Summary:
We slow down data into the database to the rate of options.delayed_write_rate (a new option) with this patch.
The thread synchronization approach I take is to still synchronize write controller by DB mutex and GetDelay() is inside DB mutex. Try to minimize the frequency of getting time in GetDelay(). I verified it through db_bench and it seems to work
hard_rate_limit is deprecated.
options.delayed_write_rate is still not dynamically changeable. Need to work on it as a follow-up.
Test Plan: Add new unit tests in db_test
Reviewers: yhchiang, rven, kradhakrishnan, anthony, MarkCallaghan, igor
Reviewed By: igor
Subscribers: ikabiljo, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D36351
Summary:
Adding largest sequence number to FlushJobInfo
and passing flushed file metadata to NotifyOnFlushCompleted which include alot of other values that we may want to expose in FlushJobInfo
Test Plan: make check
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D39927
Summary:
EventListener::OnFlushCompleted() now passes a structure instead
of a list of parameters. This minimizes the API change in the
future.
Test Plan:
listener_test
compact_files_test
example/compact_files_example
Reviewers: kradhakrishnan, sdong, IslamAbdelRahman, rven, igor
Reviewed By: rven, igor
Subscribers: IslamAbdelRahman, rven, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39543
Summary:
This diff updates the logic of how we do trivial move, now trivial move can run on any number of files in input level as long as they are not overlapping
The conditions for trivial move have been updated
Introduced conditions:
- Trivial move cannot happen if we have a compaction filter (except if the compaction is not manual)
- Input level files cannot be overlapping
Removed conditions:
- Trivial move only run when the compaction is not manual
- Input level should can contain only 1 file
More context on what tests failed because of Trivial move
```
DBTest.CompactionsGenerateMultipleFiles
This test is expecting compaction on a file in L0 to generate multiple files in L1, this test will fail with trivial move because we end up with one file in L1
```
```
DBTest.NoSpaceCompactRange
This test expect compaction to fail when we force environment to report running out of space, of course this is not valid in trivial move situation
because trivial move does not need any extra space, and did not check for that
```
```
DBTest.DropWrites
Similar to DBTest.NoSpaceCompactRange
```
```
DBTest.DeleteObsoleteFilesPendingOutputs
This test expect that a file in L2 is deleted after it's moved to L3, this is not valid with trivial move because although the file was moved it is now used by L3
```
```
CuckooTableDBTest.CompactionIntoMultipleFiles
Same as DBTest.CompactionsGenerateMultipleFiles
```
This diff is based on a work by @sdong https://reviews.facebook.net/D34149
Test Plan: make -j64 check
Reviewers: rven, sdong, igor
Reviewed By: igor
Subscribers: yhchiang, ott, march, dhruba, sdong
Differential Revision: https://reviews.facebook.net/D34797
Summary:
Allow EventListener::OnCompactionCompleted to return CompactionJobStats,
which contains useful information about a compaction.
Example CompactionJobStats returned by OnCompactionCompleted():
smallest_output_key_prefix 05000000
largest_output_key_prefix 06990000
elapsed_time 42419
num_input_records 300
num_input_files 3
num_input_files_at_output_level 2
num_output_records 200
num_output_files 1
actual_bytes_input 167200
actual_bytes_output 110688
total_input_raw_key_bytes 5400
total_input_raw_value_bytes 300000
num_records_replaced 100
is_manual_compaction 1
Test Plan: Developed a mega test in db_test which covers 20 variables in CompactionJobStats.
Reviewers: rven, igor, anthony, sdong
Reviewed By: sdong
Subscribers: tnovak, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38463
Summary:
Add EventListener::OnTableFileCreated(), which will be called
when a table file is created. This patch is part of the
EventLogger and EventListener integration.
Test Plan: Augment existing test in db/listener_test.cc
Reviewers: anthony, kradhakrishnan, rven, igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38865
Summary: In DB::CompactRange(), change parameter "reduce_level" to "change_level". Users can compact all data to the last level if needed. By doing it, users can migrate the DB to options.level_compaction_dynamic_level_bytes=true.
Test Plan: Add a unit test for it.
