Summary:
merger.h was always a confusing name for me, simply give the file a better name
Closes https://github.com/facebook/rocksdb/pull/1836

Differential Revision: D4505357

Pulled By: IslamAbdelRahman

fbshipit-source-id: 07b28d8

Summary:
The Env registration framework supports registering client Envs and selecting which one to instantiate according to a text field. This enabled things like adding the -env_uri argument to db_bench, so the same binary could be reused with different Envs just by changing CLI config.

Now this problem has come up again in a non-Env context, as I want to instantiate a client Statistics implementation from db_bench, which is configured entirely via text parameters. Also, in the future we may wish to use it for deserializing client objects when loading OPTIONS file.

This diff generalizes the Env registration logic to work with arbitrary types.

- Generalized registration and instantiation code by templating them
- The entire implementation is in a header file as that's Google style guide's recommendation for template definitions
- Pattern match with std::regex_match rather than checking prefix, which was the previous behavior
- Rename functions/files to be non-Env-specific
Closes https://github.com/facebook/rocksdb/pull/1776

Differential Revision: D4421933

Pulled By: ajkr

fbshipit-source-id: 34647d1

Summary:
Iterator should be in corrupted status if merge operator return false.
Also add test to make sure if max_successive_merges is hit during write,
data will not be lost.
Closes https://github.com/facebook/rocksdb/pull/1665

Differential Revision: D4322695

Pulled By: yiwu-arbug

fbshipit-source-id: b327b05

Summary:
Now that we have userspace persisted cache, we don't need flashcache anymore.
Closes https://github.com/facebook/rocksdb/pull/1588

Differential Revision: D4245114

Pulled By: igorcanadi

fbshipit-source-id: e2c1c72

Summary: Closes https://github.com/facebook/rocksdb/pull/1578

Differential Revision: D4241171

Pulled By: ajkr

fbshipit-source-id: ce5fd83

Summary:
Changes in the diff

API changes:
- Introduce IngestExternalFile to replace AddFile (I think this make the API more clear)
- Introduce IngestExternalFileOptions (This struct will encapsulate the options for ingesting the external file)
- Deprecate AddFile() API

Logic changes:
- If our file overlap with the memtable we will flush the memtable
- We will find the first level in the LSM tree that our file key range overlap with the keys in it
- We will find the lowest level in the LSM tree above the the level we found in step 2 that our file can fit in and ingest our file in it
- We will assign a global sequence number to our new file
- Remove AddFile restrictions by using global sequence numbers

Other changes:
- Refactor all AddFile logic to be encapsulated in ExternalSstFileIngestionJob

Test Plan:
unit tests (still need to add more)
addfile_stress (https://reviews.facebook.net/D65037)

Reviewers: yiwu, andrewkr, lightmark, yhchiang, sdong

Reviewed By: sdong

Subscribers: jkedgar, hcz, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D65061

Summary:
This diff introduces RangeDelAggregator, which takes ownership of iterators
provided to it via AddTombstones(). The tombstones are organized in a two-level
map (snapshot stripe -> begin key -> tombstone). Tombstone creation avoids data
copy by holding Slices returned by the iterator, which remain valid thanks to pinning.

For compaction, we create a hierarchical range tombstone iterator with structure
matching the iterator over compaction input data. An aggregator based on that
iterator is used by CompactionIterator to determine which keys are covered by
range tombstones. In case of merge operand, the same aggregator is used by
MergeHelper. Upon finishing each file in the compaction, relevant range tombstones
are added to the output file's range tombstone metablock and file boundaries are
updated accordingly.

To check whether a key is covered by range tombstone, RangeDelAggregator::ShouldDelete()
considers tombstones in the key's snapshot stripe. When this function is used outside of
compaction, it also checks newer stripes, which can contain covering tombstones. Currently
the intra-stripe check involves a linear scan; however, in the future we plan to collapse ranges
within a stripe such that binary search can be used.

RangeDelAggregator::AddToBuilder() adds all range tombstones in the table's key-range
to a new table's range tombstone meta-block. Since range tombstones may fall in the gap
between files, we may need to extend some files' key-ranges. The strategy is (1) first file
extends as far left as possible and other files do not extend left, (2) all files extend right
until either the start of the next file or the end of the last range tombstone in the gap,
whichever comes first.

One other notable change is adding release/move semantics to ScopedArenaIterator
such that it can be used to transfer ownership of an arena-allocated iterator, similar to
how unique_ptr is used for malloc'd data.

