Summary:
Currently log_writer->AddRecord in WriteImpl is protected from concurrent calls via FlushWAL only if two_write_queues_ option is set. The patch fixes the problem by i) skip log_writer->AddRecord in FlushWAL if manual_wal_flush is not set, ii) protects log_writer->AddRecord in WriteImpl via log_write_mutex_ if manual_wal_flush_ is set but two_write_queues_ is not.
Fixes#3599
Closes https://github.com/facebook/rocksdb/pull/3656
Differential Revision: D7405608
Pulled By: maysamyabandeh
fbshipit-source-id: d6cc265051c77ae49c7c6df4f427350baaf46934
Summary:
`Writer::WriteBuffer` was always called at the beginning of checkpoint/backup. But that log writer has no internal synchronization, which meant the same buffer could be flushed twice in a race condition case, causing a WAL entry to be duplicated. Then subsequent WAL entries would be at unexpected offsets, causing the 32KB block boundaries to be overlapped and manifesting as a corruption.
This PR fixes the behavior to only use `WriteBuffer` (via `FlushWAL`) in checkpoint/backup when manual WAL flush is enabled. In that case, users are responsible for providing synchronization between WAL flushes. We can also consider removing the call entirely.
Closes https://github.com/facebook/rocksdb/pull/3603
Differential Revision: D7277447
Pulled By: ajkr
fbshipit-source-id: 1b15bd7fd930511222b075418c10de0aaa70a35a
Summary:
- made `CreateCheckpoint` properly return `InvalidArgument` when called with an empty directory. Previously it triggered an assertion failure due to a bug in the logic.
- made `ldb` set empty `checkpoint_dir` if that's what the user specifies, so that we can use it to properly test `CreateCheckpoint` in the future.
Differential Revision: D6874562
fbshipit-source-id: dcc1bd41768261d9338987fa7711444289707ed7
Summary:
previously if `checkpoint_dir` contained a trailing slash, we'd attempt to create the `.tmp` directory under `checkpoint_dir` due to simply concatenating `checkpoint_dir + ".tmp"`. This failed because `checkpoint_dir` hadn't been created yet and our directory creation is non-recursive. This PR fixes the issue by always creating the `.tmp` directory in the same parent as `checkpoint_dir` by stripping trailing slashes before concatenating.
Closes https://github.com/facebook/rocksdb/pull/3275
Differential Revision: D6574952
Pulled By: ajkr
fbshipit-source-id: a6daa6777a901eac2460cd0140c9515f7241aefc
Summary:
This reverts the previous commit 1d7048c598, which broke the build.
Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627
Differential Revision: D5476473
Pulled By: sagar0
fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
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
Summary:
These code paths forked when checkpoint was introduced by copy/pasting the core backup logic. Over time they diverged and bug fixes were sometimes applied to one but not the other (like fix to include all relevant WALs for 2PC), or it required extra effort to fix both (like fix to forge CURRENT file). This diff reunites the code paths by extracting the core logic into a function, CreateCustomCheckpoint(), that is customizable via callbacks to implement both checkpoint and backup.
Related changes:
- flush_before_backup is now forcibly enabled when 2PC is enabled
- Extracted CheckpointImpl class definition into a header file. This is so the function, CreateCustomCheckpoint(), can be called by internal rocksdb code but not exposed to users.
- Implemented more functions in DummyDB/DummyLogFile (in backupable_db_test.cc) that are used by CreateCustomCheckpoint().
Closes https://github.com/facebook/rocksdb/pull/1932
Differential Revision: D4622986
Pulled By: ajkr
fbshipit-source-id: 157723884236ee3999a682673b64f7457a7a0d87
