merges` > 0. The feature is also incompatible with `enable_pipelined_write` = true as well as with `allow_concurrent_memtable_write` = false.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5218
Differential Revision: D15219029
Pulled By: maysamyabandeh
fbshipit-source-id: 38f2abc4af8780148c6128acdba2b3227bc81759
Summary:
Previous code may call `~ColumnFamilyData` in `DBImpl::AtomicFlushMemTablesToOutputFiles` if the column family is dropped or `cfd->IsFlushPending() == false`. In `~ColumnFamilyData`, the db mutex is released briefly and re-acquired. This can cause correctness issue. The reason is as follows.
Assume there are more bg flush threads. After bg_flush_thr1 releases the db mutex, bg_flush_thr2 can grab it and pop an element from the flush queue. This will cause bg_flush_thr2 to accidentally pick some memtables which should have been picked by bg_flush_thr1. To make the matter worse, bg_flush_thr2 can clear `flush_requested_` flag for the memtable list, causing a subsequent call to `MemTableList::IsFlushPending()` by bg_flush_thr1 to return false, which is wrong.
The fix is to delay `ColumnFamilyData::Unref` and `~ColumnFamilyData` for column families not selected for flush until `AtomicFlushMemTablesToOutputFiles` returns. Furthermore, a bg flush thread should not clear `MemTableList::flush_requested_` in `MemTableList::PickMemtablesToFlush` unless atomic flush is not used **or** the memtable list does not have unpicked memtables.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5294
Differential Revision: D15295297
Pulled By: riversand963
fbshipit-source-id: 03b101205ca22c242647cbf488bcf0ed80b2ecbd
Summary:
There were no C bindings for lowering thread pool priority. This adds those.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5285
Differential Revision: D15290050
Pulled By: siying
fbshipit-source-id: b2ed94d0c39d27434ace2204829a242b53d0d67a
Summary:
When reseek happens in merging iterator, reseeking a child iterator can be avoided if:
(1) the iterator represents imutable data
(2) reseek() to a larger key than the current key
(3) the current key of the child iterator is larger than the seek key
because it is guaranteed that the result will fall into the same position.
This optimization will be useful for use cases where users keep seeking to keys nearby in ascending order.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5286
Differential Revision: D15283635
Pulled By: siying
fbshipit-source-id: 35f79ffd5ce3609146faa8cd55f2bfd733502f83
Summary:
This PR fixes a couple of bugs in FilePickerMultiGet that were causing db_stress test failures. The failures were caused by -
1. Improper handling of a key that matches the user key portion of an L0 file's largest key. In this case, the curr_index_in_curr_level file index in L0 for that key was getting incremented, but batch_iter_ was not advanced. By design, all keys in a batch are supposed to be checked against an L0 file before advancing to the next L0 file. Not advancing to the next key in the batch was causing a double increment of curr_index_in_curr_level due to the same key being processed again
2. Improper handling of a key that matches the user key portion of the largest key in the last file of L1 and higher. This was resulting in a premature end to the processing of the batch for that level when the next key in the batch is a duplicate. Typically, the keys in MultiGet will not be duplicates, but its good to handle that case correctly
Test -
asan_crash
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5292
Differential Revision: D15282530
Pulled By: anand1976
fbshipit-source-id: d1a6a86e0af273169c3632db22a44d79c66a581f
Summary:
Right now, DBIter::Next() always checks whether an entry is for the same user key as the previous entry to see whether the key should be hidden to the user. However, if previous entry's sequence number is 0, the check is not needed because 0 is the oldest possible sequence number.
We could extend it from seqnum 0 case to simply prev_seqno >= current_seqno. However, it is less robust with bug or unexpected situations, while the gain is relatively low. We can always extend it later when needed.
In a readseq benchmark with full formed LSM-tree, number of key comparisons called is reduced from 2.981 to 2.165. readseq against a fully compacted DB, no key comparison is called. Performance in this benchmark didn't show obvious improvement, which is expected because key comparisons only takes small percentage of CPU. But it may show up to be more effective if users have an expensive customized comparator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5244
Differential Revision: D15067257
Pulled By: siying
fbshipit-source-id: b7e1ef3ec4fa928cba509683d2b3246e35d270d9
Summary:
Previously in PR https://github.com/facebook/rocksdb/pull/5161 we have added the capability to do WAL tailing in `OpenAsSecondary`, in this PR we extend such feature to `TryCatchUpWithPrimary` which is useful for an secondary RocksDB instance to retrieve and apply the latest updates and refresh log readers if needed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5282
Differential Revision: D15261011
Pulled By: miasantreble
fbshipit-source-id: a15c94471e8c3b3b1f7f47c3135db1126e936949
Summary:
Part of compaction cpu goes to processing snapshot list, the larger the list the bigger the overhead. Although the lifetime of most of the snapshots is much shorter than the lifetime of compactions, the compaction conservatively operates on the list of snapshots that it initially obtained. This patch allows the snapshot list to be updated via a callback if the compaction is taking long. This should let the compaction to continue more efficiently with much smaller snapshot list.
