Commit Graph

110 Commits

Author SHA1 Message Date
Yanqin Jin
e633983cf1 Add support to flush multiple CFs atomically (#4262)
Summary:
Leverage existing `FlushJob` to implement atomic flush of multiple column families.

This PR depends on other PRs and is a subset of #3752 . This PR itself is not sufficient in fulfilling atomic flush.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4262

Differential Revision: D9283109

Pulled By: riversand963

fbshipit-source-id: 65401f913e4160b0a61c0be6cd02adc15dad28ed
2018-10-15 20:01:17 -07:00
Gauresh Rane
ad789e4e0d Adding a method for memtable class for memtable getting flushed. (#4304)
Summary:
Memtables are selected for flushing by the flush job. Currently we
have listener which is invoked when memtables for a column family are
flushed. That listener does not indicate which memtable was flushed in
the notification. If clients want to know if particular data in the
memtable was retired, there is no straight forward way to know this.
This method will help users who implement memtablerep factory and extend
interface for memtablerep, to know if the data in the memtable was
retired.
Another option that was tried, was to depend on memtable destructor to
be called after flush to mark that data was persisted. This works all
the time but sometimes there can huge delays between actual flush
happening and memtable getting destroyed. Hence, if anyone who is
waiting for data to persist will have to wait that longer.
It is expected that anyone who is implementing this method to have
return quickly as it blocks RocksDB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4304

Reviewed By: riversand963

Differential Revision: D9472312

Pulled By: gdrane

fbshipit-source-id: 8e693308dee749586af3a4c5d4fcf1fa5276ea4d
2018-08-23 17:14:25 -07:00
Maysam Yabandeh
caf0f53a74 Index value delta encoding (#3983)
Summary:
Given that index value is a BlockHandle, which is basically an <offset, size> pair we can apply delta encoding on the values. The first value at each index restart interval encoded the full BlockHandle but the rest encode only the size. Refer to IndexBlockIter::DecodeCurrentValue for the detail of the encoding. This reduces the index size which helps using the  block cache more efficiently. The feature is enabled with using format_version 4.

The feature comes with a bit of cpu overhead which should be paid back by the higher cache hits due to smaller index block size.
Results with sysbench read-only using 4k blocks and using 16 index restart interval:
Format 2:
19585   rocksdb read-only range=100
Format 3:
19569   rocksdb read-only range=100
Format 4:
19352   rocksdb read-only range=100
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3983

Differential Revision: D8361343

Pulled By: maysamyabandeh

fbshipit-source-id: f882ee082322acac32b0072e2bdbb0b5f854e651
2018-08-09 16:58:40 -07:00
Radoslaw Zarzynski
09b6bf828a InlineSkiplist: don't decode keys unnecessarily during comparisons
Summary:
Summary
========
`InlineSkipList<>::Insert` takes the `key` parameter as a C-string. Then, it performs multiple comparisons with it requiring the `GetLengthPrefixedSlice()` to be spawn in `MemTable::KeyComparator::operator()(const char* prefix_len_key1, const char* prefix_len_key2)` on the same data over and over. The patch tries to optimize that.

Rough performance comparison
=====
Big keys, no compression.

```
$ ./db_bench --writes 20000000 --benchmarks="fillrandom" --compression_type none -key_size 256
(...)
fillrandom   :       4.222 micros/op 236836 ops/sec;   80.4 MB/s
```

```
$ ./db_bench --writes 20000000 --benchmarks="fillrandom" --compression_type none -key_size 256
(...)
fillrandom   :       4.064 micros/op 246059 ops/sec;   83.5 MB/s
```

TODO
======
In ~~a separated~~ this PR:
- [x] Go outside the write path. Maybe even eradicate the C-string-taking variant of `KeyIsAfterNode` entirely.
- [x] Try to cache the transformations applied by `KeyComparator` & friends in situations where we havy many comparisons with the same key.
Closes https://github.com/facebook/rocksdb/pull/3516

Differential Revision: D7059300

Pulled By: ajkr

fbshipit-source-id: 6f027dbb619a488129f79f79b5f7dbe566fb2dbb
2018-03-23 12:14:30 -07:00
Jingguo Yao
8823487ff7 doc: fix a typo
Summary:
s/synchromization/synchronization/
Closes https://github.com/facebook/rocksdb/pull/3583

