Commit Graph

118 Commits

Author SHA1 Message Date
Jay Huh 586d78b31e Remove wait_unscheduled from waitForCompact internal API (#11443)
Summary:
Context:

In pull request https://github.com/facebook/rocksdb/issues/11436, we are introducing a new public API `waitForCompact(const WaitForCompactOptions& wait_for_compact_options)`. This API invokes the internal implementation `waitForCompact(bool wait_unscheduled=false)`. The unscheduled parameter indicates the compactions that are not yet scheduled but are required to process items in the queue.

In certain cases, we are unable to wait for compactions, such as during a shutdown or when background jobs are paused. It is important to return the appropriate status in these scenarios. For all other cases, we should wait for all compaction and flush jobs, including the unscheduled ones. The primary purpose of this new API is to wait until the system has resolved its compaction debt. Currently, the usage of `wait_unscheduled` is limited to test code.

This pull request eliminates the usage of wait_unscheduled. The internal `waitForCompact()` API now waits for unscheduled compactions unless the db is undergoing a shutdown. In the event of a shutdown, the API returns `Status::ShutdownInProgress()`.

Additionally, a new parameter, `abort_on_pause`, has been introduced with a default value of `false`. This parameter addresses the possibility of waiting indefinitely for unscheduled jobs if `PauseBackgroundWork()` was called before `waitForCompact()` is invoked. By setting `abort_on_pause` to `true`, the API will immediately return `Status::Aborted`.

Furthermore, all tests that previously called `waitForCompact(true)` have been fixed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11443

Test Plan:
Existing tests that involve a shutdown in progress:

- DBCompactionTest::CompactRangeShutdownWhileDelayed
- DBTestWithParam::PreShutdownMultipleCompaction
- DBTestWithParam::PreShutdownCompactionMiddle

Reviewed By: pdillinger

Differential Revision: D45923426

Pulled By: jaykorean

fbshipit-source-id: 7dc93fe6a6841a7d9d2d72866fa647090dba8eae
2023-05-17 18:13:50 -07:00
sdong 4720ba4391 Remove RocksDB LITE (#11147)
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.

Most of changes were done through following comments:

unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'`

by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147

Test Plan: See CI

Reviewed By: pdillinger

Differential Revision: D42796341

fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
2023-01-27 13:14:19 -08:00
Yanqin Jin 75aca74017 Replace member variable lambda with methods (#10924)
Summary:
In transaction unit tests, replace a few member variable lambdas with
non-static methods. It's easier for gdb to work with variables in methods than in lambdas.
(Seen similar things to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86675).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10924

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D41072241

Pulled By: riversand963

fbshipit-source-id: e4fa491de573c4656225a86a75af926c1df827f6
2022-11-07 12:31:48 -08:00
Yanqin Jin 0547cecb81 Reduce access to atomic variables in a test (#10909)
Summary:
With TSAN build on CircleCI (see mini-tsan in .circleci/config).
Sometimes `SeqAdvanceConcurrentTest.SeqAdvanceConcurrent` will get stuck when an experimental feature called
"unordered write" is enabled. Stack trace will be the following
```
Thread 7 (Thread 0x7f2284a1c700 (LWP 481523) "write_prepared_"):
#0  0x00000000004fa3f5 in __tsan_atomic64_load () at ./db/merge_context.h:15
https://github.com/facebook/rocksdb/issues/1  0x00000000005e5942 in std::__atomic_base<unsigned long>::load (this=0x7b74000012f8, __m=std::memory_order_seq_cst) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/atomic_base.h:481
https://github.com/facebook/rocksdb/issues/2  std::__atomic_base<unsigned long>::operator unsigned long (this=0x7b74000012f8) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/atomic_base.h:341
https://github.com/facebook/rocksdb/issues/3  0x00000000005bf001 in rocksdb::SeqAdvanceConcurrentTest_SeqAdvanceConcurrent_Test::TestBody()::$_9::operator()(void*) const (this=0x7b14000085e8) at utilities/transactions/write_prepared_transaction_test.cc:1702

Thread 6 (Thread 0x7f228421b700 (LWP 481521) "write_prepared_"):
#0  0x000000000052178c in __tsan::MetaMap::GetAndLock(__tsan::ThreadState*, unsigned long, unsigned long, bool, bool) () at ./db/merge_context.h:15
https://github.com/facebook/rocksdb/issues/1  0x00000000004fa48e in __tsan_atomic64_load () at ./db/merge_context.h:15
https://github.com/facebook/rocksdb/issues/2  0x00000000005e5942 in std::__atomic_base<unsigned long>::load (this=0x7b74000012f8, __m=std::memory_order_seq_cst) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/atomic_base.h:481
https://github.com/facebook/rocksdb/issues/3  std::__atomic_base<unsigned long>::operator unsigned long (this=0x7b74000012f8) at /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/atomic_base.h:341
https://github.com/facebook/rocksdb/issues/4  0x00000000005bf001 in rocksdb::SeqAdvanceConcurrentTest_SeqAdvanceConcurrent_Test::TestBody()::$_9::operator()(void*) const (this=0x7b14000085e8) at utilities/transactions/write_prepared_transaction_test.cc:1702
```

This is problematic and suspicious. Two threads will get stuck in the same place trying to load from an atomic variable.
https://github.com/facebook/rocksdb/blob/7.8.fb/utilities/transactions/write_prepared_transaction_test.cc#L1694:L1707. Not sure why two threads can reach the same point.

