Summary:
Add a counter of estimated bytes the DB needs to compact for all the compactions to finish. Expose it as a DB Property.
In the future, we can use threshold of this counter to replace soft rate limit and hard rate limit. A single threshold of estimated compaction debt in bytes will be easier for users to reason about when should slow down and stopping than more abstract soft and hard rate limits.

Test Plan: Add unit tests

Reviewers: IslamAbdelRahman, yhchiang, rven, kradhakrishnan, anthony, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D44205

Summary:
Changes include:
* don't sync-on-commit for single writer thread in readwhile... tests
* make default block size 8kb rather than 4kb to avoid too small blocks after compression
* use snappy instead of zlib to avoid stalls from compression latency
* disable statistics
* use bytes_per_sync=8M to reduce throughput loss on disk
* use open_files=-1 to reduce mutex contention

Task ID: #

Blame Rev:

Test Plan:
run benchmark

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44961

Summary:
Currently, ThreadStatusFlush uses two sync-points to ensure
there's a flush currently running when calling GetThreadList().
However, one of the sync-point is inside db-mutex, which could
cause deadlock in case there's a DB::Get() call.

This patch fix this issue by moving the sync-point to a better
place where the flush job does not hold the mutex.

Test Plan: db_test

Reviewers: igor, sdong, anthony, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D45045

Address windows build issues caused by introducing Subcompaction

Merge branch 'address_windows_build' of https://github.com/yuslepukhin/rocksdb into address_windows_build

 Intro SubCompactionState move functionality
 =delete copy functionality
 #ifdef SyncPoint in tests for Windows Release builds

  Intro SubCompactionState move functionality
  =delete copy functionality
  #ifdef SyncPoint in tests for Windows Release builds

Summary: Add a new DB property that calculate the total size of files used by all RocksDB Versions

Test Plan: Unittests for the new property

Reviewers: igor, yhchiang, anthony, rven, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44799

Summary: Removing two unused variables that prevented compilation.

Test Plan: make all

Reviewers: rven, sdong, yhchiang, anthony, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D44991

Summary:
This diff improves the memory utilization for tailing iterators RocksDB,
by freeing file iterators which are over the upper bound.
It is an updating on Siying's original diff for improving the memory usage for
tailing iterators. The changes for the seek and next path are now complete
and a test has been added to exercise these paths while deleting file iterators
which are above the upper bound.

Test Plan: db_tailing_iter_test.TailingIteratorTrimSeekToNext

Reviewers: march, tnovak, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43833

Summary: Update DestroyDB so that all SST files in the first path id go through DeleteScheduler instead of being deleted immediately

Test Plan: added a unittest

Reviewers: igor, yhchiang, anthony, kradhakrishnan, rven, sdong

Reviewed By: sdong

Subscribers: jeanxu2012, dhruba

Differential Revision: https://reviews.facebook.net/D44955

Summary:
Currently, GetIntProperty("rocksdb.cur-size-all-mem-tables") only returns
the memory usage by those memtables which have not yet been flushed.

This patch introduces GetIntProperty("rocksdb.size-all-mem-tables"),
which includes the memory usage by all the memtables, includes those
have been flushed but pinned by iterators.

Test Plan: Added a test in db_test

Reviewers: igor, anthony, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D44229

Summary: There is a check to fail the iterator if prefix extractor is specified but upper bound is out of the prefix for the seek key. Relax this constraint to allow users to set upper bound to the next prefix of the current one.

Test Plan: make commit-prereq

Reviewers: igor, anthony, kradhakrishnan, yhchiang, rven

Reviewed By: rven

Subscribers: tnovak, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D44949

Summary:
A couple variables were declared but only used in assertions
which causes issues when building in fbcode.

Test Plan: make dbg  and   make release

Reviewers: yhchiang, sdong, igor, anthony, MarkCallaghan

Reviewed By: MarkCallaghan

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44937

Summary:
In D43239 (https://reviews.facebook.net/D43239) the number
of subcompactions is set based on the number of L1 files with
unique starting keys. In certain cases when this number is very large
this causes issues, particularly with the overlap between files since
very small output files can be generated. This diff bounds the number
of subcompactions to the user option DBOption.num_subcompactions.

Test Plan: ./db_test ./db_compaction_test

Reviewers: sdong, igor, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44883

Summary:
Reseek mutable_iter if it is invalid in Next and immutable_iter
is invalid.

Test Plan: DBTestTailingIterator.TailingIteratorSeekToNext

Reviewers: tnovak, march, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D44865

Summary:
This patch implements DBOptions deserialization and improve
the current implementation of DBOptions serialization by
using a static structure that stores the offset of each
DBOptions member variables to perform serialization and
deserialization instead of using tons of if-then-branch
to determine the mapping between string and variables.

Test Plan: Added test in options_test.cc

Reviewers: igor, anthony, sdong, IslamAbdelRahman

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44097

Summary:
HashCuckooRep::ApproximateMemoryUsage() previously return
std::numeric_limits<size_t>::max() when it cannot accept more
entries.  This patch makes it return a more reasonable estimation.

