Summary:
There is a race condition if WAL tracking in the MANIFEST is enabled in a database that disables 2PC.
The race condition is between two background flush threads trying to install flush results to the MANIFEST.
Consider an example database with two column families: "default" (cfd0) and "cf1" (cfd1). Initially,
both column families have one mutable (active) memtable whose data backed by 6.log.
1. Trigger a manual flush for "cf1", creating a 7.log
2. Insert another key to "default", and trigger flush for "default", creating 8.log
3. BgFlushThread1 finishes writing 9.sst
4. BgFlushThread2 finishes writing 10.sst
```
Time BgFlushThread1 BgFlushThread2
| mutex_.Lock()
| precompute min_wal_to_keep as 6
| mutex_.Unlock()
| mutex_.Lock()
| precompute min_wal_to_keep as 6
| join MANIFEST write queue and mutex_.Unlock()
| write to MANIFEST
| mutex_.Lock()
| cfd1->log_number = 7
| Signal bg_flush_2 and mutex_.Unlock()
| wake up and mutex_.Lock()
| cfd0->log_number = 8
| FindObsoleteFiles() with job_context->log_number == 7
| mutex_.Unlock()
| PurgeObsoleteFiles() deletes 6.log
V
```
As shown in the above, BgFlushThread2 thinks that the min wal to keep is 6.log because "cf1" has unflushed data in 6.log (cf1.log_number=6).
Similarly, BgThread1 thinks that min wal to keep is also 6.log because "default" has unflushed data (default.log_number=6).
No WAL deletion will be written to MANIFEST because 6 is equal to `versions_->wals_.min_wal_number_to_keep`,
due to https://github.com/facebook/rocksdb/blob/7.1.fb/db/memtable_list.cc#L513:L514.
The bg flush thread that finishes last will perform file purging. `job_context.log_number` will be evaluated as 7, i.e.
the min wal that contains unflushed data, causing 6.log to be deleted. However, MANIFEST thinks 6.log should still exist.
If you close the db at this point, you won't be able to re-open it if `track_and_verify_wal_in_manifest` is true.
We must handle the case of multiple bg flush threads, and it is difficult for one bg flush thread to know
the correct min wal number until the other bg flush threads have finished committing to the manifest and updated
the `cfd::log_number`.
To fix this issue, we rename an existing variable `min_log_number_to_keep_2pc` to `min_log_number_to_keep`,
and use it to track WAL file deletion in non-2pc mode as well.
This variable is updated only 1) during recovery with mutex held, or 2) in the MANIFEST write thread.
`min_log_number_to_keep` means RocksDB will delete WALs below it, although there may be WALs
above it which are also obsolete. Formally, we will have [min_wal_to_keep, max_obsolete_wal]. During recovery, we
make sure that only WALs above max_obsolete_wal are checked and added back to `alive_log_files_`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9715
Test Plan:
```
make check
```
Also ran stress test below (with asan) to make sure it completes successfully.
```
TEST_TMPDIR=/dev/shm/rocksdb OPT=-g ASAN_OPTIONS=disable_coredump=0 \
CRASH_TEST_EXT_ARGS=--compression_type=zstd SKIP_FORMAT_BUCK_CHECKS=1 \
make J=52 -j52 blackbox_asan_crash_test
```
Reviewed By: ltamasi
Differential Revision: D34984412
Pulled By: riversand963
fbshipit-source-id: c7b21a8d84751bb55ea79c9f387103d21b231005
Summary:
Originally, a corruption will be returned by `DBImpl::WriteImpl(batch...)` if batch is
null. This is inaccurate since there is no data corruption.
Return `Status::InvalidArgument()` instead.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9744
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D35086268
Pulled By: riversand963
fbshipit-source-id: 677397b007a53bc25210eac0178d49c9797b5951
Summary:
Bloom filters generated by pre-7.0 releases are not read by
7.0.x releases (and vice-versa) due to changes to FilterPolicy::Name()
in https://github.com/facebook/rocksdb/issues/9590. This can severely impact read performance and read I/O on
upgrade or downgrade with existing DB, but not data correctness.
To fix, we go back using the old, unified name in SST metadata but (for
a while anyway) recognize the aliases that could be generated by early
7.0.x releases. This unfortunately requires a public API change to avoid
interfering with all the good changes from https://github.com/facebook/rocksdb/issues/9590, but the API change
only affects users with custom FilterPolicy, which should be very few.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9736
Test Plan:
manual
Generate DBs with
```
./db_bench.7.0 -db=/dev/shm/rocksdb.7.0 -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=fillrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0
```
and similar. Compare with
```
for IMPL in 6.29 7.0 fixed; do for DB in 6.29 7.0 fixed; do echo "Testing $IMPL on $DB:"; ./db_bench.$IMPL -db=/dev/shm/rocksdb.$DB -use_existing_db -readonly -bloom_bits=10 -benchmarks=readrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -duration=10 2>&1 | grep micros/op; done; done
```
Results:
```
Testing 6.29 on 6.29:
readrandom : 34.381 micros/op 29085 ops/sec; 3.2 MB/s (291999 of 291999 found)
Testing 6.29 on 7.0:
readrandom : 190.443 micros/op 5249 ops/sec; 0.6 MB/s (52999 of 52999 found)
Testing 6.29 on fixed:
readrandom : 40.148 micros/op 24907 ops/sec; 2.8 MB/s (249999 of 249999 found)
Testing 7.0 on 6.29:
readrandom : 229.430 micros/op 4357 ops/sec; 0.5 MB/s (43999 of 43999 found)
Testing 7.0 on 7.0:
readrandom : 33.348 micros/op 29986 ops/sec; 3.3 MB/s (299999 of 299999 found)
Testing 7.0 on fixed:
readrandom : 152.734 micros/op 6546 ops/sec; 0.7 MB/s (65999 of 65999 found)
Testing fixed on 6.29:
readrandom : 32.024 micros/op 31224 ops/sec; 3.5 MB/s (312999 of 312999 found)
Testing fixed on 7.0:
readrandom : 33.990 micros/op 29390 ops/sec; 3.3 MB/s (294999 of 294999 found)
Testing fixed on fixed:
readrandom : 28.714 micros/op 34825 ops/sec; 3.9 MB/s (348999 of 348999 found)
```
Just paying attention to order of magnitude of ops/sec (short test
durations, lots of noise), it's clear that with the fix we can read <= 6.29
& >= 7.0 at full speed, where neither 6.29 nor 7.0 can on both. And 6.29
release can properly read fixed DB at full speed.
Reviewed By: siying, ajkr
Differential Revision: D35057844
Pulled By: pdillinger
fbshipit-source-id: a46893a6af4bf084375ebe4728066d00eb08f050
Summary:
Before this PR, the following command prints only the default column
family's information in the end:
```
ldb --db=. --hex manifest_dump --verbose
```
We should print all column families instead.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9719
Test Plan:
`make check` makes sure nothing breaks.
Generate a DB, use the above command to verify all column families are
printed.
