Summary:
When ingesting multiple files
- We should use user comparator
- Should not call `cfd->current()` outside of mutex

Test Plan: unit tests

Reviewers: sdong, lightmark

Reviewed By: lightmark

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D63075

Summary: Fix using `arg[i].thread` after deleting it

Test Plan: run clang_analyze

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D63171

* Fix StatsLevel so that kExceptTimeForMutex leaves compression stats enabled and kExceptDetailedTimers disables mutex lock stats. Also change default stats level to kExceptDetailedTimers (disabling both compression and mutex timing).

* Changed order of StatsLevel enum to simplify logic for determining what stats to record.

Summary:
This takes the questions currently on the front of the Wordpress-based rocksdb.org and starts an official FAQ with them.

Depends on: https://reviews.facebook.net/D63105

Test Plan: Visual

Reviewers: IslamAbdelRahman, lgalanis

Reviewed By: lgalanis

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63123

Summary:
Tried to:

- preserve existing links
- move existing images over (there were 2)
- preserve codeblocks (modified where apprporiate)
- etc.

Also as agreed upon:

- All blog posts are preserved.
- Comments are not preserved.
- Not turning on comments for future blog posts (use the FB developer group instead).
- Like button at the end of the blog post.

Depends on https://reviews.facebook.net/D63051

Test Plan: Visual

Reviewers: IslamAbdelRahman, lgalanis

Reviewed By: lgalanis

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63105

Summary:
This moves the current Getting Started that we have hosted over to our new GitHub pages infra.

Next will be to move the blog over, along with some updates and maintenance of links, etc. in the new infra.

Depends on: https://reviews.facebook.net/D62985

Test Plan: Visual

Reviewers: IslamAbdelRahman, lgalanis

Reviewed By: lgalanis

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63051

Summary:
This is the proof of concept for the initial landing page for RocksDB when we move to GitHub pages.

The images for each feature can change, but using these as placeholders for now.

The styling may change a bit as well.

Test Plan: Visual

Reviewers: IslamAbdelRahman, lgalanis, sdong

Reviewed By: lgalanis

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62985

Summary: The content in this directory is old, has not been updated in some cases years, and superceded by the current Wordpress-based docs (soon to be changed to Jekyll)

Test Plan: visual

Reviewers: IslamAbdelRahman, lgalanis

Reviewed By: lgalanis

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62877

Merge options source_compaction_factor, max_grandparent_overlap_bytes and expanded_compaction_factor into max_compaction_bytes

Summary: To reduce number of options, merge source_compaction_factor, max_grandparent_overlap_bytes and expanded_compaction_factor into max_compaction_bytes.

Test Plan: Add two new unit tests. Run all existing tests, including jtest.

Reviewers: yhchiang, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59829

Summary: basically for SimCache stats. I find most times it is hard to pass Statistics* to SimCache constructor.

Test Plan: make all check

Reviewers: andrewkr, sdong, yiwu

Reviewed By: yiwu

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62193

Summary: not sure why travis complain about this line, works fine on my mac

Test Plan: run on my mac

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D63045

Summary:
To reduce contention for atomics when HistogramStats are shared across
threads, this diff makes them thread-specific so updates are faster. This comes
at the expense of slower reads (much less frequent), which now require merging
all histograms. In this diff,

- Thread-specific HistogramImpl is created upon the thread's first measureTime()
- Thread-specific HistogramImpl are merged and deleted upon thread termination or ThreadLocalPtr destruction, whichever comes first
- getHistogramString() and histogramData() merge all histograms, both thread-specific and previously merged ones

Test Plan:
unit tests, ran db_bench and verified histograms look similar

before:

  $ TEST_TMPDIR=/dev/shm/ perf record -g ./db_bench --benchmarks=readwhilewriting --statistics --num=1000000 --use_existing_db --threads=64 --cache_size=250000000 --compression_type=lz4
  ...
  +    7.63%  db_bench     db_bench             [.] rocksdb::HistogramStat::Add

after:

  $ TEST_TMPDIR=/dev/shm/ perf record -g ./db_bench --benchmarks=readwhilewriting --statistics --num=1000000 --use_existing_db --threads=64 --cache_size=250000000 --compression_type=lz4
  ...
  +    0.98%  db_bench     db_bench             [.] rocksdb::HistogramStat::Add

Reviewers: sdong, MarkCallaghan, kradhakrishnan, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62649

Summary: add prefix_seek_mode to db_iter_test to enable data race test for iterator when prefix_extractor != nullptr

Test Plan: make all check -j64

Reviewers: andrewkr, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63027

Summary:
Fix ClockCache memory leak found by valgrind:
# Add destructor to cleanup cached values.
# Delete key with cache handle immediately after handle is recycled, and erase table entry immediately if duplicated cache entry is inserted.