The stack trace shows that there may be a deadlock, since the two threads are on the same write thread (one is doing Prepare, while the other is trying to commit).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10909

Test Plan:
On CircleCI mini-tsan, apply a patch first so that we have a higher chance of hitting the same problematic situation,
```
 diff --git a/utilities/transactions/write_prepared_transaction_test.cc b/utilities/transactions/write_prepared_transaction_test.cc
index 4bc1f3744..bd5dc4924 100644
 --- a/utilities/transactions/write_prepared_transaction_test.cc
+++ b/utilities/transactions/write_prepared_transaction_test.cc
@@ -1714,13 +1714,13 @@ TEST_P(SeqAdvanceConcurrentTest, SeqAdvanceConcurrent) {
       size_t d = (n % base[bi + 1]) / base[bi];
       switch (d) {
         case 0:
-          threads.emplace_back(txn_t0, bi);
+          threads.emplace_back(txn_t3, bi);
           break;
         case 1:
-          threads.emplace_back(txn_t1, bi);
+          threads.emplace_back(txn_t3, bi);
           break;
         case 2:
-          threads.emplace_back(txn_t2, bi);
+          threads.emplace_back(txn_t3, bi);
           break;
         case 3:
           threads.emplace_back(txn_t3, bi);
```
then build and run tests
```
COMPILE_WITH_TSAN=1 CC=clang-13 CXX=clang++-13 ROCKSDB_DISABLE_ALIGNED_NEW=1 USE_CLANG=1 make V=1 -j32 check
gtest-parallel -r 100 ./write_prepared_transaction_test --gtest_filter=TwoWriteQueues/SeqAdvanceConcurrentTest.SeqAdvanceConcurrent/19
```
In the above, `SeqAdvanceConcurrent/19`. The tests 10 to 19 correspond to unordered write in which Prepare() and Commit() can both enter the same write thread.
Before this PR, there is a high chance of hitting the deadlock. With this PR, no deadlock has been encountered so far.

Reviewed By: ltamasi

Differential Revision: D40869387

Pulled By: riversand963

fbshipit-source-id: 81e82a70c263e4f3417597a201b081ee54f1deab
2022-11-02 14:54:58 -07:00
Yanqin Jin 95a1935cb1 Run clang-format on utilities/transactions (#10871)
Summary:
This PR is the result of running the following command
```
find ./utilities/transactions/ -name '*.cc' -o -name '*.h' -o -name '*.c' -o -name '*.hpp' -o -name '*.cpp' | xargs clang-format -i
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10871

Test Plan: make check

Reviewed By: cbi42

Differential Revision: D40686871

Pulled By: riversand963

fbshipit-source-id: 613738d667ec8f8e13cce4802e0e166d6be52211
2022-10-25 14:15:22 -07:00
Jay Zhuang fcccc412d7 Remove Travis CI (#10407)
Summary:
Travis CI is depreciated and haven't been maintained for some time.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10407

Reviewed By: ajkr

Differential Revision: D38078382

Pulled By: jay-zhuang

fbshipit-source-id: f42057f2f41f722bdce56bf195f67a94835191fb
2022-07-22 20:16:45 -07:00
sdong 736a7b5433 Remove own ToString() (#9955)
Summary:
ToString() is created as some platform doesn't support std::to_string(). However, we've already used std::to_string() by mistake for 16 months (in db/db_info_dumper.cc). This commit just remove ToString().

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9955

Test Plan: Watch CI tests

Reviewed By: riversand963

Differential Revision: D36176799

fbshipit-source-id: bdb6dcd0e3a3ab96a1ac810f5d0188f684064471
2022-05-06 13:03:58 -07:00
Yanqin Jin 2b5c29f9f3 Enforce the contract of SingleDelete (#9888)
Summary:
Enforce the contract of SingleDelete so that they are not mixed with
Delete for the same key. Otherwise, it will lead to undefined behavior.
See https://github.com/facebook/rocksdb/wiki/Single-Delete#notes.

Also fix unit tests and write-unprepared.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9888

Test Plan: make check

Reviewed By: ajkr

Differential Revision: D35837817

Pulled By: riversand963

fbshipit-source-id: acd06e4dcba8cb18df92b44ed18c57e10e5a7635
2022-04-28 14:48:27 -07:00
Yanqin Jin d13825e586 Add rollback_deletion_type_callback to TxnDBOptions (#9873)
Summary:
This PR does not affect write-committed.

Add a member, `rollback_deletion_type_callback` to TransactionDBOptions
so that a write-prepared transaction, when rolling back, can call this
callback to decide if a `Delete` or `SingleDelete` should be used to
cancel a prior `Put` written to the database during prepare phase.

The purpose of this PR is to prevent mixing `Delete` and `SingleDelete`
for the same key, causing undefined behaviors. Without this PR, the
following can happen:

```
// The application always issues SingleDelete when deleting keys.

txn1->Put('a');
txn1->Prepare(); // writes to memtable and potentially gets flushed/compacted to Lmax
txn1->Rollback();  // inserts DELETE('a')