Reviewers: yhchiang, anthony, kradhakrishnan, igor, rven
Reviewed By: rven
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39099
Summary:
DBImpl::notifying_events_ is a internal counter in DBImpl which is
used to prevent DB close when DB is notifying events. However, as
the current events all rely on either compaction or flush which
already have similar counters to prevent DB close, it is safe to
remove notifying_events_.
Test Plan:
listener_test
examples/compact_files_example
Reviewers: igor, anthony, kradhakrishnan, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39315
Summary: Optimistic transactions supporting begin/commit/rollback semantics. Currently relies on checking the memtable to determine if there are any collisions at commit time. Not yet implemented would be a way of enuring the memtable has some minimum amount of history so that we won't fail to commit when the memtable is empty. You should probably start with transaction.h to get an overview of what is currently supported.
Test Plan: Added a new test, but still need to look into stress testing.
Reviewers: yhchiang, igor, rven, sdong
Reviewed By: sdong
Subscribers: adamretter, MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D33435
Summary: Removed an unused private variable in db_impl.h
Test Plan: make db_test
Reviewers: sdong, anthony, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38925
Summary:
Added a couple functions to WriteBatchWithIndex to make it easier to query the value of a key including reading pending writes from a batch. (This is needed for transactions).
I created write_batch_with_index_internal.h to use to store an internal-only helper function since there wasn't a good place in the existing class hierarchy to store this function (and it didn't seem right to stick this function inside WriteBatchInternal::Rep).
Since I needed to access the WriteBatchEntryComparator, I moved some helper classes from write_batch_with_index.cc into write_batch_with_index_internal.h/.cc. WriteBatchIndexEntry, ReadableWriteBatch, and WriteBatchEntryComparator are all unchanged (just moved to a different file(s)).
Test Plan: Added new unit tests.
Reviewers: rven, yhchiang, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38037
Summary:
Added these events:
* Recovery start, finish and also when recovery creates a file
* Trivial move
* Compaction start, finish and when compaction creates a file
* Flush start, finish
Also includes small fix to EventLogger
Also added option ROCKSDB_PRINT_EVENTS_TO_STDOUT which is useful when we debug things. I've spent far too much time chasing LOG files.
Still didn't get sst table properties in JSON. They are written very deeply into the stack. I'll address in separate diff.
TODO:
* Write specification. Let's first use this for a while and figure out what's good data to put here, too. After that we'll write spec
* Write tools that parse and analyze LOGs. This can be in python or go. Good intern task.
Test Plan: Ran db_bench with ROCKSDB_PRINT_EVENTS_TO_STDOUT. Here's the output: https://phabricator.fb.com/P19811976
Reviewers: sdong, yhchiang, rven, MarkCallaghan, kradhakrishnan, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37521
Summary:
This diff implements a new `DB` method `PromoteL0` which moves all files in L0
to a given level skipping compaction, provided that the files have disjoint
ranges and all levels up to the target level are empty.
This method provides finer-grain control for trivial compactions, and it is
useful for bulk-loading pre-sorted keys. Compared to D34797, it does not change
the semantics of an existing operation, which can impact existing code.
PromoteL0 is designed to work well in combination with the proposed
`GetSstFileWriter`/`AddFile` interface, enabling to "design" the level structure
by populating one level at a time. Such fine-grained control can be very useful
for static or mostly-static databases.
Test Plan: `make check`
Reviewers: IslamAbdelRahman, philipp, MarkCallaghan, yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D37107
Summary:
Some Mongo+Rocks datasets in Parse's environment are not doing compactions very frequently. During the quiet period (with no IO), we'd like to schedule compactions so that our reads become faster. Also, aggressively compacting during quiet periods helps when write bursts happen. In addition, we also want to compact files that are containing deleted key ranges (like old oplog keys).
All of this is currently not possible with CompactRange() because it's single-threaded and blocks all other compactions from happening. Running CompactRange() risks an issue of blocking writes because we generate too much Level 0 files before the compaction is over. Stopping writes is very dangerous because they hold transaction locks. We tried running manual compaction once on Mongo+Rocks and everything fell apart.