Differential Revision: D7276596

Pulled By: sagar0

fbshipit-source-id: 552ec6d6935f642e1a3a7c552de6c94441ac50e0
2018-03-21 15:58:58 -07:00
Maysam Yabandeh
813719e952 WritePrepared Txn: Duplicate Keys, Memtable part
Summary:
Currently DB does not accept duplicate keys (keys with the same user key and the same sequence number). If Memtable returns false when receiving such keys, we can benefit from this signal to properly increase the sequence number in the rare cases when we have a duplicate key in the write batch written to DB under WritePrepared transactions.
Closes https://github.com/facebook/rocksdb/pull/3418

Differential Revision: D6822412

Pulled By: maysamyabandeh

fbshipit-source-id: adea3ce5073131cd38ed52b16bea0673b1a19e77
2018-01-31 18:57:07 -08:00
Yi Wu
f1cb83fcf4 Fix Flush() keep waiting after flush finish
Summary:
Flush() call could be waiting indefinitely if min_write_buffer_number_to_merge is used. Consider the sequence:
1. User call Flush() with flush_options.wait = true
2. The manual flush started in the background
3. New memtable become immutable because of writes. The new memtable will not trigger flush if min_write_buffer_number_to_merge is not reached.
4. The manual flush finish.

Because of the new memtable created at step 3 not being flush, previous logic of WaitForFlushMemTable() keep waiting, despite the memtables it intent to flush has been flushed.

Here instead of checking if there are any more memtables to flush, WaitForFlushMemTable() also check the id of the earliest memtable. If the id is larger than that of latest memtable at the time flush was initiated, it means all the memtable at the time of flush start has all been flush.
Closes https://github.com/facebook/rocksdb/pull/3378

Differential Revision: D6746789

Pulled By: yiwu-arbug

fbshipit-source-id: 35e698f71c7f90b06337a93e6825f4ea3b619bfa
2018-01-18 17:45:16 -08:00
Andrew Kryczka
c4c1f961e7 dynamically change current memtable size
Summary:
Previously setting `write_buffer_size` with `SetOptions` would only apply to new memtables. An internal user wanted it to take effect immediately, instead of at an arbitrary future point, to prevent OOM.

This PR makes the memtable's size mutable, and makes `SetOptions()` mutate it. There is one case when we preserve the old behavior, which is when memtable prefix bloom filter is enabled and the user is increasing the memtable's capacity. That's because the prefix bloom filter's size is fixed and wouldn't work as well on a larger memtable.
Closes https://github.com/facebook/rocksdb/pull/3119

Differential Revision: D6228304

Pulled By: ajkr

fbshipit-source-id: e44bd9d10a5f8c9d8c464bf7436070bb3eafdfc9
2017-11-02 22:28:10 -07:00
Yi Wu
66a2c44ef4 Add DB::Properties::kEstimateOldestKeyTime
Summary:
With FIFO compaction we would like to get the oldest data time for monitoring. The problem is we don't have timestamp for each key in the DB. As an approximation, we expose the earliest of sst file "creation_time" property.

My plan is to override the property with a more accurate value with blob db, where we actually have timestamp.
Closes https://github.com/facebook/rocksdb/pull/2842

Differential Revision: D5770600

Pulled By: yiwu-arbug

fbshipit-source-id: 03833c8f10bbfbee62f8ea5c0d03c0cafb5d853a
2017-10-23 15:27:27 -07:00
Yi Wu
d1cab2b64e Add ValueType::kTypeBlobIndex
Summary:
Add kTypeBlobIndex value type, which will be used by blob db only, to insert a (key, blob_offset) KV pair. The purpose is to
1. Make it possible to open existing rocksdb instance as blob db. Existing value will be of kTypeIndex type, while value inserted by blob db will be of kTypeBlobIndex.
2. Make rocksdb able to detect if the db contains value written by blob db, if so return error.
3. Make it possible to have blob db optionally store value in SST file (with kTypeValue type) or as a blob value (with kTypeBlobIndex type).

