Summary:
Key comparison is the single largest CPU user for CPU-bound
workloads. This diff reduces the number of comparisons in two ways.

The first is that it moves predecessor array gathering from
FindGreaterOrEqual to FindLessThan, so that FindGreaterOrEqual can
return immediately if compare_ returns 0.  As part of this change I
moved the sequential insertion optimization into Insert, to remove the
undocumented (and smelly) requirement that prev must be equal to prev_
if it is non-null.

The second optimization is that all of the search functions skip calling
compare_ when moving to a lower level that has the same Next pointer.
With a branching factor of 4 we would expect this to happen 1/4 of
the time.

On a single-threaded CPU-bound workload (-benchmarks=fillrandom -threads=1
-batch_size=1 -memtablerep=skip_list -value_size=0 --num=1600000
-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)
on my dev server this is good for a 7% perf win.

Test Plan: unit tests

Reviewers: rven, ljin, yhchiang, sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43233

Summary:
This patch provides a simplier solution to the memory leak
issue identified in patch https://reviews.facebook.net/D43677,
where a static function local variable can be used instead of
using a global static unique_ptr.

Test Plan: run db_stress on mac

Reviewers: igor, sdong, anthony, IslamAbdelRahman, maykov

Reviewed By: maykov

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43995

Summary:
This was motivated by t7518166. checkCpp crashes on db_test.cc because the file is too big :(

Couple of changes:
* Added clang-format linter. Now we can catch all code that is not formatted correctly.
* Added Howtoeven in our list of linters
* Replaced cpplint with flint
* Removed checkCpp lint. Nobody ownes it and it doesn't work on db_test.cc

Test Plan: Made a random lint error and `arc lint`. Saw an error.

Reviewers: yhchiang, kradhakrishnan, anthony, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D41949

Summary:
https://ci-builds.fb.com/view/rocksdb/job/rocksdb_clang_build/893/console
Fixing clang build

Test Plan:
make clean
USE_CLANG=1 make all -j64

Reviewers: sdong, noetzli, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43959

Summary:
wal_recovery_mode setting was not written to LOG. This diff
adds the log message

Test Plan: manually checked

Reviewers: kradhakrishnan, sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43953

Summary:
Changed compaction_job_test to support better/more thorough
tests and added two tests. Also changed MockFileContents
to order using InternalKeyComparator.

Test Plan: make compaction_job_test && ./compaction_job_test; make all && make check

Reviewers: sdong, rven, igor, yhchiang, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42837

Summary: Start measuring time spent before BackgroundEmptyTrash starts

Test Plan: delete_scheduler_test

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43857

Summary: Check in a simple auto-build manfiest so that developers can issue ad-hoc build for Windows in Appveyor.

Test Plan: Run it in test branch test_appveyor and it works well.

Reviewers: kradhakrishnan, rven, anthony, IslamAbdelRahman, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43839

Fix OSX + Windows build

Commit 257ee895 added a static destruction helper to avoid notional
"leaks" of TLS on main thread exit. This helper fails to compile on
OS X (and presumably Windows, though I haven't checked), which lacks
the __thread storage class StaticMeta::tls_ member.

This patch fixes the builds. Do note that the static cleanup mechanism
may be somewhat brittle and atexit(3) may be a more suitable approach
to releasing the main thread's TLS if it's highly desirable for this
memory to not be reported "reachable" by Valgrind at exit.

Summary: Implemented this simple wrapper for something else I was working on.  Seemed like it makes sense to expose it instead of burying it in some random code.

Test Plan: added test

Reviewers: rven, kradhakrishnan, sdong, yhchiang

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43293

Summary:
MyRocks valgrind run was showing memory leaks. The fixes are mostly self-explaining.
There is only a single usage of ThreadLocalPtr. Potentially, we may think about replacing this use with thread_local, but it will be a bigger change. Another option to consider is using thread_local instead of __thread in ThreadLocalPtr implementation. This way, tls_ can be stored using std::unique_ptr and no destructor would be required.

Test Plan:
 - make check
 - MyRocks valgrind run doesn't report leaks

Reviewers: rven, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43677

Summary: Prepare release notes for 3.13.

Test Plan: Text only

Reviewers: yhchiang, IslamAbdelRahman, rven, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43665

Summary: Use shared_ptr instead of deleting in destructor

Test Plan: DISABLE_JEMALLOC=1 make delete_scheduler_test -j64 && valgrind --error-exitcode=2 --leak-check=full ./delete_scheduler_test

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43659

Summary:
Visual Studio complains about deque<LogWriterNumber> because LogWriterNumber is non-copyable for its unique_ptr member writer. Move away from it, and do explit free.
It is less safe but I can't think of a better way to unblock it.

