Summary:
We had two proposals for lock-free commit maps. This patch implements the latter one that was simpler. We can later experiment with both proposals.
In this impl each entry is an std::atomic of uint64_t, which are accessed via memory_order_acquire/release. In x86_64 arch this is compiled to simple reads and writes from memory.
Closes https://github.com/facebook/rocksdb/pull/2861
Differential Revision: D5800724
Pulled By: maysamyabandeh
fbshipit-source-id: 41abae9a4a5df050a8eb696c43de11c2770afdda
Summary:
This patch instruments the read path to verify each read value against an optional ReadCallback class. If the value is rejected, the reader moves on to the next value. The WritePreparedTxn makes use of this feature to skip sequence numbers that are not in the read snapshot.
Closes https://github.com/facebook/rocksdb/pull/2850
Differential Revision: D5787375
Pulled By: maysamyabandeh
fbshipit-source-id: 49d808b3062ab35e7ae98ad388f659757794184c
Summary:
This patch advances the max_evicted_seq_ is larger granularities to reduce the overhead of updating the relevant data structures.
It also refactor the related code and adds testing to that. As part of this patch some of the TODOs for removing usage of non-static const members are also addressed.
Closes https://github.com/facebook/rocksdb/pull/2844
Differential Revision: D5772928
Pulled By: maysamyabandeh
fbshipit-source-id: f4fcc2948be69c034f10812cf922ce5ab82ef98c
Summary:
TransactionCallback was never used. Remove it to avoid confusion.
Closes https://github.com/facebook/rocksdb/pull/2853
Differential Revision: D5787219
Pulled By: maysamyabandeh
fbshipit-source-id: e2b6a89537e3770a269ad38be71c4b0b160a88ac
Summary:
The patch skips write_prepared_transaction_test from travis as they time out there. They are still covered in daily runs of tests.
Closes https://github.com/facebook/rocksdb/pull/2836
Differential Revision: D5767203
Pulled By: maysamyabandeh
fbshipit-source-id: 51045ef98a745197136e14b2ec02fc6f38081b75
Summary:
Add -DPORTABLE=1
port::cacheline_aligned_alloc() has arguments swapped which prevents every single test from running.
Closes https://github.com/facebook/rocksdb/pull/2815
Differential Revision: D5751661
Pulled By: siying
fbshipit-source-id: e0857d6e138ec46035b3c23d7c3c751901a0a4a0
Summary:
Divide the old snapshots to two lists: a few that fit into a cached array and the rest in a vector, which is expected to be empty in normal cases. The former is to optimize concurrent reads from snapshots without requiring locks. It is done by an array of std::atomic, from which std::memory_order_acquire reads are compiled to simple read instructions in most of the x86_64 architectures.
Closes https://github.com/facebook/rocksdb/pull/2758
Differential Revision: D5660504
Pulled By: maysamyabandeh
fbshipit-source-id: 524fcf9a8e7f90a92324536456912a99aaa6740c
Summary:
The ::Get from DB is not augmented with an overload method that takes a PinnableSlice instead of a string. Transactions however are not yet upgraded to use the new API. As a result, transaction users such as MyRocks cannot benefit from it. This patch updates the transactional API with a PinnableSlice overload.
Closes https://github.com/facebook/rocksdb/pull/2736
Differential Revision: D5645770
Pulled By: maysamyabandeh
fbshipit-source-id: f6af520df902f842de1bcf99bed3e8dfc43ad96d
Summary:
Changes:
* extended the wait_txn_map to track additional information
* designed circular buffer to store n latest deadlocks' information
* added test coverage to verify the additional information tracked is accurately stored in the buffer
Closes https://github.com/facebook/rocksdb/pull/2630
Differential Revision: D5478025
Pulled By: armishra
fbshipit-source-id: 2b138de7b5a73f5ca554fc3ff8220a3be49f39e7
Summary:
Implement the main body of WritePrepared pseudo code. This includes PrepareInternal and CommitInternal, as well as AddCommitted which updates the commit map. It also provides a IsInSnapshot method that could be later called form the read path to decide if a version is in the read snapshot or it should other be skipped.
This patch lacks unit tests and does not attempt to offer an efficient implementation. The idea is that to have the API specified so that we can work on related tasks in parallel.
