Summary: It looks like we mistakenly enable JEMALLOC even if it's not available on the machine, that's why travis is failing
Test Plan:
check on my devserver
check on my mac
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D57345
Summary:
Introduced option to dump malloc statistics using new option flag.
Added new command line option to db_bench tool to enable this
funtionality.
Also extended build to support environments with/without jemalloc.
Test Plan:
1) Build rocksdb using `make` command. Launch the following command
`./db_bench --benchmarks=fillrandom --dump_malloc_stats=true
--num=10000000` end verified that jemalloc dump is present in LOG file.
2) Build rocksdb using `DISABLE_JEMALLOC=1 make db_bench -j32` and ran
the same db_bench tool and found the following message in LOG file:
"Please compile with jemalloc to enable malloc dump".
3) Also built rocksdb using `make` command on MacOS to verify behavior
in non-FB environment.
Also to debug build configuration change temporary changed
AM_DEFAULT_VERBOSITY = 1 in Makefile to see compiler and build
tools output. For case 1) -DROCKSDB_JEMALLOC was present in compiler
command line. For both 2) and 3) this flag was not present.
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D57321
Summary: CompactedDB skips memtable. So we shouldn't use compacted DB if there is outstanding WAL files.
Test Plan: Change to options.max_open_files = -1 perf context test to create a compacted DB, which we shouldn't do.
Reviewers: yhchiang, kradhakrishnan, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D57057
Summary:
In https://reviews.facebook.net/D56271, we fixed an issue where
we consider flush as compaction. However, that makes us mistakenly
count FLUSH_WRITE_BYTES twice (one in flush_job and one in db_impl.)
This patch removes the one incremented in db_impl.
Test Plan: db_test
Reviewers: yiwu, andrewkr, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57111
Summary: It is useful to print out IO stats in flush jobs too. Extend options.compaction_measure_io_stats to flush jobs and raname it.
Test Plan: Try db_bench and see the stats are printed out.
Reviewers: yhchiang
Reviewed By: yhchiang
Subscribers: kradhakrishnan, yiwu, IslamAbdelRahman, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56769
Summary: The code assumes that if use_mmap_reads is on then use_os_buffer is also on. This make sense as by using memory mapped files for reading you are expecting the OS to cache what it needs. Add code to make sure the user does not turn off use_os_buffer when they turn on use_mmap_reads
Test Plan: New test: DBTest.MMapAndBufferOptions
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56397
Summary:
Added the column family name to the properties block. This property
is omitted only if the property is unavailable, such as when RepairDB()
writes SST files.
In a next diff, I will change RepairDB to use this new property for
deciding to which column family an existing SST file belongs. If this
property is missing, it will add it to the "unknown" column family (same
as its existing behavior).
Test Plan:
New unit test:
$ ./db_table_properties_test --gtest_filter=DBTablePropertiesTest.GetColumnFamilyNameProperty
Reviewers: IslamAbdelRahman, yhchiang, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D55605
Summary:
When a block based table file is opened, if prefetch_index_and_filter is true, it will prefetch the index and filter blocks, putting them into the block cache.
What this feature adds: when a L0 block based table file is opened, if pin_l0_filter_and_index_blocks_in_cache is true in the options (and prefetch_index_and_filter is true), then the filter and index blocks aren't released back to the block cache at the end of BlockBasedTableReader::Open(). Instead the table reader takes ownership of them, hence pinning them, ie. the LRU cache will never push them out. Meanwhile in the table reader, further accesses will not hit the block cache, thus avoiding lock contention.
Test Plan:
'export TEST_TMPDIR=/dev/shm/ && DISABLE_JEMALLOC=1 OPT=-g make all valgrind_check -j32' is OK.
I didn't run the Java tests, I don't have Java set up on my devserver.
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56133
record.size() should not be less than 12.
This "magic number" seems to be the WriteBatch header (8 byte sequence
and 4 byte count). Replaced all the places where "12" was used
by WriteBatchInternal::kHeader.
Summary:
Fix for https://github.com/facebook/mysql-5.6/issues/174
When there is no old files to purge, vector.at(i) function was crashing
if (old_info_log_file_count != 0 &&
old_info_log_file_count >= db_options_.keep_log_file_num) {
std::sort(old_info_log_files.begin(), old_info_log_files.end());
size_t end = old_info_log_file_count - db_options_.keep_log_file_num;
for (unsigned int i = 0; i <= end; i++) {
std::string& to_delete = old_info_log_files.at(i);
Added check to old_info_log_file_count be non zero.