Test Plan: valgrind check test

Reviewers: anthony, IslamAbdelRahman, kolmike, rven, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43647

Summary:
When seeking to the last occurrence of a key with sequence number 0, db_iter
ends up in an endless loop because it seeks to type kValueTypeForSeek
which is larger than kTypeDeletion/kTypeValue. Added test case that triggers
the behavior.

Test Plan: make clean all check

Reviewers: igor, rven, anthony, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43653

Summary: util/delete_scheduler_impl.cc is missing CMakeLists.txt, which fails Windows build. Add it.

Test Plan: Build in both of Windows and Linux

Reviewers: anthony, rven, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43641

Summary:
Provide a way for users to know more detailed ditribution of a histogram metrics. Example outputs:

Manually add statement
  fprintf(stdout, "%s\n", dbstats->getHistogramString(SST_READ_MICROS).c_str());
Will print out something like:

Count: 989151  Average: 1.7659  StdDev: 1.52
Min: 0.0000  Median: 1.2071  Max: 860.0000
Percentiles: P50: 1.21 P75: 1.70 P99: 5.12 P99.9: 13.67 P99.99: 21.70
------------------------------------------------------
[       0,       1 )   390839  39.513%  39.513% ########
[       1,       2 )   500918  50.641%  90.154% ##########
[       2,       3 )    79358   8.023%  98.177% ##
[       3,       4 )     6297   0.637%  98.813%
[       4,       5 )     1712   0.173%  98.986%
[       5,       6 )     1134   0.115%  99.101%
[       6,       7 )     1222   0.124%  99.224%
[       7,       8 )     1529   0.155%  99.379%
[       8,       9 )     1264   0.128%  99.507%
[       9,      10 )      988   0.100%  99.607%
[      10,      12 )     1378   0.139%  99.746%
[      12,      14 )     1828   0.185%  99.931%
[      14,      16 )      410   0.041%  99.972%
[      16,      18 )       72   0.007%  99.980%
[      18,      20 )       67   0.007%  99.986%
[      20,      25 )      106   0.011%  99.997%
[      25,      30 )       24   0.002%  99.999%
[      30,      35 )        1   0.000% 100.000%
[     250,     300 )        2   0.000% 100.000%
[     300,     350 )        1   0.000% 100.000%
[     800,     900 )        1   0.000% 100.000%

Test Plan: Manually add a print in db_bench and make sure it prints out as expected. Will add some codes to cover the function

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43611

Summary: Update DeleteScheduler tests so that they verify the used penalties for waiting instead of measuring the time spent which is not reliable

Test Plan:
make -j64 delete_scheduler_test && ./delete_scheduler_test
COMPILE_WITH_TSAN=1 make -j64 delete_scheduler_test && ./delete_scheduler_test
COMPILE_WITH_ASAN=1 make -j64 delete_scheduler_test && ./delete_scheduler_test

make -j64 db_test && ./db_test --gtest_filter="DBTest.RateLimitedDelete:DBTest.DeleteSchedulerMultipleDBPaths"
COMPILE_WITH_TSAN=1 make -j64 db_test && ./db_test --gtest_filter="DBTest.RateLimitedDelete:DBTest.DeleteSchedulerMultipleDBPaths"
COMPILE_WITH_ASAN=1 make -j64 db_test && ./db_test --gtest_filter="DBTest.RateLimitedDelete:DBTest.DeleteSchedulerMultipleDBPaths"

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43635

Summary: Currently, valgrind_check doesn't fail on test failures, which creates confusion. valgrind_check should fail if test fails.

Test Plan: Manually change tests to return test failure or cause memory leak and see valgrind_check has the correct behavior.

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

Reviewed By: rven

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43629

Summary: fix the build failure

Test Plan: make all

Reviewers: sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43623

Summary: The list of info log files of a db can be obtained using the new function.

Test Plan: New test in db_test.cc passed.

Reviewers: yhchiang, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: IslamAbdelRahman, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D41715

Summary:
Add two unit tests for SyncWAL(). One makes sure SyncWAL() doesn't block writes in the other thread. Another one makes sure SyncWAL() doesn't wait ongoing writes to finish before being executed.

Create a new test file db_wal_test and move two WAL related tests from db_test to here.