Depends on D61473

Test Plan: compaction_iterator_test, mock_table, end-to-end tests in D63927

Reviewers: sdong, IslamAbdelRahman, wanning, yhchiang, lightmark

Reviewed By: lightmark

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62205

Add Java API for SstFileWriter. Closes https://github.com/facebook/rocksdb/issues/1248

Summary: Use ImmutableDBOptions/MutableDBOptions internally and DBOptions only for user-facing APIs. MutableDBOptions is barely a placeholder for now. I'll start to move options to MutableDBOptions in following diffs.

Test Plan:
  make all check

Reviewers: yhchiang, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64065

Summary: Simply move the tests

Test Plan: make check -j64

Reviewers: andrewkr, lightmark, yiwu, yhchiang, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62529

Add 'cf_options' to source list and db_imple.cc

fix casting

Summary: There's no reference to ImmutableCFOptions elsewhere in /include/rocksdb. ImmutableCFOptions was introduced in this commit (https://github.com/facebook/rocksdb/commit/5665e5e285c25c1674567f747df92c131037d2dc) but later its reference in /include/rocksdb/table.h is removed.

Test Plan:
  make all check

Reviewers: IslamAbdelRahman, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: yhchiang, andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63177

Summary:
This diff split ThreadPool to
-ThreadPool (abstract interface exposed in include/rocksdb/threadpool.h)
-ThreadPoolImpl (actual implementation in util/threadpool_imp.h)

This allow us to expose ThreadPool to the user so we can use it as an option later

Test Plan: existing unit tests

Reviewers: andrewkr, yiwu, yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62085

Add Status to RocksDBException so that meaningful function result Status from the C++ API isn't lost (#1273)

Summary:
Clock-based cache implemenetation aim to have better concurreny than
default LRU cache. See inline comments for implementation details.

Test Plan:
Update cache_test to run on both LRUCache and ClockCache. Adding some
new tests to catch some of the bugs that I fixed while implementing the
cache.

Reviewers: kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61647

Summary:
This is a proof of concept of a RocksDB blob log file. The actual value of the Put() is appended to a blob log using normal data block format, and the handle of the block is written as the value of the key in RocksDB.

The prototype only supports Put() and Get(). It doesn't support DB restart, garbage collection, Write() call, iterator, snapshots, etc.

Test Plan: Add unit tests.

Reviewers: arahut

Reviewed By: arahut

Subscribers: kradhakrishnan, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61485

Summary: Implement a time series database that supports DateTieredCompactionStrategy. It wraps a db object and separate SST files in different column families (time windows).

Test Plan: Add `date_tiered_test`.

Reviewers: dhruba, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61653

Summary: Add a utility function that trigger necessary full compaction and put output to the correct level by looking at new options and old options.

Test Plan: Add unit tests for it.

Reviewers: andrewkr, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: muthu, sumeet, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60783

Summary:
Experiments on column-aware encodings. Supported features: 1) extract data blocks from SST file and encode with specified encodings; 2) Decode encoded data back into row format; 3) Directly extract data blocks and write in row format (without prefix encoding); 4) Get column distribution statistics for column format; 5) Dump data blocks separated by columns in human-readable format.

There is still on-going work on this diff. More refactoring is necessary.

Test Plan: Wrote tests in `column_aware_encoding_test.cc`. More tests should be added.

Reviewers: sdong

Reviewed By: sdong

Subscribers: arahut, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60027

Summary:
The patch is a continuation of part 5. It glues the abstraction for
file layout and metadata, and flush out the implementation of the API. It
adds unit tests for the implementation.

Test Plan: Run unit tests

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57549

Summary:
TickersNameMap is not consistent with Tickers enum.
this cause us to report wrong statistics and sometimes to access TickersNameMap outside it's boundary causing crashes (in Fb303 statistics)

Test Plan: added new unit test

Reviewers: sdong, kradhakrishnan

Reviewed By: kradhakrishnan

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61083

Summary:
Fix flush not being commit while writing manifest, which is a recent bug introduced by D60075.

The issue:
# Options.max_background_flushes > 1
# Background thread A pick up a flush job, flush, then commit to manifest. (Note that mutex is released before writing manifest.)
# Background thread B pick up another flush job, flush. When it gets to `MemTableList::InstallMemtableFlushResults`, it notices another thread is commiting, so it quit.
# After the first commit, thread A doesn't double check if there are more flush result need to commit, leaving the second flush uncommitted.

Test Plan: run the test. Also verify the new test hit deadlock without the fix.

Reviewers: sdong, igor, lightmark

Reviewed By: lightmark

Subscribers: andrewkr, omegaga, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60969

Summary:
Persistent cache tier is the tier abstraction that can work for any block
device based device mounted on a file system. The design/implementation can
handle any generic block device.

