Summary:
With this PR, we can measure read-amp for queries where perf_context is enabled as follows:
```
SetPerfLevel(kEnableCount);
Get(1, "foo");
double read_amp = static_cast<double>(get_perf_context()->block_read_byte / get_perf_context()->get_read_bytes);
SetPerfLevel(kDisable);
```
Our internal infra enables perf_context for a sampling of queries. So we'll be able to compute the read-amp for the sample set, which can give us a good estimate of read-amp.
Closes https://github.com/facebook/rocksdb/pull/2749
Differential Revision: D5647240
Pulled By: ajkr
fbshipit-source-id: ad73550b06990cf040cc4528fa885360f308ec12
Summary:
… headers
https://github.com/facebook/rocksdb/pull/2199 should not reference RocksDB-specific macros (like ROCKSDB_SUPPORT_THREAD_LOCAL in this case) to public headers, `iostats_context.h` and `perf_context.h`. We shouldn't do that because users have to provide these compiler flags when building their binary with RocksDB.
We should hide the thread local global variable inside our implementation and just expose a function api to retrieve these variables. It may break some users for now but good for long term.
make check -j64
Closes https://github.com/facebook/rocksdb/pull/2380
Differential Revision: D5177896
Pulled By: lightmark
fbshipit-source-id: 6fcdfac57f2e2dcfe60992b7385c5403f6dcb390
Summary:
We've had a couple CockroachDB users fail to build RocksDB on exotic platforms, so I figured I'd try my hand at solving these issues upstream. The problems stem from a) `USE_SSE=1` being too aggressive about turning on SSE4.2, even on toolchains that don't support SSE4.2 and b) RocksDB attempting to detect support for thread-local storage based on OS, even though it can vary by compiler on the same OS.
See the individual commit messages for details. Regarding SSE support, this PR should change virtually nothing for non-CMake based builds. `make`, `PORTABLE=1 make`, `USE_SSE=1 make`, and `PORTABLE=1 USE_SSE=1 make` function exactly as before, except that SSE support will be automatically disabled when a simple SSE4.2-using test program fails to compile, as it does on OpenBSD. (OpenBSD's ports GCC supports SSE4.2, but its binutils do not, so `__SSE_4_2__` is defined but an SSE4.2-using program will fail to assemble.) A warning is emitted in this case. The CMake build is modified to support the same set of options, except that `USE_SSE` is spelled `FORCE_SSE42` because `USE_SSE` is rather useless now that we can automatically detect SSE support, and I figure changing options in the CMake build is less disruptive than changing the non-CMake build.
I've tested these changes on all the platforms I can get my hands on (macOS, Windows MSVC, Windows MinGW, and OpenBSD) and it all works splendidly. Let me know if there's anything you object to—I obviously don't mean to break any of your build pipelines in the process of fixing ours downstream.
Closes https://github.com/facebook/rocksdb/pull/2199
Differential Revision: D5054042
Pulled By: yiwu-arbug
fbshipit-source-id: 938e1fc665c049c02ae15698e1409155b8e72171
Summary:
Workaround for Solaris gcc binary. Program is crashing, because when TLS of perf context that is used twice on same frame, it is damaged thus Segmentation fault.
Issue: #2153
Closes https://github.com/facebook/rocksdb/pull/2187
Differential Revision: D4922274
Pulled By: siying
fbshipit-source-id: 549105ebce9a8ce08a737f4d6b9f2312ebcde9a8
Summary:
I've needed Env timing measurements a few times now, so finally built something for it.
Closes https://github.com/facebook/rocksdb/pull/2073
Differential Revision: D4811231
Pulled By: ajkr
fbshipit-source-id: 218a249
Summary:
There still are many warnings (most of them about invalid printf format
for long long), but it builds if FAIL_ON_WARNINGS is disabled.
Closes https://github.com/facebook/rocksdb/pull/2052
Differential Revision: D4807355
Pulled By: siying
fbshipit-source-id: ef03786
Summary:
In one deployment we saw high latencies (presumably from slow iterator operations) and a lot of CPU time reported by perf with this stack:
```
rocksdb::MergingIterator::Next
rocksdb::DBIter::FindNextUserEntryInternal
rocksdb::DBIter::Seek
```
I think what's happening is:
1. we create a snapshot iterator,
2. we do lots of Put()s for the same key x; this creates lots of entries in memtable,
3. we seek the iterator to a key slightly smaller than x,
4. the seek walks over lots of entries in memtable for key x, skipping them because of high sequence numbers.