Closes https://github.com/facebook/rocksdb/pull/2713
Differential Revision: D5640021
Pulled By: maysamyabandeh
fbshipit-source-id: bfa7a05e8d8498811fab714ce4b9c21530514e1c
Summary:
This patch splits Commit and Prepare into lock-related logic and db-write-related logic. It moves lock-related logic to PessimisticTransaction to be reused by all children classes and movies the existing impl of db-write-related to PrepareInternal, CommitSingleInternal, and CommitInternal in WriteCommittedTxnImpl.
Closes https://github.com/facebook/rocksdb/pull/2691
Differential Revision: D5569464
Pulled By: maysamyabandeh
fbshipit-source-id: d1b8698e69801a4126c7bc211745d05c636f5325
Summary:
This opens space for the new implementations of TransactionDBImpl such as WritePreparedTxnDBImpl that has a different policy of how to write to DB.
Closes https://github.com/facebook/rocksdb/pull/2689
Differential Revision: D5568918
Pulled By: maysamyabandeh
fbshipit-source-id: f7eac866e175daf3793ae79da108f65cc7dc7b25
Summary:
This patch refactors TransactionImpl by separating the logic for pessimistic concurrency control from the implementation of how to write the data to rocksdb. The existing implementation is named WriteCommittedTxnImpl as it writes committed data to the db. A template named WritePreparedTxnImpl is also added which will be later completed to provide a an alternative implementation.
Closes https://github.com/facebook/rocksdb/pull/2676
Differential Revision: D5549998
Pulled By: maysamyabandeh
fbshipit-source-id: 16298e86b43ca4849324c1f35c731913c6d17bec
Summary:
Replace dynamic_cast<> so that users can choose to build with RTTI off, so that they can save several bytes per object, and get tiny more memory available.
Some nontrivial changes:
1. Add Comparator::GetRootComparator() to get around the internal comparator hack
2. Add the two experiemental functions to DB
3. Add TableFactory::GetOptionString() to avoid unnecessary casting to get the option string
4. Since 3 is done, move the parsing option functions for table factory to table factory files too, to be symmetric.
Closes https://github.com/facebook/rocksdb/pull/2645
Differential Revision: D5502723
Pulled By: siying
fbshipit-source-id: fd13cec5601cf68a554d87bfcf056f2ffa5fbf7c
Summary:
Currently this test times out with tsan. This is likely due to decreased speed with tsan. By lowering the number of iterations we can still catch a bug as the test is run regularly and multiple runs of the test is equivalent with running the test with more iterations.
Closes https://github.com/facebook/rocksdb/pull/2639
Differential Revision: D5490549
Pulled By: maysamyabandeh
fbshipit-source-id: bd69c42a9728d337ac95a06a401088384e51731a
Summary:
This reverts the previous commit 1d7048c598, which broke the build.
Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627
Differential Revision: D5476473
Pulled By: sagar0
fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
Summary:
Throughput: 46k tps in our sysbench settings (filling the details later)
The idea is to have the simplest change that gives us a reasonable boost
in 2PC throughput.
Major design changes:
1. The WAL file internal buffer is not flushed after each write. Instead
it is flushed before critical operations (WAL copy via fs) or when
FlushWAL is called by MySQL. Flushing the WAL buffer is also protected
via mutex_.
2. Use two sequence numbers: last seq, and last seq for write. Last seq
is the last visible sequence number for reads. Last seq for write is the
next sequence number that should be used to write to WAL/memtable. This
allows to have a memtable write be in parallel to WAL writes.
3. BatchGroup is not used for writes. This means that we can have
parallel writers which changes a major assumption in the code base. To
accommodate for that i) allow only 1 WriteImpl that intends to write to
memtable via mem_mutex_--which is fine since in 2PC almost all of the memtable writes
come via group commit phase which is serial anyway, ii) make all the
parts in the code base that assumed to be the only writer (via
EnterUnbatched) to also acquire mem_mutex_, iii) stat updates are
protected via a stat_mutex_.
Note: the first commit has the approach figured out but is not clean.
Submitting the PR anyway to get the early feedback on the approach. If
we are ok with the approach I will go ahead with this updates:
0) Rebase with Yi's pipelining changes
1) Currently batching is disabled by default to make sure that it will be
consistent with all unit tests. Will make this optional via a config.
2) A couple of unit tests are disabled. They need to be updated with the
serial commit of 2PC taken into account.
3) Replacing BatchGroup with mem_mutex_ got a bit ugly as it requires
releasing mutex_ beforehand (the same way EnterUnbatched does). This
needs to be cleaned up.