Any generic block support is achieved by generalizing the access patten as
{io-size, q-depth, direct-io/buffered}.

We have specifically tested and adapted the IO path for NVM and SSD.

Persistent cache tier consists of there parts :

1) File layout

Provides the implementation for handling IO path for reading and writing data
(key/value pair).

2) Meta-data
Provides the implementation for handling the index for persistent read cache.

3) Implementation
It binds (1) and (2) and flushed out the PersistentCacheTier interface

This patch provides implementation for (1)(2). Follow up patch will provide (3)
and tests.

Test Plan: Compile and run check

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57117

Summary: Refactor cache.cc so that I can plugin clock cache (D55581). Mainly move `ShardedCache` to separate file, move `LRUHandle` back to cache.cc and rename it lru_cache.cc.

Test Plan:
    make check -j64

Reviewers: lightmark, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59655

Summary:
When write stalls because of auto compaction is disabled, or stop write trigger is reached,
user may change these two options to unblock writes. Unfortunately we had issue where the write
thread will block the attempt to persist the options, thus creating a deadlock. This diff
fix the issue and add two test cases to detect such deadlock.

Test Plan:
Run unit tests.

Also, revert db_impl.cc to master (but don't revert `DBImpl::BackgroundCompaction:Finish` sync point) and run db_options_test. Both tests should hit deadlock.

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60627

Summary: In D33849 we updated Makefile to generate .d files for all .cc sources. Since we have more types of source files now, this needs to be updated so that this mechanism can work for new files.

Test Plan: change a dependent .h file, re-make and see if .o file is recompiled.

Reviewers: sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60591

Summary:
DB::AddFile() right now always add the ingested file to L0
update the logic to add the file to the lowest possible level

Test Plan: unit tests

Reviewers: jkedgar, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, yoshinorim

Differential Revision: https://reviews.facebook.net/D59637

Summary: It confuses some compilers to have slice.cc under multiple directories. Merge them.

Test Plan: Run existing tests

Reviewers: andrewkr, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59409

Summary: AFIK, options builder is not used by anyone. Remove it.

Test Plan: Run all existing tests.

Reviewers: IslamAbdelRahman, andrewkr, igor

Reviewed By: igor

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59319

Summary:
This provides provides an implementation of PersistentCacheTier that is
specialized for RAM. This tier does not persist data though.

Why do we need this tier ?

This is ideal as tier 0. This tier can host data that is too hot.

Why can't we use Cache variants ?

Yes you can use them instead. This tier can potentially outperform BlockCache
in RAW mode by virtue of compression and compressed cache in block cache doesn't
seem very popular. Potentially this tier can be modified to under stand the
disadvantage of the tier below and retain data that the tier below is bad at
handling (for example index and bloom data that is huge in size)

Test Plan: Run unit tests added

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57069

Summary:
This diff provides the basic interface definitions of persistent read
cache system

PersistentCacheOptions captures the persistent read cache options used to
configure and control the system
PersistentCacheTier provides the basic building block for constructing tiered
cache
PersistentTieredCache provides a logical abstraction of tiers of cache layered
over one another

Test Plan: Compile

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57051

Summary:
Extracted basic Env-related tests from mock_env_test and memenv_test into a
parameterized test for Envs: env_basic_test.

Depends on D58449. (The dependency is here only so I can keep this series of
diffs in a chain -- there is no dependency on that diff's code.)

Test Plan: ran tests

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58635

Summary:
This enables configurable Envs without recompiling. For example, my
next diff will make env_test test an Env created by NewEnvFromUri(). Then,
users can determine which Env is tested simply by providing the URI for
NewEnvFromUri() (e.g., through a CLI argument or environment variable).

The registration process allows us to register any Env that is linked with the
RocksDB library, so we can register our internal Envs as well.

The registration code is inspired by our internal InitRegistry.

Test Plan: new unit test

Reviewers: IslamAbdelRahman, lightmark, ldemailly, sdong

Reviewed By: sdong

Subscribers: leveldb, dhruba, andrewkr

Differential Revision: https://reviews.facebook.net/D58449

Summary:
This patch allows db_bench to initialize it's RocksDB Options via a
options file, specified by the --options_file flag.  Note that if
--options_file flag is set, then it has higher priority than the
command-line argument.