Test Plan:
    make DISABLE_JEMALLOC=1 valgrind_check

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62973

Summary: Fix travis for mac by using gflags package instead of doing `brew install`

Test Plan: https://travis-ci.org/facebook/rocksdb/builds/156358515

Reviewers: sdong, andrewkr, lightmark, yiwu

Reviewed By: yiwu

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62997

Summary:
core dump when run
`./db_stress --max_background_compactions=1 --max_write_buffer_number=3 --sync=0 --reopen=20 --write_buffer_size=33554432 --delpercent=5 --log2_keys_per_lock=10 --block_size=16384 --allow_concurrent_memtable_write=1 --test_batches_snapshots=0 --max_bytes_for_level_base=67108864 --progress_reports=0 --mmap_read=1 --kill_prefix_blacklist=WritableFileWriter::Append,WritableFileWriter::WriteBuffered --writepercent=35 --disable_data_sync=0 --readpercent=50 --subcompactions=3 --ops_per_thread=20000000 --memtablerep=skip_list --prefix_size=0 --target_file_size_multiplier=1 --column_families=1 --db=/dev/shm/rocksdb/rocksdb_crashtest_whitebox --threads=32 --disable_wal=0 --open_files=500000 --destroy_db_initially=0 --target_file_size_base=16777216 --nooverwritepercent=1 --iterpercent=10 --max_key=100000000 --prefixpercent=0 --use_clock_cache=false --kill_random_test=189 --cache_size=1048576 --verify_checksum=1`
Actually the relevant flag is `--threads`, data race when --thread > 1 cause problem.
It is possible that multiple
threads read/write memtable simultaneously. After one thread
calls Prev(), another thread may insert a new key just between
the current key and the key next, which may cause the
assert(current_ == CurrentForward()) failure when the first
thread calls Next() again if in prefix seek mode

Test Plan: rerun db_stress with >1 thread / make all check -j64

Reviewers: sdong, andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62979

Summary: patch for D62361

Test Plan: make all check

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62883

Summary: Update the docs `README.md` to be more specific to RocksDB as opposed to the more generic information that is there now.

Test Plan: visual

Reviewers: lgalanis, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62733

Summary: As title, make sure Prev() works as expected with Next() when the current iter->key() in the range of the same prefix in prefix seek mode

Test Plan: make all check -j64 (add prefix_test with PrefixSeekModePrev test case)

Reviewers: andrewkr, sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: yoshinorim, andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61419

Summary: Refactor cache_test to get around gtest valgrind failure.

Test Plan:
    make valgrind_check

Reviewers: sdong, kradhakrishnan, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62817

* Fix the download location of Snappy, no longer available from Google Code

* Ensure that curl follows any redirect headers when downloading binaries

Summary:
Add ReadOptions::read_amp_bytes_per_bit option which allow us to create a bitmap for every data block we read
the bitmap will contain (block_size / read_amp_bytes_per_bit) bits.

We will use this bitmap to mark which bytes have been used of the block so we can calculate the read amplification

Test Plan: added new tests

Reviewers: andrewkr, yhchiang, sdong

Reviewed By: sdong

Subscribers: yiwu, leveldb, march, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58707

Summary:
Make sure prefix extractor name is stored in SST files and if DB is opened with a prefix extractor of a different name, prefix bloom is skipped when read the file.
Also add unit tests for that.

Test Plan:
before change:
```
Note: Google Test filter = BlockBasedTableTest.SkipPrefixBloomFilter
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from BlockBasedTableTest
[ RUN      ] BlockBasedTableTest.SkipPrefixBloomFilter
table/table_test.cc:1421: Failure
Value of: db_iter->Valid()
Actual: false
Expected: true
[  FAILED  ] BlockBasedTableTest.SkipPrefixBloomFilter (1 ms)
[----------] 1 test from BlockBasedTableTest (1 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (1 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] BlockBasedTableTest.SkipPrefixBloomFilter

1 FAILED TEST
```
after:
```
Note: Google Test filter = BlockBasedTableTest.SkipPrefixBloomFilter
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from BlockBasedTableTest
[ RUN      ] BlockBasedTableTest.SkipPrefixBloomFilter
[       OK ] BlockBasedTableTest.SkipPrefixBloomFilter (0 ms)
[----------] 1 test from BlockBasedTableTest (0 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (0 ms total)
[  PASSED  ] 1 test.
```

Reviewers: sdong, andrewkr, yiwu, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61215

Summary: as title

Test Plan: make all check

Reviewers: yiwu

Reviewed By: yiwu

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62493

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

Summary:
Update History.md to reflect recent change that ensures unpersisted data
is flushed even if clients call CancelAllBackgroundWork() directly.

Test Plan: Review rendering of markdown.