CC IslamAbdelRahman
Closes https://github.com/facebook/rocksdb/pull/1413
Differential Revision: D4083879
Pulled By: IslamAbdelRahman
fbshipit-source-id: a83ddae
Summary:
Add new Iterator API, `SeekForPrev`: find the last key that <= target key
support prefix_extractor
support prefix_same_as_start
support upper_bound
not supported in iterators without Prev()
Also add tests in db_iter_test and db_iterator_test
Pass all tests
Cheers!
Test Plan: make all check -j64
Reviewers: andrewkr, yiwu, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D64149
Summary: Some grammer mistakes in code comments in include/rocksdb/perf_context.h. Also polish it a liitlebit.
Test Plan: Not needed
Reviewers: IslamAbdelRahman, yhchiang, yiwu, andrewkr
Reviewed By: andrewkr
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56307
Summary: Include the time unit in the comment of perf_context timers
Test Plan: make perf_context_test
Reviewers: igor, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D48663
Summary:
hit and miss bloom filter stats for memtable and SST
stats added to perf_context struct
key matches and prefix matches combined into one stat
Test Plan: unit test veryfing the functionality added, see BloomStatsTest in db_test.cc for details
Reviewers: yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D47859
Summary:
This patch fixes#7460559. It introduces SingleDelete as a new database
operation. This operation can be used to delete keys that were never
overwritten (no put following another put of the same key). If an overwritten
key is single deleted the behavior is undefined. Single deletion of a
non-existent key has no effect but multiple consecutive single deletions are
not allowed (see limitations).
In contrast to the conventional Delete() operation, the deletion entry is
removed along with the value when the two are lined up in a compaction. Note:
The semantics are similar to @igor's prototype that allowed to have this
behavior on the granularity of a column family (
https://reviews.facebook.net/D42093 ). This new patch, however, is more
aggressive when it comes to removing tombstones: It removes the SingleDelete
together with the value whenever there is no snapshot between them while the
older patch only did this when the sequence number of the deletion was older
than the earliest snapshot.
Most of the complex additions are in the Compaction Iterator, all other changes
should be relatively straightforward. The patch also includes basic support for
single deletions in db_stress and db_bench.
Limitations:
- Not compatible with cuckoo hash tables
- Single deletions cannot be used in combination with merges and normal
deletions on the same key (other keys are not affected by this)
- Consecutive single deletions are currently not allowed (and older version of
this patch supported this so it could be resurrected if needed)
Test Plan: make all check
Reviewers: yhchiang, sdong, rven, anthony, yoshinorim, igor
Reviewed By: igor
Subscribers: maykov, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D43179
- Remove make file defines from public headers and use _WIN32 because it is compiler defined
- use __GNUC__ and __clang__ to guard non-portable attributes
- add #include "port/port.h" to some new .cc files.
- minor changes in CMakeLists to reflect recent changes
Summary:
Public API depends on port/port.h which is wrong. Fix it.
Also with gcc 4.8.1 build was broken as MAX_INT32 was not recognized. Fix it by using ::max in linux.
Test Plan: Build it and try to build an external project on top of it.
Reviewers: anthony, yhchiang, kradhakrishnan, igor
Reviewed By: igor
Subscribers: yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41745
Summary:
new_table_iterator_nanos is not cleaned in PerfContext::Reset() while new_table_block_iter_nanos is cleaned twice. Fix it.
Also fix a comment.
Test Plan: Build and db_bench with --perf_context to see the value shown.
Reviewers: kradhakrishnan, anthony, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41721
Summary: Add a perf context counter to help users figure out time spent on reading indexes and bloom filter blocks.
Test Plan: Will write a unit test
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41433
Summary: Make RocksDb build and run on Windows to be functionally
complete and performant. All existing test cases run with no
regressions. Performance numbers are in the pull-request.
Test plan: make all of the existing unit tests pass, obtain perf numbers.
