Summary:
A generic rate limiter that can be shared by threads and rocksdb
instances. Will use this to smooth out write traffic generated by
compaction and flush. This will help us get better p99 behavior on flash
storage.
Test Plan:
unit test output
==== Test RateLimiterTest.Rate
request size [1 - 1023], limit 10 KB/sec, actual rate: 10.374969 KB/sec, elapsed 2002265
request size [1 - 2047], limit 20 KB/sec, actual rate: 20.771242 KB/sec, elapsed 2002139
request size [1 - 4095], limit 40 KB/sec, actual rate: 41.285299 KB/sec, elapsed 2202424
request size [1 - 8191], limit 80 KB/sec, actual rate: 81.371605 KB/sec, elapsed 2402558
request size [1 - 16383], limit 160 KB/sec, actual rate: 162.541268 KB/sec, elapsed 3303500
Reviewers: yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19359
Summary:
Use search hint to reduce FindFile range thus avoid comparison
For a small DB with 50M keys, perf_context counter shows it reduces
comparison from 2B to 1.3B for a 15-minute run. No perf change was
observed for 1 seek thread, but quite good improvement was seen for 32
seek threads, when CPU was busy.
will post detail results when ready
Test Plan: db_bench and db_test
Reviewers: haobo, sdong, dhruba, igor
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D18879
Summary: stackable_db doesn't have GetLiveFilesMetaData() implemented. Add it
Test Plan: make all check
Reviewers: yhchiang, ljin, igor
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19491
Summary:
Changes:
- Adding numa_aware flag to db_bench.cc
- Using numa.h library to bind memory and cpu of threads to a fixed NUMA node
Result: There seems to be no significant change in the micros/op time with numa_aware enabled. I also tried this with other implementations, including a combination of pthread_setaffinity_np, sched_setaffinity and set_mempolicy methods. It'd be great if someone could point out where I'm going wrong and if we can achieve a better micors/op.
Test Plan:
Ran db_bench tests using following command:
./db_bench --db=/mnt/tmp --num_levels=6 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --block_size=4096 --cache_size=17179869184 --cache_numshardbits=6 --compression_type=none --compression_ratio=1 --min_level_to_compress=-1 --disable_seek_compaction=1 --hard_rate_limit=2 --write_buffer_size=134217728 --max_write_buffer_number=2 --level0_file_num_compaction_trigger=8 --target_file_size_base=134217728 --max_bytes_for_level_base=1073741824 --disable_wal=0 --wal_dir=/mnt/tmp --sync=0 --disable_data_sync=1 --verify_checksum=1 --delete_obsolete_files_period_micros=314572800 --max_grandparent_overlap_factor=10 --max_background_compactions=4 --max_background_flushes=0 --level0_slowdown_writes_trigger=16 --level0_stop_writes_trigger=24 --statistics=0 --stats_per_interval=0 --stats_interval=1048576 --histogram=0 --use_plain_table=1 --open_files=-1 --mmap_read=1 --mmap_write=0 --memtablerep=prefix_hash --bloom_bits=10 --bloom_locality=1 --perf_level=0 --duration=300 --benchmarks=readwhilewriting --use_existing_db=1 --num=157286400 --threads=24 --writes_per_second=10240 --numa_aware=[False/True]
The tests were run in private devserver with 24 cores and the db was prepopulated using filluniquerandom test. The tests resulted in 0.145 us/op with numa_aware=False and 0.161 us/op with numa_aware=True.
Reviewers: sdong, yhchiang, ljin, igor
Reviewed By: ljin, igor
Subscribers: igor, leveldb
Differential Revision: https://reviews.facebook.net/D19353
Summary:
SimpleWriteTimeoutTest has two parts: 1) insert two large key/values
to make memtable full and expect both of them are successful; 2) insert
another key / value and expect it to be timed-out. Previously we also
set a timeout in the first step, but this might sometimes cause
false alarm.
This diff makes the first two writes run without timeout setting.
Test Plan:
export ROCKSDB_TESTS=Time
make db_test
Reviewers: sdong, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19461
Summary:
ReadInternalKey() will assign correct value anyway. Initialize it to
true to suppress compiler error reported
https://github.com/facebook/rocksdb/issues/186
Test Plan: I cannot reproduce it but this is obvious
Reviewers: sdong, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19467
Summary: Removed a variable that is only used in assertion check.