Test Plan: run existing tests
Reviewers: gunnarku, vasilep, sdong, yhchiang
Reviewed By: yhchiang
Subscribers: andrewkr, webscalesql-eng, dhruba
Differential Revision: https://reviews.facebook.net/D55245
Summary:
- Keep track of obsolete manifests in VersionSet
- Updated FindObsoleteFiles() to put obsolete manifests in the JobContext for later use by PurgeObsoleteFiles()
- Added test case that verifies a stale manifest is deleted by a non-full purge
Test Plan:
$ ./backupable_db_test --gtest_filter=BackupableDBTest.ChangeManifestDuringBackupCreation
Reviewers: IslamAbdelRahman, yoshinorim, sdong
Reviewed By: sdong
Subscribers: andrewkr, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D55269
Summary:
This is a follow-up patch of https://reviews.facebook.net/D54891.
As the information about files being compacted will also be used
when making compaction decision, it is necessary to update the compaction
score when a compaction plan has been made but not yet execute.
This patch adds a missing call to update the compaction score in
CompactFiles().
Test Plan: compact_files_test
Reviewers: sdong, IslamAbdelRahman, kradhakrishnan, yiwu, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D55227
Summary:
Currently, when rocksdb tries to run manual compaction to refit data into a level,
there's a ReFitLevel() process that requires no bg work is currently running.
When RocksDB plans to ReFitLevel(), it will do the following:
1. pause scheduling new bg work.
2. wait until all bg work finished
3. do the ReFitLevel()
4. unpause scheduling new bg work.
However, as it pause scheduling new bg work at step one and waiting for all bg work
finished in step 2, RocksDB will stop flushing until all bg work is done (which
could take a long time.)
This patch fix this issue by changing the way ReFitLevel() pause the background work:
1. pause scheduling compaction.
2. wait until all bg work finished.
3. pause scheduling flush
4. do ReFitLevel()
5. unpause both flush and compaction.
The major difference is that. We only pause scheduling compaction in step 1 and wait
for all bg work finished in step 2. This prevent flush being blocked for a long time.
Although there's a very rare case that ReFitLevel() might be in starvation in step 2,
but it's less likely the case as flush typically finish very fast.
Test Plan: existing test.
Reviewers: anthony, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D55029
Summary:
The call to
```
CaptureCurrentFileNumberInPendingOutputs()
```
should be before
```
versions_->NewFileNumber()
```
Right now we are not actually protecting the file from being deleted
Test Plan: make check
Reviewers: sdong, anthony, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D54645
Summary: We want to provide a way to detect whether an iterator is stale and needs to be recreated. Add a iterator property to return version number.
Test Plan: Add two unit tests for it.
Reviewers: IslamAbdelRahman, yhchiang, anthony, kradhakrishnan, andrewkr
Reviewed By: andrewkr
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54921
Summary:
In some situations the DB will scan all existing files in the DB path and delete the ones that are Obsolete.
If this happen during adding an external sst file. this could cause the file to be deleted while we are adding it.
This diff fix this issue
Test Plan:
unit test to reproduce the bug
existing unit tests
Reviewers: sdong, yhchiang, andrewkr
Reviewed By: andrewkr
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D54627
Summary: DBImpl::SyncWAL() releases db mutex before calling DBImpl::MarkLogsSynced(), while inside DBImpl::MarkLogsSynced() we assert there is none or one outstanding log file. However, a memtable switch can happen in between and causing two or outstanding logs there, failing the assert. The diff adds a unit test that repros the issue and fix the assert so that the unit test passes.
Test Plan: Run the new tests.
Reviewers: anthony, kolmike, yhchiang, IslamAbdelRahman, kradhakrishnan, andrewkr
Reviewed By: andrewkr
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54621
Summary:
We started getting two kinds of crashes since we started using `DB::CompactFiles()`:
(1) `CompactFiles()` fails saying something like "/data/logdevice/4440/shard12/012302.sst: No such file or directory", and presumably makes DB read-only,
(2) DB fails to open saying "Corruption: Can't access /267000.sst: IO error: /data/logdevice/4440/shard1/267000.sst: No such file or directory".
AFAICT, both can be explained by background thread deleting compaction output as "obsolete" while it's being written, before it's committed to manifest. If it ends up committed to the manifest, we get (2); if compaction notices the disappearance and fails, we get (1). The internal tasks t10068021 and t10134177 have some details about the investigation that led to this.
