Commit Graph

18 Commits

Author SHA1 Message Date
Maysam Yabandeh
1e34d07e18 Simplify and document sync rules for logs_ etc
Summary:
Adding/Correcting inline comments and clarify the sync rules. To make it simple to reason, the rules are a big general which ended up to some extra synchronizations. However such synchronizations are not on the fast path, and they are worth the simplicity.
Closes https://github.com/facebook/rocksdb/pull/2517

Differential Revision: D5348239

Pulled By: maysamyabandeh

fbshipit-source-id: ff2e59fb1e568c122d2cdbf598310f3613b7d212
2017-06-30 09:42:28 -07:00
Maysam Yabandeh
e9f91a5176 Add a fetch_add variation to AddDBStats
Summary:
AddDBStats is in two steps of load and store, which is more efficient than fetch_add. This is however not thread-safe. Currently we have to protect concurrent access to AddDBStats with a mutex which is less efficient that fetch_add.

This patch adds the option to do fetch_add when AddDBStats. The results for my 2pc benchmark on sysbench is:
- vanilla: 68618 tps
- removing mutex on AddDBStats (unsafe): 69767 tps
- fetch_add for all AddDBStats: 69200 tps
- fetch_add only for concurrently access AddDBStats (this patch): 69579 tps
Closes https://github.com/facebook/rocksdb/pull/2505

Differential Revision: D5330656

Pulled By: maysamyabandeh

fbshipit-source-id: af64d7bee135b0e86b4fac323a4f9d9113eaa383
2017-06-29 17:12:19 -07:00
Siying Dong
18c63af6ef Make "make analyze" happy
Summary:
"make analyze" is reporting some errors. It's complicated to look but it seems to me that they are all false positive. Anyway, I think cleaning them up is a good idea. Some of the changes are hacky but I don't know a better way.
Closes https://github.com/facebook/rocksdb/pull/2508

Differential Revision: D5341710

Pulled By: siying

fbshipit-source-id: 6070e430e0e41a080ef441e05e8ec827d45efab6
2017-06-28 15:42:27 -07:00
Maysam Yabandeh
01534db24c Fix the reported asan issues
Summary:
This is to resolve the asan complains. In the meanwhile I am working on clarifying/revisiting the sync rules.
Closes https://github.com/facebook/rocksdb/pull/2510

Differential Revision: D5338660

Pulled By: yiwu-arbug

fbshipit-source-id: ce6f6e0826d43a2c0bfa4328a00c78f73cd6498a
2017-06-28 13:13:22 -07:00
Maysam Yabandeh
8e6345d2df Update rename of ParanoidCheck
Summary: Closes https://github.com/facebook/rocksdb/pull/2494

Differential Revision: D5317902

Pulled By: maysamyabandeh

fbshipit-source-id: 097330292180816b3d0c9f4cbbdb6f68f0180200
2017-06-24 18:12:03 -07:00
Maysam Yabandeh
499ebb3ab5 Optimize for serial commits in 2PC
Summary:
Throughput: 46k tps in our sysbench settings (filling the details later)

The idea is to have the simplest change that gives us a reasonable boost
in 2PC throughput.

Major design changes:
1. The WAL file internal buffer is not flushed after each write. Instead
it is flushed before critical operations (WAL copy via fs) or when
FlushWAL is called by MySQL. Flushing the WAL buffer is also protected
via mutex_.
2. Use two sequence numbers: last seq, and last seq for write. Last seq
is the last visible sequence number for reads. Last seq for write is the
next sequence number that should be used to write to WAL/memtable. This
allows to have a memtable write be in parallel to WAL writes.
3. BatchGroup is not used for writes. This means that we can have
parallel writers which changes a major assumption in the code base. To
accommodate for that i) allow only 1 WriteImpl that intends to write to
memtable via mem_mutex_--which is fine since in 2PC almost all of the memtable writes
come via group commit phase which is serial anyway, ii) make all the
parts in the code base that assumed to be the only writer (via
EnterUnbatched) to also acquire mem_mutex_, iii) stat updates are
protected via a stat_mutex_.