Closes https://github.com/facebook/rocksdb/pull/2345
Differential Revision: D5210732
Pulled By: maysamyabandeh
fbshipit-source-id: 78653bd95a35cd1e831e555e0e57bdfd695355a4
Summary:
Fixing two types of clang-analyzer false positives:
* db is deleted and then reopen, and clang-analyzer thinks we are reusing the pointer after it has been deleted. Adding asserts to hint clang-analyzer the pointer is recreated.
* ParsedInternalKey is (intentionally) uninitialized. Initialize the struct only when clang-analyzer is running.
Closes https://github.com/facebook/rocksdb/pull/2334
Differential Revision: D5093801
Pulled By: yiwu-arbug
fbshipit-source-id: f51355382098eb3da5ab9f64e094c6d03e6bdf7d
Summary:
Upgrading a shared lock was silently succeeding because the actual locking code was skipped. This is because if the keys are tracked, it is assumed that they are already locked and do not require locking. Fix this by recording in tracked keys whether the key was locked exclusively or not.
Note that lock downgrades are impossible, which is the behaviour we expect.
This fixesfacebook/mysql-5.6#587.
Closes https://github.com/facebook/rocksdb/pull/2122
Differential Revision: D4861489
Pulled By: IslamAbdelRahman
fbshipit-source-id: 58c7ebe7af098bf01b9774b666d3e9867747d8fd
Summary:
Extend TransactionOptions to include max_write_batch_size which determines the maximum size of the writebatch representation. If memory limit is exceeded, the operation will abort with subcode kMemoryLimit.
Closes https://github.com/facebook/rocksdb/pull/2124
Differential Revision: D4861842
Pulled By: lth
fbshipit-source-id: 46fd172ea67cc90bbba829bf0d70cfab2261c161
Summary:
Move some files under util/ to new directories env/, monitoring/ options/ and cache/
Closes https://github.com/facebook/rocksdb/pull/2090
Differential Revision: D4833681
Pulled By: siying
fbshipit-source-id: 2fd8bef
Summary:
Refactor WriteImpl() so when I plug-in the pipeline write code (which is
an alternative approach for WriteThread), some of the logic can be
reuse. I split out the following methods from WriteImpl():
* PreprocessWrite()
* HandleWALFull() (previous MaybeFlushColumnFamilies())
* HandleWriteBufferFull()
* WriteToWAL()
Also adding a constructor to WriteThread::Writer, and move WriteContext into db_impl.h.
No real logic change in this patch.
Closes https://github.com/facebook/rocksdb/pull/2042
Differential Revision: D4781014
Pulled By: yiwu-arbug
fbshipit-source-id: d45ca18
Summary:
introduce new methods into a public threadpool interface,
- allow submission of std::functions as they allow greater flexibility.
- add Joining methods to the implementation to join scheduled and submitted jobs with
an option to cancel jobs that did not start executing.
- Remove ugly `#ifdefs` between pthread and std implementation, make it uniform.
- introduce pimpl for a drop in replacement of the implementation
- Introduce rocksdb::port::Thread typedef which is a replacement for std::thread. On Posix Thread defaults as before std::thread.
- Implement WindowsThread that allocates memory in a more controllable manner than windows std::thread with a replaceable implementation.
- should be no functionality changes.
Closes https://github.com/facebook/rocksdb/pull/1823
Differential Revision: D4492902
Pulled By: siying
fbshipit-source-id: c74cb11
Summary:
Consider the following single column family scenario:
prepare in log A
commit in log B
*WAL is too large, flush all CFs to releast log A*
*CFA is on log B so we do not see CFA is depending on log A so no flush is requested*
To fix this we must also consider the log containing the prepare section when determining what log a CF is dependent on.
Closes https://github.com/facebook/rocksdb/pull/1768
Differential Revision: D4403265
Pulled By: reidHoruff
fbshipit-source-id: ce800ff
Summary:
Enable directIO on WritableFileImpl::Append
with offset being current length of the file.
Enable UniqueID tests on Windows, disable others but
leeting them to compile. Unique tests are valuable to
detect failures on different filesystems and upcoming
ReFS.
Clear output in WinEnv Getchildren.This is different from
previous strategy, do not touch output on failure.