MarkForCompaction() solves all of those problems. This is very light-weight manual compaction. It is lower priority than automatic compactions, which means it shouldn't interfere with background process keeping the LSM tree clean. However, if no automatic compactions need to be run (or we have extra background threads available), we will start compacting files that are marked for compaction.
Test Plan: added a new unit test
Reviewers: yhchiang, rven, MarkCallaghan, sdong
Reviewed By: sdong
Subscribers: yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37083
Summary:
Cleaning up log files can do heavy IO, since we call ftruncate() in the destructor. We don't want to call ftruncate() in user threads.
This diff moves cleaning to background threads (flush and compaction)
Test Plan: make check, will also run valgrind
Reviewers: yhchiang, rven, MarkCallaghan, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D36177
Summary: Some suggestions for cleanup from Igor.
Test Plan: Regression tests.
Reviewers: igor
Reviewed By: igor
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D35169
Summary:
Here's my proposal for making our LOGs easier to read by machines.
The idea is to dump all events as JSON objects. JSON is easy to read by humans, but more importantly, it's easy to read by machines. That way, we can parse this, load into SQLite/mongo and then query or visualize.
I started with table_create and table_delete events, but if everybody agrees, I'll continue by adding more events (flush/compaction/etc etc)
Test Plan:
Ran db_bench. Observed:
2015/01/15-14:13:25.788019 1105ef000 EVENT_LOG_v1 {"time_micros": 1421360005788015, "event": "table_file_creation", "file_number": 12, "file_size": 1909699}
2015/01/15-14:13:25.956500 110740000 EVENT_LOG_v1 {"time_micros": 1421360005956498, "event": "table_file_deletion", "file_number": 12}
Reviewers: yhchiang, rven, dhruba, MarkCallaghan, lgalanis, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D31647
Summary:
Provide an API which enables users to infor Rocksdb that it is
shutting down.
Test Plan: db_test
Reviewers: sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D34617
Summary:
When using latest clang (3.6 or 3.7/trunck) rocksdb is failing with many errors. Almost all of them are missing override errors. This diff adds missing override keyword. No manual changes.
Prerequisites: bear and clang 3.5 build with extra tools
```lang=bash
% USE_CLANG=1 bear make all # generate a compilation database http://clang.llvm.org/docs/JSONCompilationDatabase.html
% clang-modernize -p . -include . -add-override
% make format
```
Test Plan:
Make sure all tests are passing.
```lang=bash
% #Use default fb code clang.
% make check
```
Verify less error and no missing override errors.
```lang=bash
% # Have trunk clang present in path.
% ROCKSDB_NO_FBCODE=1 CC=clang CXX=clang++ make
```
Reviewers: igor, kradhakrishnan, rven, meyering, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D34077
Summary:
It would be good to assing background job their IDs. Two benefits:
1) makes LOGs more readable
2) I might use it in my EventLogger, which will try to make our LOG easier to read/query/visualize
Test Plan: ran rocksdb, read the LOG
Reviewers: sdong, rven, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D31617
Summary:
Add a counter for collecting the wait time on db mutex.
Also add MutexWrapper and CondVarWrapper for measuring wait time.
Test Plan:
./db_test
export ROCKSDB_TESTS=MutexWaitStats
./db_test
verify stats output using db_bench
make clean
make release
./db_bench --statistics=1 --benchmarks=fillseq,readwhilewriting --num=10000 --threads=10
Sample output:
rocksdb.db.mutex.wait.micros COUNT : 7546866
Reviewers: MarkCallaghan, rven, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D32787
Summary: This adds a listener for compactions, and gives some useful statistics on each compaction pass.
Test Plan: Unit tests.
Reviewers: sdong, igor, rven, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D31641
Summary: log_dir_unsynced_ is a confusing name. Rename it to log_dir_synced_ and flip the value.
Test Plan: Run ./fault_injection_test
Reviewers: rven, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D32235
Summary:
1. If WAL directory is different from db directory. Sync the directory after creating a log file under it.
2. After creating an SST file, sync its parent directory instead of DB directory.
3. change the check of kResetDeleteUnsyncedFiles in fault_injection_test. Since we changed the behavior to sync log files' parent directory after first WAL sync, instead of creating, kResetDeleteUnsyncedFiles will not guarantee to show post sync updates.