Test Plan: `make -j check`; the new test fails to reopen the DB without the fix
Reviewers: yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, sdong
Differential Revision: https://reviews.facebook.net/D54561
Summary:
Introude SstFileManager::SetMaxAllowedSpaceUsage() that can be used to limit the maximum space usage allowed for RocksDB.
When this limit is exceeded WriteImpl() will fail and return Status::Aborted()
Test Plan: unit testing
Reviewers: yhchiang, anthony, andrewkr, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D53763
Summary: There is an issue in DBImpl::WriteImpl where if an empty writebatch comes in and sync=true then the logs will be marked as being synced yet the sync never actually happens because there is no data in the writebatch. This causes the next incoming batch to hang while waiting for the logs to complete syncing. This fix syncs logs even if the writebatch is empty.
Test Plan: DoubleEmptyBatch unit test in transaction_test.
Reviewers: yoshinorim, hermanlee4, sdong, ngbronson, anthony
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54057
Summary:
Add kSstFileTier to ReadTier, which allows Get and MultiGet to
read only directly from SST files and skip mem-tables.
kSstFileTier = 0x2 // data in SST files.
// Note that this ReadTier currently only supports
// Get and MultiGet and does not support iterators.
Test Plan: add new test in db_test.
Reviewers: anthony, IslamAbdelRahman, rven, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: igor, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53511
Summary:
copy from task 8196669:
1) Optimistic transactions do not support batching writes from different threads.
2) Pessimistic transactions do not support batching writes if an expiration time is set.
In these 2 cases, we currently do not do any write batching in DBImpl::WriteImpl() because there is a WriteCallback that could decide at the last minute to abort the write. But we could support batching write operations with callbacks if we make sure to process the callbacks correctly.
To do this, we would first need to modify write_thread.cc to stop preventing writes with callbacks from being batched together. Then we would need to change DBImpl::WriteImpl() to call all WriteCallback's in a batch, only write the batches that succeed, and correctly set the state of each batch's WriteThread::Writer.
Test Plan: Added test WriteWithCallbackTest to write_callback_test.cc which creates multiple client threads and verifies that writes are batched and executed properly.
Reviewers: hermanlee4, anthony, ngbronson
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D52863
Summary:
Before this diff, there were duplicated constants to refer to properties (user-
facing API had strings and InternalStats had an enum). I noticed these were
inconsistent in terms of which constants are provided, names of constants, and
documentation of constants. Overall it seemed annoying/error-prone to maintain
these duplicated constants.
So, this diff gets rid of InternalStats's constants and replaces them with a map
keyed on the user-facing constant. The value in that map contains a function
pointer to get the property value, so we don't need to do string matching while
holding db->mutex_. This approach has a side benefit of making many small
handler functions rather than a giant switch-statement.
Test Plan: db_properties_test passes, running "make commit-prereq -j32"
Reviewers: sdong, yhchiang, kradhakrishnan, IslamAbdelRahman, rven, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53253
Summary:
Concurrent memtable adds were incorrectly computing
the last sequence number for a write batch group when the
write batches were not solitary. This is the cause of
https://github.com/facebook/mysql-5.6/issues/155
Test Plan:
1. unit tests
2. new unit test
3. parallel db_bench stress tests with batch size of 10 and asserts enabled
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: IslamAbdelRahman, MarkCallaghan, dhruba
Differential Revision: https://reviews.facebook.net/D53595
Summary:
If options.base_background_compactions is given, we try to schedule number of compactions not existing this number, only when L0 files increase to certain number, or pending compaction bytes more than certain threshold, we schedule compactions based on options.max_background_compactions.
The watermarks are calculated based on slowdown thresholds.
Test Plan:
Add new test cases in column_family_test.
Adding more unit tests.
Reviewers: IslamAbdelRahman, yhchiang, kradhakrishnan, rven, anthony
Reviewed By: anthony
Subscribers: leveldb, dhruba, yoshinorim
Differential Revision: https://reviews.facebook.net/D53409
Summary:
Add a new class SstFileTracker that will be notified whenever a DB add/delete/move and sst file, it will also replace DeleteScheduler
SstFileTracker can be used later to abort writes when we exceed a specific size
Test Plan: unit tests
Reviewers: rven, anthony, yhchiang, sdong
Reviewed By: sdong
Subscribers: igor, lovro, march, dhruba
Differential Revision: https://reviews.facebook.net/D50469
Summary:
We can avoid the dependency by forward-declaring ColumnFamilyData and
then treating it as a black box. That means callers of ThreadStatusUtil need to
explicitly provide more options, even if they can be derived from the
ColumnFamilyData, since ThreadStatusUtil doesn't include the definition.
