Summary:
I found that CleanupSuperVersion() may block Get() for 30ms+ （per MemTable is 256MB）.
Then I found "delete sv" in ~SuperVersion() takes the time.
The backtrace looks like this
DBImpl::GetImpl() -> DBImpl::ReturnAndCleanupSuperVersion() ->
DBImpl::CleanupSuperVersion() : delete sv; -> ~SuperVersion()
I think it's better to delete in a background thread, please review it。
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6146
Differential Revision: D18972066
fbshipit-source-id: 0f7b0b70b9bb1e27ad6fc1c8a408fbbf237ae08c
Summary:
The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc.
This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO.
The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before.
This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection.
The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761
Differential Revision: D18868376
Pulled By: anand1976
fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
Summary:
It's easy to cause coredump when closing ColumnFamilyHandle with unreleased iterators, especially iterators release is controlled by java GC when using JNI.
This patch fixed concurrent CF iteration and drop, we let iterators(actually SuperVersion) hold a ColumnFamilyData reference to prevent the CF from being released too early.
fixed https://github.com/facebook/rocksdb/issues/5982
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6147
Differential Revision: D18926378
fbshipit-source-id: 1dff6d068c603d012b81446812368bfee95a5e15
Summary:
**Summary:**
This PR fixes two unordered_write related issues:
- ingestion job may skip the necessary memtable flush https://github.com/facebook/rocksdb/issues/6026
- compact range may cause memtable is flushed before pending unordered write finished
1. `CompactRange` triggers memtable flush but doesn't wait for pending-writes
2. there are some pending writes but memtable is already flushed
3. the memtable related WAL is removed( note that the pending-writes were recorded in that WAL).
4. pending-writes write to newer created memtable
5. there is a restart
6. missing the previous pending-writes because WAL is removed but they aren't included in SST.
**How to solve:**
- Wait pending memtable writes before ingestion job check memtable key range
- Wait pending memtable writes before flush memtable.
**Note that: `CompactRange` calls `RangesOverlapWithMemtables` too without waiting for pending waits, but I'm not sure whether it affects the correctness.**
**Test Plan:**
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6113
Differential Revision: D18895674
Pulled By: maysamyabandeh
fbshipit-source-id: da22b4476fc7e06c176020e7cc171eb78189ecaf
Summary:
RocksDB should decrement the counter `unscheduled_flushes_` as soon as the bg
thread is scheduled. Before this fix, the counter is decremented only when the
bg thread starts and picks an element from the flush queue. This may cause more
than necessary bg threads to be scheduled. Not a correctness issue, but may
affect flush thread count.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6104
Test Plan:
```
make check
```
Differential Revision: D18735584
Pulled By: riversand963
fbshipit-source-id: d36272d4a08a494aeeab6200a3cff7a3d1a2dc10
Summary:
options.periodic_compaction_seconds isn't supported when options.max_open_files != -1. It's because that the information of file creation time is stored in table properties and are not guaranteed to be loaded unless options.max_open_files = -1. Relax this constraint by storing the information in manifest.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6090
Test Plan: Pass all existing tests; Modify an existing test to force the manifest value to take 0 to simulate backward compatibility case; manually open the DB generated with the change by release 4.2.
Differential Revision: D18702268
fbshipit-source-id: 13e0bd94f546498a04f3dc5fc0d9dff5125ec9eb
Summary:
Previously, options.ttl cannot be set with options.max_open_files = -1, because it makes use of creation_time field in table properties, which is not available unless max_open_files = -1. With this commit, the information will be stored in manifest and when it is available, will be used instead.
Note that, this change will break forward compatibility for release 5.1 and older.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6060
Test Plan: Extend existing test case to options.max_open_files != -1, and simulate backward compatility in one test case by forcing the value to be 0.
Differential Revision: D18631623
fbshipit-source-id: 30c232a8672de5432ce9608bb2488ecc19138830
Summary:
When two_write_queue enable, IngestExternalFile performs EnterUnbatched on both write queues. SwitchMemtable also EnterUnbatched on 2nd write queue when this option is enabled. When the call stack includes IngestExternalFile -> FlushMemTable -> SwitchMemtable, this results into a deadlock.