Reviewed By: akankshamahajan15
Differential Revision: D34992453
Pulled By: riversand963
fbshipit-source-id: de1d38c4539cd89f74e1a6240ad7a6e2416bf198
Summary:
The param name force_erase may be misleading, since the handle is erased only if it has last reference even if the param is set true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9728
Reviewed By: pdillinger
Differential Revision: D35038673
Pulled By: gitbw95
fbshipit-source-id: 0d16d1e8fed17b97eba7fb53207119332f659a5f
Summary:
Multiplier here should be 1e6 to get microseconds.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9695
Reviewed By: ajkr
Differential Revision: D34897086
Pulled By: jay-zhuang
fbshipit-source-id: 9c1d0811ea740ba0a007edc2da199edbd000b88b
Summary:
The goal of this change is to allow changes to the "current" (in
FileSystem) file temperatures to feed back into DB metadata, so that
they can inform decisions and stats reporting. In part because of
modular code factoring, it doesn't seem easy to do this automagically,
where opening an SST file and observing current Temperature different
from expected would trigger a change in metadata and DB manifest write
(essentially giving the deep read path access to the write path). It is also
difficult to do this while the DB is open because of the limitations of
LogAndApply.
This change allows updating file temperature metadata on a closed DB
using an experimental utility function UpdateManifestForFilesState()
or `ldb update_manifest --update_temperatures`. This should suffice for
"migration" scenarios where outside tooling has placed or re-arranged DB
files into a (different) tiered configuration without going through
RocksDB itself (currently, only compaction can change temperature
metadata).
Some details:
* Refactored and added unit test for `ldb unsafe_remove_sst_file` because
of shared functionality
* Pulled in autovector.h changes from https://github.com/facebook/rocksdb/issues/9546 to fix SuperVersionContext
move constructor (related to an older draft of this change)
Possible follow-up work:
* Support updating manifest with file checksums, such as when a
new checksum function is used and want existing DB metadata updated
for it.
* It's possible that for some repair scenarios, lighter weight than
full repair, we might want to support UpdateManifestForFilesState() to
modify critical file details like size or checksum using same
algorithm. But let's make sure these are differentiated from modifying
file details in ways that don't suspect corruption (or require extreme
trust).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9683
Test Plan: unit tests added
Reviewed By: jay-zhuang
Differential Revision: D34798828
Pulled By: pdillinger
fbshipit-source-id: cfd83e8fb10761d8c9e7f9c020d68c9106a95554
Summary:
On CircleCI MacOS instances, we have been seeing the following assertion error:
```
Assertion failed: (alive_log_files_tail_ == alive_log_files_.rbegin()), function WriteToWAL, file /Users/distiller/project/db/db_impl/db_impl_write.cc, line 1213.
Received signal 6 (Abort trap: 6)
#0 0x1
https://github.com/facebook/rocksdb/issues/1 abort (in libsystem_c.dylib) + 120
https://github.com/facebook/rocksdb/issues/2 err (in libsystem_c.dylib) + 0
https://github.com/facebook/rocksdb/issues/3 rocksdb::DBImpl::WriteToWAL(rocksdb::WriteBatch const&, rocksdb::log::Writer*, unsigned long long*, unsigned long long*, rocksdb::Env::IOPriority, bool, bool) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:1213)
https://github.com/facebook/rocksdb/issues/4 rocksdb::DBImpl::WriteToWAL(rocksdb::WriteThread::WriteGroup const&, rocksdb::log::Writer*, unsigned long long*, bool, bool, unsigned long long) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:1251)
https://github.com/facebook/rocksdb/issues/5 rocksdb::DBImpl::WriteImpl(rocksdb::WriteOptions const&, rocksdb::WriteBatch*, rocksdb::WriteCallback*, unsigned long long*, unsigned long long, bool, unsigned long long*, unsigned long, rocksdb::PreReleaseCallback*) (in librocksdb.7.0.0.dylib) (db_impl_ rite.cc:421)
https://github.com/facebook/rocksdb/issues/6 rocksdb::DBImpl::Write(rocksdb::WriteOptions const&, rocksdb::WriteBatch*) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:109)
https://github.com/facebook/rocksdb/issues/7 rocksdb::DB::Put(rocksdb::WriteOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:2159)
https://github.com/facebook/rocksdb/issues/8 rocksdb::DBImpl::Put(rocksdb::WriteOptions const&, rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) (in librocksdb.7.0.0.dylib) (db_impl_write.cc:37)
https://github.com/facebook/rocksdb/issues/9 rocksdb::DB::Put(rocksdb::WriteOptions const&, rocksdb::Slice const&, rocksdb::Slice const&, rocksdb::Slice const&) (in librocksdb.7.0.0.dylib) (db.h:382)
https://github.com/facebook/rocksdb/issues/10 rocksdb::DBBasicTestWithTimestampPrefixSeek_IterateWithPrefix_Test::TestBody() (in db_with_timestamp_basic_test) (db_with_timestamp_basic_test.cc:2926)
https://github.com/facebook/rocksdb/issues/11 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3899)
https://github.com/facebook/rocksdb/issues/12 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3935)
https://github.com/facebook/rocksdb/issues/13 testing::Test::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:3980)
https://github.com/facebook/rocksdb/issues/14 testing::TestInfo::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:4153)
https://github.com/facebook/rocksdb/issues/15 testing::TestCase::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:4266)
https://github.com/facebook/rocksdb/issues/16 testing::internal::UnitTestImpl::RunAllTests() (in db_with_timestamp_basic_test) (gtest-all.cc:6632)
https://github.com/facebook/rocksdb/issues/17 bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3899)
https://github.com/facebook/rocksdb/issues/18 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) (in db_with_timestamp_basic_test) (gtest-all.cc:3935)
https://github.com/facebook/rocksdb/issues/19 testing::UnitTest::Run() (in db_with_timestamp_basic_test) (gtest-all.cc:6242)
https://github.com/facebook/rocksdb/issues/20 RUN_ALL_TESTS() (in db_with_timestamp_basic_test) (gtest.h:22110)
https://github.com/facebook/rocksdb/issues/21 main (in db_with_timestamp_basic_test) (db_with_timestamp_basic_test.cc:3150)
https://github.com/facebook/rocksdb/issues/22 start (in libdyld.dylib) + 1
```
It's likely caused by concurrent, unprotected access to the deque, even though `back()` is never popped,
and we are comparing `rbegin()` with a cached `riterator`. To be safe, do the comparison only if we have mutex.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9717
Test Plan:
One example
Ssh to one CircleCI MacOS instance.
```
gtest-parallel -r 1000 -w 8 ./db_test --gtest_filter=DBTest.FlushesInParallelWithCompactRange
```
Reviewed By: pdillinger
Differential Revision: D34990696
Pulled By: riversand963
fbshipit-source-id: 62dd48ae6fedbda53d0a64d73de9b948b4c26eee
Summary:
The primary goal of this change is to add support for backing up and
restoring (applying on restore) file temperature metadata, without
committing to either the DB manifest or the FS reported "current"
temperatures being exclusive "source of truth".
To achieve this goal, we need to add temperature information to backup
metadata, which requires updated backup meta schema. Fortunately I
prepared for this in https://github.com/facebook/rocksdb/issues/8069, which began forward compatibility in version
6.19.0 for this kind of schema update. (Previously, backup meta schema
was not extensible! Making this schema update public will allow some
other "nice to have" features like taking backups with hard links, and
avoiding crc32c checksum computation when another checksum is already
available.) While schema version 2 is newly public, the default schema
version is still 1. Until we change the default, users will need to set
to 2 to enable features like temperature data backup+restore. New
metadata like temperature information will be ignored with a warning
in versions before this change and since 6.19.0. The metadata is
considered ignorable because a functioning DB can be restored without
it.
Some detail:
* Some renaming because "future schema" is now just public schema 2.
* Initialize some atomics in TestFs (linter reported)
* Add temperature hint support to SstFileDumper (used by BackupEngine)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9660
Test Plan:
related unit test majorly updated for the new functionality,
including some shared testing support for tracking temperatures in a FS.