Test Plan: make all check
Reviewers: yhchiang, rven, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D32067
Summary:
There are two versions of FindObsoleteFiles():
* full scan, which is executed every 6 hours (and it's terribly slow)
* no full scan, which is executed every time a background process finishes and iterator is deleted
This diff is optimizing the second case (no full scan). Here's what we do before the diff:
* Get the list of obsolete files (files with ref==0). Some files in obsolete_files set might actually be live.
* Get the list of live files to avoid deleting files that are live.
* Delete files that are in obsolete_files and not in live_files.
After this diff:
* The only files with ref==0 that are still live are files that have been part of move compaction. Don't include moved files in obsolete_files.
* Get the list of obsolete files (which exclude moved files).
* No need to get the list of live files, since all files in obsolete_files need to be deleted.
I'll post the benchmark results, but you can get the feel of it here: https://reviews.facebook.net/D30123
This depends on D30123.
P.S. We should do full scan only in failure scenarios, not every 6 hours. I'll do this in a follow-up diff.
Test Plan:
One new unit test. Made sure that unit test fails if we don't have a `if (!f->moved)` safeguard in ~Version.
make check
Big number of compactions and flushes:
./db_stress --threads=30 --ops_per_thread=20000000 --max_key=10000 --column_families=20 --clear_column_family_one_in=10000000 --verify_before_write=0 --reopen=15 --max_background_compactions=10 --max_background_flushes=10 --db=/fast-rocksdb-tmp/db_stress --prefixpercent=0 --iterpercent=0 --writepercent=75 --db_write_buffer_size=2000000
Reviewers: yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D30249
Summary:
When scaling to higher number of column families, the worst bottleneck was MaybeScheduleFlushOrCompaction(), which did a for loop over all column families while holding a mutex. This patch addresses the issue.
The approach is similar to our earlier efforts: instead of a pull-model, where we do something for every column family, we can do a push-based model -- when we detect that column family is ready to be flushed/compacted, we add it to the flush_queue_/compaction_queue_. That way we don't need to loop over every column family in MaybeScheduleFlushOrCompaction.
Here are the performance results:
Command:
./db_bench --write_buffer_size=268435456 --db_write_buffer_size=268435456 --db=/fast-rocksdb-tmp/rocks_lots_of_cf --use_existing_db=0 --open_files=55000 --statistics=1 --histogram=1 --disable_data_sync=1 --max_write_buffer_number=2 --sync=0 --benchmarks=fillrandom --threads=16 --num_column_families=5000 --disable_wal=1 --max_background_flushes=16 --max_background_compactions=16 --level0_file_num_compaction_trigger=2 --level0_slowdown_writes_trigger=2 --level0_stop_writes_trigger=3 --hard_rate_limit=1 --num=33333333 --writes=33333333
Before the patch:
fillrandom : 26.950 micros/op 37105 ops/sec; 4.1 MB/s
After the patch:
fillrandom : 17.404 micros/op 57456 ops/sec; 6.4 MB/s
Next bottleneck is VersionSet::AddLiveFiles, which is painfully slow when we have a lot of files. This is coming in the next patch, but when I removed that code, here's what I got:
fillrandom : 7.590 micros/op 131758 ops/sec; 14.6 MB/s
Test Plan:
make check
two stress tests:
Big number of compactions and flushes:
./db_stress --threads=30 --ops_per_thread=20000000 --max_key=10000 --column_families=20 --clear_column_family_one_in=10000000 --verify_before_write=0 --reopen=15 --max_background_compactions=10 --max_background_flushes=10 --db=/fast-rocksdb-tmp/db_stress --prefixpercent=0 --iterpercent=0 --writepercent=75 --db_write_buffer_size=2000000
max_background_flushes=0, to verify that this case also works correctly
./db_stress --threads=30 --ops_per_thread=2000000 --max_key=10000 --column_families=20 --clear_column_family_one_in=10000000 --verify_before_write=0 --reopen=3 --max_background_compactions=3 --max_background_flushes=0 --db=/fast-rocksdb-tmp/db_stress --prefixpercent=0 --iterpercent=0 --writepercent=75 --db_write_buffer_size=2000000
Reviewers: ljin, rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D30123
Summary: Now DB::GetSnapshot() doesn't scale to more column families, as it needs to go through all the column families to find whether snapshot is supported. This patch optimizes it.