txn2->Put('a');
txn2->Commit();  // writes to memtable and potentially gets flushed/compacted
```

In the database, we may have
```
L0:   [PUT('a', s=100)]
L1:   [DELETE('a', s=90)]
Lmax: [PUT('a', s=0)]
```

If a compaction compacts L0 and L1, then we have
```
L1:    [PUT('a', s=100)]
Lmax:  [PUT('a', s=0)]
```

If a future transaction issues a SingleDelete, we have
```
L0:    [SD('a', s=110)]
L1:    [PUT('a', s=100)]
Lmax:  [PUT('a', s=0)]
```

Then, a compaction including L0, L1 and Lmax leads to
```
Lmax:  [PUT('a', s=0)]
```

which is incorrect.

Similar bugs reported and addressed in
https://github.com/cockroachdb/pebble/issues/1255. Based on our team's
current priority, we have decided to take this approach for now. We may
come back and revisit in the future.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9873

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D35762170

Pulled By: riversand963

fbshipit-source-id: b28d56eefc786b53c9844b9ef4a7807acdd82c8d
2022-04-20 18:57:32 -07:00
Hui Xiao cd85439632 Make TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAcces less flaky (#9281)
Summary:
Context:
[Rapid thread creation and deletion](https://github.com/facebook/rocksdb/blob/6.27.fb/utilities/transactions/write_prepared_transaction_test.cc#L439-L444) in  `SnapshotConcurrentAccessTest.SnapshotConcurrentAcces` inside a [potentially big loop](https://github.com/facebook/rocksdb/blob/6.27.fb/utilities/transactions/write_prepared_transaction_test.cc#L1238-L1248) can lead to heavy-loading the system with many threads due to delay in actually cleaning up thread's resource in the kernel sometime. We ran into some [flaky failure](https://app.circleci.com/pipelines/github/facebook/rocksdb/10383/workflows/136f1005-80a9-4515-aee9-fe36ac6462a1/jobs/253289) in CI and reproduced it by below:

- Command
```
Added `ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();` like https://github.com/facebook/rocksdb/pull/9276
DEBUG_LEVEL=2 make -j56 write_prepared_transaction_test
GTEST_CATCH_EXCEPTIONS=0 ~/gtest-parallel/gtest-parallel -r 200 -w 200 ./write_prepared_transaction_test --gtest_filter=TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
```
- Stack, where `write_prepared_transaction_test.cc:442` in `https://github.com/facebook/rocksdb/issues/9` points to thread creation
```
[ RUN      ] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
....terminate called after throwing an instance of 'std::system_error'
  what():  Resource temporarily unavailable
Received signal 6 (Aborted)
#0   /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x38) [0x7fc114f39438]
...
https://github.com/facebook/rocksdb/issues/7   /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0xb8e73) [0x7fc1158a5e73] ??	??:0
https://github.com/facebook/rocksdb/issues/8   ./write_prepared_transaction_test() [0x4ca86c] std:🧵:thread<rocksdb::WritePreparedTransactionTestBase::SnapshotConcurrentAccessTestInternal(rocksdb::WritePreparedTxnDB*, std::vector<unsigned long, std::allocator<unsigned long> > const&, std::vector<unsigned long, std::allocator<unsigned long> 	 const&, rocksdb::WritePreparedTxnDB::CommitEntry&, unsigned long&, unsigned long, unsigned long, unsigned long, unsigned long)::{lambda()https://github.com/facebook/rocksdb/issues/1}>(rocksdb::WritePreparedTransactionTestBase::SnapshotConcurrentAccessTestInternal(rocksdb::WritePreparedTxnDB*, s	d::vector<unsigned long, std::allocator<unsigned long> > const&, std::vector<unsigned long, std::allocator<unsigned long> > const&, rocksdb::WritePreparedTxnDB::CommitEntry&, unsigned long&, unsigned long, unsigned long, unsigned long, unsigned long)::{l	mbda()https://github.com/facebook/rocksdb/issues/1}&&)	/usr/include/c++/5/thread:137 (discriminator 4)
https://github.com/facebook/rocksdb/issues/9   ./write_prepared_transaction_test() [0x4bb80c] rocksdb::WritePreparedTransactionTestBase::SnapshotConcurrentAccessTestInternal(rocksdb::WritePreparedTxnDB*, std::vector<unsigned long, std::allocator<unsigned long> > const&, std::vector<unsigned long, std::allocator<unsigned long> > const&, rocksdb::W	itePreparedTxnDB::CommitEntry&, unsigned long&, unsigned long, unsigned long, unsigned long, unsigned long)	/home/circleci/project/utilities/transactions/write_prepared_transaction_test.cc:442
https://github.com/facebook/rocksdb/issues/10  ./write_prepared_transaction_test() [0x4407b6] rocksdb::SnapshotConcurrentAccessTest_SnapshotConcurrentAccess_Test::TestBody()	/home/circleci/project/utilities/transactions/write_prepared_transaction_test.cc:1244
...
[109/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1 returned/aborted with exit code -6 (34462 ms)
```

- Move thread 2's work into current thread to avoid half of the thread creation cuz there is no difference in doing so. We expect this can make the thread-creation error less often, even though we can't gurantee it from happening again. Considering this is a trivial change with positive impact, it's still worth landing and monitor if it's enough to solve the problem in reality.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9281

Test Plan:
Before the change, repeating the test 200 times with 200 workers failed
`~/gtest-parallel/gtest-parallel -r 200 -w 200 ./write_prepared_transaction_test --gtest_filter=TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1`

```
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from TwoWriteQueues/SnapshotConcurrentAccessTest
[ RUN      ] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
..unknown file: Failure
C++ exception with description "Resource temporarily unavailable" thrown in the test body.
[  FAILED  ] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1, where GetParam() = (false, true, 1, 0, 1, 20) (11882 ms)
[----------] 1 test from TwoWriteQueues/SnapshotConcurrentAccessTest (11882 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (11882 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1, where GetParam() = (false, true, 1, 0, 1, 20)
```

After the change: repeating the test 200 times with 200 workers didn't fail, even with repeating the "repeating" for 10 times like below
`for i in {1..10}; do ~/gtest-parallel/gtest-parallel -r 200 -w 200 ./write_prepared_transaction_test --gtest_filter=TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1; done`

```
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[200/200] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
```

It does failed when repeating the test 400 times with 400 workers
`~/project$ ~/gtest-parallel/gtest-parallel -r 400 -w 400 ./write_prepared_transaction_test --gtest_filter=TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1`

