Summary:
Added an option, `-use_existing_keys`, which can be set to run
benchmarks against an arbitrary existing database. Now users can
benchmark against their actual database rather than synthetic data.

Before the run begins, it loads all the keys into memory, then uses that
set of keys rather than synthesizing new ones in `GenerateKeyFromInt`.
This is mainly intended for small-scale DBs where the memory consumption
is not a concern.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5017

Differential Revision: D14270303

Pulled By: riversand963

fbshipit-source-id: 6328df9dffb5e19170270dd00a69f4bbe424e5ed

Summary:
Right now, users can change statistics.stats_level while DB is running, but TSAN may report
data race. We make stats_level_ to be atomic, and access them using accessors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5030

Differential Revision: D14267519

Pulled By: siying

fbshipit-source-id: 37d7ebeff7a43a406230143422a16af899163f73

[sync fix] Add defs.bzl

Summary:
This the hackish script we used to find the root cause of failures in transaction stress tests. It is not well-written and does not require rigorous reviewing but it is better than starting from scratch each time we observe an issue. The stress tests would just say that at which snapshots the sum of all the keys in a set is inconsistent with another set. To help debugging one need to know which key exactly returned inconsistent results. The script looks at the transactions between two conflicting snapshots, and performs thee changes manually to see for which key the read value was inconsistent.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5033

Differential Revision: D14280362

Pulled By: maysamyabandeh

fbshipit-source-id: d5826055c46711460ba81480d96cb5ea082814a5

Summary:
PreReleaseCallback meant to be called before the writes are visible to the readers. Since the sequence number is known after the WAL write, there is no reason to delay calling PreReleaseCallback to after the memtable write, which would complicates the reader's logic in presence of our memtable writes that are made visible by the other write thread.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5015

Differential Revision: D14221670

Pulled By: maysamyabandeh

fbshipit-source-id: a504dd665cf923226d7af09cc8e9c7739a25edc6

Summary:
When two_write_queues is enabled we call ::AddPrepared only from the main queue, which writes to both WAL and memtable, and call ::AddCommitted from the 2nd queue, which writes only to WAL. This simplifies the logic by avoiding concurrency between AddPrepared and also between AddCommitted. The patch fixes one case that did not conform with the rule above. This would allow future refactoring. For example AdvaneMaxEvictedSeq, which is invoked by AddCommitted, can be simplified by assuming lack of concurrent calls to it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5014

Differential Revision: D14210493

Pulled By: maysamyabandeh

fbshipit-source-id: 6db5ba372a294a568a14caa010576460917a4eab

Summary:
`DefaultEnvTest.incBackgroundThreadsIfNeeded` jtest should assert that the number of threads is greater than or equal to the minimum number of threads.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5021

Differential Revision: D14268311

Pulled By: sagar0

fbshipit-source-id: 01fb32b5b3ce636451d162fa1a2bbc5bd1974682

Summary:
Replace the integers used for setting and querying the various
flags in LRUHandle with enum values to improve readability.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5024

Differential Revision: D14263429

Pulled By: ltamasi

fbshipit-source-id: b1b9ba95635265f122c2b40da73850eaac18227a

Summary:
Statistics cost too much CPU for some use cases. Add two stats levels
so that people can choose to skip two types of expensive stats, timers and
histograms.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5027

Differential Revision: D14252765

Pulled By: siying

fbshipit-source-id: 75ecec9eaa44c06118229df4f80c366115346592

Summary:
The read path includes a callback function, ReadCallback, which would eventually calls IsInSnapshot to figure if a particular seq is in the reading snapshot or not. This callback is virtual, which adds the cost of multiple virtual function call to each read. The first few checks in IsInSnapshot, however, are quite trivial and take care of majority of the cases. The patch moves those to a non-virtual function in the the parent class, ReadCallback, to lower the virtual callback cost.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5018

Differential Revision: D14226562

Pulled By: maysamyabandeh

fbshipit-source-id: 6feed5b34f3b082e52092c5ef143e29b49c46b44

Summary:
This is my latest round of changes to add missing items to RocksJava. More to come in future PRs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4833