Test Plan:
Add unit tests to cover negative cases.
make all check
Reviewers: yhchiang, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D30093
Summary: This is a regression bug introduced by https://reviews.facebook.net/D24729 . max_total_wal_size would be off the target it should be more and more in the case that the a user holds the current super version after flush or compaction. This patch fixes it
Test Plan: make all check
Reviewers: yhchiang, rven, igor
Reviewed By: igor
Subscribers: ljin, yoshinorim, MarkCallaghan, hermanlee4, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D29961
Summary:
Add a counter in SnapshotList to show number of snapshots. Also a unix timestamp in every snapshot.
Add two DB Properties to return number of snapshots and timestamp of the oldest one.
Test Plan: Add unit test checking
Reviewers: yhchiang, rven, igor
Reviewed By: igor
Subscribers: leveldb, dhruba, MarkCallaghan
Differential Revision: https://reviews.facebook.net/D29919
Summary:
Introduces a new class for managing write buffer memory across column
families. We supplement ColumnFamilyOptions::write_buffer_size with
ColumnFamilyOptions::write_buffer, a shared pointer to a WriteBuffer
instance that enforces memory limits before flushing out to disk.
Test Plan: Added SharedWriteBuffer unit test to db_test.cc
Reviewers: sdong, rven, ljin, igor
Reviewed By: igor
Subscribers: tnovak, yhchiang, dhruba, xjin, MarkCallaghan, yoshinorim
Differential Revision: https://reviews.facebook.net/D22581
Summary:
Add GetThreadList API, which allows developer to track the
status of each process. Currently, calling GetThreadList will
only get the list of background threads in RocksDB with their
thread-id and thread-type (priority) set. Will add more support
on this in the later diffs.
ThreadStatus currently has the following properties:
// An unique ID for the thread.
const uint64_t thread_id;
// The type of the thread, it could be ROCKSDB_HIGH_PRIORITY,
// ROCKSDB_LOW_PRIORITY, and USER_THREAD
const ThreadType thread_type;
// The name of the DB instance where the thread is currently
// involved with. It would be set to empty string if the thread
// does not involve in any DB operation.
const std::string db_name;
// The name of the column family where the thread is currently
// It would be set to empty string if the thread does not involve
// in any column family.
const std::string cf_name;
// The event that the current thread is involved.
// It would be set to empty string if the information about event
// is not currently available.
Test Plan:
./thread_list_test
export ROCKSDB_TESTS=GetThreadList
./db_test
Reviewers: rven, igor, sdong, ljin
Reviewed By: ljin
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D25047
Summary: This way we can gurantee that old MemTables get destructed before DBImpl gets destructed, which might be useful if we want to make them depend on state from DBImpl.
Test Plan: make check with asserts in JobContext's destructor
Reviewers: ljin, sdong, yhchiang, rven, jonahcohen
Reviewed By: jonahcohen
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28959
Summary: Store links to live files in directory on same disk
Test Plan:
Take snapshot and open it. Added a test GetSnapshotLink in
db_test.
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28713
Summary: So iOS size_t is 32-bit, so we need to static_cast<size_t> any uint64_t :(
Test Plan: TARGET_OS=IOS make static_lib
Reviewers: dhruba, ljin, yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28743
Summary:
This diff adds three sets of APIs to RocksDB.
= GetColumnFamilyMetaData =
* This APIs allow users to obtain the current state of a RocksDB instance on one column family.
* See GetColumnFamilyMetaData in include/rocksdb/db.h
= EventListener =
* A virtual class that allows users to implement a set of
call-back functions which will be called when specific
events of a RocksDB instance happens.
* To register EventListener, simply insert an EventListener to ColumnFamilyOptions::listeners
= CompactFiles =
* CompactFiles API inputs a set of file numbers and an output level, and RocksDB
will try to compact those files into the specified level.
= Example =
* Example code can be found in example/compact_files_example.cc, which implements
a simple external compactor using EventListener, GetColumnFamilyMetaData, and
CompactFiles API.