The root db (DBImpl) basically pretended kTypeBlobIndex are normal value on write. On Get if is_blob is provided, return whether the value read is of kTypeBlobIndex type, or return Status::NotSupported() status if is_blob is not provided. On scan allow_blob flag is pass and if the flag is true, return wether the value is of kTypeBlobIndex type via iter->IsBlob().

Changes on blob db side will be in a separate patch.
Closes https://github.com/facebook/rocksdb/pull/2886

Differential Revision: D5838431

Pulled By: yiwu-arbug

fbshipit-source-id: 3c5306c62bc13bb11abc03422ec5cbcea1203cca
2017-10-03 09:11:23 -07:00
Maysam Yabandeh
f46464d383 write-prepared txn: call IsInSnapshot
Summary:
This patch instruments the read path to verify each read value against an optional ReadCallback class. If the value is rejected, the reader moves on to the next value. The WritePreparedTxn makes use of this feature to skip sequence numbers that are not in the read snapshot.
Closes https://github.com/facebook/rocksdb/pull/2850

Differential Revision: D5787375

Pulled By: maysamyabandeh

fbshipit-source-id: 49d808b3062ab35e7ae98ad388f659757794184c
2017-09-11 09:14:48 -07:00
Siying Dong
3c327ac2d0 Change RocksDB License
Summary: Closes https://github.com/facebook/rocksdb/pull/2589

Differential Revision: D5431502

Pulled By: siying

fbshipit-source-id: 8ebf8c87883daa9daa54b2303d11ce01ab1f6f75
2017-07-15 16:11:23 -07:00
Siying Dong
95b0e89b5d Improve write buffer manager (and allow the size to be tracked in block cache)
Summary:
Improve write buffer manager in several ways:
1. Size is tracked when arena block is allocated, rather than every allocation, so that it can better track actual memory usage and the tracking overhead is slightly lower.
2. We start to trigger memtable flush when 7/8 of the memory cap hits, instead of 100%, and make 100% much harder to hit.
3. Allow a cache object to be passed into buffer manager and the size allocated by memtable can be costed there. This can help users have one single memory cap across block cache and memtable.
Closes https://github.com/facebook/rocksdb/pull/2350

Differential Revision: D5110648

Pulled By: siying

fbshipit-source-id: b4238113094bf22574001e446b5d88523ba00017
2017-06-02 14:26:56 -07:00
Andrew Kryczka
a4d9c02511 Pass CF ID to MemTableRepFactory
Summary:
Some users want to monitor column family activity in their custom memtable implementations. Previously there was no way to figure out with which column family a memtable is associated. This diff:

- adds an overload to MemTableRepFactory::CreateMemTableRep() that provides the CF ID. For compatibility, its default implementation calls the old overload.
- updates MemTable to create MemTableRep's using the new overload.
Closes https://github.com/facebook/rocksdb/pull/2346

Differential Revision: D5108061

Pulled By: ajkr

fbshipit-source-id: 3a1921214a348dd8ea0f54e1cab3b71c3d46d616
2017-06-02 12:12:06 -07:00
Siying Dong
d616ebea23 Add GPLv2 as an alternative license.
Summary: Closes https://github.com/facebook/rocksdb/pull/2226

Differential Revision: D4967547

Pulled By: siying

fbshipit-source-id: dd3b58ae1e7a106ab6bb6f37ab5c88575b125ab4
2017-04-27 18:06:12 -07:00
Yi Wu
df6f5a3772 Move memtable related files into memtable directory
Summary:
Move memtable related files into memtable directory.
Closes https://github.com/facebook/rocksdb/pull/2087

Differential Revision: D4829242

Pulled By: yiwu-arbug

fbshipit-source-id: ca70ab6
2017-04-06 14:09:13 -07:00
Siying Dong
d2dce5611a Move some files under util/ to separate dirs
Summary:
Move some files under util/ to new directories env/, monitoring/ options/ and cache/
Closes https://github.com/facebook/rocksdb/pull/2090