This is part of a series of diffs to eliminate circular dependencies between
directories (e.g., db/* files depending on util/* files and vice-versa).
Test Plan:
$ ./db_test --gtest_filter=DBTest.GetThreadStatus
$ make -j32 commit-prereq
Reviewers: sdong, yhchiang, IslamAbdelRahman
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53361
Summary:
I split the db-specific test points out into a separate file under db/
directory. There were also a few bugs to fix in xfunc.{h,cc} that prevented it
from compiling previously; see https://reviews.facebook.net/D36825.
Test Plan:
compilation works now, below command works, will also run "make xfunc".
$ make check ROCKSDB_XFUNC_TEST='managed_new' tests-regexp='DBTest' -j32
Reviewers: sdong, yhchiang
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D53343
Summary:
SstFileWriter may create an sst file with no entries
Right now this will fail when being ingested using DB::AddFile() saying that the keys are corrupted
Test Plan: make check
Reviewers: yhchiang, rven, anthony, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D52815
Makefile adjust paths for solaris build
Makefile enable _GLIBCXX_USE_C99 so that std::to_string is available
db_compaction_test.cc Initialise a variable to avoid a compilation error
db_impl.cc Include <alloca.h>
db_test.cc Include <alloca.h>
Environment.java recognise solaris envrionment
options_bulder.cc Make log unambiguous
geodb_impl.cc Make log and floor unambiguous
Summary:
While running the myrocks regression suite, I found that while
dropping a table soon after inserting rows into it resulted in an
assertion failure in CheckConsistencyForDeletes for not finding
a file which was recently added or moved. Marking the files to be
deleted as being compacted before calling LogAndApplyChange
fixed the assertion failures.
Test Plan: DBCompactionTest.DeleteFileRange
Reviewers: IslamAbdelRahman, anthony, yhchiang, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba, yoshinorim, leveldb
Differential Revision: https://reviews.facebook.net/D52599
Summary: DBImpl::GetLatestSequenceForKey() can do memcpy's to load a value that will never be used. This can be optimized by changing all the Get() functions called to optionally not fetch the value (and only fetch the sequencenumber).
Test Plan: optimistic_transaction_test and transaction_test
Reviewers: anthony
Reviewed By: anthony
Subscribers: leveldb, dhruba, hermanlee4
Differential Revision: https://reviews.facebook.net/D52227
Summary:
We need to clean the job context if we end up not deleting any
files because no files are in the range specified.
Test Plan: DBCompactionTest.DeleteFileRange
Reviewers: sdong, anthony, yhchiang, kradhakrishnan, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D52467
Summary:
myrocks seems to build rocksdb using
-Wmissing-field-initializers (and treats warnings as errors). This diff
adds that flag to the rocksdb build, and fixes the compilation failures
that result. I have not checked for any other differences in the build
flags for rocksdb build as part of myrocks.
Test Plan: make check
Reviewers: sdong, rven
Reviewed By: rven
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D52443
Summary:
This is an initial diff for providing the ability to delete
files which are completely within a given range of keys.
Test Plan: DBCompactionTest.DeleteRange
Reviewers: IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D52293
Summary: Fix some CLANG errors introduced in 7d87f02799
Test Plan: Build with both of CLANG and gcc
Reviewers: rven, yhchiang, kradhakrishnan, anthony, IslamAbdelRahman, ngbronson
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D52329
Summary:
This diff adds support for concurrent adds to the skiplist memtable
implementations. Memory allocation is made thread-safe by the addition of
a spinlock, with small per-core buffers to avoid contention. Concurrent
memtable writes are made via an additional method and don't impose a
performance overhead on the non-concurrent case, so parallelism can be
selected on a per-batch basis.
Write thread synchronization is an increasing bottleneck for higher levels
of concurrency, so this diff adds --enable_write_thread_adaptive_yield
(default off). This feature causes threads joining a write batch
group to spin for a short time (default 100 usec) using sched_yield,
rather than going to sleep on a mutex. If the timing of the yield calls
indicates that another thread has actually run during the yield then
spinning is avoided. This option improves performance for concurrent
situations even without parallel adds, although it has the potential to
increase CPU usage (and the heuristic adaptation is not yet mature).