```
[1/400] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1 (2928 ms)
Note: Google Test filter = TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from TwoWriteQueues/SnapshotConcurrentAccessTest
[ RUN      ] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1
unknown file: Failure
C++ exception with description "std::bad_alloc" thrown in the test body.
[  FAILED  ] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/1, where GetParam() = (false, true, 1, 0, 1, 20) (2597 ms)
[----------] 1 test from TwoWriteQueues/SnapshotConcurrentAccessTest (2597 ms total)
```

Reviewed By: ajkr

Differential Revision: D33026776

Pulled By: hx235

fbshipit-source-id: 509f57126392821e835e48396e5bf224f4f5dcac
2021-12-10 12:52:33 -08:00
Peter Dillinger aec95b8c09 Debug "Resource temporarily unavailable" exception in CircleCI (#9276)
Summary:
This changes write_prepared_transaction_test under CircleCI to
print a stack trace on unhandled exception, so that we can debug rare
exceptions seen in CircleCI:

    [ RUN      ] TwoWriteQueues/SnapshotConcurrentAccessTest.SnapshotConcurrentAccess/24
    .......unknown file: Failure
    C++ exception with description "Resource temporarily unavailable" thrown in the test body.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9276

Test Plan:
manual run test with seeded 'throw', with and without
CIRCLECI=true environment variable

Reviewed By: ajkr, hx235

Differential Revision: D32996993

Pulled By: pdillinger

fbshipit-source-id: e790408ce204b676d3d84a290e41be511b203bfa
2021-12-09 12:58:46 -08:00
Yanqin Jin 5237b39d2e Fix assertion error during compaction with write-prepared txn enabled (#9105)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9105

The user contract of SingleDelete is that: a SingleDelete can only be issued to
a key that exists and has NOT been updated. For example, application can insert
one key `key`, and uses a SingleDelete to delete it in the future. The `key`
cannot be updated or removed using Delete.
In reality, especially when write-prepared transaction is being used, things
can get tricky. For example, a prepared transaction already writes `key` to the
memtable after a successful Prepare(). Afterwards, should the transaction
rollback, it will insert a Delete into the memtable to cancel out the prior
Put. Consider the following sequence of operations.

```
// operation sequence 1
Begin txn
Put(key)
Prepare()
Flush()

Rollback txn
Flush()
```

There will be two SSTs resulting from above. One of the contains a PUT, while
the second one contains a Delete. It is also known that releasing a snapshot
can lead to an L0 containing only a SD for a particular key. Consider the
following operations following the above block.

```
// operation sequence 2
db->Put(key)
db->SingleDelete(key)
Flush()
```

The operation sequence 2 can result in an L0 with only the SD.

Should there be a snapshot for conflict checking created before operation
sequence 1, then an attempt to compact the db may hit the assertion failure
below, because ikey_.type is Delete (from a rollback).

```
else if (clear_and_output_next_key_) {
  assert(ikey_.type == kTypeValue || ikey_.type == kTypeBlobIndex);
}
```

To fix the assertion failure, we can skip the SingleDelete if we detect an
earlier Delete in the same snapshot interval.

Reviewed By: ltamasi

Differential Revision: D32056848

fbshipit-source-id: 23620a91e28562d91c45cf7e95f414b54b729748
2021-11-05 15:29:18 -07:00
Yanqin Jin 9b53f14a35 Fixed a bug in CompactionIterator when write-preared transaction is used (#9060)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9060

RocksDB bottommost level compaction may zero out an internal key's sequence if
the key's sequence is in the earliest_snapshot.
In write-prepared transaction, checking the visibility of a certain sequence in
a specific released snapshot may return a "snapshot released" result.
Therefore, it is possible, after a certain sequence of events, a PUT has its
sequence zeroed out, but a subsequent SingleDelete of the same key will still
be output with its original sequence. This violates the ascending order of
keys and leads to incorrect result.

The solution is to use an extra variable `last_key_seq_zeroed_` to track the
information about visibility in earliest snapshot. With this variable, we can
know for sure that a SingleDelete is in the earliest snapshot even if the said
snapshot is released during compaction before processing the SD.

Reviewed By: ltamasi

Differential Revision: D31813016

fbshipit-source-id: d8cff59d6f34e0bdf282614034aaea99be9174e1
2021-11-03 15:55:00 -07:00
Yanqin Jin fdf2a0d7eb Fix a compaction bug for write-prepared txn (#9061)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9061

In write-prepared txn, checking a sequence's visibility in a released (old)
snapshot may return "Snapshot released". Suppose we have two snapshots:

```
earliest_snap < earliest_write_conflict_snap
```

If we release `earliest_write_conflict_snap` but keep `earliest_snap` during
bottommost level compaction, then it is possible that certain sequence of
events can lead to a PUT being seq-zeroed followed by a SingleDelete of the
same key. This violates the ascending order of keys, and will cause data
inconsistency.

Reviewed By: ltamasi

Differential Revision: D31813017

fbshipit-source-id: dc68ba2541d1228489b93cf3edda5f37ed06f285
2021-10-29 15:23:17 -07:00
Yanqin Jin 2b367fa8cc Fix bug caused by releasing snapshot(s) during compaction (#8608)
Summary:
In debug mode, we are seeing assertion failure as follows