Co-authored-by: Praveen Rao praveensinghrao@outlook.com
Co-authored-by: Sherlock Huang baihan.huang@gmail.com
Co-authored-by: Alex Zinoviev alexander.zinoviev@me.com
Co-authored-by: Dmitri Smirnov dmitrism@microsoft.com
Summary:
We occasionally get write stalls (>1s Write() calls) on HDD under read load. The following timers explain almost all of the stalls:
- perf_context.db_mutex_lock_nanos
- perf_context.db_condition_wait_nanos
- iostats_context.open_time
- iostats_context.allocate_time
- iostats_context.write_time
- iostats_context.range_sync_time
- iostats_context.logger_time
In my experiments each of these occasionally takes >1s on write path under some workload. There are rare cases when Write() takes long but none of these takes long.
Test Plan: Added code to our application to write the listed timings to log for slow writes. They usually add up to almost exactly the time Write() call took.
Reviewers: rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: march, dhruba, tnovak
Differential Revision: https://reviews.facebook.net/D39177
Summary:
We have addded new stats and perf_context for measuring the merge and filter operation time consumption.
We have bounded all the merge operations within the GUARD statment and collected the total time for these operations in the DB.
Test Plan: WIP
Reviewers: rven, yhchiang, kradhakrishnan, igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D34377
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 function to return the perf level. It is to allow a wrapper of DB to increase the perf level and restore the original perf level after finishing the function call.
Test Plan: Add a verification in db_test
Reviewers: yhchiang, igor, ljin
Reviewed By: ljin
Subscribers: xjin, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D19551
Summary: This will allow us to disable them completely for iOS or for better performance
Test Plan: will run make all check
Reviewers: igor, haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17511
Summary:
I had to make number of changes to the code and Makefile:
* Add `make lib`, that will create static library without debug info. We need this to avoid growing binary too much. Currently it's 14MB.
* Remove cpuinfo() function and use __SSE4_2__ macro. We actually used the macro as part of Fast_CRC32() function.
As a result, I also accidentally fixed this issue: https://www.facebook.com/groups/rocksdb.dev/permalink/549700778461774/?stream_ref=2
* Remove __thread locals in OS_MACOSX
Test Plan: `make lib PLATFORM=IOS`
Reviewers: ljin, haobo, dhruba, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17475
Summary:
Add helper function to print perf context data in db_bench if enabled.
I didn't find any code that actually exports perf context data. Not sure
if I missed anything
Test Plan: ran db_bench
Reviewers: haobo, sdong, igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16575
Summary:
Provide a framework to profile a query in detail to figure out latency bottleneck. Currently, in Get(), Put() and iterators, 2-3 simple timing is used. We can easily add more profile counters to the framework later.
Test Plan: Enable this profiling in seveal existing tests.
Reviewers: haobo, dhruba, kailiu, emayanke, vamsi, igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D14001
Conflicts:
table/merger.cc
Summary: as title
Test Plan: make check; ./perf_context_test
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13629
Summary:
The previous release 2.4 had a mapping to alias the older
namespace to rocksdb. This mapping is not needed in the new
release.
Test Plan:
make check
make release
Reviewers: emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13359
Summary:
Change namespace from leveldb to rocksdb. This allows a single
application to link in open-source leveldb code as well as
rocksdb code into the same process.
Test Plan: compile rocksdb
Reviewers: emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13287
Summary: as title. unit test not polished. this is for a quick live test
Test Plan: live
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D13221
Summary: The pupose of this diff is to expose per user-call level precise timing of block read, so that we can answer questions like: a Get() costs me 100ms, is that somehow related to loading blocks from file system, or sth else? We will answer that with EXACTLY how many blocks have been read, how much time was spent on transfering the bytes from os, how much time was spent on checksum verification and how much time was spent on block decompression, just for that one Get. A nano second stopwatch was introduced to track time with higher precision. The cost/precision of the stopwatch is also measured in unit-test. On my dev box, retrieving one time instance costs about 30ns, on average. The deviation of timing results is good enough to track 100ns-1us level events. And the overhead could be safely ignored for 100us level events (10000 instances/s), for example, a viewstate thrift call.
Test Plan: perf_context_test, also testing with viewstate shadow traffic.
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb, xjin
Differential Revision: https://reviews.facebook.net/D12351
Summary: Replace include/leveldb with include/rocksdb.
Test Plan:
make clean; make check
make clean; make release
Differential Revision: https://reviews.facebook.net/D12489