Test Plan: make release
Reviewers: ljin, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19455
Summary:
This diff allows the I/O stats about Flush and Compaction to be reported
in a more accurate way. Instead of measuring the size of a file, it
measure I/O cost in per read / write basis.
Test Plan: make all check
Reviewers: sdong, igor, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19383
Summary: Update HISTORY.md to include TimeOut write API and compaction update.
Test Plan: n/a
Reviewers: ljin, sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19449
Summary:
This diff adds timeout_hint_us to WriteOptions. If it's non-zero, then
1) writes associated with this options MAY be aborted when it has been
waiting for longer than the specified time. If an abortion happens,
associated writes will return Status::TimeOut.
2) the stall time of the associated write caused by flush or compaction
will be limited by timeout_hint_us.
The default value of timeout_hint_us is 0 (i.e., OFF.)
The statistics of timeout writes will be recorded in WRITE_TIMEDOUT.
Test Plan:
export ROCKSDB_TESTS=WriteTimeoutAndDelayTest
make db_test
./db_test
Reviewers: igor, ljin, haobo, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18837
Summary:
Add TimedWait() API to CondVar, which will be used in the future to
support TimedOut Write API and Rate limiter.
Test Plan: make db_test -j32
Reviewers: sdong, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19431
Summary:
In this patch, we allow RocksDB to support multiple DB paths internally.
No user interface is supported yet so this patch is silent to users.
Test Plan: make all check
Reviewers: igor, haobo, ljin, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18921
Summary:
Before this diff, we're deciding enable_compression in CompactionPicker and then we're deciding final compression type in DBImpl. This is kind of confusing.
After the diff, the final compression type will be decided in CompactionPicker.
The reason for this is that I want CompactFiles() to specify output compression type, so that people can mix and match compression styles in their compaction algorithms. This diff makes it much easier to do that.
Test Plan: make check
Reviewers: dhruba, haobo, sdong, yhchiang, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19137
Commit 6634844dba by sdong
Two small fixes in db_test
Summary:
Two fixes:
(1) WalDir to pick a directory under TmpDir to allow two tests running in parallel without impacting each other
(2) kBlockBasedTableWithWholeKeyHashIndex is disabled by mistake (I assume). Enable it.
Test Plan: ./db_test
Reviewers: yhchiang, ljin
Reviewed By: ljin
Subscribers: nkg-, igor, dhruba, haobo, leveldb
Differential Revision: https://reviews.facebook.net/D19389
Summary:
In this patch, we enhance HashLinkList memtable to reduce performance outliers when a bucket contains too many entries. We switch to skip list for this case to enable binary search.
Add threshold_use_skiplist parameter to determine when a bucket needs to switch to skip list.
The new data structure is documented in comments in the codes.
Test Plan:
make all check
set threshold_use_skiplist in several tests
Reviewers: yhchiang, haobo, ljin
Reviewed By: yhchiang, ljin
Subscribers: nkg-, xjin, dhruba, yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D19299
Summary:
Two fixes:
(1) WalDir to pick a directory under TmpDir to allow two tests running in parallel without impacting each other
(2) kBlockBasedTableWithWholeKeyHashIndex is disabled by mistake (I assume). Enable it.
Test Plan: ./db_test
Reviewers: yhchiang, ljin
Reviewed By: ljin
Subscribers: nkg-, igor, dhruba, haobo, leveldb
Differential Revision: https://reviews.facebook.net/D19389
Summary:
Now that the arena is used to allocate space for hashskiplist's bucket. The bucket size
need to be set small enough to avoid "should_flush_" failure in memtable's assertion.
Test Plan:
make all check
Reviewers: sdong
Reviewed By: sdong
Subscribers: igor
Differential Revision: https://reviews.facebook.net/D19371
Summary: files_by_size_ is sorted by time in case of universal compaction. However, Version::files_ is also sorted by time. So no need for files_by_size_
Test Plan:
1) make check with the change
2) make check with `assert(last_index == c->input_version_->files_[level].size() - 1);` in compaction picker
Reviewers: dhruba, haobo, yhchiang, sdong, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19125