Some other tests and testing hooks into production code also updated for
making the backup meta schema change public.
Reviewed By: ajkr
Differential Revision: D34686968
Pulled By: pdillinger
fbshipit-source-id: 3ac1fa3e67ee97ca8a5103d79cc87d872c1d862a
Summary:
Fix and enhance the background error recovery logic to handle the
following situations -
1. Background read errors during flush/compaction (previously was
resulting in unrecoverable state)
2. Fix auto recovery failure on read/write errors during atomic flush.
It was failing due to a bug in setting the resuming_from_bg_err variable
in AtomicFlushMemTablesToOutputFiles.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9679
Test Plan: Add new unit tests in error_handler_fs_test
Reviewed By: riversand963
Differential Revision: D34770097
Pulled By: anand1976
fbshipit-source-id: 136da973a28d684b9c74bdf668519b0cbbbe1742
Summary:
In https://github.com/facebook/rocksdb/issues/9659, when `DisableManualCompaction()` is issued, the foreground
manual compaction thread does not have to wait background compaction
thread to finish. Which could be a problem that the user re-enable
manual compaction with `EnableManualCompaction()`, it may re-enable the
BG compaction which supposed be cancelled.
This patch makes the FG compaction wait on
`manual_compaction_state.done`, which either be set by BG compaction or
Unschedule callback. Then when FG manual compaction thread returns, it
should not have BG compaction running. So shared_ptr is no longer needed
for `manual_compaction_state`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9694
Test Plan: a StressTest and unittest
Reviewed By: ajkr
Differential Revision: D34885472
Pulled By: jay-zhuang
fbshipit-source-id: e6476175b43e8c59cd49f5c09241036a0716c274
Summary:
PR9686 makes `WriteToWAL()` call `assert(...!=rend())` while not holding
db mutex or log mutex. Another thread may concurrently call
`pop_front()`, causing race condition.
To fix, assert only if mutex is held.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9698
Test Plan: COMPILE_WITH_TSAN=1 make check
Reviewed By: jay-zhuang
Differential Revision: D34898535
Pulled By: riversand963
fbshipit-source-id: 1ddfa5bf1b6ae8d409cab6ff6e1b5321c6803da9
Summary:
In the original code, the value of `NO_FILE_OPENS` corresponding to the Ticker item will be increased regardless of whether the file is successfully opened or not. Even counts are repeated, which can lead to skewed counts.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9677
Reviewed By: jay-zhuang
Differential Revision: D34725733
Pulled By: ajkr
fbshipit-source-id: 841234ed03802c0105fd2107d82a740265ead576
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9686
According to https://www.cplusplus.com/reference/deque/deque/back/,
"
The container is accessed (neither the const nor the non-const versions modify the container).
The last element is potentially accessed or modified by the caller. Concurrently accessing or modifying other elements is safe.
"
Also according to https://www.cplusplus.com/reference/deque/deque/pop_front/,
"
The container is modified.
The first element is modified. Concurrently accessing or modifying other elements is safe (although see iterator validity above).
"
In RocksDB, we never pop the last element of `DBImpl::alive_log_files_`. We have been
exploiting this fact and the above two properties when ensuring correctness when
`DBImpl::alive_log_files_` may be accessed concurrently. Specifically, it can be accessed
in the write path when db mutex is released. Sometimes, the log_mute_ is held. It can also be accessed in `FindObsoleteFiles()`
when db mutex is always held. It can also be accessed
during recovery when db mutex is also held.
Given the fact that we never pop the last element of alive_log_files_, we currently do not
acquire additional locks when accessing it in `WriteToWAL()` as follows
```
alive_log_files_.back().AddSize(log_entry.size());
```
This is problematic.
Check source code of deque.h
```
back() _GLIBCXX_NOEXCEPT
{
__glibcxx_requires_nonempty();
...
}
pop_front() _GLIBCXX_NOEXCEPT
{
...
if (this->_M_impl._M_start._M_cur
!= this->_M_impl._M_start._M_last - 1)
{
...
++this->_M_impl._M_start._M_cur;
}
...
}
```
`back()` will actually call `__glibcxx_requires_nonempty()` first.
If `__glibcxx_requires_nonempty()` is enabled and not an empty macro,
it will call `empty()`
```
bool empty() {
return this->_M_impl._M_finish == this->_M_impl._M_start;
}
```
You can see that it will access `this->_M_impl._M_start`, racing with `pop_front()`.
Therefore, TSAN will actually catch the bug in this case.
To be able to use TSAN on our library and unit tests, we should always coordinate
concurrent accesses to STL containers properly.
We need to pass information about db mutex and log mutex into `WriteToWAL()`, otherwise
it's impossible to know which mutex to acquire inside the function.
To fix this, we can catch the tail of `alive_log_files_` by reference, so that we do not have to call `back()` in `WriteToWAL()`.
Reviewed By: pdillinger
Differential Revision: D34780309
fbshipit-source-id: 1def9821f0c437f2736c6a26445d75890377889b
Summary:
https://github.com/facebook/rocksdb/issues/9625 didn't change the unschedule condition which was waiting for the background thread to clean-up the compaction.
make sure we only unschedule the task when it's scheduled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9659
Reviewed By: ajkr
Differential Revision: D34651820
Pulled By: jay-zhuang
fbshipit-source-id: 23f42081b15ec8886cd81cbf131b116e0c74dc2f
Summary:
Timer crash when multiple DB instances doing heavy DB open and close
operations concurrently. Which is caused by adding a timer task with
smaller timestamp than the current running task. Fix it by moving the
getting new task timestamp part within timer mutex protection.
And other fixes:
- Disallow adding duplicated function name to timer
- Fix a minor memory leak in timer when a running task is cancelled
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9656
Reviewed By: ajkr
Differential Revision: D34626296
Pulled By: jay-zhuang
fbshipit-source-id: 6b6d96a5149746bf503546244912a9e41a0c5f6b
Summary:
As disscussed in (https://github.com/facebook/rocksdb/issues/9223), Here added a new API named DB::OpenAndTrimHistory, this API will open DB and trim data to the timestamp specofied by **trim_ts** (The data with newer timestamp than specified trim bound will be removed). This API should only be used at a timestamp-enabled db instance recovery.
And this PR implemented a new iterator named HistoryTrimmingIterator to support trimming history with a new API named DB::OpenAndTrimHistory. HistoryTrimmingIterator wrapped around the underlying InternalITerator such that keys whose timestamps newer than **trim_ts** should not be returned to the compaction iterator while **trim_ts** is not null.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9410
Reviewed By: ltamasi
Differential Revision: D34410207
Pulled By: riversand963
fbshipit-source-id: e54049dc234eccd673244c566b15df58df5a6236
Summary:
Change the `MemPurge` code to address a failure during a crash test reported in https://github.com/facebook/rocksdb/issues/8958.
### Details and results of the crash investigation:
These failures happened in a specific scenario where the list of immutable tables was composed of 2 or more memtables, and the last memtable was the output of a previous `Mempurge` operation. Because the `PickMemtablesToFlush` function included a sorting of the memtables (previous PR related to the Mempurge project), and because the `VersionEdit` of the flush class is piggybacked onto a single one of these memtables, the `VersionEdit` was not properly selected and applied to the `VersionSet` of the DB. Since the `VersionSet` was not edited properly, the database was losing track of the SST file created during the flush process, which was subsequently deleted (and as you can expect, caused the tests to crash).