Differential Revision: D4833681

Pulled By: siying

fbshipit-source-id: 2fd8bef
2017-04-05 19:09:16 -07:00
Siying Dong
8f5bf04468 Flush triggered by DB write buffer size picks the oldest unflushed CF
Summary:
Previously, when DB write buffer size triggers, we always pick the CF with most data in its memtable to flush. This approach can minimize total flush happens. Change the behavior to always pick the oldest unflushed CF, which makes it the same behavior when max_total_wal_size hits. This approach will minimize size used by max_total_wal_size.
Closes https://github.com/facebook/rocksdb/pull/1987

Differential Revision: D4703214

Pulled By: siying

fbshipit-source-id: 9ff8b09
2017-03-21 11:09:10 -07:00
Vitaliy Liptchinsky
1aaa898cf1 Adding GetApproximateMemTableStats method
Summary:
Added method that returns approx num of entries as well as size for memtables.
Closes https://github.com/facebook/rocksdb/pull/1841

Differential Revision: D4511990

Pulled By: VitaliyLi

fbshipit-source-id: 9a4576e
2017-02-06 14:54:16 -08:00
Maysam Yabandeh
d0ba8ec8f9 Revert "PinnableSlice"
Summary:
This reverts commit 54d94e9c2c.

The pull request was landed by mistake.
Closes https://github.com/facebook/rocksdb/pull/1755

Differential Revision: D4391678

Pulled By: maysamyabandeh

fbshipit-source-id: 36d5149
2017-01-08 14:24:12 -08:00
Maysam Yabandeh
54d94e9c2c PinnableSlice
Summary:
Currently the point lookup values are copied to a string provided by the user.
This incures an extra memcpy cost. This patch allows doing point lookup
via a PinnableSlice which pins the source memory location (instead of
copying their content) and releases them after the content is consumed
by the user. The old API of Get(string) is translated to the new API
underneath.

 Here is the summary for improvements:
 1. value 100 byte: 1.8%  regular, 1.2% merge values
 2. value 1k   byte: 11.5% regular, 7.5% merge values
 3. value 10k byte: 26% regular,    29.9% merge values

 The improvement for merge could be more if we extend this approach to
 pin the merge output and delay the full merge operation until the user
 actually needs it. We have put that for future work.

PS:
Sometimes we observe a small decrease in performance when switching from
t5452014 to this patch but with the old Get(string) API. The difference
is a little and could be noise. More importantly it is safely
cancelled
Closes https://github.com/facebook/rocksdb/pull/1732

Differential Revision: D4374613

Pulled By: maysamyabandeh

fbshipit-source-id: a077f1a
2017-01-08 13:54:13 -08:00
Andrew Kryczka
fd43ee09da Range deletion microoptimizations
Summary:
- Made RangeDelAggregator's InternalKeyComparator member a reference-to-const so we don't need to copy-construct it. Also added InternalKeyComparator to ImmutableCFOptions so we don't need to construct one for each DBIter.
- Made MemTable::NewRangeTombstoneIterator and the table readers' NewRangeTombstoneIterator() functions return nullptr instead of NewEmptyInternalIterator to avoid the allocation. Updated callers accordingly.
Closes https://github.com/facebook/rocksdb/pull/1548

Differential Revision: D4208169

Pulled By: ajkr

fbshipit-source-id: 2fd65cf
2016-11-21 12:24:13 -08:00
Andrew Kryczka
fe349db57b Remove Arena in RangeDelAggregator
Summary:
The Arena construction/destruction introduced significant overhead to read-heavy workload just by creating empty vectors for its blocks, so avoid it in RangeDelAggregator.
Closes https://github.com/facebook/rocksdb/pull/1547

Differential Revision: D4207781

Pulled By: ajkr

fbshipit-source-id: 9d1c130
2016-11-19 14:24:12 -08:00
Yi Wu
1ea79a78c9 Optimize sequential insert into memtable - Part 1: Interface
Summary:
Currently our skip-list have an optimization to speedup sequential
inserts from a single stream, by remembering the last insert position.
We extend the idea to support sequential inserts from multiple streams,
and even tolerate small reordering wihtin each stream.