Differential Revision: D14152266

Pulled By: sagar0

fbshipit-source-id: d6cff67e26da06c131491b5cf6911a8cd0db0775

Summary:
When closing a BlobDB, it only waits for background tasks
to finish as the last thing, but the background task may access
some variables that are destroyed. The fix is to introduce a
shutdown function in the timer queue and call the function as
the first thing when destorying BlobDB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5005

Differential Revision: D14170342

Pulled By: siying

fbshipit-source-id: 081e6a2d99b9765d5956cf6cdfc290c07270c233

Summary:
This PR adds public `GetStatsHistory` API to retrieve stats history in the form of an std map. The key of the map is the timestamp in microseconds when the stats snapshot is taken, the value is another std map from stats name to stats value (stored in std string). Two DBOptions are introduced: `stats_persist_period_sec` (default 10 minutes) controls the intervals between two snapshots are taken; `max_stats_history_count` (default 10) controls the max number of history snapshots to keep in memory. RocksDB will stop collecting stats snapshots if `stats_persist_period_sec` is set to 0.

(This PR is the in-memory part of https://github.com/facebook/rocksdb/pull/4535)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4748

Differential Revision: D13961471

Pulled By: miasantreble

fbshipit-source-id: ac836d401ecb84ea92216bf9966f969dedf4ad04

Summary:
Currently the transaction stress tests use thread id as the seed. Since the thread ids are likely to be the same across multiple runs, the seed is thus going to be the same. The patch includes time in calculating the seed to help covering a very different part of state space in each run of the stress tests. To be able to reproduce the bug in case the stress tests failed, it also prints out the time that was used to calculate the seed value.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5004

Differential Revision: D14144356

Pulled By: maysamyabandeh

fbshipit-source-id: 728ed522f550fc8b4f5f9f373259c05fe9a54556

Summary:
The transaction stress tests, stress a high concurrency scenario. In WritePrepared/WriteUnPrepared we need to also stress the scenarios where an inserting/reading transaction is very slow. This would stress the corner cases that the caching is not sufficient and other slower data structures are engaged. To emulate such cases we make use of slow inserter/verifier threads and also reduce the size of cache data structures.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4974

Differential Revision: D14143070

Pulled By: maysamyabandeh

fbshipit-source-id: 81eb674678faf9fae0f654cd60ebcc74e26aeee7

Summary:
max_evicted_seq_ could be updated in the middle of the read in ::IsInSnapshot. The code to be correct in presence of this update would be complicated. The patch simplifies it by checking the value of max_evicted_seq_ before and after looking into commit_cache_ and retries in the unlucky case that it was changed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4955

Differential Revision: D13999556

Pulled By: maysamyabandeh

fbshipit-source-id: 7a1bdfa95ea8b5d8d73ddff3263ed31d7297b39c

Summary:
DBTest2.PresetCompressionDict is flaky. Temparily disable it for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5003

Differential Revision: D14139505

Pulled By: siying

fbshipit-source-id: ebf1872d364b76b2cb021b489ea2f17ee997116a

Summary:
Currently crash test covers cases with and without atomic flush, but takes too
long to finish. Therefore it may be a better idea to put crash test with atomic
flush in a separate set of tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4945

Differential Revision: D13947548

Pulled By: riversand963

fbshipit-source-id: 177c6de865290fd650b0103408339eaa3f801d8c

Summary:
Use C++11’s override and remove virtual where applicable.
Change are automatically generated.

bypass-lint
drop-conflicts

Reviewed By: igorsugak

Differential Revision: D14131816

fbshipit-source-id: f20e7f7cecf2e699d70f5fa036f72c0e3f59b50e

Summary:
MyRocks calls `GetForUpdate` on `INSERT`, for unique key check, and in almost all cases GetForUpdate returns empty result. For such cases, whole key bloom filter is helpful.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4985

