Summary:
The last key may hit index of out bound exception when id = 9.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6574
Reviewed By: riversand963
Differential Revision: D20699791
Pulled By: cheng-chang
fbshipit-source-id: 8e2c5be5ff0e53e9857cfd59cea97cff21446819
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
Summary:
For write unprepared, some applications may bypass the transaction api, and write keys directly into the write batch. However, since they are not tracked, rollbacks (both for savepoint and transaction) are not aware that these keys have to be rolled back.
The fix is to track them in `WriteUnpreparedTxn::untracked_keys_`. This is populated whenever we flush unprepared batches into the DB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6404
Differential Revision: D19842023
Pulled By: lth
fbshipit-source-id: a9edfc643d5c905fc89da9a9a9094d30c9b70108
Summary:
ReadYourOwnWriteStress occasionally times out on some platforms. The patch splits it to three.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5776
Differential Revision: D17231743
Pulled By: maysamyabandeh
fbshipit-source-id: d42eeaf22f61a48d50f9c404d98b1081ae8dac94
Summary:
Fix a bug in write unprepared savepoints. When flushing the write batch according to savepoint boundaries, we were forgetting to flush the last write batch after the last savepoint, meaning that some data was not written to DB.
Also, add a small optimization where we avoid flushing empty batches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5703
Differential Revision: D16811996
Pulled By: lth
fbshipit-source-id: 600c7e0e520ad7a8fad32d77e11d932453e68e3f
Summary:
In MyRocks, there are cases where we write while iterating through keys. This currently breaks WBWIIterator, because if a write batch flushes during iteration, the delta iterator would point to invalid memory.
For now, fix by disallowing flush if there are active iterators. In the future, we will loop through all the iterators on a transaction, and refresh the iterators when a write batch is flushed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5699
Differential Revision: D16794157
Pulled By: lth
fbshipit-source-id: 5d5bf70688bd68fe58e8a766475ae88fd1be3190
Summary:
Currently, if a write is done without a snapshot, then `largest_validated_seq_` is set to `kMaxSequenceNumber`. This is too aggressive, because an iterator with a snapshot created after this write should be valid.
Set `largest_validated_seq_` to `GetLastPublishedSequence` instead. The variable means that no keys in the current tracked key set has changed by other transactions since `largest_validated_seq_`.
Also, do some extra cleanup in Clear() for safety.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5697
Differential Revision: D16788613
Pulled By: lth
fbshipit-source-id: f2aa40b8b12e0c0cf9e38c940fecc8f1cc0d2385
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
Summary:
It sometimes times out when run under valgrind taking around 20m. The patch skips the test under Valgrind.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5671
Differential Revision: D16652382
Pulled By: maysamyabandeh
fbshipit-source-id: 0f6f4f76d37337d56226b689e01b14523dd07aae
Summary:
Instead of reusing `TransactionOptions::max_write_batch_size` for determining when to flush a write batch for write unprepared, add a new variable called `write_batch_flush_threshold` for this use case instead.
Also add `TransactionDBOptions::default_write_batch_flush_threshold` which sets the default value if `TransactionOptions::write_batch_flush_threshold` is unspecified.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5633
Differential Revision: D16520364
Pulled By: lth
fbshipit-source-id: d75ae5a2141ce7708982d5069dc3f0b58d250e8c
Summary:
There are a number of fixes in this PR (with most bugs found via the added stress tests):
1. Re-enable reseek optimization. This was initially disabled to avoid infinite loops in https://github.com/facebook/rocksdb/pull/3955 but this can be resolved by remembering not to reseek after a reseek has already been done. This problem only affects forward iteration in `DBIter::FindNextUserEntryInternal`, as we already disable reseeking in `DBIter::FindValueForCurrentKeyUsingSeek`.
2. Verify that ReadOption.snapshot can be safely used for iterator creation. Some snapshots would not give correct results because snaphsot validation would not be enforced, breaking some assumptions in Prev() iteration.
3. In the non-snapshot Get() case, reads done at `LastPublishedSequence` may not be enough, because unprepared sequence numbers are not published. Use `std::max(published_seq, max_visible_seq)` to do lookups instead.