This change is necessary in order to make GetIntProperty("rocksdb.cur-size-all-mem-tables")
handles HashCuckooRep properly in diff https://reviews.facebook.net/D44229.

Test Plan: db_test

Reviewers: sdong, anthony, IslamAbdelRahman, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44241

Summary:
In D43239 (https://reviews.facebook.net/D43239) there is an
assertion to make sure a subcompaction's output is never empty at the
end of execution. This assertion however breaks the build because some
tests lead to exactly that scenario. So instead I have altered the logic
to handle this case instead of just failing the assertion.

The reason that it is possible for a subcompaction's output to be empty is
that during a sequential execution of subcompactions, if a user aborts the
compaction job then some of the later subcompactions to be executed may
have yet to process any keys and therefore have yet to generate output files.
This becomes very rare once the subcompactions are executed in parallel,
but for now they are still sequential so the case is possible when there is an
early termination, as in some of the tests.

Test Plan: ./db_test  ./db_compaction_test

Reviewers: sdong, igor, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44877

Summary:
In prepration for running multiple threads at the same time during
a compaction job, this patch assigns each subcompaction its own state
(instead of sharing the one global CompactionState). Each subcompaction then
uses this state to update its statistics, keep track of its snapshots, etc.
during the course of execution. Then at the end of all the executions the
statistics are aggregated across the subcompactions so that the final result
is the same as if only one larger compaction had run.

Test Plan: ./db_test  ./db_compaction_test  ./compaction_job_test

Reviewers: sdong, anthony, igor, noetzli, yhchiang

Reviewed By: yhchiang

Subscribers: MarkCallaghan, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43239

Summary:
While working on supporting mixing merge operators with
single deletes ( https://reviews.facebook.net/D43179 ),
I realized that returning and dealing with merge results
can be made simpler. Submitting this as a separate diff
because it is not directly related to single deletes.

Before, callers of merge helper had to retrieve the merge
result in one of two ways depending on whether the merge
was successful or not (success = result of merge was single
kTypeValue). For successful merges, the caller could query
the resulting key/value pair and for unsuccessful merges,
the result could be retrieved in the form of two deques of
keys and values. However, with single deletes, a successful merge
does not return a single key/value pair (if merge
operands are merged with a single delete, we have to generate
a value and keep the original single delete around to make
sure that we are not accidentially producing a key overwrite).
In addition, the two existing call sites of the merge
helper were taking the same actions independently from whether
the merge was successful or not, so this patch simplifies that.

Test Plan: make clean all check

Reviewers: rven, sdong, yhchiang, anthony, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43353

Summary: In internal stats, remember read latency histogram, if statistics is enabled. It can be retrieved from DB::GetProperty() with "rocksdb.dbstats" property, if it is enabled.

Test Plan: Manually run db_bench and prints out "rocksdb.dbstats" by hand and make sure it prints out as expected

Reviewers: igor, IslamAbdelRahman, rven, kradhakrishnan, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: MarkCallaghan, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D44193

Summary:
This diff allows a Writer to join the next write batch group
without acquiring any locks. Waiting is performed via a per-Writer mutex,
so all of the non-leader writers never need to acquire the db mutex.
It is now possible to join a write batch group after the leader has been
chosen but before the batch has been constructed. This diff doesn't
increase parallelism, but reduces synchronization overheads.

For some CPU-bound workloads (no WAL, RAM-sized working set) this can
substantially reduce contention on the db mutex in a multi-threaded
environment.  With T=8 N=500000 in a CPU-bound scenario (see the test
plan) this is good for a 33% perf win.  Not all scenarios see such a
win, but none show a loss.  This code is slightly faster even for the
single-threaded case (about 2% for the CPU-bound scenario below).

Test Plan:
1. unit tests
2. COMPILE_WITH_TSAN=1 make check
3. stress high-contention scenarios with db_bench -benchmarks=fillrandom -threads=$T -batch_size=1 -memtablerep=skip_list -value_size=0 --num=$N -level0_slowdown_writes_trigger=9999 -level0_stop_writes_trigger=9999 -disable_auto_compactions --max_write_buffer_number=8 -max_background_flushes=8 --disable_wal --write_buffer_size=160000000

Reviewers: sdong, igor, rven, ljin, yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43887

Summary:
Add options.compaction_measure_io_stats to print out / pass to listener accumulated time spent on write calls. Example outputs in info logs:

2015/08/12-16:27:59.463944 7fd428bff700 (Original Log Time 2015/08/12-16:27:59.463922) EVENT_LOG_v1 {"time_micros": 1439422079463897, "job": 6, "event": "compaction_finished", "output_level": 1, "num_output_files": 4, "total_output_size": 6900525, "num_input_records": 111483, "num_output_records": 106877, "file_write_nanos": 15663206, "file_range_sync_nanos": 649588, "file_fsync_nanos": 349614797, "file_prepare_write_nanos": 1505812, "lsm_state": [2, 4, 0, 0, 0, 0, 0]}

Add two more counters in iostats_context.

Also add a parameter of db_bench.