The following command consistently failed, which was quite convenient to investigate the issue:
`$ while rm -rf /dev/shm/single_stress && ./db_stress --clear_column_family_one_in=0 --column_families=1 --db=/dev/shm/single_stress --experimental_mempurge_threshold=5.493146827397074 --flush_one_in=10000 --reopen=0 --write_buffer_size=262144 --value_size_mult=33 --max_write_buffer_number=3 -ops_per_thread=10000; do : ; done`
### Solution proposed
The memtables are no longer sorted based on their `memtableID` in the `PickMemtablesToFlush` function. Additionally, the `next_log_number` of the memtable created as an output of the `Mempurge` function now takes in the correct value (the log number of the first memtable being mempurged). Finally, the VersionEdit object of the flush class now takes the maximum `next_log_number` of the stack of memtables being flushed, which doesnt change anything when Mempurge is `off` but becomes necessary when Mempurge is `on`.
### Testing of the solution
The following command no longer fails:
``$ while rm -rf /dev/shm/single_stress && ./db_stress --clear_column_family_one_in=0 --column_families=1 --db=/dev/shm/single_stress --experimental_mempurge_threshold=5.493146827397074 --flush_one_in=10000 --reopen=0 --write_buffer_size=262144 --value_size_mult=33 --max_write_buffer_number=3 -ops_per_thread=10000; do : ; done``
Additionally, I ran `db_crashtest` (`whitebox` and `blackbox`) for 2.5 hours with MemPurge on and did not observe any crash.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9671
Reviewed By: pdillinger
Differential Revision: D34697424
Pulled By: bjlemaire
fbshipit-source-id: d1ab675b361904351ac81a35c184030e52222874
Summary:
Integrate the streaming compress/uncompress API into WAL compression.
The streaming compression object is stored in the log_writer along with a reusable output buffer to store the compressed buffer(s).
The streaming uncompress object is stored in the log_reader along with a reusable output buffer to store the uncompressed buffer(s).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9642
Test Plan:
Added unit tests to verify different scenarios - large buffers, split compressed buffers, etc.
Future optimizations:
The overhead for small records is quite high, so it makes sense to compress only buffers above a certain threshold and use a separate record type to indicate that those records are compressed.
Reviewed By: anand1976
Differential Revision: D34709167
Pulled By: sidroyc
fbshipit-source-id: a37a3cd1301adff6152fb3fcd23726106af07dd4
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9629
Pessimistic transactions use pessimistic concurrency control, i.e. locking. Keys are
locked upon first operation that writes the key or has the intention of writing. For example,
`PessimisticTransaction::Put()`, `PessimisticTransaction::Delete()`,
`PessimisticTransaction::SingleDelete()` will write to or delete a key, while
`PessimisticTransaction::GetForUpdate()` is used by application to indicate
to RocksDB that the transaction has the intention of performing write operation later
in the same transaction.
Pessimistic transactions support two-phase commit (2PC). A transaction can be
`Prepared()`'ed and then `Commit()`. The prepare phase is similar to a promise: once
`Prepare()` succeeds, the transaction has acquired the necessary resources to commit.
The resources include locks, persistence of WAL, etc.
Write-committed transaction is the default pessimistic transaction implementation. In
RocksDB write-committed transaction, `Prepare()` will write data to the WAL as a prepare
section. `Commit()` will write a commit marker to the WAL and then write data to the
memtables. While writing to the memtables, different keys in the transaction's write batch
will be assigned different sequence numbers in ascending order.
Until commit/rollback, the transaction holds locks on the keys so that no other transaction
can write to the same keys. Furthermore, the keys' sequence numbers represent the order
in which they are committed and should be made visible. This is convenient for us to
implement support for user-defined timestamps.
Since column families with and without timestamps can co-exist in the same database,
a transaction may or may not involve timestamps. Based on this observation, we add two
optional members to each `PessimisticTransaction`, `read_timestamp_` and
`commit_timestamp_`. If no key in the transaction's write batch has timestamp, then
setting these two variables do not have any effect. For the rest of this commit, we discuss
only the cases when these two variables are meaningful.
read_timestamp_ is used mainly for validation, and should be set before first call to
`GetForUpdate()`. Otherwise, the latter will return non-ok status. `GetForUpdate()` calls
`TryLock()` that can verify if another transaction has written the same key since
`read_timestamp_` till this call to `GetForUpdate()`. If another transaction has indeed
written the same key, then validation fails, and RocksDB allows this transaction to
refine `read_timestamp_` by increasing it. Note that a transaction can still use `Get()`
with a different timestamp to read, but the result of the read should not be used to
determine data that will be written later.
commit_timestamp_ must be set after finishing writing and before transaction commit.
This applies to both 2PC and non-2PC cases. In the case of 2PC, it's usually set after
prepare phase succeeds.
We currently require that the commit timestamp be chosen after all keys are locked. This
means we disallow the `TransactionDB`-level APIs if user-defined timestamp is used
by the transaction. Specifically, calling `PessimisticTransactionDB::Put()`,
`PessimisticTransactionDB::Delete()`, `PessimisticTransactionDB::SingleDelete()`,
etc. will return non-ok status because they specify timestamps before locking the keys.
Users are also prompted to use the `Transaction` APIs when they receive the non-ok status.
Reviewed By: ltamasi
Differential Revision: D31822445
fbshipit-source-id: b82abf8e230216dc89cc519564a588224a88fd43
Summary:
- Make `compression_per_level` dynamical changeable with `SetOptions`;
- Fix a bug that `compression_per_level` is not used for flush;
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9658
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D34700749
Pulled By: jay-zhuang
fbshipit-source-id: a23b9dfa7ad03d393c1d71781d19e91de796f49c
Summary:
In preparation for more support for file Temperatures in BackupEngine,
this change does some test refactoring:
* Move DBTest2::BackupFileTemperature test to
BackupEngineTest::FileTemperatures, with some updates to make it work
in the new home. This test will soon be expanded for deeper backup work.
* Move FileTemperatureTestFS from db_test2.cc to db_test_util.h, to
support sharing because of above moved test, but split off the "no link"
part to the test needing it.
* Use custom FileSystems in backupable_db_test rather than custom Envs,
because going through Env file interfaces doesn't support temperatures.
* Fix RemapFileSystem to map DirFsyncOptions::renamed_new_name
parameter to FsyncWithDirOptions, which was required because this
limitation caused a crash only after moving to higher fidelity of
FileSystem interface (vs. LegacyDirectoryWrapper throwing away some
parameter details)
* `backupable_options_` -> `engine_options_` as part of the ongoing
work to get rid of the obsolete "backupable" naming.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9655
Test Plan: test code updates only
Reviewed By: jay-zhuang
Differential Revision: D34622183
Pulled By: pdillinger
fbshipit-source-id: f24b7a596a89b9e089e960f4e5d772575513e93f
Summary:
**Context:**
`DBLogicalBlockSizeCacheTest.CreateColumnFamilies` is flaky on a rare occurrence of assertion failure below
```
db/db_logical_block_size_cache_test.cc:210
Expected equality of these values:
1
cache_->GetRefCount(cf_path_0_)
Which is: 2
```
Root-cause: `ASSERT_OK(db->DestroyColumnFamilyHandle(cfs[0]));` in the test may not successfully decrease the ref count of `cf_path_0_` since the decreasing only happens in the clean-up of `ColumnFamilyData` when `ColumnFamilyData` has no referencing to it, which may not be true when `db->DestroyColumnFamilyHandle(cfs[0])` is called since background work such as `DumpStats()` can hold reference to that `ColumnFamilyData` (suggested and repro-d by ajkr ). Similar case `ASSERT_OK(db->DestroyColumnFamilyHandle(cfs[1]));`.