```
db/compaction/compaction_iterator.cc:980: void rocksdb::CompactionIterator::PrepareOutput(): \
Assertion `ikey_.type != kTypeDeletion && ikey_.type != kTypeSingleDeletion' failed.
```

It is caused by releasing earliest snapshot during compaction between the execution of
`NextFromInput()` and `PrepareOutput()`.

In one case, as demonstrated in unit test `WritePreparedTransaction.ReleaseEarliestSnapshotDuringCompaction_WithSD2`,
incorrect result may be returned by a following range scan if we disable assertion, as in opt compilation
level: the SingleDelete marker's sequence number is zeroed out, but the preceding PUT is also
outputted to the SST file after compaction. Due to the logic of DBIter, the PUT will not be
skipped and will be returned by iterator in range scan. https://github.com/facebook/rocksdb/issues/8661 illustrates what happened.

Fix by taking a more conservative approach: make compaction zero out sequence number only
if key is in the earliest snapshot when the compaction starts.

Another assertion failure is
```
Assertion `current_user_key_snapshot_ == last_snapshot' failed.
```

It's caused by releasing the snapshot between the PUT and SingleDelete during compaction.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8608

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D30145645

Pulled By: riversand963

fbshipit-source-id: 699f58e66faf70732ad53810ccef43935d3bbe81
2021-08-17 22:14:20 -07:00
Andrew Kryczka ed8eb436db Move slow valgrind tests behind -DROCKSDB_FULL_VALGRIND_RUN (#8475)
Summary:
Various tests had disabled valgrind due to it slowing down and timing
out (as is the case right now) the CI runs. Where a test was disabled with no comment,
I assumed slowness was the cause. For these tests that were slow under
valgrind, as well as the ones identified in https://github.com/facebook/rocksdb/issues/8352, this PR moves them
behind the compiler flag `-DROCKSDB_FULL_VALGRIND_RUN`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8475

Test Plan: running `make full_valgrind_test`, `make valgrind_test`, `make check`; will verify they appear working correctly

Reviewed By: jay-zhuang

Differential Revision: D29504843

Pulled By: ajkr

fbshipit-source-id: 2aac90749cfbd30d5ce11cb29a07a1b9314eeea7
2021-07-07 11:14:05 -07:00
Jay Zhuang f89423a57a Revert "Revert "Snapshot release triggered compaction without multiple tombstones (#8357)" (#8410)" (#8438)
Summary:
This reverts commit 25be1ed66a.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8438

Test Plan: Run the impacted mysql test 40 times

Reviewed By: ajkr

Differential Revision: D29286247

Pulled By: jay-zhuang

fbshipit-source-id: d3bd056971a19a8b012d5d0295fa045c012b3c04
2021-06-22 11:10:03 -07:00
Andrew Kryczka 25be1ed66a Revert "Snapshot release triggered compaction without multiple tombstones (#8357)" (#8410)
Summary:
This reverts commit 9167ece586.

It was found to reliably trip a compaction picking conflict assertion in a MyRocks unit test. We don't understand why yet so reverting in the meantime.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8410

Test Plan: `make check -j48`

Reviewed By: jay-zhuang

Differential Revision: D29150300

Pulled By: ajkr

fbshipit-source-id: 2de8664f355d6da015e84e5fec2e3f90f49741c8
2021-06-15 18:15:15 -07:00
Andrew Kryczka 9167ece586 Snapshot release triggered compaction without multiple tombstones (#8357)
Summary:
This is a duplicate of https://github.com/facebook/rocksdb/issues/4948 by mzhaom to fix tests after rebase.

This change is a follow-up to https://github.com/facebook/rocksdb/issues/4927, which made this possible by allowing tombstone dropping/seqnum zeroing optimizations on the last key in the compaction. Now the `largest_seqno != 0` condition suffices to prevent snapshot release triggered compaction from entering an infinite loop.

The issues caused by the extraneous condition `level_and_file.second->num_deletions > 1` are:

- files could have `largest_seqno > 0` forever making it impossible to tell they cannot contain any covering keys
- it doesn't trigger compaction when there are many overwritten keys. Some MyRocks use case actually doesn't use Delete but instead calls Put with empty value to "delete" keys, so we'd like to be able to trigger compaction in this case too.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8357

Test Plan: - make check

Reviewed By: jay-zhuang

Differential Revision: D28855340

Pulled By: ajkr

fbshipit-source-id: a261b51eecafec492499e6d01e8e43112f801798
2021-06-04 00:21:40 -07:00
Adam Retter 8ff6557e7f Add further tests to ASSERT_STATUS_CHECKED (2) (#7698)
Summary:
Second batch of adding more tests to ASSERT_STATUS_CHECKED.

* external_sst_file_basic_test
* checkpoint_test
* db_wal_test
* db_block_cache_test
* db_logical_block_size_cache_test
* db_blob_index_test
* optimistic_transaction_test
* transaction_test
* point_lock_manager_test
* write_prepared_transaction_test
* write_unprepared_transaction_test

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7698

Reviewed By: cheng-chang

Differential Revision: D25441664

Pulled By: pdillinger

fbshipit-source-id: 9e78867f32321db5d4833e95eb96c5734526ef00
2020-12-09 21:21:16 -08:00
sdong 5aacef9712 Disable fsync in SeqAdvanceConcurrentTest (#7302)
Summary:
SeqAdvanceConcurrentTest sometimes runs too long on some platforms. Disable fsync to speed it up.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7302

Test Plan: Run the tests and watch CI.

Reviewed By: ajkr

Differential Revision: D23298192

fbshipit-source-id: 2185eed4e0958c3de5e8a3f94ceed5be5945ed37
2020-08-24 13:22:06 -07:00
mrambacher c7c7b07f06 More Makefile Cleanup (#7097)
Summary:
Cleans up some of the dependencies on test code in the Makefile while building tools:
- Moves the test::RandomString, DBBaseTest::RandomString into Random
- Moves the test::RandomHumanReadableString into Random
- Moves the DestroyDir method into file_utils
- Moves the SetupSyncPointsToMockDirectIO into sync_point.
- Moves the FaultInjection Env and FS classes under env

These changes allow all of the tools to build without dependencies on test_util, thereby simplifying the build dependencies.  By moving the FaultInjection code, the dependency in db_stress on different libraries for debug vs release was eliminated.

Tested both release and debug builds via Make and CMake for both static and shared libraries.

More work remains to clean up how the tools are built and remove some unnecessary dependencies.  There is also more work that should be done to get the Makefile and CMake to align in their builds -- what is in the libraries and the sizes of the executables are different.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7097

