Commit Graph

7 Commits

Author SHA1 Message Date
sdong
4f1534bdb0 Whole DBTest to skip fsync (#7049)
Summary:
After https://github.com/facebook/rocksdb/pull/7036, we still see extra DBTest that can timeout when running 10 or 20 in parallel. Expand skip-fsync mode in whole DBTest. Still preserve other tests from doing this mode to be conservative.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7049

Test Plan: Run all existing files.

Reviewed By: pdillinger

Differential Revision: D22301700

fbshipit-source-id: f9a9e3b3b26ce640665a47cb8bff33ba0c89b565
2020-07-01 19:37:56 -07:00
Peter Dillinger
079e77ff9e Revamp cache_bench to resemble a real workload (#6629)
Summary:
I suspect LRUCache could use some optimization, and to support
such an effort, a good benchmarking tool is needed. The existing
cache_bench was heavily skewed toward insertion and lookup misses, and
did not saturate memory with other work. This change should improve
those things to better resemble a real workload.

(All below using clang compiler, for some consistency, but not
necessarily same version and settings.)

The real workload is from production MySQL on RocksDB, filtering stacks
containing "LRU", "ShardedCache" or "CacheShard."
Lookup inclusive: 66%
Insert inclusive: 17%
Release inclusive: 15%

An alternate simulated workload is MySQL running a LinkBench read test:
Lookup inclusive: 54%
Insert inclusive: 24%
Release inclusive: 21%

cache_bench default settings, prior to this change:
Lookup inclusive: 35.8%
Insert inclusive: 63.6%
Release inclusive: 0%

cache_bench after this change (intended as somewhat "tighter" workload
than average production, more like LinkBench):
Lookup inclusive: 52%
Insert inclusive: 20%
Release inclusive: 26%

And top exclusive stacks (portion of stack samples as filtered above):
Production MySQL:
LRUHandleTable::FindPointer: 25.3%
rocksdb::operator==: 15.1%  <-- Slice ==
LRUCacheShard::LRU_Remove: 13.8%
ShardedCache::Lookup: 8.9%
__pthread_mutex_lock: 7.1%
LRUCacheShard::LRU_Insert: 6.3%
MurmurHash64A: 4.8%  <-- Since upgraded to XXH3p
...

Old cache_bench:
LRUHandleTable::FindPointer: 23.6%
__pthread_mutex_lock: 15.0%
__pthread_mutex_unlock_usercnt: 11.7%
__lll_lock_wait: 8.6%
__lll_unlock_wake: 6.8%
LRUCacheShard::LRU_Insert: 6.0%
ShardedCache::Lookup: 4.4%
LRUCacheShard::LRU_Remove: 2.8%
...
rocksdb::operator==: 0.2%  <-- Slice ==
...

New cache_bench:
LRUHandleTable::FindPointer: 22.8%
__pthread_mutex_unlock_usercnt: 14.3%
rocksdb::operator==: 10.5%  <-- Slice ==
LRUCacheShard::LRU_Insert: 9.0%
__pthread_mutex_lock: 5.9%
LRUCacheShard::LRU_Remove: 5.0%
...
ShardedCache::Lookup: 2.9%
...

So there's a bit more lock contention in the benchmark than in
production, but otherwise looks similar enough to me. At least it's a
big improvement over the existing code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6629

Test Plan: No production code changes, ran cache_bench with ASAN

Reviewed By: ltamasi

Differential Revision: D20824318

Pulled By: pdillinger

fbshipit-source-id: 6f8dc5891ead0f87edbed3a615ecd5289d9abe12
2020-04-03 10:26:49 -07:00
Zhichao Cao
ef088f0e93 Fix the multi-thread Manifest write dependency in error_handler_fs_test (#6637)
Summary:
In CompactionManifestWriteRetryableError in error_handler_fs_test, the manifest write of flush should pass with no fs error. After flush, fs is set to error status and the manifest write of compaction should fail due to the IO Error. Currently, the manifest write of flush is not synced with the compaction in order, which might cause manifest write fails, which will cause test failure. Fixed by adding the LoadDependency of sync-point after flush and before compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6637

Test Plan: pass error_hanlder_fs_tes. Pass make asan_check

Reviewed By: anand1976

Differential Revision: D20826969

Pulled By: zhichao-cao

fbshipit-source-id: fb2e702caa19bd63c82570320536b7acda870ff1
2020-04-02 18:08:46 -07:00
Cheng Chang
ee50b8d499 Be able to decrease background thread's CPU priority when creating database backup (#6602)
Summary:
When creating a database backup, the background threads will not only consume IO resources by copying files, but also consuming CPU such as by computing checksums. During peak times, the CPU consumption by the background threads might affect online queries.