See following for a deterministic repro:
```
diff --git a/db/db_impl/db_impl.cc b/db/db_impl/db_impl.cc
index 196b428a3..4e7a834c4 100644
--- a/db/db_impl/db_impl.cc
+++ b/db/db_impl/db_impl.cc
@@ -956,10 +956,16 @@ void DBImpl::DumpStats() {
// near-atomically.
// Get a ref before unlocking
cfd->Ref();
+ if (cfd->GetName() == "cf1" || cfd->GetName() == "cf2") {
+ TEST_SYNC_POINT("DBImpl::DumpStats:PostCFDRef");
+ }
{
InstrumentedMutexUnlock u(&mutex_);
cfd->internal_stats()->CollectCacheEntryStats(/*foreground=*/false);
}
+ if (cfd->GetName() == "cf1" || cfd->GetName() == "cf2") {
+ TEST_SYNC_POINT("DBImpl::DumpStats::PreCFDUnrefAndTryDelete");
+ }
cfd->UnrefAndTryDelete();
}
}
diff --git a/db/db_logical_block_size_cache_test.cc b/db/db_logical_block_size_cache_test.cc
index 1057871c9..c3872c036 100644
--- a/db/db_logical_block_size_cache_test.cc
+++ b/db/db_logical_block_size_cache_test.cc
@@ -9,6 +9,7 @@
#include "env/io_posix.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
+#include "test_util/sync_point.h"
namespace ROCKSDB_NAMESPACE {
class EnvWithCustomLogicalBlockSizeCache : public EnvWrapper {
@@ -183,6 +184,15 @@ TEST_F(DBLogicalBlockSizeCacheTest, CreateColumnFamilies) {
ASSERT_EQ(1, cache_->GetRefCount(dbname_));
std::vector<ColumnFamilyHandle*> cfs;
+ ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+ ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->LoadDependency(
+ {{"DBLogicalBlockSizeCacheTest::CreateColumnFamilies::PostSetupTwoCFH",
+ "DBImpl::DumpStats:StartRunning"},
+ {"DBImpl::DumpStats:PostCFDRef",
+ "DBLogicalBlockSizeCacheTest::CreateColumnFamilies::PreDeleteTwoCFH"},
+ {"DBLogicalBlockSizeCacheTest::CreateColumnFamilies::"
+ "PostFinishCheckingRef",
+ "DBImpl::DumpStats::PreCFDUnrefAndTryDelete"}});
ASSERT_OK(db->CreateColumnFamilies(cf_options, {"cf1", "cf2"}, &cfs));
ASSERT_EQ(2, cache_->Size());
ASSERT_TRUE(cache_->Contains(dbname_));
@@ -190,7 +200,7 @@ TEST_F(DBLogicalBlockSizeCacheTest, CreateColumnFamilies) {
ASSERT_TRUE(cache_->Contains(cf_path_0_));
ASSERT_EQ(2, cache_->GetRefCount(cf_path_0_));
}
// Delete one handle will not drop cache because another handle is still
// referencing cf_path_0_.
+ TEST_SYNC_POINT(
+ "DBLogicalBlockSizeCacheTest::CreateColumnFamilies::PostSetupTwoCFH");
+ TEST_SYNC_POINT(
+ "DBLogicalBlockSizeCacheTest::CreateColumnFamilies::PreDeleteTwoCFH");
ASSERT_OK(db->DestroyColumnFamilyHandle(cfs[0]));
ASSERT_EQ(2, cache_->Size());
ASSERT_TRUE(cache_->Contains(dbname_));
@@ -209,16 +221,20 @@ TEST_F(DBLogicalBlockSizeCacheTest, CreateColumnFamilies) {
ASSERT_TRUE(cache_->Contains(cf_path_0_));
// Will fail
ASSERT_EQ(1, cache_->GetRefCount(cf_path_0_));
// Delete the last handle will drop cache.
ASSERT_OK(db->DestroyColumnFamilyHandle(cfs[1]));
ASSERT_EQ(1, cache_->Size());
ASSERT_TRUE(cache_->Contains(dbname_));
// Will fail
ASSERT_EQ(1, cache_->GetRefCount(dbname_));
+ TEST_SYNC_POINT(
+ "DBLogicalBlockSizeCacheTest::CreateColumnFamilies::"
+ "PostFinishCheckingRef");
delete db;
ASSERT_EQ(0, cache_->Size());
ASSERT_OK(DestroyDB(dbname_, options,
{{"cf1", cf_options}, {"cf2", cf_options}}));
+ ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
}
```
**Summary**
- Removed the flaky assertion
- Clarified the comments for the test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9516
Test Plan:
- CI
- Monitor for future flakiness
Reviewed By: ajkr
Differential Revision: D34055232
Pulled By: hx235
fbshipit-source-id: 9bf83ae5fa88bf6fc829876494d4692082e4c357
Summary:
**Context/Summary:**
As requested, `BlockBasedTableOptions::detect_filter_construct_corruption` can now be dynamically configured using `DB::SetOptions` after this PR
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9654
Test Plan: - New unit test
Reviewed By: pdillinger
Differential Revision: D34622609
Pulled By: hx235
fbshipit-source-id: c06773ef3d029e6bf1724d3a72dffd37a8ec66d9
Summary:
This bug affects use cases that meet the following conditions
- (has only the default column family or disables WAL) and
- has at least one event listener
- atomic flush is NOT affected.
If the above conditions meet, then RocksDB can release the db mutex before picking all the
existing memtables to flush. In the meantime, a snapshot can be created and db's sequence
number can still be incremented. The upcoming flush will ignore this snapshot.
A later read using this snapshot can return incorrect result.
To fix this issue, we call the listeners callbacks after picking the memtables so that we avoid
creating snapshots during this interval.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9648
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D34555456
Pulled By: riversand963
fbshipit-source-id: 1438981e9f069a5916686b1a0ad7627f734cf0ee
Summary:
Certain STLs use raw pointers and ADL does not work for them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9608
Reviewed By: ajkr
Differential Revision: D34583012
Pulled By: riversand963
fbshipit-source-id: 7de6bbc8a080c3e7243ce0d758fe83f1663168aa
Summary:
PR https://github.com/facebook/rocksdb/issues/9557 introduced a race condition between manual compaction
foreground thread and background compaction thread.
This PR adds the ability to really unschedule manual compaction from
thread-pool queue by differentiate tag name for manual compaction and
other tasks.
Also fix an issue that db `close()` didn't cancel the manual compaction thread.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9625
Test Plan: unittest not hang
Reviewed By: ajkr
Differential Revision: D34410811
Pulled By: jay-zhuang
fbshipit-source-id: cb14065eabb8cf1345fa042b5652d4f788c0c40c
Summary:
BlockBasedTableOptions.hash_index_allow_collision is already deprecated and has no effect. Delete it for preparing 7.0 release.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9454
Test Plan: Run all existing tests.