Test Plan:
listener_test
compactor_test
example/compact_files_example
export ROCKSDB_TESTS=CompactFiles
db_test
export ROCKSDB_TESTS=MetaData
db_test
Reviewers: ljin, igor, rven, sdong
Reviewed By: sdong
Subscribers: MarkCallaghan, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D24705
Summary:
Here's a prototype of redesigning pending_outputs_. This way, we don't have to expose pending_outputs_ to other classes (CompactionJob, FlushJob, MemtableList). DBImpl takes care of it.
Still have to write some comments, but should be good enough to start the discussion.
Test Plan: make check, will also run stress test
Reviewers: ljin, sdong, rven, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28353
Summary: as title
Test Plan: ./db_test
Reviewers: sdong, yhchiang, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28269
Summary:
Long awaited CompactionJob class! Move most compaction-related things from DBImpl to CompactionJob, making CompactionJob easier to test and understand.
Currently this is just replicating exactly the same functionality with as little as change as possible. As future work, we should:
1. Add CompactionJob tests (I think I'll do that tomorrow)
2. Reduce CompactionJob's state that it inherits from DBImpl
3. Figure out how to do yielding to flush better. Currently I implemented a callback as we agreed yesterday, but I don't think it's a good long term solution.
This reduces db_impl.cc from 5000+ LOC to 3400!
Test Plan: make check, will add CompactionJob-specific tests, probably also move some tests from db_test to compaction_job_test
Reviewers: rven, yhchiang, sdong, ljin
Reviewed By: ljin
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27957
Summary: Decoupling code that deals with archived log files outside of DBImpl. That will make this code easier to reason about and test. It will also make the code easier to improve, because an improver doesn't have to understand DBImpl code in entirety.
Test Plan: added test
Reviewers: ljin, yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27873
Summary:
Abstract out FlushProcess and take it out of DBImpl.
This also includes taking DeletionState outside of DBImpl.
Currently this diff is only doing the refactoring. Future work includes:
1. Decoupling flush_process.cc, make it depend on less state
2. Write flush_process_test, which will mock out everything that FlushProcess depends on and test it in isolation
Test Plan: make check
Reviewers: rven, yhchiang, sdong, ljin
Reviewed By: ljin
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27561
Summary: RocksDB already depends on C++11, so we might as well all the goodness that C++11 provides. This means that we don't need AtomicPointer anymore. The less things in port/, the easier it will be to port to other platforms.
Test Plan: make check + careful visual review verifying that NoBarried got memory_order_relaxed, while Acquire/Release methods got memory_order_acquire and memory_order_release
Reviewers: rven, yhchiang, ljin, sdong
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D27543
Summary: as title
Test Plan: unit test
Reviewers: sdong, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D24729
Summary:
Add two stats to compaction summary:
1. Total input records from previous level
2. Total number of records dropped after compaction
Test Plan: See outputs of printing when runnning locally
Reviewers: ljin, igor, MarkCallaghan
Reviewed By: MarkCallaghan
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D24411
Summary:
make compaction related options changeable. Most of changes are tedious,
following the same convention: grabs MutableCFOptions at the beginning
of compaction under mutex, then pass it throughout the job and register
it in SuperVersion at the end.
Test Plan: make all check
Reviewers: igor, yhchiang, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23349
Summary:
Add a CompactedDBImpl that will enabled when calling OpenForReadOnly()
and the DB only has one level (>0) of files. As a performan comparison,
CuckooTable performs 2.1M/s with CompactedDBImpl vs. 1.78M/s with
ReadOnlyDBImpl.
Test Plan: db_bench
Reviewers: yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23553
Summary: as title
Test Plan:
make all check
I will think a way to set up stress test for this
Reviewers: sdong, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23055
Summary: This diff just moves the write thread control out of the DBImpl. I will need this as I will control column family data concurrency by only accessing some data in the write thread. That way, we won't have to lock our accesses to column family hash table (mappings from IDs to CFDs).
Test Plan: make check
Reviewers: sdong, yhchiang, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23301
Summary:
When memtable is full it calls the registered callback. That callback then registers column family as needing the flush. Every write checks if there are some column families that need to be flushed. This completely eliminates the need for MakeRoomForWrite() function and simplifies our Write code-path.