Reviewed By: riversand963

Differential Revision: D22463160

Pulled By: pdillinger

fbshipit-source-id: e19462b53324ab3f0b7c72459dbc73165cc382b2
2020-07-09 14:35:17 -07:00
Jay Zhuang 00de699096 Replace reinterpret_cast with static_cast_with_check (#7067)
Summary:
Replace `reinterpret_cast` with `static_cast_with_check` for `DBImpl` and `ColumnFamilyHandleImpl`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7067

Reviewed By: siying

Differential Revision: D22361587

Pulled By: jay-zhuang

fbshipit-source-id: dfe9e8f3af39c3d27cc372c55ab9ad905eb0a5a1
2020-07-02 19:25:41 -07:00
sdong afa3518839 Revert "Update googletest from 1.8.1 to 1.10.0 (#6808)" (#6923)
Summary:
This reverts commit 8d87e9cea1.

Based on offline discussions, it's too early to upgrade to gtest 1.10, as it prevents some developers from using an older version of gtest to integrate to some other systems. Revert it for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6923

Reviewed By: pdillinger

Differential Revision: D21864799

fbshipit-source-id: d0726b1ff649fc911b9378f1763316200bd363fc
2020-06-03 15:55:03 -07:00
Zhichao Cao 2adb7e3768 Fix potential overflow of unsigned type in for loop (#6902)
Summary:
x.size() -1 or y - 1 can overflow to an extremely large value when x.size() pr y is 0 when they are unsigned type. The end condition of i in the for loop will be extremely large, potentially causes segment fault. Fix them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6902

Test Plan: pass make asan_check

Reviewed By: ajkr

Differential Revision: D21843767

Pulled By: zhichao-cao

fbshipit-source-id: 5b8b88155ac5a93d86246d832e89905a783bb5a1
2020-06-02 15:05:07 -07:00
Adam Retter 8d87e9cea1 Update googletest from 1.8.1 to 1.10.0 (#6808)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6808

Reviewed By: anand1976

Differential Revision: D21483984

Pulled By: pdillinger

fbshipit-source-id: 70c5eff2bd54ddba469761d95e4cd4611fb8e598
2020-06-01 20:33:42 -07:00
sdong fdf882ded2 Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433

Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.

Differential Revision: D19977691

fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
2020-02-20 12:09:57 -08:00
Yanqin Jin f2fbc5d668 Shorten certain test names to avoid infra failure (#6352)
Summary:
Unit test names, together with other components,  are used to create log files
during some internal testing. Overly long names cause infra failure due to file
names being too long.

Look for internal tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6352

Differential Revision: D19649307

Pulled By: riversand963

fbshipit-source-id: 6f29de096e33c0eaa87d9c8702f810eda50059e7
2020-01-30 23:10:24 -08:00
Maysam Yabandeh 0058daef7b Disable SmallestUnCommittedSeq in Valgrind run (#6035)
Summary:
SmallestUnCommittedSeq sometimes takes too long when run under Valgrind. The patch disables it when the tests are run under Valgrind.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6035

Differential Revision: D18509198

Pulled By: maysamyabandeh

fbshipit-source-id: 1191443b9fedb6b9c50d6b76f5c92371f5030230
2019-11-14 14:41:52 -08:00
Maysam Yabandeh 52733b4498 WritePrepared: Fix flaky test MaxCatchupWithNewSnapshot (#5850)
Summary:
MaxCatchupWithNewSnapshot tests that the snapshot sequence number will be larger than the max sequence number when the snapshot was taken. However since the test does not have access to the max sequence number when the snapshot was taken, it uses max sequence number after that, which could have advanced the snapshot by then, thus making the test flaky.
The fix is to compare with max sequence number before the snapshot was taken, which is a lower bound for the value when the snapshot was taken.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5850

Test Plan: ~/gtest-parallel/gtest-parallel --repeat=12800 ./write_prepared_transaction_test --gtest_filter="*MaxCatchupWithNewSnapshot*"

Differential Revision: D17608926

Pulled By: maysamyabandeh

fbshipit-source-id: b122ae5a27f982b290bd60da852e28d3c5eb0136
2019-11-04 16:23:57 -08:00
Peter Dillinger ca7ccbe2ea Misc hashing updates / upgrades (#5909)
Summary:
- Updated our included xxhash implementation to version 0.7.2 (== the latest dev version as of 2019-10-09).
- Using XXH_NAMESPACE (like other fb projects) to avoid potential name collisions.
- Added fastrange64, and unit tests for it and fastrange32. These are faster alternatives to hash % range.
- Use preview version of XXH3 instead of MurmurHash64A for NPHash64
-- Had to update cache_test to increase probability of passing for any given hash function.
- Use fastrange64 instead of % with uses of NPHash64
-- Had to fix WritePreparedTransactionTest.CommitOfDelayedPrepared to avoid deadlock apparently caused by new hash collision.
- Set default seed for NPHash64 because specifying a seed rarely makes sense for it.
- Removed unnecessary include xxhash.h in a popular .h file
- Rename preview version of XXH3 to XXH3p for clarity and to ease backward compatibility in case final version of XXH3 is integrated.

Relying on existing unit tests for NPHash64-related changes. Each new implementation of fastrange64 passed unit tests when manipulating my local build to select it. I haven't done any integration performance tests, but I consider the improved performance of the pieces being swapped in to be well established.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5909

Differential Revision: D18125196

Pulled By: pdillinger

fbshipit-source-id: f6bf83d49d20cbb2549926adf454fd035f0ecc0d
2019-10-24 17:16:46 -07:00
sdong e8263dbdaa Apply formatter to recent 200+ commits. (#5830)
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
2019-09-20 12:04:26 -07:00
Manuel Ung 6f0f82de87 WriteUnPrepared: increase test coverage in transaction_test (#5658)
Summary:
The changes transaction_test to set `txn_db_options.default_write_batch_flush_threshold = 1` in order to give better test coverage for WriteUnprepared.

As part of the change, some tests had to be updated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5658

Differential Revision: D16740468

Pulled By: lth

fbshipit-source-id: 3821eec20baf13917c8c1fab444332f75a509de9
2019-08-12 12:16:04 -07:00
Maysam Yabandeh 12eaacb71d WritePrepared: Fix SmallestUnCommittedSeq bug (#5683)
Summary:
SmallestUnCommittedSeq reads two data structures, prepared_txns_ and delayed_prepared_. These two are updated in CheckPreparedAgainstMax when max_evicted_seq_ advances some prepared entires. To avoid the cost of acquiring a mutex, the read from them in SmallestUnCommittedSeq is not atomic. This creates a potential race condition.
The fix is to read the two data structures in the reverse order of their update. CheckPreparedAgainstMax copies the prepared entry to delayed_prepared_ before removing it from prepared_txns_ and SmallestUnCommittedSeq looks into prepared_txns_ before reading delayed_prepared_.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5683

Differential Revision: D16744699

Pulled By: maysamyabandeh

fbshipit-source-id: b1bdb134018beb0b9de58827f512662bea35cad0
2019-08-09 16:40:00 -07:00
Maysam Yabandeh 208556ee13 WritePrepared: fix Get without snapshot (#5664)
Summary:
if read_options.snapshot is not set, ::Get will take the last sequence number after taking a super-version and uses that as the sequence number. Theoretically max_eviceted_seq_ could advance this sequence number. This could lead ::IsInSnapshot that will be invoked by the ReadCallback to notice the absence of the snapshot. In this case, the ReadCallback should have passed a non-value to snap_released so that it could be set by the ::IsInSnapshot. The patch does that, and adds a unit test to verify it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5664

Differential Revision: D16614033

Pulled By: maysamyabandeh

fbshipit-source-id: 06fb3fd4aacd75806ed1a1acec7961f5d02486f2
2019-08-05 13:41:21 -07:00
Maysam Yabandeh 60f3ec2ca5 Fix appveyor compliant about passing const to thread (#5447)
Summary:
CLANG would complain if we pass const to lambda function and appveyor complains if we don't (https://github.com/facebook/rocksdb/pull/5443). The patch fixes that by using the default capture mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5447

Differential Revision: D15788722

Pulled By: maysamyabandeh

fbshipit-source-id: 47e7f49264afe31fdafe42cb8bf93da126abfca9
2019-06-12 15:06:22 -07:00
Maysam Yabandeh 4a285d0dd3 Remove passing const variable to thread (#5443)
Summary:
CLANG complains that passing const to thread is not necessary. The patch removes it form PreparedHeap::Concurrent test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5443

Differential Revision: D15781598

Pulled By: maysamyabandeh

fbshipit-source-id: 3aceb05d96182fa4726d6d37eed45fd3aac4c016
2019-06-12 09:45:57 -07:00
Maysam Yabandeh 773f914a40 WritePrepared: switch PreparedHeap from priority_queue to deque (#5436)
Summary:
Internally PreparedHeap is currently using a priority_queue. The rationale was the in the initial design PreparedHeap::AddPrepared could be called in arbitrary order. With the recent optimizations, we call ::AddPrepared only from the main write queue, which results into in-order insertion into PreparedHeap. The patch thus replaces the underlying priority_queue with a more efficient deque implementation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5436

Differential Revision: D15752147

Pulled By: maysamyabandeh

fbshipit-source-id: e6960f2b2097e13137dded1ceeff3b10b03b0aeb
2019-06-11 19:55:14 -07:00
sdong 58c4aee42e TransactionUtil::CheckKey() to skip unnecessary history (#4941)
Summary:
If a memtable definitely covers a key, there isn't a need to check older memtables.
We can skip them by checking the earliest sequence number.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4941

Differential Revision: D13932666

fbshipit-source-id: b9d52f234b8ad9dd3bf6547645cd457175a3ca9b
2019-06-11 11:46:42 -07:00
Maysam Yabandeh c292dc8540 WritePrepared: reduce prepared_mutex_ overhead (#5420)
Summary:
The patch reduces the contention over prepared_mutex_ using these techniques:
1) Move ::RemovePrepared() to be called from the commit callback when we have two write queues.
2) Use two separate mutex for PreparedHeap, one prepared_mutex_ needed for ::RemovePrepared, and one ::push_pop_mutex() needed for ::AddPrepared(). Given that we call ::AddPrepared only from the first write queue and ::RemovePrepared mostly from the 2nd, this will result into each the two write queues not competing with each other over a single mutex. ::RemovePrepared might occasionally need to acquire ::push_pop_mutex() if ::erase() ends up with calling ::pop()
3) Acquire ::push_pop_mutex() on the first callback of the write queue and release it on the last.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5420

Differential Revision: D15741985

Pulled By: maysamyabandeh

fbshipit-source-id: 84ce8016007e88bb6e10da5760ba1f0d26347735
2019-06-10 11:53:31 -07:00
Zhongyi Xie d68f9f4580 simplify include directive involving inttypes (#5402)
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
2019-06-06 13:56:07 -07:00
Vijay Nadimpalli 49c5a12dbe Organizing rocksdb/db directory
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5390

Differential Revision: D15579388

Pulled By: vjnadimpalli

fbshipit-source-id: 5bfc95e31554b8ff05b97b76d6534113f527f366
2019-05-31 11:57:01 -07:00
Siying Dong 8843129ece Move some memory related files from util/ to memory/ (#5382)
Summary:
Move arena, allocator, and memory tools under util to a separate memory/ directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5382

Differential Revision: D15564655

Pulled By: siying

fbshipit-source-id: 9cd6b5d0d3d52b39606e19221fa154596e5852a5
2019-05-30 17:44:09 -07:00
Siying Dong e9e0101ca4 Move test related files under util/ to test_util/ (#5377)
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377

Differential Revision: D15551366

Pulled By: siying

fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
2019-05-30 11:25:51 -07:00
Maysam Yabandeh f5576c3317 WritePrepared: disableWAL in commit without prepare (#5327)
Summary:
When committing a transaction without prepare, WritePrepared simply writes the batch to db and add the commit entry to CommitCache. When two_write_queues=true, following the rule of committing only from 2nd write queue, the first write, writes the batch and the only thing the 2nd write does is to write the commit entry to CommitCache. Currently the write batch in 2nd write is set to an empty LogData entry, while the write to the WAL could simply be entirely disabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5327

Differential Revision: D15424546

Pulled By: maysamyabandeh

fbshipit-source-id: 3d9ea3922d5196984c584d62a3ed57e1f7ca7b9f
2019-05-28 14:21:52 -07:00
Maysam Yabandeh 5c0e304170 WritePrepared: Clarify the need for two_write_queues in unordered_write (#5313)