Reviewed By: ajkr
Differential Revision: D33805827
fbshipit-source-id: ed8a436d1d083173ec6aef2a762ba02e1eefdc9d
Summary:
We found a case of cacheline bouncing due to writers locking/unlocking `mutex_` and readers accessing `block_cache_tracer_`. We discovered it only after the issue was fixed by https://github.com/facebook/rocksdb/issues/9462 shifting the `DBImpl` members such that `mutex_` and `block_cache_tracer_` were naturally placed in separate cachelines in our regression testing setup. This PR forces the cacheline alignment of `mutex_` so we don't accidentally reintroduce the problem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9637
Reviewed By: riversand963
Differential Revision: D34502233
Pulled By: ajkr
fbshipit-source-id: 46aa313b7fe83e80c3de254e332b6fb242434c07
Summary:
**Context:**
As part of https://github.com/facebook/rocksdb/pull/6949, file deletion is disabled for faulty database on the IOError of MANIFEST write/sync and [re-enabled again during `DBImpl::Resume()` if all recovery is completed](e66199d848 (diff-d9341fbe2a5d4089b93b22c5ed7f666bc311b378c26d0786f4b50c290e460187R396)). Before re-enabling file deletion, it `assert(versions_->io_status().ok());`, which IMO assumes `versions_` is **the** `version_` in the recovery process.
However, this is not necessarily true due to `s = error_handler_.ClearBGError();` happening before that assertion can unblock some foreground thread by [`EventHelpers::NotifyOnErrorRecoveryEnd()`](3122cb4358/db/error_handler.cc (L552-L553)) as part of the `ClearBGError()`. That foreground thread can do whatever it wants including closing/reopening the db and clean up that same `versions_`.
As a consequence, `assert(versions_->io_status().ok());`, will access `io_status()` of a nullptr and test like `DBErrorHandlingFSTest.MultiCFWALWriteError` becomes flaky. The unblocked foreground thread (in this case, the testing thread) proceeds to [reopen the db](https://github.com/facebook/rocksdb/blob/6.29.fb/db/error_handler_fs_test.cc?fbclid=IwAR1kQOxSbTUmaHQPAGz5jdMHXtDsDFKiFl8rifX-vIz4B23Y0S9jBkssSCg#L1494), where [`versions_` gets reset to nullptr](https://github.com/facebook/rocksdb/blob/6.29.fb/db/db_impl/db_impl.cc?fbclid=IwAR2uRhwBiPKgmE9q_6CM2mzbfwjoRgsGpXOrHruSJUDcAKc9rYZtVSvKdOY#L678) as part of the old db clean-up. If this happens right before `assert(versions_->io_status().ok()); ` gets excuted in the background thread, then we can see error like
```
db/db_impl/db_impl.cc:420:5: runtime error: member call on null pointer of type 'rocksdb::VersionSet'
assert(versions_->io_status().ok());
```
**Summary:**
- I proposed to call `s = error_handler_.ClearBGError();` after we know it's fine to wake up foreground, which I think is right before we LOG `ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");`
- As the context, the orignal https://github.com/facebook/rocksdb/pull/3997 introducing `DBImpl::Resume()` calls `s = error_handler_.ClearBGError();` very close to calling `ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");` while the later https://github.com/facebook/rocksdb/pull/6949 distances these two calls a bit.
- And it seems fine to me that `s = error_handler_.ClearBGError();` happens after `EnableFileDeletions(/*force=*/true);` at least syntax-wise since these two functions are orthogonal. And it also seems okay to me that we re-enable file deletion before `s = error_handler_.ClearBGError();`, which basically is resetting some state variables.
- In addition, to preserve the previous behavior of https://github.com/facebook/rocksdb/pull/6949 where status of re-enabling file deletion is not taken account into the general status of resuming the db, I separated `enable_file_deletion_s` from the general `s`
- In addition, to make `ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");` more clear, I separated it into its own if-block.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9496
Test Plan:
- Manually reproduce the assertion failure in`DBErrorHandlingFSTest.MultiCFWALWriteError` by injecting sleep like below so that it's more likely for `assert(versions_->io_status().ok());` to execute after [reopening the db](https://github.com/facebook/rocksdb/blob/6.29.fb/db/error_handler_fs_test.cc?fbclid=IwAR1kQOxSbTUmaHQPAGz5jdMHXtDsDFKiFl8rifX-vIz4B23Y0S9jBkssSCg#L1494) in the foreground (i.e, testing) thread
```
sleep(1);
assert(versions_->io_status().ok());
```
`python3 gtest-parallel/gtest_parallel.py -r 100 -w 100 rocksdb/error_handler_fs_test --gtest_filter=DBErrorHandlingFSTest.MultiCFWALWriteError`
```
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from DBErrorHandlingFSTest
[ RUN ] DBErrorHandlingFSTest.MultiCFWALWriteError
Received signal 11 (Segmentation fault)
#0 rocksdb/error_handler_fs_test() [0x5818a4] rocksdb::DBImpl::ResumeImpl(rocksdb::DBRecoverContext) /data/users/huixiao/rocksdb/db/db_impl/db_impl.cc:421
https://github.com/facebook/rocksdb/issues/1 rocksdb/error_handler_fs_test() [0x6379ff] rocksdb::ErrorHandler::RecoverFromBGError(bool) /data/users/huixiao/rocksdb/db/error_handler.cc:600
https://github.com/facebook/rocksdb/issues/2 rocksdb/error_handler_fs_test() [0x7c5362] rocksdb::SstFileManagerImpl::ClearError() /data/users/huixiao/rocksdb/file/sst_file_manager_impl.cc:310
https://github.com/facebook/rocksdb/issues/3 rocksdb/error_handler_fs_test()
```
- The assertion failure does not happen with PR
`python3 gtest-parallel/gtest_parallel.py -r 100 -w 100 rocksdb/error_handler_fs_test --gtest_filter=DBErrorHandlingFSTest.MultiCFWALWriteError`
`[100/100] DBErrorHandlingFSTest.MultiCFWALWriteError (43785 ms) `
Reviewed By: riversand963, anand1976
Differential Revision: D33990099
Pulled By: hx235
fbshipit-source-id: 2e0259a471fa8892ff177da91b3e1c0792dd7bab
Summary:
Implement a streaming compression API (compress/uncompress) to use for WAL compression. The log_writer would use the compress class/API to compress a record before writing it out in chunks. The log_reader would use the uncompress class/API to uncompress the chunks and combine into a single record.
Added unit test to verify the API for different sizes/compression types.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9619
Test Plan: make -j24 check
Reviewed By: anand1976
Differential Revision: D34437346
Pulled By: sidroyc
fbshipit-source-id: b180569ad2ddcf3106380f8758b556cc0ad18382
Summary:
This PR supports inserting keys to a `WriteBatchWithIndex` for column families that enable user-defined timestamps
and reading the keys back. **The index does not have timestamps.**
Writing a key to WBWI is unchanged, because the underlying WriteBatch already supports it.
When reading the keys back, we need to make sure to distinguish between keys with and without timestamps before
comparison.
When user calls `GetFromBatchAndDB()`, no timestamp is needed to query the batch, but a timestamp has to be
provided to query the db. The assumption is that data in the batch must be newer than data from the db.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9603
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D34354849
Pulled By: riversand963
fbshipit-source-id: d25d1f84e2240ce543e521fa30595082fb8db9a0
Summary:
We often see flaky tests due to `DB::Flush()` or `DBImpl::TEST_WaitForFlushMemTable()` not waiting until event listeners complete. For example, https://github.com/facebook/rocksdb/issues/9084, https://github.com/facebook/rocksdb/issues/9400, https://github.com/facebook/rocksdb/issues/9528, plus two new ones this week: "EventListenerTest.OnSingleDBFlushTest" and "DBFlushTest.FireOnFlushCompletedAfterCommittedResult". I ran a `make check` with the below race condition-coercing patch and fixed issues it found besides old BlobDB.