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62703

Summary:
After 1b8a2e8f, DB Pointer is passed to WriteBatchInternal::InsertInto() while DB recovery. This can cause deadlock if options.max_successive_merges hits. In that case DB::Get() will be called. Get() will try to acquire the DB mutex, which is already held by the DB::Open(), causing a deadlock condition.

This commit mitigates the problem by not passing the DB pointer unless 2PC is allowed.

Test Plan: Add a new test and run it.

Reviewers: IslamAbdelRahman, andrewkr, kradhakrishnan, horuff

Reviewed By: kradhakrishnan

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62625

[db_bench] Support single benchmark arguments (Repeat for X times, Warm up for X times), Support CombinedStats (AVG / MEDIAN)

Summary:
This diff allow us to run a single benchmark X times and warm it up for Y times. and see the AVG & MEDIAN throughput of these X runs
for example

```
$ ./db_bench --benchmarks="fillseq,readseq[X5-W2]"
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 4.12
Date:       Wed Aug 24 10:45:26 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: 1
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
DB path: [/tmp/rocksdbtest-8616/dbbench]
fillseq      :       4.695 micros/op 212971 ops/sec;   23.6 MB/s
DB path: [/tmp/rocksdbtest-8616/dbbench]
Warming up benchmark by running 2 times
readseq      :       0.214 micros/op 4677005 ops/sec;  517.4 MB/s
readseq      :       0.212 micros/op 4706834 ops/sec;  520.7 MB/s
Running benchmark for 5 times
readseq      :       0.218 micros/op 4588187 ops/sec;  507.6 MB/s
readseq      :       0.208 micros/op 4816538 ops/sec;  532.8 MB/s
readseq      :       0.213 micros/op 4685376 ops/sec;  518.3 MB/s
readseq      :       0.214 micros/op 4676787 ops/sec;  517.4 MB/s
readseq      :       0.217 micros/op 4618532 ops/sec;  510.9 MB/s
readseq [AVG    5 runs] : 4677084 ops/sec;  517.4 MB/sec
readseq [MEDIAN 5 runs] : 4676787 ops/sec;  517.4 MB/sec
```

Test Plan: run db_bench

Reviewers: sdong, andrewkr, yhchiang

Reviewed By: yhchiang

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62235

Summary:
Instead of doing a cat for all the log files, we first sort them and by exit code and cat the failing tests at the end.
This will make it easier to debug failing tests, since we will just need to look at the end of the logs instead of searching in them

Test Plan: run it locally

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

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62211

Summary:
Move the manual memtable flush for databases containing data that has
bypassed the WAL from DBImpl's destructor to CancleAllBackgroundWork().

CancelAllBackgroundWork() is a publicly exposed API which allows
async operations performed by background threads to be disabled on a
database. In effect, this places the database into a "shutdown" state
in advance of calling the database object's destructor. No compactions
or flushing of SST files can occur once a call to this API completes.

When writes are issued to a database with WriteOptions::disableWAL
set to true, DBImpl::has_unpersisted_data_ is set so that
memtables can be flushed when the database object is destroyed. If
CancelAllBackgroundWork() has been called prior to DBImpl's destructor,
this flush operation is not possible and is skipped, causing unnecessary
loss of data.

Since CancelAllBackgroundWork() is already invoked by DBImpl's destructor
in order to perform the thread join portion of its cleanup processing,
moving the manual memtable flush to CancelAllBackgroundWork() ensures
data is persisted regardless of client behavior.

Test Plan:
Write an amount of data that will not cause a memtable flush to a rocksdb
database with all writes marked with WriteOptions::disableWAL. Properly
"close" the database. Reopen database and verify that the data was
persisted.

Reviewers: IslamAbdelRahman, yiwu, yoshinorim, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62277

Summary:
I just realized that when we run parallel valgrind we actually don't run the parallel tests under valgrind (we run the normally)
This patch make sure that we run both parallel and non-parallel tests with valgrind

Test Plan: DISABLE_JEMALLOC=1 make valgrind_check -j64

Reviewers: andrewkr, yiwu, lightmark, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62469

Summary: see discussion in D62337

Test Plan: unit tests

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62577

Fix the Windows build of RocksDB Java. Similar to https://github.com/facebook/rocksdb/issues/1220 (#1284)

Summary:
We've got a crash with this stack trace:

  Program terminated with signal SIGTRAP, Trace/breakpoint trap.