Test Plan: Add a unit test. Also manually verify LOG outputs in db_bench

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D44115

Summary: Change master version to 3.14

Test Plan: simple change

Reviewers: sdong, yhchiang, kradhakrishnan, rven, anthony, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44187

Add a 'tools' target.

My use case is to build the rocksdb static library and tools, and
ideally I'd like to not spend time building the shared library and other
targets that I won't use.

Summary: Iterator has a bug: if a child iterator reaches its end, and user issues a Prev(), and just before SeekToLast() of the child iterator is called, some extra rows is added in the end, the position of iterator can be misplaced.

Test Plan: Run the tests with or without valgrind

Reviewers: rven, yhchiang, IslamAbdelRahman, anthony

Reviewed By: anthony

Subscribers: tnovak, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43671

Summary: RandomRWFile is not used anywhere in out code base, this patch remove RandomRWFile

Test Plan:
make check -j64
USE_CLANG=1 make all -j64
OPT=-DROCKSDB_LITE make release -j64

Reviewers: sdong, yhchiang, anthony, kradhakrishnan, rven, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44091

Summary:
Clean up transactions to use the new RollbackToSavePoint api in WriteBatchWithIndex.

Note, this diff depends on Pessimistic Transactions diff and ManagedSnapshot diff (D40869 and D43293).

Test Plan: unit tests

Reviewers: rven, yhchiang, kradhakrishnan, spetrunia, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43371

Summary:
Based on feedback from spetrunia, we should better differentiate error statuses for transaction failures.

https://github.com/MySQLOnRocksDB/mysql-5.6/issues/86#issuecomment-124605954

Test Plan: unit tests

Reviewers: rven, kradhakrishnan, spetrunia, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43323

Summary:
Initial implementation of Pessimistic Transactions.  This diff contains the api changes discussed in D38913.  This diff is pretty large, so let me know if people would prefer to meet up to discuss it.

MyRocks folks:  please take a look at the API in include/rocksdb/utilities/transaction[_db].h and let me know if you have any issues.

Also, you'll notice a couple of TODOs in the implementation of RollbackToSavePoint().  After chatting with Siying, I'm going to send out a separate diff for an alternate implementation of this feature that implements the rollback inside of WriteBatch/WriteBatchWithIndex.  We can then decide which route is preferable.

Next, I'm planning on doing some perf testing and then integrating this diff into MongoRocks for further testing.

Test Plan: Unit tests, db_bench parallel testing.

Reviewers: igor, rven, sdong, yhchiang, yoshinorim

Reviewed By: sdong

Subscribers: hermanlee4, maykov, spetrunia, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D40869

Summary:
Under certain conditions (disable compression) the compactions that are created in compaction_job_test will pass the trivial_move conditions
This will cause problems since we assert that we dont run a compaction if it's a trivial move
https://github.com/facebook/rocksdb/blob/master/db/compaction_job.cc#L144-L147

for example when we disable compression, compactions become a valid trivial move and the assert fails
https://ci-builds.fb.com/view/rocksdb/job/rocksdb_no_compression/180/console

Test Plan: compaction_job_test

Reviewers: sdong, yhchiang, noetzli, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43983

Test Plan: untested

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D44049

Summary:
This patch fixes the following clang-build error in util/thread_local.cc by using a cleaner macro blocker:

12:26:31 util/thread_local.cc:157:19: error: declaration shadows a static data member of 'rocksdb::ThreadLocalPtr::StaticMeta' [-Werror,-Wshadow]
12:26:31       ThreadData* tls_ =
12:26:31                   ^
12:26:31 util/thread_local.cc:19:66: note: previous declaration is here
12:26:31 __thread ThreadLocalPtr::ThreadData* ThreadLocalPtr::StaticMeta::tls_ = nullptr;
12:26:31                                                                  ^

Test Plan: db_test

Reviewers: sdong, anthony, IslamAbdelRahman, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44043

Summary: Add a new option that all LoadTableHandlers to use multiple threads to load files on DB Open and Recover

Test Plan:
make check -j64
COMPILE_WITH_TSAN=1 make check -j64
DISABLE_JEMALLOC=1 make all valgrind_check -j64 (still running)

Reviewers: yhchiang, anthony, rven, kradhakrishnan, igor, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43755

Summary:
While working on single delete support for db_bench, I realized that
db_bench/db_stress contain a bunch of duplicate code related to
copmression and found some typos. This patch removes duplicate code,
typos and a redundant #ifndef in internal_stats.cc.

Test Plan: make db_stress && make db_bench && ./db_bench --benchmarks=compress,uncompress

Reviewers: yhchiang, sdong, rven, anthony, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43965

Summary:
Our linters assume that clang-format is installed at /mnt/vol/engshare/admin/scripts/clang-format and flint is installed at /home/engshare/tools/flint. This makes them fail on non-fb machines. This change will:
* if clang-format is not on a specified path, it will try running generic clang-format. Linters will still fail if clang-format is not installed, but this shouldn't be a big issue, since it's pretty easy to install it.
* flint will not be run if /home/engshare/tools/flint is not present

Test Plan: Made a change on a mac machine. Ran `arc lint`. No failures observed.

Reviewers: aekmekji, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D44031