Test Plan: db_bench_tool_test

Reviewers: sdong, IslamAbdelRahman, kradhakrishnan, yiwu, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58533

Summary: add class SimCache(base class with instrumentation api) and SimLRUCache(derived class with detailed implementation) which is used as an instrumented block cache that can predict hit rate for different cache size

Test Plan:
Add a test case in `db_block_cache_test.cc` called `SimCacheTest` to test basic logic of SimCache.
Also add option `-simcache_size` in db_bench. if set with a value other than -1, then the benchmark will use this value as the size of the simulator cache and finally output the simulation result.
```
[gzh@dev9927.prn1 ~/local/rocksdb] ./db_bench -benchmarks "fillseq,readrandom" -cache_size 1000000 -simcache_size 1000000
RocksDB:    version 4.8
Date:       Tue May 17 16:56:16 2016
CPU:        32 * Intel(R) Xeon(R) CPU E5-2660 0 @ 2.20GHz
CPUCache:   20480 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Write rate: 0 bytes/second
Compression: Snappy
Memtablerep: skip_list
Perf Level: 0
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/rocksdbtest-112628/dbbench]
fillseq      :       6.809 micros/op 146874 ops/sec;   16.2 MB/s
DB path: [/tmp/rocksdbtest-112628/dbbench]
readrandom   :       6.343 micros/op 157665 ops/sec;   17.4 MB/s (1000000 of 1000000 found)

SIMULATOR CACHE STATISTICS:
SimCache LOOKUPs: 986559
SimCache HITs:    264760
SimCache HITRATE: 26.84%

[gzh@dev9927.prn1 ~/local/rocksdb] ./db_bench -benchmarks "fillseq,readrandom" -cache_size 1000000 -simcache_size 10000000
RocksDB:    version 4.8
Date:       Tue May 17 16:57:10 2016
CPU:        32 * Intel(R) Xeon(R) CPU E5-2660 0 @ 2.20GHz
CPUCache:   20480 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Write rate: 0 bytes/second
Compression: Snappy
Memtablerep: skip_list
Perf Level: 0
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/rocksdbtest-112628/dbbench]
fillseq      :       5.066 micros/op 197394 ops/sec;   21.8 MB/s
DB path: [/tmp/rocksdbtest-112628/dbbench]
readrandom   :       6.457 micros/op 154870 ops/sec;   17.1 MB/s (1000000 of 1000000 found)

SIMULATOR CACHE STATISTICS:
SimCache LOOKUPs: 1059764
SimCache HITs:    374501
SimCache HITRATE: 35.34%

[gzh@dev9927.prn1 ~/local/rocksdb] ./db_bench -benchmarks "fillseq,readrandom" -cache_size 1000000 -simcache_size 100000000
RocksDB:    version 4.8
Date:       Tue May 17 16:57:32 2016
CPU:        32 * Intel(R) Xeon(R) CPU E5-2660 0 @ 2.20GHz
CPUCache:   20480 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Write rate: 0 bytes/second
Compression: Snappy
Memtablerep: skip_list
Perf Level: 0
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/rocksdbtest-112628/dbbench]
fillseq      :       5.632 micros/op 177572 ops/sec;   19.6 MB/s
DB path: [/tmp/rocksdbtest-112628/dbbench]
readrandom   :       6.892 micros/op 145094 ops/sec;   16.1 MB/s (1000000 of 1000000 found)

SIMULATOR CACHE STATISTICS:
SimCache LOOKUPs: 1150767
SimCache HITs:    1034535
SimCache HITRATE: 89.90%
```

Reviewers: IslamAbdelRahman, andrewkr, sdong

Reviewed By: sdong

Subscribers: MarkCallaghan, andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57999

Summary: Deprecate this one option and delete code and tests that are now superfluous.

Test Plan: all tests pass

Reviewers: igor, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: msalib, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D55317

Summary:
Introduce MaxOperator a simple merge operator that return the max of all operands.
This merge operand help me in benchmarking

Test Plan: Add new unitttests

Reviewers: sdong, andrewkr, yhchiang

Reviewed By: yhchiang

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57873

Summary:
This is a part of effort to reduce the size of db_test.cc. We move the following tests to a separate file `db_io_failure_test.cc`:

* DropWrites
* DropWritesFlush
* NoSpaceCompactRange
* NonWritableFileSystem
* ManifestWriteError
* PutFailsParanoid

Test Plan: Run `make check` to see if the tests are working properly.

Reviewers: sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58341

Summary:
Added a new abstraction to cache page to RocksDB designed for the read
cache use.

RocksDB current block cache is more of an object cache. For the persistent read cache
project, what we need is a page cache equivalent. This changes adds a cache
abstraction to RocksDB to cache pages called PersistentCache. PersistentCache can cache
uncompressed pages or raw pages (content as in filesystem). The user can
choose to operate PersistentCache either in  COMPRESSED or UNCOMPRESSED mode.

Blame Rev:

Test Plan: Run unit tests

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55707