  #0  0x00007fc85f2f4009 in raise () from /usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/libpthread.so.0
  #1  0x00000000005c8f61 in facebook::logdevice::handle_sigsegv(int) () at logdevice/server/sigsegv.cpp:159
  #2  0x00007fc85f2f4150 in <signal handler called> () at /usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/libpthread.so.0
  #3  0x00000000031ed80c in rocksdb::NewReadaheadRandomAccessFile() at util/file_reader_writer.cc:383
  #4  0x00000000031ed80c in rocksdb::NewReadaheadRandomAccessFile() at util/file_reader_writer.cc:472
  #5  0x00000000031558e7 in rocksdb::TableCache::GetTableReader() at db/table_cache.cc:99
  #6  0x0000000003156329 in rocksdb::TableCache::NewIterator() at db/table_cache.cc:198
  #7  0x0000000003166568 in rocksdb::VersionSet::MakeInputIterator() at db/version_set.cc:3345
  #8  0x000000000324a94f in rocksdb::CompactionJob::ProcessKeyValueCompaction(rocksdb::CompactionJob::SubcompactionState*) () at db/compaction_job.cc:650
  #9  0x000000000324c2f6 in rocksdb::CompactionJob::Run() () at db/compaction_job.cc:530
  #10 0x00000000030f5ae5 in rocksdb::DBImpl::BackgroundCompaction() at db/db_impl.cc:3269
  #11 0x0000000003108d36 in rocksdb::DBImpl::BackgroundCallCompaction(void*) () at db/db_impl.cc:2970
  #12 0x00000000029a2a9a in facebook::logdevice::RocksDBEnv::callback(void*) () at logdevice/server/locallogstore/RocksDBEnv.cpp:26
  #13 0x00000000029a2a9a in facebook::logdevice::RocksDBEnv::callback(void*) () at logdevice/server/locallogstore/RocksDBEnv.cpp:30
  #14 0x00000000031e7521 in rocksdb::ThreadPool::BGThread() at util/threadpool.cc:230
  #15 0x00000000031e7663 in rocksdb::BGThreadWrapper(void*) () at util/threadpool.cc:254
  #16 0x00007fc85f2ea7f1 in start_thread () at /usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/libpthread.so.0
  #17 0x00007fc85e8fb46d in clone () at /usr/local/fbcode/gcc-4.9-glibc-2.20-fb/lib/libc.so.6

From looking at the code, probably what happened is this:
 - `TableCache::GetTableReader()` called `Env::NewRandomAccessFile()`, which dispatched to a `PosixEnv::NewRandomAccessFile()`, where probably an `open()` call failed, so the `NewRandomAccessFile()` left a nullptr in the resulting file,
 - `TableCache::GetTableReader()` called `NewReadaheadRandomAccessFile()` with that `nullptr` file,
 - it tried to call file's method and crashed.

This diff is a trivial fix to this crash.

Test Plan: `make -j check`

Reviewers: sdong, andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62451

Summary:
The global atomics we previously used for tickers had poor cache performance
since they were typically updated from different threads, causing frequent
invalidations. In this diff,

- recordTick() updates a local ticker value specific to the thread in which it was called
- When a thread exits, its local ticker value is added into merged_sum
- getTickerCount() returns the sum of all threads' local ticker values and the merged_sum
- setTickerCount() resets all threads' local ticker values and sets merged_sum to the value provided by the caller.

In a next diff I will make a similar change for histogram stats.

Test Plan:
before:

  $ TEST_TMPDIR=/dev/shm/ perf record -g ./db_bench --benchmarks=readwhilewriting --statistics --num=1000000 --use_existing_db --threads=64 --cache_size=250000000 --compression_type=lz4
  $ perf report -g --stdio | grep recordTick
  7.59%  db_bench     db_bench             [.] rocksdb::StatisticsImpl::recordTick
  ...

after:

  $ TEST_TMPDIR=/dev/shm/ perf record -g ./db_bench --benchmarks=readwhilewriting --statistics --num=1000000 --use_existing_db --threads=64 --cache_size=250000000 --compression_type=lz4
  $ perf report -g --stdio | grep recordTick
  1.46%  db_bench     db_bench             [.] rocksdb::StatisticsImpl::recordTick
  ...

Reviewers: kradhakrishnan, MarkCallaghan, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: yiwu, andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62337

This is the initial commit with the templates necessary to have our RocksDB user documentation hosted on GitHub pages.

Ensure you meet requirements here: https://help.github.com/articles/setting-up-your-github-pages-site-locally-with-jekyll/#requirements

Then you can run this right now by doing the following:

```
% bundle install
% bundle exec jekyll serve --config=_config.yml,_config_local_dev.yml
```

Then go to: http://127.0.0.1:4000/

Obviously, this is just the skeleton. Moving forward we will do these things in separate pull requests:

- Replace logos with RocksDB logos
- Update the color schemes
- Add current information on rocksdb.org to markdown in this infra
- Migrate current Wodpress blog to Jekyll and Disqus comments
- Etc.

Summary: Disable flaky test

Test Plan: run it

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

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62487