This PR is the interface part adding the following:
- Add `memtable_insert_prefix_extractor` to allow specifying prefix for each key.
- Add `InsertWithHint()` interface to memtable, to allow underlying
  implementation to return a hint of insert position, which can be later
  pass back to optimize inserts.
- Memtable will maintain a map from prefix to hints and pass the hint
  via `InsertWithHint()` if `memtable_insert_prefix_extractor` is non-null.
Closes https://github.com/facebook/rocksdb/pull/1419

Differential Revision: D4079367

Pulled By: yiwu-arbug

fbshipit-source-id: 3555326
2016-11-13 19:09:18 -08:00
Andrew Kryczka
f998c9790f DeleteRange Get support
Summary:
During Get()/MultiGet(), build up a RangeDelAggregator with range
tombstones as we search through live memtable, immutable memtables, and
SST files. This aggregator is then used by memtable.cc's SaveValue() and
GetContext::SaveValue() to check whether keys are covered.

added tests for Get on memtables/files; end-to-end tests mainly in https://reviews.facebook.net/D64761
Closes https://github.com/facebook/rocksdb/pull/1456

Differential Revision: D4111271

Pulled By: ajkr

fbshipit-source-id: 6e388d4
2016-11-03 18:54:20 -07:00
Andrew Kryczka
6009c473c7 Store range tombstones in memtable
Summary:
- Store range tombstones in a separate MemTableRep instantiated with ColumnFamilyOptions::memtable_factory
- MemTable::NewRangeTombstoneIterator() returns a MemTableIterator over the separate MemTableRep
- Part of the read path is not implemented yet (i.e., MemTable::Get())

Test Plan: see unit tests

Reviewers: wanning

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62217
2016-09-30 09:06:43 -07:00
Yi Wu
a88677d2cf Remove ImmutableCFOptions from public API
Summary: There's no reference to ImmutableCFOptions elsewhere in /include/rocksdb. ImmutableCFOptions was introduced in this commit (5665e5e285) but later its reference in /include/rocksdb/table.h is removed.

Test Plan:
  make all check

Reviewers: IslamAbdelRahman, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: yhchiang, andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63177
2016-09-02 14:16:31 -07:00
sdong
e5b5f12b81 Change options memtable_prefix_bloom_huge_page_tlb_size => memtable_huge_page_size and cover huge page to memtable too
Summary: Extend the option memtable_prefix_bloom_huge_page_tlb_size from just putting memtable bloom filter to huge page to memtable itself too.

Test Plan: Run all existing tests.

Reviewers: IslamAbdelRahman, yhchiang, andrewkr

Reviewed By: andrewkr

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60513
2016-07-26 18:15:11 -07:00
sdong
e70ba4e40e MemTable::PostProcess() can skip updating num_deletes if the delta is 0
Summary: In many use cases there is no deletes. No need to pay the overhead of atomically updating num_deletes.

Test Plan: Run existing test.

Reviewers: ngbronson, yiwu, andrewkr, igor

Reviewed By: andrewkr

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60555
2016-07-19 18:10:18 -07:00
sdong
907f24d0e1 Concurrent memtable inserter to update counters and flush state after all inserts
Summary: In concurrent memtable insert case, updating counters in MemTable::Add() can count for 5% CPU usage. By batch all the counters and update in the end of the write batch, the CPU overheads are overhead in the use cases where more than one key is updated in one write batch.

Test Plan:
Write throughput increases 12% with this benchmark setting:

TEST_TMPDIR=/dev/shm/ ./db_bench --benchmarks=fillrandom -disable_auto_compactions -level0_slowdown_writes_trigger=9999 -level0_stop_writes_trigger=9999 -num=10000000 --writes=1000000 -max_background_flushes=16 -max_write_buffer_number=16 --threads=64 --batch_size=128   -allow_concurrent_memtable_write -enable_write_thread_adaptive_yield

Reviewers: andrewkr, IslamAbdelRahman, ngbronson, igor

Reviewed By: ngbronson

Subscribers: ngbronson, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60495
2016-07-08 10:19:55 -07:00
sdong
32df9733d1 Add options.write_buffer_manager: control total memtable size across DB instances
Summary: Add option write_buffer_manager to help users control total memory spent on memtables across multiple DB instances.

Test Plan: Add a new unit test.