Differential Revision: D14118257

Pulled By: miasantreble

fbshipit-source-id: d35cb7109c62fd5ad541a26968e3a3e16d3e85ea

Summary:
The info log header feature never worked well, because log level Header was not
translated to Logger::LogHeader() call. Fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4980

Differential Revision: D14087283

Pulled By: siying

fbshipit-source-id: 7e7d03ce35fa8d13d4ee549f46f7326f7bc0006d

Summary:
Right now when a flush is triggered, the memory consumption is logged but data size is not.
It's useful to log both when we debug unexpected small flushed file size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4979

Differential Revision: D14071979

Pulled By: siying

fbshipit-source-id: 0cd60449c5205eb00e0fbc299084418f609904ed

Summary:
LITE mode has EventListener to be an empty class. However in db_bench,
it is used. When "override" is added to the functions, the build breaks. Fix it
by keeping the listener empty in LITE mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4989

Differential Revision: D14108132

Pulled By: siying

fbshipit-source-id: 80121aab35b1120e502b37b782301dd700692697

Summary:
We introduced ttl option in CompactionOptionsFIFO when ttl-based file
deletion (compaction) was supported only as part of FIFO Compaction. But
with the extension of ttl semantics even to Level compaction,
CompactionOptionsFIFO.ttl can now be deprecated. Instead we will start
using ColumnFamilyOptions.ttl for FIFO compaction as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4965

Differential Revision: D14072960

Pulled By: sagar0

fbshipit-source-id: c98cc2ae695a28136295787cd88d36a220fc219e

Summary:
Use C++11’s override and remove virtual where applicable.
Change are automatically generated.

Reviewed By: Orvid

Differential Revision: D14090024

fbshipit-source-id: 1e9432e87d2657e1ff0028e15370a85d1739ba2a

Summary:
If `CompressionOptions::max_dict_bytes` and/or `CompressionOptions::zstd_max_train_bytes` are set, `SstFileWriter` will now generate files respecting those options.

I refactored the logic a bit for deciding when to use dictionary compression. Previously we plumbed `is_bottommost_level` down to the table builder and used that. However it was kind of confusing in `SstFileWriter`'s context since we don't know what level the file will be ingested to. Instead, now the higher-level callers (e.g., flush, compaction, file writer) are responsible for building the right `CompressionOptions` to give the table builder.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4978

Differential Revision: D14060763

Pulled By: ajkr

fbshipit-source-id: dc802c327896df2b319dc162d6acc82b9cdb452a

Summary:
if an operation just involves a single column family, then we do
not have to set the kInAtomicGroup tag when writing to MANIFEST. This change
can fix a compatibility test failure, i.e. 5.15 and earlier cannot recognize
kInAtomicGroup tag.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4981

Differential Revision: D14072687

Pulled By: riversand963

fbshipit-source-id: 46b0c61e399f16c6b7169de0b33430d0ed90d6d4

Summary:
We should strip `-DZSTD` to prevent ZSTD from being used in the no compression tests, similarly to how we prevent all other compression libraries from being used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4982

Differential Revision: D14075349

Pulled By: ajkr

fbshipit-source-id: 8bd861516cf28a568c2b701ad33d0bb658db93b2

Reviewed By: siying

Differential Revision: D13993686

fbshipit-source-id: 0c55e8952307bcf457c1d78d527a0c86b59628e8

Summary:
as title. For people who continue to need Lua compaction filter, you
can copy the include/rocksdb/utilities/rocks_lua/lua_compaction_filter.h and
utilities/lua/rocks_lua_compaction_filter.cc to your own codebase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4971

Differential Revision: D14047468

Pulled By: riversand963

fbshipit-source-id: 9ad1a6484a7c94e478f1e108127a3184e4069f70

Summary:
Make file ingestion atomic.

 as title.
Ingesting external SST files into multiple column families should be atomic. If
a crash occurs and db reopens, either all column families have successfully
ingested the files before the crash, or non of the ingestions have any effect
on the state of the db.