The implemented solution is to pass on the existing writes_stopped argument in FlushMemTable to skip EnterUnbatched in SwitchMemtable.
Fixes https://github.com/facebook/rocksdb/issues/5974
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5976
Differential Revision: D18535943
Pulled By: maysamyabandeh
fbshipit-source-id: a4f9d4964c10d4a7ca06b1e0102ca2ec395512bc
Summary:
FlushJobInfo and CompactionJobInfo are aggregates; we should use the
aggregate initialization syntax to ensure members (specifically those of
built-in types) are value-initialized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5997
Test Plan: make check
Differential Revision: D18273398
Pulled By: ltamasi
fbshipit-source-id: 35b1a63ad9ca01605d288329858af72fffd7f392
Summary:
This patch adds a number of new information elements to the FlushJobInfo and
CompactionJobInfo structures that are passed to EventListeners via the
OnFlush{Begin, Completed} and OnCompaction{Begin, Completed} callbacks.
Namely, for flushes, the file numbers of the new SST and the oldest blob file it
references are propagated. For compactions, the new pieces of information are
the file number, level, and the oldest blob file referenced by each compaction
input and output file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5962
Test Plan:
Extended the EventListener unit tests with logic that checks that these information
elements are correctly propagated from the corresponding FileMetaData.
Differential Revision: D18095568
Pulled By: ltamasi
fbshipit-source-id: 6874359a6aadb53366b5fe87adcb2f9bd27a0a56
Summary:
When there are concurrent flush job on the same CF, `OnFlushCompleted` can be called before the flush result being install to LSM. Fixing the issue by passing `FlushJobInfo` through `MemTable`, and the thread who commit the flush result can fetch the `FlushJobInfo` and fire `OnFlushCompleted` on behave of the thread actually writing the SST.
Fix https://github.com/facebook/rocksdb/issues/5892
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5908
Test Plan: Add new test. The test will fail without the fix.
Differential Revision: D17916144
Pulled By: riversand963
fbshipit-source-id: e18df67d9533b5baee52ae3605026cdeb05cbe10
Summary:
This is groundwork for adding garbage collection support to BlobDB. The
patch adds logic that keeps track of the oldest blob file referred to by
each SST file. The oldest blob file is identified during flush/
compaction (similarly to how the range of keys covered by the SST is
identified), and persisted in the manifest as a custom field of the new
file edit record. Blob indexes with TTL are ignored for the purposes of
identifying the oldest blob file (since such blob files are cleaned up by the
TTL logic in BlobDB).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5903
Test Plan:
Added new unit tests; also ran db_bench in BlobDB mode, inspected the
manifest using ldb, and confirmed (by scanning the SST files using
sst_dump) that the value of the oldest blob file number field matches
the contents of the file for each SST.
Differential Revision: D17859997
Pulled By: ltamasi
fbshipit-source-id: 21662c137c6259a6af70446faaf3a9912c550e90
Summary:
Further apply formatter to more recent commits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830
Test Plan: Run all existing tests.
Differential Revision: D17488031
fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab
Summary:
Some recent commits might not have passed through the formatter. I formatted recent 45 commits. The script hangs for more commits so I stopped there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5827
Test Plan: Run all existing tests.
Differential Revision: D17483727
fbshipit-source-id: af23113ee63015d8a43d89a3bc2c1056189afe8f
Summary:
purge_queue_ maybe contains thousands sst files, for example manual compact a range. If full scan is triggered at the same time and the total sst files number is large, RocksDB will be blocked at https://github.com/facebook/rocksdb/blob/master/db/db_impl_files.cc#L150 for several seconds. In our environment we have 140,000 sst files and the manual compaction delete about 1000 sst files, it blocked about 2 minutes.
Commandeering https://github.com/facebook/rocksdb/issues/5290.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5796
Differential Revision: D17357775
Pulled By: riversand963
fbshipit-source-id: 20eacca917355b8de975ccc7b1c9a3e7bd5b201a
Summary:
Manual compaction may bring in very high load because sometime the amount of data involved in a compaction could be large, which may affect online service. So it would be good if the running compaction making the server busy can be stopped immediately. In this implementation, stopping manual compaction condition is only checked in slow process. We let deletion compaction and trivial move go through.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3971
Test Plan: add tests at more spots.