4. Add stress test to test reading own writes.
5. Minor bug in the allow_concurrent_memtable_write case where we forgot to pass in batch_per_txn_.
6. Minor performance optimization in `CalcMaxUnpreparedSequenceNumber` by assigning by reference instead of value.
7. Add some more comments everywhere.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5573
Differential Revision: D16276089
Pulled By: lth
fbshipit-source-id: 18029c944eb427a90a87dee76ac1b23f37ec1ccb
Summary:
When using `PRIu64` type of printf specifier, current code base does the following:
```
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
```
However, this can be simplified to
```
#include <cinttypes>
```
as long as flag `-std=c++11` is used.
This should solve issues like https://github.com/facebook/rocksdb/issues/5159
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5402
Differential Revision: D15701195
Pulled By: miasantreble
fbshipit-source-id: 6dac0a05f52aadb55e9728038599d3d2e4b59d03
Summary:
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
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
Summary:
This adds support for writing unprepared batches based on size defined in `TransactionOptions::max_write_batch_size`. This is done by overriding methods that modify data (Put/Delete/SingleDelete/Merge) and checking first if write batch size has exceeded threshold. If so, the write batch is written to DB as an unprepared batch.
Support for Commit/Rollback for unprepared batch is added as well. This has been done by simply extending the WritePrepared Commit/Rollback logic to take care of all unprep_seq numbers either when updating prepare heap, or adding to commit map. For updating the commit map, this logic exists inside `WriteUnpreparedCommitEntryPreReleaseCallback`.
A test change was also made to have transactions unregister themselves when committing without prepare. This is because with write unprepared, there may be unprepared entries (which act similarly to prepared entries) already when a commit is done without prepare.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4104
Differential Revision: D8785717
Pulled By: lth
fbshipit-source-id: c02006e281ec1ce00f628e2a7beec0ee73096a91
Summary:
This adds support for recovering WriteUnprepared transactions through the following changes:
- The information in `RecoveredTransaction` is extended so that it can reference multiple batches.
- `MarkBeginPrepare` is extended with a bool indicating whether it is an unprepared begin, and this is passed down to `InsertRecoveredTransaction` to indicate whether the current transaction is prepared or not.
- `WriteUnpreparedTxnDB::Initialize` is overridden so that it will rollback unprepared transactions from the recovered transactions. This can be done without updating the prepare heap/commit map, because this is before the DB has finished initializing, and after writing the rollback batch, those data structures should not contain information about the rolled back transaction anyway.
Commit/Rollback of live transactions is still unimplemented and will come later.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4078
Differential Revision: D8703382
Pulled By: lth
fbshipit-source-id: 7e0aada6c23bd39299f1f20d6c060492e0e6b60a
Summary:
This is implemented by extending ReadCallback with another function `MaxUnpreparedSequenceNumber` which returns the largest visible sequence number for the current transaction, if there is uncommitted data written to DB. Otherwise, it returns zero, indicating no uncommitted data.
There are the places where reads had to be modified.
- Get and Seek/Next was just updated to seek to max(snapshot_seq, MaxUnpreparedSequenceNumber()) instead, and iterate until a key was visible.
- Prev did not need need updates since it did not use the Seek to sequence number optimization. Assuming that locks were held when writing unprepared keys, and ValidateSnapshot runs, there should only be committed keys and unprepared keys of the current transaction, all of which are visible. Prev will simply iterate to get the last visible key.
- Reseeking to skip keys optimization was also disabled for write unprepared, since it's possible to hit the max_skip condition even while reseeking. There needs to be some way to resolve infinite looping in this case.
Closes https://github.com/facebook/rocksdb/pull/3955
Differential Revision: D8286688
Pulled By: lth
fbshipit-source-id: 25e42f47fdeb5f7accea0f4fd350ef35198caafe
Summary:
As titled.
I have not extended the Compatibility tests because the new WAL markers are still unimplemented.
Closes https://github.com/facebook/rocksdb/pull/3941
Differential Revision: D8238394
Pulled By: lth
fbshipit-source-id: 980e3d44837bbf2cfa64047f9738f559dfac4b1d