Reviewers: yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: adela, benj, sumeet, muthu, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59925
2016-07-05 18:11:25 -07:00
sdong
7b79238b65 Deprectate filter_deletes
Summary: filter_deltes is not a frequently used feature. Remove it.

Test Plan: Run all test suites.

Reviewers: igor, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59427
2016-06-17 10:30:47 -07:00
sdong
20699df843 memtable_prefix_bloom_bits -> memtable_prefix_bloom_bits_ratio and deprecate memtable_prefix_bloom_probes
Summary:
memtable_prefix_bloom_probes is not a critical option. Remove it to reduce number of options.
It's easier for users to make mistakes with memtable_prefix_bloom_bits, turn it to memtable_prefix_bloom_bits_ratio

Test Plan: Run all existing tests

Reviewers: yhchiang, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: gunnarku, yoshinorim, MarkCallaghan, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59199
2016-06-10 12:12:10 -07:00
Reid Horuff
1b8a2e8fdd [rocksdb] Memtable Log Referencing and Prepared Batch Recovery
Summary:
This diff is built on top of WriteBatch modification: https://reviews.facebook.net/D54093 and adds the required functionality to rocksdb core necessary for rocksdb to support 2PC.

modfication of DBImpl::WriteImpl()
- added two arguments *uint64_t log_used = nullptr, uint64_t log_ref = 0;
- *log_used is an output argument which will return the log number which the incoming batch was inserted into, 0 if no WAL insert took place.
-  log_ref is a supplied log_number which all memtables inserted into will reference after the batch insert takes place. This number will reside in 'FindMinPrepLogReferencedByMemTable()' until all Memtables insertinto have flushed.

- Recovery/writepath is now aware of prepared batches and commit and rollback markers.

Test Plan: There is currently no test on this diff. All testing of this functionality takes place in the Transaction layer/diff but I will add some testing.

Reviewers: IslamAbdelRahman, sdong

Subscribers: leveldb, santoshb, andrewkr, vasilep, dhruba, hermanlee4

Differential Revision: https://reviews.facebook.net/D56919
2016-05-10 14:06:07 -07:00
Baraa Hamodi
21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
Nathan Bronson
7d87f02799 support for concurrent adds to memtable
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
2015-12-25 11:03:40 -08:00
Zhipeng Jia
99ae549d37 Fix typo 2015-12-15 23:47:47 +08:00
sdong
35ad531be3 Seperate InternalIterator from Iterator
Summary:
Separate a new class InternalIterator from class Iterator, when the look-up is done internally, which also means they operate on key with sequence ID and type.

This change will enable potential future optimizations but for now InternalIterator's functions are still the same as Iterator's.
At the same time, separate the cleanup function to a separate class and let both of InternalIterator and Iterator inherit from it.

Test Plan: Run all existing tests.

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

Reviewed By: rven

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48549
2015-10-13 15:32:13 -07:00
sdong
40f562e747 Allow GetApproximateSize() to include mem table size if it is skip list memtable
Summary:
Add an option in GetApproximateSize() so that the result will include estimated sizes in mem tables.
To implement it, implement an estimated count from the beginning to a key in skip list. The approach is to count to find the entry, how many Next() is issued from each level, and sum them with a weight that is <branching factor> ^ <level>.

Test Plan: Add a test case

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D40119
2015-06-16 18:13:23 -07:00
agiardullo
dc9d70de65 Optimistic Transactions
Summary: Optimistic transactions supporting begin/commit/rollback semantics.  Currently relies on checking the memtable to determine if there are any collisions at commit time.  Not yet implemented would be a way of enuring the memtable has some minimum amount of history so that we won't fail to commit when the memtable is empty.  You should probably start with transaction.h to get an overview of what is currently supported.

Test Plan: Added a new test, but still need to look into stress testing.

Reviewers: yhchiang, igor, rven, sdong

Reviewed By: sdong

Subscribers: adamretter, MarkCallaghan, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D33435
2015-05-29 14:36:35 -07:00
agiardullo
84c5bd7eb9 Add thread-safety documentation to MemTable and related classes
Summary: Other than making some class members private, this is a documentation-only change

Test Plan: unit tests

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D36567
2015-04-08 21:10:35 -07:00
Anurag Indu
3d1a924ff3 Adding stats for the merge and filter operation
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
2015-03-24 14:42:04 -07:00
sdong
0831a35994 Add a DB Property For Number of Deletions in Memtables
Summary: Add a DB property for number of deletions in memtables. It can sometimes help people debug slowness because of too many deletes.