Differential Revision: D17369043
fbshipit-source-id: 575a624fb992ce0bb07d9443eb209e547740043c
Summary:
The comments of snap_refresh_nanos advertise that the snapshot refresh feature will be disabled when the option is set to 0. This contract is however not honored in the code: https://github.com/facebook/rocksdb/pull/5278
The patch fixes that and also adds an assert to ensure that the feature is not used when the option is zero.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5724
Differential Revision: D16918185
Pulled By: maysamyabandeh
fbshipit-source-id: fec167287df7d85093e087fc39c0eb243e3bbd7e
Summary:
This is to prevent bg flush thread from unrefing and deleting the cfd that has been dropped by a concurrent thread.
Before RocksDB calls `DBImpl::WaitForFlushMemTables`, we should increase the refcount of each `ColumnFamilyData` so that its ref count will not drop to 0 even if the column family is dropped by another thread. Otherwise the bg flush thread can deref the cfd and deletes it, causing a segfault in `WaitForFlushMemtables` upon accessing `cfd`.
Test plan (on devserver):
```
$make clean && COMPILE_WITH_ASAN=1 make -j32
$make check
```
All unit tests must pass.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5513
Differential Revision: D16062898
Pulled By: riversand963
fbshipit-source-id: 37dc511f1dc99f036d0201bbd7f0a8f5677c763d
Summary:
WAL records RocksDB writes to all column families. When user flushes a a column family, the old WAL will not accept new writes but cannot be deleted yet because it may still contain live data for other column families. (See https://github.com/facebook/rocksdb/wiki/Write-Ahead-Log#life-cycle-of-a-wal for detailed explanation)
Because of this, if there is a column family that receive very infrequent writes and no manual flush is called for it, it could prevent a lot of WALs from being deleted. PR https://github.com/facebook/rocksdb/pull/5046 introduced persistent stats column family which is a good example of such column families. Depending on the config, it may have long intervals between writes, and user is unaware of it which makes it difficult to call manual flush for it.
This PR addresses the problem for persistent stats column family by forcing a flush for persistent stats column family when 1) another column family is flushed 2) persistent stats column family's log number is the smallest among all column families, this way persistent stats column family will keep advancing its log number when necessary, allowing RocksDB to delete old WAL files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5509
Differential Revision: D16045896
Pulled By: miasantreble
fbshipit-source-id: 286837b633e988417f0096ff38384742d3b40ef4
Summary:
I'm not able to prove it, but the stress test failure may be caused by the following sequence of events -
1. Crash db_stress while writing the log file. This should result in a corrupted WAL.
2. Run db_stress with recycle_log_file_num=1. Crash during recovery immediately after writing manifest and updating the current file. The old log from the previous run is left behind, but the memtable would have been flushed during recovery and the CF log number will point to the newer log
3. Run db_stress with recycle_log_file_num=0. During recovery, the old log file will be processed and the corruption will be detected. Since the CF has moved ahead, we get the "SST file is ahead of WAL" error
Test -
1. stress_crash
2. make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5412
Differential Revision: D15699120
Pulled By: anand1976
fbshipit-source-id: 9092ce81e7c4a0b4b4e66560c23ea4812a4d9cbe
Summary:
When using `PRIu64` type of printf specifier, current code base does the following:
```
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
```
However, this can be simplified to
```
#include <cinttypes>
```
as long as flag `-std=c++11` is used.
This should solve issues like https://github.com/facebook/rocksdb/issues/5159
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5402
Differential Revision: D15701195
Pulled By: miasantreble
fbshipit-source-id: 6dac0a05f52aadb55e9728038599d3d2e4b59d03
Summary:
The PR #5275 separated the column dropped and shutdown status codes. However, there were a couple of places in compaction where this change ended up treating a ShutdownInProgress() error as a real error and set bg_error. This caused MyRocks unit test to fail due to WAL writes during shutdown returning this error. Fix it by ignoring the shutdown status during compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5400
Differential Revision: D15611680
Pulled By: anand1976
fbshipit-source-id: c602e97840e3ae24eb420d61e0ce95d3e6258632