Note: the first commit has the approach figured out but is not clean.
Submitting the PR anyway to get the early feedback on the approach. If
we are ok with the approach I will go ahead with this updates:
0) Rebase with Yi's pipelining changes
1) Currently batching is disabled by default to make sure that it will be
consistent with all unit tests. Will make this optional via a config.
2) A couple of unit tests are disabled. They need to be updated with the
serial commit of 2PC taken into account.
3) Replacing BatchGroup with mem_mutex_ got a bit ugly as it requires
releasing mutex_ beforehand (the same way EnterUnbatched does). This
needs to be cleaned up.
Closes https://github.com/facebook/rocksdb/pull/2345

Differential Revision: D5210732

Pulled By: maysamyabandeh

fbshipit-source-id: 78653bd95a35cd1e831e555e0e57bdfd695355a4
2017-06-24 14:11:29 -07:00
Andrew Kryczka
71f5bcb730 Introduce OnBackgroundError callback
Summary:
Some users want to prevent rocksdb from entering read-only mode in certain error cases. This diff gives them a callback, `OnBackgroundError`, that they can use to achieve it.

- call `OnBackgroundError` every time we consider setting `bg_error_`. Use its result to assign `bg_error_` but not to change the function's return status.
- classified calls using `BackgroundErrorReason` to give the callback some info about where the error happened
- renamed `ParanoidCheck` to something more specific so we can provide a clear `BackgroundErrorReason`
- unit tests for the most common cases: flush or compaction errors
Closes https://github.com/facebook/rocksdb/pull/2477

Differential Revision: D5300190

Pulled By: ajkr

fbshipit-source-id: a0ea4564249719b83428e3f4c6ca2c49e366e9b3
2017-06-22 19:41:50 -07:00
Andrew Kryczka
c217e0b9c7 Call RateLimiter for compaction reads
Summary:
Allow users to rate limit background work based on read bytes, written bytes, or sum of read and written bytes. Support these by changing the RateLimiter API, so no additional options were needed.
Closes https://github.com/facebook/rocksdb/pull/2433

Differential Revision: D5216946

Pulled By: ajkr

fbshipit-source-id: aec57a8357dbb4bfde2003261094d786d94f724e
2017-06-13 14:56:46 -07:00
Siying Dong
52a7f38b19 WriteOptions.low_pri which can throttle low pri writes if needed
Summary:
If ReadOptions.low_pri=true and compaction is behind, the write will either return immediate or be slowed down based on ReadOptions.no_slowdown.
Closes https://github.com/facebook/rocksdb/pull/2369

Differential Revision: D5127619

Pulled By: siying

fbshipit-source-id: d30e1cff515890af0eff32dfb869d2e4c9545eb0
2017-06-05 15:02:35 -07:00
Yi Wu
ad19eb8686 Fixing blob db sequence number handling
Summary:
Blob db rely on base db returning sequence number through write batch after DB::Write(). However after recent changes to the write path, DB::Writ()e no longer return sequence number in some cases. Fixing it by have WriteBatchInternal::InsertInto() always encode sequence number into write batch.

Stacking on #2375.
Closes https://github.com/facebook/rocksdb/pull/2385

Differential Revision: D5148358

Pulled By: yiwu-arbug

fbshipit-source-id: 8bda0aa07b9334ed03ed381548b39d167dc20c33
2017-05-31 10:56:45 -07:00
Yi Wu
07bdcb91fe New WriteImpl to pipeline WAL/memtable write
Summary:
PipelineWriteImpl is an alternative approach to WriteImpl. In WriteImpl, only one thread is allow to write at the same time. This thread will do both WAL and memtable writes for all write threads in the write group. Pending writers wait in queue until the current writer finishes. In the pipeline write approach, two queue is maintained: one WAL writer queue and one memtable writer queue. All writers (regardless of whether they need to write WAL) will still need to first join the WAL writer queue, and after the house keeping work and WAL writing, they will need to join memtable writer queue if needed. The benefit of this approach is that
1. Writers without memtable writes (e.g. the prepare phase of two phase commit) can exit write thread once WAL write is finish. They don't need to wait for memtable writes in case of group commit.
2. Pending writers only need to wait for previous WAL writer finish to be able to join the write thread, instead of wait also for previous memtable writes.