Also add unit tests for atomic ingestion.

Note that the unit test here does not cover the case of incomplete atomic group
in the MANIFEST, which is covered in VersionSetTest already.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4895

Differential Revision: D13718245

Pulled By: riversand963

fbshipit-source-id: 7df97cc483af73ad44dd6993008f99b083852198

Summary:
Closes https://github.com/facebook/rocksdb/pull/1570
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4797

Differential Revision: D13961770

Pulled By: sagar0

fbshipit-source-id: e34fd6250d0cd3ebb0bd688e8801fe8947fd464d

Summary:
Previously, stats were logged in warning level. This was done in that way because
people reported that it wasn't logged in MyRocks. However, later we learned that it turns
out to be due to a bug in MyRocks, which is fixed in
https://github.com/facebook/mysql-5.6/commit/79bb705e74b239d7030b724ea6bbd635eceec531

Now we revert the stats logging to INFO level, so that it doesn't pollute the warning
level logging.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4977

Differential Revision: D14058485

Pulled By: siying

fbshipit-source-id: 19fab323c19d9bc88184287f209551f9a77ca0e6

Summary:
Fix issues found by Clang Analyzer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4976

Differential Revision: D14054211

Pulled By: sagar0

fbshipit-source-id: ec2053bae43af3b2ff3425306824c677e3ba70c2

Summary:
In `DBImpl::AtomicFlushMemTablesToOutputFiles`, we need to call fsync only once
on the same data directory. If two column families share a common directory for
their data, we call fsync only once.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4817

Differential Revision: D13543689

Pulled By: riversand963

fbshipit-source-id: 4701d77c96a47802fbf6cb9f3337ee65d46b95f5

Summary:
Our previous approach was to train one compression dictionary per compaction, using the first output SST to train a dictionary, and then applying it on subsequent SSTs in the same compaction. While this was great for minimizing CPU/memory/I/O overhead, it did not achieve good compression ratios in practice. In our most promising potential use case, moderate reductions in a dictionary's scope make a major difference on compression ratio.

So, this PR changes compression dictionary to be scoped per-SST. It accepts the tradeoff during table building to use more memory and CPU. Important changes include:

- The `BlockBasedTableBuilder` has a new state when dictionary compression is in-use: `kBuffered`. In that state it accumulates uncompressed data in-memory whenever `Add` is called.
- After accumulating target file size bytes or calling `BlockBasedTableBuilder::Finish`, a `BlockBasedTableBuilder` moves to the `kUnbuffered` state. The transition (`EnterUnbuffered()`) involves sampling the buffered data, training a dictionary, and compressing/writing out all buffered data. In the `kUnbuffered` state, a `BlockBasedTableBuilder` behaves the same as before -- blocks are compressed/written out as soon as they fill up.
- Samples are now whole uncompressed data blocks, except the final sample may be a partial data block so we don't breach the user's configured `max_dict_bytes` or `zstd_max_train_bytes`. The dictionary trainer is supposed to work better when we pass it real units of compression. Previously we were passing 64-byte KV samples which was not realistic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4952

Differential Revision: D13967980

Pulled By: ajkr

fbshipit-source-id: 82bea6f7537e1529c7a1a4cdee84585f5949300f

Summary:
See https://github.com/facebook/rocksdb/issues/4884
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4929

Differential Revision: D14028333

Pulled By: sagar0

fbshipit-source-id: eed12bceae85385a34aaa6dd303bf0f53c4c7b06

Summary:
Enhance ::Insert and ::Verify test functions to add artificial delay between prepare and commit, and take snapshot and reads respectively.  A future PR will make use of these to improve stress tests to test against long-running transactions as well as long-running backup jobs. Also randomly sets set_snapshot to false for inserters to skip setting the snapshot in the initialization phase and let the snapshot be taken later explicitly.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4970

Differential Revision: D14031342

Pulled By: maysamyabandeh

fbshipit-source-id: b52b453751f0b25b81b23c48892bc1d152464cab