For simplicity, to avoid the feature is disabled in two cases: i) When more than one sub-compaction are sharing the same snapshot list, ii) when Range Delete is used in which the range delete aggregator has its own copy of snapshot list.
This fixes the reverted https://github.com/facebook/rocksdb/pull/5099 issue with range deletes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5278
Differential Revision: D15203291
Pulled By: maysamyabandeh
fbshipit-source-id: fa645611e606aa222c7ce53176dc5bb6f259c258
Summary:
This PR fixes three memory issues found by ASAN
* in db_stress, the key vector for MultiGet is created using `emplace_back` which could potentially invalidates references to the underlying storage (vector<string>) due to auto resizing. Fix by calling reserve in advance.
* Similar issue in construction of GetContext autovector in version_set.cc
* In multiget_context.h use T[] specialization for unique_ptr that holds a char array
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5279
Differential Revision: D15202893
Pulled By: miasantreble
fbshipit-source-id: 14cc2cda0ed64d29f2a1e264a6bfdaa4294ee75d
Summary:
Right now, when Seek() is called again, RocksDB always does a binary search against the files and index blocks, even if they end up with the same file/block. Improve it as following:
1. in LevelIterator, reseek first try to check the boundary of the current file. If it falls into the same file, skip the binary search to find the file
2. in block based table iterator, reseek skip to reseek the iterator block if the seek key is larger than the current key and lower than the index key (boundary of the current block and the next block).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5256
Differential Revision: D15105072
Pulled By: siying
fbshipit-source-id: 39634bdb4a881082451fa39cecd7ecf12160bf80
Summary:
Sometimes, users might make mistake of not releasing snapshots before closing the DB. This is undocumented use of RocksDB and the behavior is unknown. We return DB::Close() to provide a way to check it for the users. Aborted() will be returned to users when they call DB::Close().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5272
Differential Revision: D15159713
Pulled By: siying
fbshipit-source-id: 39369def612398d9f239d83d396b5a28e5af65cd
Summary:
Our daily stress tests are failing after this feature. Reverting temporarily until we figure the reason for test failures.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5269
Differential Revision: D15151285
Pulled By: maysamyabandeh
fbshipit-source-id: e4002b99690a97df30d4b4b58bf0f61e9591bc6e
Summary:
With atomic flush, RocksDB background flush will flush memtables of a column family up to the largest memtable id in the immutable memtable list. This can introduce a bug in the following scenario. A user thread inserts into a column family until the memtable is full and triggers a flush. This will add the column family to flush_scheduler_. Then the user thread writes another record to the column family. In the PreprocessWrite function, the user thread picks the column family from flush_scheduler_ and schedules a flush request. The flush request gaurantees to flush all the memtables up to the current largest memtable ID of the immutable memtable list. Then the user thread writes new data to the newly-created active memtable. After the write returns, the user thread closes the db. This can cause assertion failure when the background flush thread tries to install superversion for the column family. The solution is to not install flush results if the db has already set `shutting_down_` to true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5254
Differential Revision: D15124149
Pulled By: riversand963
fbshipit-source-id: 0a667a41339dedb5a18bcb01b0bf11c275c04df0
Summary:
Improve the iterators performance when the user explicitly sets the readahead size via `ReadOptions.readahead_size`.
1. Stop creating new table readers when the user explicitly sets readahead size.
2. Make use of an internal buffer based on `FilePrefetchBuffer` instead of using `ReadaheadRandomAccessFileReader`, to handle the user readahead requests (for both buffered and direct io cases).
3. Add `readahead_size` to db_bench.
**Benchmarks:**
https://gist.github.com/sagar0/53693edc320a18abeaeca94ca32f5737
For 1 MB readahead, Buffered IO performance improves by 28% and Direct IO performance improves by 50%.
For 512KB readahead, Buffered IO performance improves by 30% and Direct IO performance improves by 67%.