Merging #2056 and #2058 into this PR.
Closes https://github.com/facebook/rocksdb/pull/2286

Differential Revision: D5054606

Pulled By: yiwu-arbug

fbshipit-source-id: ee5b11efd19d3e39d6b7210937b11cefdd4d1c8d
2017-05-19 14:26:42 -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
e9e6e53247 Simplify write thread logic
Summary:
The concept about early exit in write thread implementation is a confusing one. It means that if early exit is allowed, batch group leader will not responsible to exit the batch group, but the last finished writer do. In case we need to mark log synced, or encounter memtable insert error, early exit is disallowed.

This patch remove such a concept by:
* In all cases, the last finished writer (not necessary leader) is responsible to exit batch group.
* In case of parallel memtable write, leader will also mark log synced after memtable insert and before signal finish (call `CompleteParallelWorker()`). The purpose is to allow mark log synced (which require locking mutex) can run in parallel to memtable insert in other writers.
* The last finish writer should handle memtable insert error (update bg_error_) before exiting batch group.
Closes https://github.com/facebook/rocksdb/pull/2134

Differential Revision: D4869667

Pulled By: yiwu-arbug

fbshipit-source-id: aec170847c85b90f4179d6a4608a4fe1361544e3
2017-04-13 16:12:04 -07:00
Igor Canadi
b6b9359ece Fix BYTES_WRITTEN accounting
Summary:
BYTES_WRITTEN accounting doesn't work with disabled WAL. For example, this is what we
get in the LOG:

```
Cumulative writes: 9794K writes, 228M keys, 9794K commit groups, 1.0
writes per commit group, ingest: 0.00 GB, 0.00 MB/s
```

WAL bytes are tracked in a different statistic:
https://github.com/facebook/rocksdb/blob/master/db/internal_stats.h#L105.
BYTES_WRITTEN should count all the writes.
Closes https://github.com/facebook/rocksdb/pull/2133

Differential Revision: D4880615

Pulled By: yiwu-arbug

fbshipit-source-id: 8fd0b223099f3f5ad7df79d4e737d313687fec69
2017-04-13 16:12:03 -07:00
Maysam Yabandeh
20778f2f92 Adding comments to the write path
Summary:
also did minor refactoring
Closes https://github.com/facebook/rocksdb/pull/2115

Differential Revision: D4855818

Pulled By: maysamyabandeh

fbshipit-source-id: fbca6ac57e5c6677fffe8354f7291e596a50cb77
2017-04-10 12:43:34 -07:00
Siying Dong
ff97287016 Refactor compaction picker code
Summary:
1. Move universal compaction picker to separate files compaction_picker_universal.cc and compaction_picker_universal.h.
2. Rename some functions to make the code easier to understand.
3. Move leveled compaction picking code to a dedicated class, so that we we don't need to pass some common variable around when calling functions. It also allowed us to break down LevelCompactionPicker::PickCompaction() to smaller functions.
Closes https://github.com/facebook/rocksdb/pull/2100

Differential Revision: D4845948

Pulled By: siying

fbshipit-source-id: efa0ab4
2017-04-06 20:09:34 -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
ce64b8b719 Divide db/db_impl.cc
Summary:
db_impl.cc is too large to manage. Divide db_impl.cc into db/db_impl.cc, db/db_impl_compaction_flush.cc, db/db_impl_files.cc, db/db_impl_open.cc and db/db_impl_write.cc.
Closes https://github.com/facebook/rocksdb/pull/2095

Differential Revision: D4838188

Pulled By: siying

fbshipit-source-id: c5f3059
2017-04-05 17:24:19 -07:00