Make sure DBTest.OpenWhenOpen works with windows error message
Closes https://github.com/facebook/rocksdb/pull/1746
Differential Revision: D4385681
Pulled By: IslamAbdelRahman
fbshipit-source-id: c07b702
Summary:
In the test the last change to AAAZZZ in handles[1] is deleting it. The
result of the get must be NotFound then. Previosuly the test did not
check for the return value of Get and assumed that the status is ok. It
then move ahead asserting the returned value. The passed-by-reference
string value however was not changed (since the key was not found) and
the asserted value is what it contained before doing the Get.
Closes https://github.com/facebook/rocksdb/pull/1753
Differential Revision: D4390982
Pulled By: maysamyabandeh
fbshipit-source-id: dd55a34
Summary:
Fixes compile error:
In file included from ./util/statistics.h:17:0,
from ./util/stop_watch.h:8,
from ./util/perf_step_timer.h:9,
from ./util/iostats_context_imp.h:8,
from ./util/posix_logger.h:27,
from ./port/util_logger.h:18,
from ./db/auto_roll_logger.h:15,
from db/auto_roll_logger.cc:6:
./util/thread_local.h:65:16: error: 'function' in namespace 'std' does not name a template type
typedef std::function<void(void*, void*)> FoldFunc;
Closes https://github.com/facebook/rocksdb/pull/1656
Differential Revision: D4318702
Pulled By: yiwu-arbug
fbshipit-source-id: 8c5d17a
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
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
Summary:
Originally sequence ids were calculated, in recovery, based off of the first seqid found if the first log recovered. The working seqid was then incremented from that value based on every insertion that took place. This was faulty because of the potential for missing log files or inserts that skipped the WAL. The current recovery scheme grabs sequence from current recovering batch and increments using memtableinserter to track how many actual inserts take place. This works for 2PC batches as well scenarios where some logs are missing or inserts that skip the WAL.
Closes https://github.com/facebook/rocksdb/pull/1486
Differential Revision: D4156064
Pulled By: reidHoruff
fbshipit-source-id: a6da8d9
Summary:
copied from: 5ebfd2623a
Opening existing RocksDB attempts recovery from log files, which uses
wrong sequence number to create the memtable. This is a regression
introduced in change a400336.
This change includes a test demonstrating the problem, without the fix
the test fails with "Operation failed. Try again.: Transaction could not
check for conflicts for operation at SequenceNumber 1 as the MemTable
only contains changes newer than SequenceNumber 2. Increasing the value
of the max_write_buffer_number_to_maintain option could reduce the
frequency of this error"
This change is a joint effort by Peter 'Stig' Edwards thatsafunnyname
and me.
Closes https://github.com/facebook/rocksdb/pull/1458
Differential Revision: D4143791
Pulled By: reidHoruff
fbshipit-source-id: 5a25033
Summary: Make `IsDeadlockDetect()` virtual member of base class `Transaction` for ease of use in MyRocks
Test Plan: compiles. compiles into MyRocks call-site.
Reviewers: mung
Reviewed By: mung
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65385
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
Summary: Modifies the lock info export test to test multiple column families after I was experiencing a bug while developing the MyRocks front-end for this.
Test Plan: is test.
Reviewers: mung
Reviewed By: mung
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D64725
Summary:
This exposes a transactions state through a public api rather than through a public member variable. I also do some name refactoring.
ExecutionStatus => TransactionState
exec_status_ => trx_state_
Test Plan: It compiles and transaction_test passes.
Reviewers: IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, mung, dhruba, sdong
Differential Revision: https://reviews.facebook.net/D64689
Summary:
When constructing a write batch a client may now call MarkWalTerminationPoint() on that batch. No batch operations after this call will be added written to the WAL but will still be inserted into the Memtable. This facility is used to remove one of the three WriteImpl calls in 2PC transactions. This produces a ~1% perf improvement.
```
RocksDB - unoptimized 2pc, sync_binlog=1, disable_2pc=off
INFO 2016-08-31 14:30:38,814 [main]: REQUEST PHASE COMPLETED. 75000000 requests done in 2619 seconds. Requests/second = 28628
RocksDB - optimized 2pc , sync_binlog=1, disable_2pc=off
INFO 2016-08-31 16:26:59,442 [main]: REQUEST PHASE COMPLETED. 75000000 requests done in 2581 seconds. Requests/second = 29054
```
Test Plan: Two unit tests added.
Reviewers: sdong, yiwu, IslamAbdelRahman
Reviewed By: yiwu
Subscribers: hermanlee4, dhruba, andrewkr
Differential Revision: https://reviews.facebook.net/D64599
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