```
diff --git a/db/db_impl/db_impl_compaction_flush.cc b/db/db_impl/db_impl_compaction_flush.cc
index 0e1864788..aaba68c4a 100644
--- a/db/db_impl/db_impl_compaction_flush.cc
+++ b/db/db_impl/db_impl_compaction_flush.cc
@@ -861,6 +861,8 @@ void DBImpl::NotifyOnFlushCompleted(
mutable_cf_options.level0_stop_writes_trigger);
// release lock while notifying events
mutex_.Unlock();
+ bg_cv_.SignalAll();
+ sleep(1);
{
for (auto& info : *flush_jobs_info) {
info->triggered_writes_slowdown = triggered_writes_slowdown;
```
The reason I did not fix old BlobDB issues is because it appears to have a fundamental (non-test) issue. In particular, it uses an EventListener to keep track of the files. OnFlushCompleted() could be delayed until even after a compaction involving that flushed file completes, causing the compaction to unexpectedly delete an untracked file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9617
Test Plan: `make check` including the race condition coercing patch
Reviewed By: hx235
Differential Revision: D34384022
Pulled By: ajkr
fbshipit-source-id: 2652ded39b415277c5d6a628414345223930514e
Summary:
Valgrind was failing with the below error because we forgot to destroy
the `BackupEngine` object:
```
==421173== Command: ./db_test2 --gtest_filter=DBTest2.BackupFileTemperature
==421173==
Note: Google Test filter = DBTest2.BackupFileTemperature
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from DBTest2
[ RUN ] DBTest2.BackupFileTemperature
--421173-- WARNING: unhandled amd64-linux syscall: 425
--421173-- You may be able to write your own handler.
--421173-- Read the file README_MISSING_SYSCALL_OR_IOCTL.
--421173-- Nevertheless we consider this a bug. Please report
--421173-- it at http://valgrind.org/support/bug_reports.html.
[ OK ] DBTest2.BackupFileTemperature (3366 ms)
[----------] 1 test from DBTest2 (3371 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (3413 ms total)
[ PASSED ] 1 test.
==421173==
==421173== HEAP SUMMARY:
==421173== in use at exit: 13,042 bytes in 195 blocks
==421173== total heap usage: 26,022 allocs, 25,827 frees, 27,555,265 bytes allocated
==421173==
==421173== 8 bytes in 1 blocks are possibly lost in loss record 6 of 167
==421173== at 0x4838DBF: operator new(unsigned long) (vg_replace_malloc.c:344)
==421173== by 0x8D4606: allocate (new_allocator.h:114)
==421173== by 0x8D4606: allocate (alloc_traits.h:445)
==421173== by 0x8D4606: _M_allocate (stl_vector.h:343)
==421173== by 0x8D4606: reserve (vector.tcc:78)
==421173== by 0x8D4606: rocksdb::BackupEngineImpl::Initialize() (backupable_db.cc:1174)
==421173== by 0x8D5473: Initialize (backupable_db.cc:918)
==421173== by 0x8D5473: rocksdb::BackupEngine::Open(rocksdb::BackupEngineOptions const&, rocksdb::Env*, rocksdb::BackupEngine**) (backupable_db.cc:937)
==421173== by 0x50AC8F: Open (backup_engine.h:585)
==421173== by 0x50AC8F: rocksdb::DBTest2_BackupFileTemperature_Test::TestBody() (db_test2.cc:6996)
...
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9610
Test Plan:
```
$ make -j24 ROCKSDBTESTS_SUBSET=db_test2 valgrind_check_some
```
Reviewed By: akankshamahajan15
Differential Revision: D34371210
Pulled By: ajkr
fbshipit-source-id: 68154fcb0c51b28222efa23fa4ee02df8d925a18
Summary:
Add Temperature hints information from RocksDB in API
`NewSequentialFile()`. backup and checkpoint operations need to open the
source files with `NewSequentialFile()`, which will have the temperature
hints. Other operations are not covered.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9499
Test Plan: Added unittest
Reviewed By: pdillinger
Differential Revision: D34006115
Pulled By: jay-zhuang
fbshipit-source-id: 568b34602b76520e53128672bd07e9d886786a2f
Summary:
[Compaction::IsTrivialMove](a2b9be42b6/db/compaction/compaction.cc (L318)) checks whether allow_trivial_move is set, and if so it returns the value of is_trivial_move_. The allow_trivial_move option is there for universal compaction. So when this is set and leveled compaction is enabled, then useful code that follows this block never gets a chance to run.
A check that [compaction_style == kCompactionStyleUniversal](320d9a8e8a/db/db_impl/db_impl_compaction_flush.cc (L1030)) should be added to avoid doing the wrong thing for leveled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9586
Test Plan:
To reproduce this:
First edit db/compaction/compaction.cc with
```
diff --git a/db/compaction/compaction.cc b/db/compaction/compaction.cc
index 7ae50b91e..52dd489b1 100644
--- a/db/compaction/compaction.cc
+++ b/db/compaction/compaction.cc
@@ -319,6 +319,8 @@ bool Compaction::IsTrivialMove() const {
// input files are non overlapping
if ((mutable_cf_options_.compaction_options_universal.allow_trivial_move) &&
(output_level_ != 0)) {
+ printf("IsTrivialMove:: return %d because universal allow_trivial_move\n", (int) is_trivial_move_);
+ // abort();
return is_trivial_move_;
}
```
And then run
```
./db_bench --benchmarks=fillseq --allow_concurrent_memtable_write=false --level0_file_num_compaction_trigger=4 --level0_slowdown_writes_trigger=20 --level0_stop_writes_trigger=30 --max_background_jobs=8 --max_write_buffer_number=8 --db=/data/m/rx --wal_dir=/data/m/rx --num=800000000 --num_levels=8 --key_size=20 --value_size=400 --block_size=8192 --cache_size=51539607552 --cache_numshardbits=6 --compression_max_dict_bytes=0 --compression_ratio=0.5 --compression_type=lz4 --bytes_per_sync=8388608 --cache_index_and_filter_blocks=1 --cache_high_pri_pool_ratio=0.5 --benchmark_write_rate_limit=0 --write_buffer_size=16777216 --target_file_size_base=16777216 --max_bytes_for_level_base=67108864 --verify_checksum=1 --delete_obsolete_files_period_micros=62914560 --max_bytes_for_level_multiplier=8 --statistics=0 --stats_per_interval=1 --stats_interval_seconds=20 --histogram=1 --memtablerep=skip_list --bloom_bits=10 --open_files=-1 --subcompactions=1 --compaction_style=0 --min_level_to_compress=3 --level_compaction_dynamic_level_bytes=true --pin_l0_filter_and_index_blocks_in_cache=1 --soft_pending_compaction_bytes_limit=167503724544 --hard_pending_compaction_bytes_limit=335007449088 --min_level_to_compress=0 --use_existing_db=0 --sync=0 --threads=1 --memtablerep=vector --allow_concurrent_memtable_write=false --disable_wal=1 --seed=1641328309 --universal_allow_trivial_move=1
```
Example output with the debug code added
```
IsTrivialMove:: return 0 because universal allow_trivial_move
IsTrivialMove:: return 0 because universal allow_trivial_move
```
After this PR, the bug is fixed.