Test Plan: Add test cases.

Reviewers: rven, yhchiang, kradhakrishnan, igor

Reviewed By: igor

Subscribers: leveldb, dhruba, yoshinorim

Differential Revision: https://reviews.facebook.net/D35247
2015-03-18 17:03:59 -07:00
Igor Sugak
62247ffa3b rocksdb: Add missing override
Summary:
When using latest clang (3.6 or 3.7/trunck) rocksdb is failing with many errors. Almost all of them are missing override errors. This diff adds missing override keyword. No manual changes.

Prerequisites: bear and clang 3.5 build with extra tools

```lang=bash
% USE_CLANG=1 bear make all # generate a compilation database http://clang.llvm.org/docs/JSONCompilationDatabase.html
% clang-modernize -p . -include . -add-override
% make format
```

Test Plan:
Make sure all tests are passing.
```lang=bash
% #Use default fb code clang.
% make check
```
Verify less error and no missing override errors.
```lang=bash
% # Have trunk clang present in path.
% ROCKSDB_NO_FBCODE=1 CC=clang CXX=clang++ make
```

Reviewers: igor, kradhakrishnan, rven, meyering, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34077
2015-02-26 11:28:41 -08:00
Venkatesh Radhakrishnan
dad98dd4ae Changes for supporting cross functional tests for inplace_update
Summary:
This diff containes the changes to the code and db_test
for supporting cross functional tests for inplace_update

Test Plan: Run XF with inplace_test and also without

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D32367
2015-02-03 12:19:56 -08:00
Jonah Cohen
a14b7873ee Enforce write buffer memory limit across column families
Summary:
Introduces a new class for managing write buffer memory across column
families.  We supplement ColumnFamilyOptions::write_buffer_size with
ColumnFamilyOptions::write_buffer, a shared pointer to a WriteBuffer
instance that enforces memory limits before flushing out to disk.

Test Plan: Added SharedWriteBuffer unit test to db_test.cc

Reviewers: sdong, rven, ljin, igor

Reviewed By: igor

Subscribers: tnovak, yhchiang, dhruba, xjin, MarkCallaghan, yoshinorim

Differential Revision: https://reviews.facebook.net/D22581
2014-12-02 12:09:20 -08:00
Lei Jin
f1841985e4 dynamic inplace_update options
Summary:
Make inplace_update_support and inplace_update_num_locks dynamic.
inplace_callback becomes immutable
We are almost free of references to cfd->options() in db_impl

Test Plan: unit test

Reviewers: igor, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D25293
2014-10-27 12:10:13 -07:00
Lei Jin
a062e1f2c4 SetOptions() for memtable related options
Summary: as title

Test Plan:
make all check
I will think a way to set up stress test for this

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23055
2014-09-17 12:49:13 -07:00
Igor Canadi
3d9e6f7759 Push model for flushing memtables
Summary:
When memtable is full it calls the registered callback. That callback then registers column family as needing the flush. Every write checks if there are some column families that need to be flushed. This completely eliminates the need for MakeRoomForWrite() function and simplifies our Write code-path.

There is some complexity with the concurrency when the column family is dropped. I made it a bit less complex by dropping the column family from the write thread in https://reviews.facebook.net/D22965. Let me know if you want to discuss this.

Test Plan: make check works. I'll also run db_stress with creating and dropping column families for a while.

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23067
2014-09-10 18:46:09 -07:00
sdong
06d986252a Always pass MergeContext as pointer, not reference
Summary: To follow the coding convention and make sure when passing reference as a parameter it is also const, pass MergeContext as a pointer to mem tables.

Test Plan: make all check

Reviewers: ljin, igor

Reviewed By: igor

Subscribers: leveldb, dhruba, yhchiang

Differential Revision: https://reviews.facebook.net/D23085
2014-09-09 11:37:32 -07:00