There is some complexity with the concurrency when the column family is dropped. I made it a bit less complex by dropping the column family from the write thread in https://reviews.facebook.net/D22965. Let me know if you want to discuss this.
Test Plan: make check works. I'll also run db_stress with creating and dropping column families for a while.
Reviewers: yhchiang, sdong, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23067
Summary: Avoid creating unnecessary sst files while db opening
Test Plan: make all check
Reviewers: sdong, igor
Reviewed By: igor
Subscribers: zagfox, yhchiang, ljin, leveldb
Differential Revision: https://reviews.facebook.net/D20661
Summary:
Introducing WriteController, which is a source of truth about per-DB write delays. Let's define an DB epoch as a period where there are no flushes and compactions (i.e. new epoch is started when flush or compaction finishes). Each epoch can either:
* proceed with all writes without delay
* delay all writes by fixed time
* stop all writes
The three modes are recomputed at each epoch change (flush, compaction), rather than on every write (which is currently the case).
When we have a lot of column families, our current pull behavior adds a big overhead, since we need to loop over every column family for every write. With new push model, overhead on Write code-path is minimal.
This is just the start. Next step is to also take care of stalls introduced by slow memtable flushes. The final goal is to eliminate function MakeRoomForWrite(), which currently needs to be called for every column family by every write.
Test Plan: make check for now. I'll add some unit tests later. Also, perf test.
Reviewers: dhruba, yhchiang, MarkCallaghan, sdong, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D22791
Summary: If we drop column family only from (single) write thread, we can be sure that nobody will drop the column family while we're writing (and our mutex is released). This greatly simplifies my patch that's getting rid of MakeRoomForWrite().
Test Plan: make check, but also running stress test
Reviewers: ljin, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D22965
Summary: as title
Test Plan: make release
Reviewers: sdong, igor
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D22935
Summary:
Simply code by removing code path which does not use Arena
from NewInternalIterator
Test Plan:
make all check
make valgrind_check
Reviewers: sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D22395
Summary:
As a preparation to support updating some options dynamically, I'd like
to first introduce ImmutableOptions, which is a subset of Options that
cannot be changed during the course of a DB lifetime without restart.
ColumnFamily will keep both Options and ImmutableOptions. Any component
below ColumnFamily should only take ImmutableOptions in their
constructor. Other options should be taken from APIs, which will be
allowed to adjust dynamically.
I am yet to make changes to memtable and other related classes to take
ImmutableOptions in their ctor. That can be done in a seprate diff as
this one is already pretty big.
Test Plan: make all check
Reviewers: yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D22545
Summary:
I will move compression related options in a separate diff since this
diff is already pretty lengthy.
I guess I will also need to change JNI accordingly :(
Test Plan: make all check
Reviewers: yhchiang, igor, sdong
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D21915
Summary: 1. write db MANIFEST, CURRENT, IDENTITY, sst files, log files to log before open
Test Plan: run db and check LOG file
Reviewers: ljin, yhchiang, igor, dhruba, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D21459
Summary:
Currently DBImpl::Flush() triggers flushes in all column families.
Instead we need to trigger just the column family specified.
Test Plan: make all check
Reviewers: igor, ljin, yhchiang, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D20841
* Script for building the unity.cc file via Makefile
* Unity executable Makefile target for testing builds
* Source code changes to fix compilation of unity build
Summary:
Add a DB Property "rocksdb.estimate-table-readers-mem" to return estimated memory usage by all loaded table readers, other than allocated from block cache.
Refactor the property codes to allow getting property from a version, with DB mutex not acquired.
Test Plan: Add several checks of this new property in existing codes for various cases.
Reviewers: yhchiang, ljin
Reviewed By: ljin
Subscribers: xjin, igor, leveldb
Differential Revision: https://reviews.facebook.net/D20733
Summary: We have quite some properties that are integers and we are adding more. Add a function to directly return them as an integer, instead of a string
Test Plan: Add several unit test checks
Reviewers: yhchiang, igor, dhruba, haobo, ljin
Reviewed By: ljin
Subscribers: yoshinorim, leveldb
Differential Revision: https://reviews.facebook.net/D20637
Summary:
Make StatisticsImpl being able to forward stats to provided statistics
implementation. The main purpose is to allow us to collect internal
stats in the future even when user supplies custom statistics
implementation. It avoids intrumenting 2 sets of stats collection code.