Test Plan: Run the new tests

Reviewers: IslamAbdelRahman, rven, kradhakrishnan, kolmike, tnovak, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43605

Summary: Measure read latency histogram and put in statistics. Compaction inputs are excluded from it when possible (unfortunately usually no possible as we usually take table reader from table cache.

Test Plan:
Run db_bench and it shows the stats, like:

rocksdb.sst.read.micros statistics Percentiles :=> 50 : 1.238522 95 : 2.529740 99 : 3.912180

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

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43275

Summary: "make commit-prereq" fails to clean up java, which can cause rocksjava failure.

Test Plan: Run commit-prepreq

Reviewers: IslamAbdelRahman, rven, kradhakrishnan, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43575

Summary: This patch will fix the false positive of DBTest.FlushSchedule under TSAN, we dont need to disable this test

Test Plan: COMPILE_WITH_TSAN=1 make -j64 db_test && ./db_test --gtest_filter="DBTest.FlushSchedule"

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43599

Summary: Fixing TSAN false positive and relaxing the conditions when we are running under TSAN

Test Plan: COMPILE_WITH_TSAN=1 make -j64 delete_scheduler_test && ./delete_scheduler_test

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43593

Summary:
While doing forward iterating, if current key is merge, internal iterator position is placed to the next key. If Prev() is called now, needs to do extra Prev() to recover the location.
This is second attempt of fixing after reverting ec70fea4. This time shrink the fix to only merge key is the current key and avoid the reseeking logic for max_iterating skipping

Test Plan: enable the two disabled tests and make sure they pass

Reviewers: rven, IslamAbdelRahman, kradhakrishnan, tnovak, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43557

Summary:
While working on https://reviews.facebook.net/D43179 , I found
duplicate code in the tests. This patch removes it.

Test Plan: make clean all check

Reviewers: igor, sdong, rven, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43263

Summary:
Subj. We really need this feature.

Previous diff D40899 has most of the changes to make this possible, this diff just adds the method.

Test Plan: `make check`, the new test fails without this diff; ran with ASAN, TSAN and valgrind.

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

Reviewed By: sdong

Subscribers: MarkCallaghan, maykov, hermanlee4, yoshinorim, tnovak, dhruba

Differential Revision: https://reviews.facebook.net/D40905

Summary:
Updated DBTest DBCompactionTest and CompactionJobStatsTest
to run compaction-related tests once with subcompactions enabled and
once disabled using the TEST_P test type in the Google Test suite.

Test Plan: ./db_test  ./db_compaction-test  ./compaction_job_stats_test

Reviewers: sdong, igor, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43443

Summary:
Introduce DeleteScheduler that allow enforcing a rate limit on file deletion
Instead of deleting files immediately, files are moved to trash directory and deleted in a background thread that apply sleep penalty between deletes if needed.

I have updated PurgeObsoleteFiles and PurgeObsoleteWALFiles to use the delete_scheduler instead of env_->DeleteFile

Test Plan:
added delete_scheduler_test
existing unit tests

Reviewers: kradhakrishnan, anthony, rven, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43221

Summary: Update JAVA-HISTORY.md for v3.13

Test Plan: no code change.

Reviewers: igor, anthony, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43539

Fix shared library names on OSX

Summary:
Fixed RocksJava test failure of shouldSetTestCappedPrefixExtractor
by adding the missing native implementation of
useCappedPrefixExtractor.

Test Plan:
make jclean
make rocksdbjava -j32
make jtest

Reviewers: igor, anthony, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43551

RemoveEmptyValueCompactionFilter

Summary:
MyRocks is using jemalloc latest version, not 3.6.0.
Combining multiple versions (3.6.0 in RocksDB and latest in MyRocks)
broke some features -- for example, getting SIGSEGV when heap profiling
was enabled.
This diff switches to use jemalloc latest, if
env variable ROCKSDB_FBCODE_BUILD_WITH_481=1 was set.
My understanding is this env was used by MyRocks only so it would be
safe to change.

Test Plan: building MyRocks then verified jemalloc heap profiling worked

Reviewers: igor, rven, yhchiang, jtolmer, maykov, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D43479

Summary:
Merge pull request #665 by adamretter

Exposes BackupEngine from C++ to the Java API. Previously only BackupableDB was available

Test Plan: BackupEngineTest.java

Reviewers: fyrz, igor, ankgup87, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D42873

Another attempt at adding the Java API and tests to the travis build