Summary:
WritePrepared transactions when configured with two_write_queues=true offers higher throughput with unordered_write feature without however compromising the rocksdb guarantees. This is because it performs ordering among writes in a 2nd step that is not tied to memtable write speed. The 2nd step is naturally provided by 2PC when the commit phase does the ordering as well. Without 2PC, the 2nd step would only be provided when we use two_write_queues=true, where WritePrepared after performing the writes, in a 2nd step uses the 2nd queue to assign order to the writes.
The patch clarifies the need for two_write_queues=true in the HISTORY and inline comments of unordered_writes. Moreover it extends the stress tests of WritePrepared to unordred_write.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5313

Differential Revision: D15379977

Pulled By: maysamyabandeh

fbshipit-source-id: 5b6f05b9b59285dcbf3b0532215ba9fe7d926e00
2019-05-20 07:49:20 -07:00
Thomas Fersch a42757607d Use pre-increment instead of post-increment for iterators (#5296)
Summary:
Google C++ style guide indicates pre-increment should be used for iterators: https://google.github.io/styleguide/cppguide.html#Preincrement_and_Predecrement. Replaced all instances of ' it++' by ' ++it' (where type is iterator). So this covers the cases where iterators are named 'it'.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5296

Differential Revision: D15301256

Pulled By: tfersch

fbshipit-source-id: 2803483c1392504ad3b281d21db615429c71114b
2019-05-15 13:19:15 -07:00
Maysam Yabandeh f383641a1d Unordered Writes (#5218)
Summary:
Performing unordered writes in rocksdb when unordered_write option is set to true. When enabled the writes to memtable are done without joining any write thread. This offers much higher write throughput since the upcoming writes would not have to wait for the slowest memtable write to finish. The tradeoff is that the writes visible to a snapshot might change over time. If the application cannot tolerate that, it should implement its own mechanisms to work around that. Using TransactionDB with WRITE_PREPARED write policy is one way to achieve that. Doing so increases the max throughput by 2.2x without however compromising the snapshot guarantees.
The patch is prepared based on an original by siying
Existing unit tests are extended to include unordered_write option.

Benchmark Results:
```
TEST_TMPDIR=/dev/shm/ ./db_bench_unordered --benchmarks=fillrandom --threads=32 --num=10000000 -max_write_buffer_number=16 --max_background_jobs=64 --batch_size=8 --writes=3000000 -level0_file_num_compaction_trigger=99999 --level0_slowdown_writes_trigger=99999 --level0_stop_writes_trigger=99999 -enable_pipelined_write=false -disable_auto_compactions  --unordered_write=1
```
With WAL
- Vanilla RocksDB: 78.6 MB/s
- WRITER_PREPARED with unordered_write: 177.8 MB/s (2.2x)
- unordered_write: 368.9 MB/s (4.7x with relaxed snapshot guarantees)

Without WAL
- Vanilla RocksDB: 111.3 MB/s
- WRITER_PREPARED with unordered_write: 259.3 MB/s MB/s (2.3x)
- unordered_write: 645.6 MB/s (5.8x with relaxed snapshot guarantees)

- WRITER_PREPARED with unordered_write disable concurrency control: 185.3 MB/s MB/s (2.35x)

Limitations:
- The feature is not yet extended to `max_successive_merges` > 0. The feature is also incompatible with `enable_pipelined_write` = true as well as with `allow_concurrent_memtable_write` = false.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5218

Differential Revision: D15219029

Pulled By: maysamyabandeh

fbshipit-source-id: 38f2abc4af8780148c6128acdba2b3227bc81759
2019-05-13 17:47:21 -07:00
Maysam Yabandeh fe642cbee6 WritePrepared: fix race condition in reading batch with duplicate keys (#5147)
Summary:
When ReadOption doesn't specify a snapshot, WritePrepared::Get used kMaxSequenceNumber to avoid the cost of creating a new snapshot object (that requires sync over db_mutex). This creates a race condition if it is reading from the writes of a transaction that had duplicate keys: each instance of duplicate key is inserted with a different sequence number and depending on the ordering the ::Get might skip the newer one and read the older one that is obsolete.
The patch fixes that by using last published seq as the snapshot sequence number. It also adds a check after the read is done to ensure that the max_evicted_seq has not advanced the aforementioned seq, which is a very unlikely event. If it did, then the read is not valid since the seq is not backed by an actually snapshot to let IsInSnapshot handle that properly when an overlapping commit is evicted from commit cache.
A unit  test is added to reproduce the race condition with duplicate keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5147

Differential Revision: D14758815

Pulled By: maysamyabandeh

fbshipit-source-id: a56915657132cf6ba5e3f5ea1b5d78c803407719
2019-04-12 14:40:41 -07:00
Maysam Yabandeh 14b3f683a1 WriteUnPrepared: less virtual in iterator callback (#5049)
Summary:
WriteUnPrepared adds a virtual function, MaxUnpreparedSequenceNumber, to ReadCallback, which returns 0 unless WriteUnPrepared is enabled and the transaction has uncommitted data written to the DB. Together with snapshot sequence number, this determines the last sequence that is visible to reads.
The patch clarifies the guarantees of the GetIterator API in WriteUnPrepared transactions and make use of that to statically initialize the read callback and thus avoid the virtual call.
Furthermore it increases the minimum value for min_uncommitted from 0 to 1 as seq 0 is used only for last level keys that are committed in all snapshots.

The following benchmark shows +0.26% higher throughput in seekrandom benchmark.

Benchmark:
./db_bench --benchmarks=fillrandom --use_existing_db=0 --num=1000000 --db=/dev/shm/dbbench

./db_bench --benchmarks=seekrandom[X10] --use_existing_db=1 --db=/dev/shm/dbbench --num=1000000 --duration=60 --seek_nexts=100
seekrandom [AVG    10 runs] : 20355 ops/sec;  225.2 MB/sec
seekrandom [MEDIAN 10 runs] : 20425 ops/sec;  225.9 MB/sec

./db_bench_lessvirtual3 --benchmarks=seekrandom[X10] --use_existing_db=1 --db=/dev/shm/dbbench --num=1000000 --duration=60 --seek_nexts=100
seekrandom [AVG    10 runs] : 20409 ops/sec;  225.8 MB/sec
seekrandom [MEDIAN 10 runs] : 20487 ops/sec;  226.6 MB/sec
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5049

Differential Revision: D14366459

Pulled By: maysamyabandeh

fbshipit-source-id: ebaff8908332a5ae9af7defeadabcb624be660ef
2019-04-02 14:47:16 -07:00