Summary: Measuring mutex duration will measure time inside DB mutex, which breaks our best practice. Add a stat level in Statistics class. By default, disable to measure the mutex operations.
Test Plan: Add a unit test to make sure it is off by default.
Reviewers: rven, anthony, IslamAbdelRahman, kradhakrishnan, andrewkr, yhchiang
Reviewed By: yhchiang
Subscribers: MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D53367
Summary: Timing mutex operations can impact scalability of the system. Add a new perf context level that can measure time counters except for mutex.
Test Plan: Add a new unit test case to make sure it is not set.
Reviewers: IslamAbdelRahman, rven, kradhakrishnan, yhchiang, anthony
Reviewed By: anthony
Subscribers: MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D53199
Summary:
In the current implementation, perf_context.db_mutex_lock_nanos and
perf_context.db_condition_wait_nanos also include the mutex-wait time
other than DB Mutex.
This patch fix this issue by incrementing the counters only when it detects
a DB mutex.
Test Plan: perf_context_test
Reviewers: anthony, IslamAbdelRahman, sdong, igor
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D48555
Summary: Add counters in perf context to allow users to figure out how time spent on waiting for DB mutex
Test Plan: Add a test and run it.
Reviewers: yhchiang, rven, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D33177
Summary:
Add a counter for collecting the wait time on db mutex.
Also add MutexWrapper and CondVarWrapper for measuring wait time.
Test Plan:
./db_test
export ROCKSDB_TESTS=MutexWaitStats
./db_test
verify stats output using db_bench
make clean
make release
./db_bench --statistics=1 --benchmarks=fillseq,readwhilewriting --num=10000 --threads=10
Sample output:
rocksdb.db.mutex.wait.micros COUNT : 7546866
Reviewers: MarkCallaghan, rven, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D32787