This PR makes it possible to decrease CPU priority of these threads when creating a new backup.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6602

Test Plan: make check

Reviewed By: siying, zhichao-cao

Differential Revision: D20683216

Pulled By: cheng-chang

fbshipit-source-id: 9978b9ed9488e8ce135e90ca083e5b4b7221fd84
2020-03-28 19:07:25 -07:00
Zhichao Cao
4246888101 Pass IOStatus to write path and set retryable IO Error as hard error in BG jobs (#6487)
Summary:
In the current code base, we use Status to get and store the returned status from the call. Specifically, for IO related functions, the current Status cannot reflect the IO Error details such as error scope, error retryable attribute, and others. With the implementation of https://github.com/facebook/rocksdb/issues/5761, we have the new Wrapper for IO, which returns IOStatus instead of Status. However, the IOStatus is purged at the lower level of write path and transferred to Status.

The first job of this PR is to pass the IOStatus to the write path (flush, WAL write, and Compaction). The second job is to identify the Retryable IO Error as HardError, and set the bg_error_ as HardError. In this case, the DB Instance becomes read only. User is informed of the Status and need to take actions to deal with it (e.g., call db->Resume()).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6487

Test Plan: Added the testing case to error_handler_fs_test. Pass make asan_check

Reviewed By: anand1976

Differential Revision: D20685017

Pulled By: zhichao-cao

fbshipit-source-id: ff85f042896243abcd6ef37877834e26f36b6eb0
2020-03-27 16:04:43 -07:00
anand76
a9d168cfd7 Simplify migration to FileSystem API (#6552)
Summary:
The current Env/FileSystem API separation has a couple of issues -
1. It requires the user to specify 2 options - ```Options::env``` and ```Options::file_system``` - which means they have to make code changes to benefit from the new APIs. Furthermore, there is a risk of accessing the same APIs in two different ways, through Env in the old way and through FileSystem in the new way. The two may not always match, for example, if env is ```PosixEnv``` and FileSystem is a custom implementation. Any stray RocksDB calls to env will use the ```PosixEnv``` implementation rather than the file_system implementation.
2. There needs to be a simple way for the FileSystem developer to instantiate an Env for backward compatibility purposes.

This PR solves the above issues and simplifies the migration in the following ways -
1. Embed a shared_ptr to the ```FileSystem``` in the ```Env```, and remove ```Options::file_system``` as a configurable option. This way, no code changes will be required in application code to benefit from the new API. The default Env constructor uses a ```LegacyFileSystemWrapper``` as the embedded ```FileSystem```.
1a. - This also makes it more robust by ensuring that even if RocksDB
  has some stray calls to Env APIs rather than FileSystem, they will go
  through the same object and thus there is no risk of getting out of
  sync.
2. Provide a ```NewCompositeEnv()``` API that can be used to construct a
PosixEnv with a custom FileSystem implementation. This eliminates an
indirection to call Env APIs, and relieves the FileSystem developer of
the burden of having to implement wrappers for the Env APIs.
3. Add a couple of missing FileSystem APIs - ```SanitizeEnvOptions()``` and
```NewLogger()```

Tests:
1. New unit tests
2. make check and make asan_check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6552

Reviewed By: riversand963

Differential Revision: D20592038

Pulled By: anand1976

fbshipit-source-id: c3801ad4153f96d21d5a3ae26c92ba454d1bf1f7
2020-03-23 21:54:21 -07:00
Zhichao Cao
e62fe50634 Introduce FaultInjectionTestFS to test fault File system instead of Env (#6414)
Summary:
In the current code base, we can use FaultInjectionTestEnv to simulate the env issue such as file write/read errors, which are used in most of the test. The PR https://github.com/facebook/rocksdb/issues/5761 introduce the File System as a new Env API. This PR implement the FaultInjectionTestFS, which can be used to simulate when File System has issues such as IO error. user can specify any IOStatus error as input, such that FS corresponding actions will return certain error to the caller.

A set of ErrorHandlerFSTests are introduced for testing
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6414

Test Plan: pass make asan_check, pass error_handler_fs_test.

Differential Revision: D20252421

Pulled By: zhichao-cao

fbshipit-source-id: e922038f8ce7e6d1da329fd0bba7283c4b779a21
2020-03-04 12:35:05 -08:00