Commit Graph

12 Commits

Author SHA1 Message Date
Yi Wu
c26a4d8e8a Fix compile error in trasaction_lock_mgr.cc
Summary:
Fix error on mac/windows build since they don't recognize `uint`.
Closes https://github.com/facebook/rocksdb/pull/1624

Differential Revision: D4287139

Pulled By: yiwu-arbug

fbshipit-source-id: b7cc88f
2016-12-06 14:39:16 -08:00
Manuel Ung
2005c88a75 Implement non-exclusive locks
Summary:
This is an implementation of non-exclusive locks for pessimistic transactions. It is relatively simple and does not prevent starvation (ie. it's possible that request for exclusive access will never be granted if there are always threads holding shared access). It is done by changing `KeyLockInfo` to hold an set a transaction ids, instead of just one, and adding a flag specifying whether this lock is currently held with exclusive access or not.

Some implementation notes:
- Some lock diagnostic functions had to be updated to return a set of transaction ids for a given lock, eg. `GetWaitingTxn` and `GetLockStatusData`.
- Deadlock detection is a bit more complicated since a transaction can now wait on multiple other transactions. A BFS is done in this case, and deadlock detection depth is now just a limit on the number of transactions we visit.
- Expirable transactions do not work efficiently with shared locks at the moment, but that's okay for now.
Closes https://github.com/facebook/rocksdb/pull/1573

Differential Revision: D4239097

Pulled By: lth

fbshipit-source-id: da7c074
2016-12-05 17:39:17 -08:00
Manuel Ung
e63350e726 Use more efficient hash map for deadlock detection
Summary:
Currently, deadlock cycles are held in std::unordered_map. The problem with it is that it allocates/deallocates memory on every insertion/deletion. This limits throughput since we're doing this expensive operation while holding a global mutex. Fix this by using a vector which caches memory instead.

Running the deadlock stress test, this change increased throughput from 39k txns/s -> 49k txns/s. The effect is more noticeable in MyRocks.
Closes https://github.com/facebook/rocksdb/pull/1545

Differential Revision: D4205662

Pulled By: lth

fbshipit-source-id: ff990e4
2016-11-19 11:39:15 -08:00
Manuel Ung
4edd39fda2 Implement deadlock detection
Summary: Implement deadlock detection. This is done by maintaining a TxnID -> TxnID map which represents the edges in the wait for graph (this is named `wait_txn_map_`).

Test Plan: transaction_test

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D64491
2016-10-19 19:45:57 -07:00
Manuel Ung
be1f1092c9 Expose transaction id, lock state information and transaction wait information
Summary:
This diff does 3 things:

Expose TransactionID so that we can identify transactions when we retrieve locking and lock wait information. This is exposed as `Transaction::GetID`.

Expose lock state information by locking all stripes in all column families and copying their contents to a data structure. This is exposed as `TransactionDB::GetLockStatusData`.

Adds support for tracking the transaction and the key being waited on, and exposes this as `Transaction::GetWaitingTxn`.

Test Plan: unit tests

Reviewers: horuff, sdong

Reviewed By: sdong

Subscribers: vasilep, hermanlee4, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D64413
2016-09-30 11:41:21 -07:00
Li Peng
6d4832a998 Merge pull request #1101 from flyd1005/wip-fix-typo
fix typos and remove duplicated words
2016-04-28 02:30:44 -07:00
Baraa Hamodi
21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
Gabriela Jacques da Silva
0c2bd5cb4b Removing data race from expirable transactions
Summary:
Doing inline checking of transaction expiration instead of
using a callback.

Test Plan: To be added

Reviewers: anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53673
2016-02-02 18:37:44 -08:00
agiardullo
5e94f68f35 TransactionDB Custom Locking API
Summary:
Prototype of API to allow MyRocks to override default Mutex/CondVar used by transactions with their own implementations.  They would simply need to pass their own implementations of Mutex/CondVar to the templated TransactionDB::Open().

Default implementation of TransactionDBMutex/TransactionDBCondVar provided (but the code is not currently changed to use this).

Let me know if this API makes sense or if it should be changed

Test Plan: n/a

Reviewers: yhchiang, rven, igor, sdong, spetrunia

Reviewed By: spetrunia

Subscribers: maykov, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43761
2015-09-08 17:03:57 -07:00
agiardullo
77a28615ec Support static Status messages
Summary: Provide a way to specify a detailed static error message for a Status without incurring a memcpy.  Let me know what people think of this approach.

Test Plan: added simple test

Reviewers: igor, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D44259
2015-08-31 16:13:29 -07:00
agiardullo
0db807ec28 Transaction error statuses
Summary:
Based on feedback from spetrunia, we should better differentiate error statuses for transaction failures.

https://github.com/MySQLOnRocksDB/mysql-5.6/issues/86#issuecomment-124605954

Test Plan: unit tests

Reviewers: rven, kradhakrishnan, spetrunia, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43323
2015-08-11 17:52:56 -07:00
agiardullo
c2f2cb0214 Pessimistic Transactions
Summary:
Initial implementation of Pessimistic Transactions.  This diff contains the api changes discussed in D38913.  This diff is pretty large, so let me know if people would prefer to meet up to discuss it.

MyRocks folks:  please take a look at the API in include/rocksdb/utilities/transaction[_db].h and let me know if you have any issues.

Also, you'll notice a couple of TODOs in the implementation of RollbackToSavePoint().  After chatting with Siying, I'm going to send out a separate diff for an alternate implementation of this feature that implements the rollback inside of WriteBatch/WriteBatchWithIndex.  We can then decide which route is preferable.

Next, I'm planning on doing some perf testing and then integrating this diff into MongoRocks for further testing.

Test Plan: Unit tests, db_bench parallel testing.

Reviewers: igor, rven, sdong, yhchiang, yoshinorim

Reviewed By: sdong

Subscribers: hermanlee4, maykov, spetrunia, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D40869
2015-08-11 17:52:23 -07:00