Reviewed By: ajkr
Differential Revision: D34350451
Pulled By: gitbw95
fbshipit-source-id: 3232005cc47c40a7e75d316cfc7960beb5bdff3a
Summary:
Make FilterPolicy into a Customizable class. Allow new FilterPolicy to be discovered through the ObjectRegistry
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9590
Reviewed By: pdillinger
Differential Revision: D34327367
Pulled By: mrambacher
fbshipit-source-id: 37e7edac90ec9457422b72f359ab8ef48829c190
Summary:
RocksDB try to provide temperature information in the event
listener callbacks. The information is not guaranteed, as some operation
like backup won't have these information.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9591
Test Plan: Added unittest
Reviewed By: siying, pdillinger
Differential Revision: D34309339
Pulled By: jay-zhuang
fbshipit-source-id: 4aca4f270f99fa49186d85d300da42594663d6d7
Summary:
The NUM_INDEX_AND_FILTER_BLOCKS_READ_PER_LEVEL, NUM_DATA_BLOCKS_READ_PER_LEVEL, and NUM_SST_READ_PER_LEVEL stats were being recorded only when the last file in a level happened to have hits. They are supposed to be updated for every level. Also, there was some overcounting of GetContextStats. This PR fixes both the problems.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9583
Test Plan: Update the unit test in db_basic_test
Reviewed By: akankshamahajan15
Differential Revision: D34308044
Pulled By: anand1976
fbshipit-source-id: b3b36020fda26ba91bc6e0e47d52d58f4d7f656e
Summary:
When WAL compression is enabled, add a record (new record type) to store the compression type to indicate that all subsequent records are compressed. The log reader will store the compression type when this record is encountered and use the type to uncompress the subsequent records. Compress and uncompress to be implemented in subsequent diffs.
Enabled WAL compression in some WAL tests to check for regressions. Some tests that rely on offsets have been disabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9556
Reviewed By: anand1976
Differential Revision: D34308216
Pulled By: sidroyc
fbshipit-source-id: 7f10595e46f3277f1ea2d309fbf95e2e935a8705
Summary:
Users can set the priority for file reads associated with their operation by setting `ReadOptions::rate_limiter_priority` to something other than `Env::IO_TOTAL`. Rate limiting `VerifyChecksum()` and `VerifyFileChecksums()` is the motivation for this PR, so it also includes benchmarks and minor bug fixes to get that working.
`RandomAccessFileReader::Read()` already had support for rate limiting compaction reads. I changed that rate limiting to be non-specific to compaction, but rather performed according to the passed in `Env::IOPriority`. Now the compaction read rate limiting is supported by setting `rate_limiter_priority = Env::IO_LOW` on its `ReadOptions`.
There is no default value for the new `Env::IOPriority` parameter to `RandomAccessFileReader::Read()`. That means this PR goes through all callers (in some cases multiple layers up the call stack) to find a `ReadOptions` to provide the priority. There are TODOs for cases I believe it would be good to let user control the priority some day (e.g., file footer reads), and no TODO in cases I believe it doesn't matter (e.g., trace file reads).
The API doc only lists the missing cases where a file read associated with a provided `ReadOptions` cannot be rate limited. For cases like file ingestion checksum calculation, there is no API to provide `ReadOptions` or `Env::IOPriority`, so I didn't count that as missing.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9424
Test Plan:
- new unit tests
- new benchmarks on ~50MB database with 1MB/s read rate limit and 100ms refill interval; verified with strace reads are chunked (at 0.1MB per chunk) and spaced roughly 100ms apart.
- setup command: `./db_bench -benchmarks=fillrandom,compact -db=/tmp/testdb -target_file_size_base=1048576 -disable_auto_compactions=true -file_checksum=true`
- benchmarks command: `strace -ttfe pread64 ./db_bench -benchmarks=verifychecksum,verifyfilechecksums -use_existing_db=true -db=/tmp/testdb -rate_limiter_bytes_per_sec=1048576 -rate_limit_bg_reads=1 -rate_limit_user_ops=true -file_checksum=true`
- crash test using IO_USER priority on non-validation reads with https://github.com/facebook/rocksdb/issues/9567 reverted: `python3 tools/db_crashtest.py blackbox --max_key=1000000 --write_buffer_size=524288 --target_file_size_base=524288 --level_compaction_dynamic_level_bytes=true --duration=3600 --rate_limit_bg_reads=true --rate_limit_user_ops=true --rate_limiter_bytes_per_sec=10485760 --interval=10`
Reviewed By: hx235
Differential Revision: D33747386
Pulled By: ajkr
fbshipit-source-id: a2d985e97912fba8c54763798e04f006ccc56e0c
Summary:
The following sequence of events can cause silent data loss for write-committed
transactions.
```
Time thread 1 bg flush
| db->Put("a")
| txn = NewTxn()
| txn->Put("b", "v")
| txn->Prepare() // writes only to 5.log
| db->SwitchMemtable() // memtable 1 has "a"
| // close 5.log,
| // creates 8.log
| trigger flush
| pick memtable 1
| unlock db mutex
| write new sst
| txn->ctwb->Put("gtid", "1") // writes 8.log
| txn->Commit() // writes to 8.log
| // writes to memtable 2
| compute min_log_number_to_keep_2pc, this
| will be 8 (incorrect).
|
| Purge obsolete wals, including 5.log
|
V
```
At this point, writes of txn exists only in memtable. Close db without flush because db thinks the data in
memtable are backed by log. Then reopen, the writes are lost except key-value pair {"gtid"->"1"},
only the commit marker of txn is in 8.log
The reason lies in `PrecomputeMinLogNumberToKeep2PC()` which calls `FindMinPrepLogReferencedByMemTable()`.
In the above example, when bg flush thread tries to find obsolete wals, it uses the information
computed by `PrecomputeMinLogNumberToKeep2PC()`. The return value of `PrecomputeMinLogNumberToKeep2PC()`
depends on three components
- `PrecomputeMinLogNumberToKeepNon2PC()`. This represents the WAL that has unflushed data. As the name of this method suggests, it does not account for 2PC. Although the keys reside in the prepare section of a previous WAL, the column family references the current WAL when they are actually inserted into the memtable during txn commit.
- `prep_tracker->FindMinLogContainingOutstandingPrep()`. This represents the WAL with a prepare section but the txn hasn't committed.
- `FindMinPrepLogReferencedByMemTable()`. This represents the WAL on which some memtables (mutable and immutable) depend for their unflushed data.
The bug lies in `FindMinPrepLogReferencedByMemTable()`. Originally, this function skips checking the column families
that are being flushed, but the unit test added in this PR shows that they should not be. In this unit test, there is
only the default column family, and one of its memtables has unflushed data backed by a prepare section in 5.log.
We should return this information via `FindMinPrepLogReferencedByMemTable()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9571
Test Plan:
```
./transaction_test --gtest_filter=*/TransactionTest.SwitchMemtableDuringPrepareAndCommit_WC/*
make check
```
Reviewed By: siying
Differential Revision: D34235236
Pulled By: riversand963
fbshipit-source-id: 120eb21a666728a38dda77b96276c6af72b008b1
Summary:
As in
```
db_stress: table/block_based/filter_policy.cc:316: rocksdb::{anonymous}::FastLocalBloomBitsBuilder::FastLocalBloomBitsBuilder(int, std::atomic<long int>*, std::shared_ptr<rocksdb::CacheReservationManager>, bool): Assertion `millibits_per_key >= 1000' failed.
```
This assertion failure was actually happening with our RibbonFilterPolicy
which falls back to Bloom for some cases, often for flush, but was
missing new special logic to skip generating filter for 0 bits per key
case. Fixed by adding the logic in other builtin FilterPolicy
implementations.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9585
Test Plan:
Updated db_bloom_filter_test to do more integration testing
of the RibbonFilterPolicy ("auto Ribbon") class, incl regression test
this with SkipFilterOnEssentiallyZeroBpk
Reviewed By: ajkr
Differential Revision: D34295101
Pulled By: pdillinger
fbshipit-source-id: 3488eb207fc1d67bbbd1301313714aa1b6406e6e