**Test Plan:**
Updated `DBIteratorTest.ReadAhead` test to make sure that:
- no new table readers are created for iterators on setting ReadOptions.readahead_size
- At least "readahead" number of bytes are actually getting read on each iterator read.
TODO later:
- Use similar logic for compactions as well.
- This ties in nicely with #4052 and paves the way for removing ReadaheadRandomAcessFile later.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5246
Differential Revision: D15107946
Pulled By: sagar0
fbshipit-source-id: 2c1149729ca7d779e4e8b7710ba6f4e8cbfd3bea
Summary:
The newly added test CompactionJobTest.SnapshotRefresh sets the snapshot refresh period to 0 to stress the feature. This results into large number of refresh events, which in turn results into an UBSAN failure when a bitwise shift operand goes beyond the uint64_t size.
The patch fixes that by simplifying the shift logic to be done only by 2 bits after each refresh. Furthermore it verifies that the shift operation does not result in decreasing the refresh period.
Testing:
COMPILE_WITH_UBSAN=1 make -j32 compaction_job_test
./compaction_job_test --gtest_filter=CompactionJobTest.SnapshotRefresh
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5257
Differential Revision: D15106463
Pulled By: maysamyabandeh
fbshipit-source-id: f2718898ea7ba4fa9f7e87b70cf98fe647c0de80
Summary:
Part of compaction cpu goes to processing snapshot list, the larger the list the bigger the overhead. Although the lifetime of most of the snapshots is much shorter than the lifetime of compactions, the compaction conservatively operates on the list of snapshots that it initially obtained. This patch allows the snapshot list to be updated via a callback if the compaction is taking long. This should let the compaction to continue more efficiently with much smaller snapshot list.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5099
Differential Revision: D15086710
Pulled By: maysamyabandeh
fbshipit-source-id: 7649f56c3b6b2fb334962048150142a3bf9c1a12
Summary:
Currently one thread in RocksDB keeps a WAL file open while another thread
deletes it. Although the first thread never writes to the WAL again, it still
tries to close it in the end. This is fine on POSIX, but can be problematic on
other platforms, e.g. HDFS, etc.. It will either cause a lot of warning messages or
throw exceptions. The solution is to let the second thread close the WAL before deleting it.
RocksDB keeps the writers of the logs to delete in `logs_to_free_`, which is passed to `job_context` during `FindObsoleteFiles` (holding mutex). Then in `PurgeObsoleteFiles` (without mutex), these writers should close the logs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5233
Differential Revision: D15032670
Pulled By: riversand963
fbshipit-source-id: c55e8a612db8cc2306644001a5e6d53842a8f754
Summary:
We have a DB with ~4k column families and ~70k files. On shutdown, destroying the 4k ColumnFamilyHandle-s takes over 2 minutes. Most of this time is spent in VersionSet::AddLiveFiles() called from FindObsoleteFiles() from ~ColumnFamilyHandleImpl(). It's just iterating over the list of files in memory. This seems completely unnecessary as no obsolete files are actually found since the CFs are not even dropped. This PR fixes that.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5238
Differential Revision: D15056342
Pulled By: siying
fbshipit-source-id: 2aa342ef3770b4aa384ce81f8768e485480e4f08
Summary: PR https://github.com/facebook/rocksdb/pull/4899 implemented the general framework for RocksDB secondary instances. This PR adds the support for WAL tailing in `OpenAsSecondary`, which means after the `OpenAsSecondary` call, the secondary is now able to see primary's writes that are yet to be flushed. The secondary can see primary's writes in the WAL up to the moment of `OpenAsSecondary` call starts.
Differential Revision: D15059905
Pulled By: miasantreble
fbshipit-source-id: 44f71f548a30b38179a7940165e138f622de1f10
Summary:
In some cases, we want to known the smallest and largest sequence numbers of sstable files, to help us get more details.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5231
Differential Revision: D15038087
Pulled By: siying
fbshipit-source-id: c473c1ca07b53efe2f1884fa1ecdc8686f455ed8
Summary:
It's hard to get DBIter to directly use InternalIterator::NextAndGetResult() because the code change would be complicated. Instead, use IteratorWrapper, where Next() is already using NextAndGetResult(). Performance number is hard to measure because it is small and ther is variation. I run readseq many times, and there seems to be 1% gain.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5214
Differential Revision: D15003635
Pulled By: siying
fbshipit-source-id: 17af1965c409c2fe90cd85037fbd2c5a1364f82a