Parallel writes are not currently compatible with
inplace updates, update callbacks, or delete filtering.
Enable it with --allow_concurrent_memtable_write (and
--enable_write_thread_adaptive_yield). Parallel memtable writes
are performance neutral when there is no actual parallelism, and in
my experiments (SSD server-class Linux and varying contention and key
sizes for fillrandom) they are always a performance win when there is
more than one thread.
Statistics are updated earlier in the write path, dropping the number
of DB mutex acquisitions from 2 to 1 for almost all cases.
This diff was motivated and inspired by Yahoo's cLSM work. It is more
conservative than cLSM: RocksDB's write batch group leader role is
preserved (along with all of the existing flush and write throttling
logic) and concurrent writers are blocked until all memtable insertions
have completed and the sequence number has been advanced, to preserve
linearizability.
My test config is "db_bench -benchmarks=fillrandom -threads=$T
-batch_size=1 -memtablerep=skip_list -value_size=100 --num=1000000/$T
-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
--block_size=16384 --allow_concurrent_memtable_write" on a two-socket
Xeon E5-2660 @ 2.2Ghz with lots of memory and an SSD hard drive. With 1
thread I get ~440Kops/sec. Peak performance for 1 socket (numactl
-N1) is slightly more than 1Mops/sec, at 16 threads. Peak performance
across both sockets happens at 30 threads, and is ~900Kops/sec, although
with fewer threads there is less performance loss when the system has
background work.
Test Plan:
1. concurrent stress tests for InlineSkipList and DynamicBloom
2. make clean; make check
3. make clean; DISABLE_JEMALLOC=1 make valgrind_check; valgrind db_bench
4. make clean; COMPILE_WITH_TSAN=1 make all check; db_bench
5. make clean; COMPILE_WITH_ASAN=1 make all check; db_bench
6. make clean; OPT=-DROCKSDB_LITE make check
7. verify no perf regressions when disabled
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: MarkCallaghan, IslamAbdelRahman, anthony, yhchiang, rven, sdong, guyg8, kradhakrishnan, dhruba
Differential Revision: https://reviews.facebook.net/D50589
Summary:
Add CompactionReason to CompactionJobInfo
This will allow users to understand why compaction started which will help options tuning
Test Plan:
added new tests
make check -j64
Reviewers: yhchiang, anthony, kradhakrishnan, sdong, rven
Reviewed By: rven
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D51975
Summary:
This patch fixes https://github.com/facebook/mysql-5.6/issues/121
There is a recent change in rocksdb to disable auto compactions on startup: https://reviews.facebook.net/D51147. However, there is a small timing window where a column family needs to be compacted and schedules a compaction, but the scheduled compaction fails when it checks the disable_auto_compactions setting. The expectation is once the application is ready, it will call EnableAutoCompactions() to allow new compactions to go through. However, if the Column family is stalled because L0 is full, and no writes can go through, it is possible the column family may never have a new compaction request get scheduled. EnableAutoCompaction() should probably schedule an new flush and compaction event when it resets disable_auto_compaction.
Using InstallSuperVersionAndScheduleWork, we call SchedulePendingFlush,
SchedulePendingCompaction, as well as MaybeScheduleFlushOrcompaction on all the
column families to avoid the situation above.
This is still a first pass for feedback.
Could also just call SchedePendingFlush and SchedulePendingCompaction directly.
Test Plan:
Run on Asan build
cd _build-5.6-ASan/ && ./mysql-test/mtr --mem --big --testcase-timeout=36000 --suite-timeout=12000 --parallel=16 --suite=rocksdb,rocksdb_rpl,rocksdb_sys_vars --mysqld=--default-storage-engine=rocksdb --mysqld=--skip-innodb --mysqld=--default-tmp-storage-engine=MyISAM --mysqld=--rocksdb rocksdb_rpl.rpl_rocksdb_stress_crash --repeat=1000
Ensure that it no longer hangs during the test.
Reviewers: hermanlee4, yhchiang, anthony
Reviewed By: anthony
Subscribers: leveldb, yhchiang, dhruba
Differential Revision: https://reviews.facebook.net/D51747
Summary:
When there are waiting manual compactions, we need to signal
them after removing the current manual compaction from the deque.
Test Plan: ColumnFamilytTest.SameCFManualManualCommaction
Reviewers: anthony, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba, yoshinorim
Differential Revision: https://reviews.facebook.net/D52119