One immediate use case is tuning advisor, which needs to collect some
internal stats, users may not be interested.
Test Plan:
ran db_bench and see stats show up at the end of run
Will run make all check since some tests rely on statistics
Reviewers: yhchiang, sdong, igor
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D20145
Summary: Add a parameter path_id to DB::CompactRange(), to indicate where the output file should be placed to.
Test Plan: add a unit test
Reviewers: yhchiang, ljin
Reviewed By: ljin
Subscribers: xjin, igor, dhruba, MarkCallaghan, leveldb
Differential Revision: https://reviews.facebook.net/D20085
Summary: Browsing through the code, looks like StatsLogger is not used at all!
Test Plan: compiles
Reviewers: ljin, sdong, yhchiang, dhruba
Reviewed By: dhruba
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D19827
Summary:
This diff allows the I/O stats about Flush and Compaction to be reported
in a more accurate way. Instead of measuring the size of a file, it
measure I/O cost in per read / write basis.
Test Plan: make all check
Reviewers: sdong, igor, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19383
Summary:
This diff adds timeout_hint_us to WriteOptions. If it's non-zero, then
1) writes associated with this options MAY be aborted when it has been
waiting for longer than the specified time. If an abortion happens,
associated writes will return Status::TimeOut.
2) the stall time of the associated write caused by flush or compaction
will be limited by timeout_hint_us.
The default value of timeout_hint_us is 0 (i.e., OFF.)
The statistics of timeout writes will be recorded in WRITE_TIMEDOUT.
Test Plan:
export ROCKSDB_TESTS=WriteTimeoutAndDelayTest
make db_test
./db_test
Reviewers: igor, ljin, haobo, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18837
Summary:
In this patch, we allow RocksDB to support multiple DB paths internally.
No user interface is supported yet so this patch is silent to users.
Test Plan: make all check
Reviewers: igor, haobo, ljin, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18921
Summary:
Before this diff, we're deciding enable_compression in CompactionPicker and then we're deciding final compression type in DBImpl. This is kind of confusing.
After the diff, the final compression type will be decided in CompactionPicker.
The reason for this is that I want CompactFiles() to specify output compression type, so that people can mix and match compression styles in their compaction algorithms. This diff makes it much easier to do that.
Test Plan: make check
Reviewers: dhruba, haobo, sdong, yhchiang, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19137
Summary: asan_crash_test is failing on segfault
Test Plan: running asan_crash_test
Reviewers: sdong, igor
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19149
Summary: We have a perf regression of Write() even with one column family. Make fast path for single column family to avoid the perf regression. See task #4455480
Test Plan: make check
Reviewers: sdong, ljin
Reviewed By: sdong, ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D18963
Summary:
In this patch, try to allocate the whole iterator tree starting from DBIter from an arena
1. ArenaWrappedDBIter is created when serves as the entry point of an iterator tree, with an arena in it.
2. Add an option to create iterator from arena for following iterators: DBIter, MergingIterator, MemtableIterator, all mem table's iterators, all table reader's iterators and two level iterator.
3. MergeIteratorBuilder is created to incrementally build the tree of internal iterators. It is passed to mem table list and version set and add iterators to it.
Limitations:
(1) Only DB::NewIterator() without tailing uses the arena. Other cases, including readonly DB and compactions are still from malloc
(2) Two level iterator itself is allocated in arena, but not iterators inside it.
Test Plan: make all check
Reviewers: ljin, haobo
Reviewed By: haobo
Subscribers: leveldb, dhruba, yhchiang, igor
Differential Revision: https://reviews.facebook.net/D18513
Summary:
At the end of BackgroundCallCompaction(), we call SignalAll(), even though we don't need to. If compaction hasn't done anything and there's another compaction running, there is no need to signal on the condition variable. Doing so creates a tight feedback loop which results in log files like:
wait for memtable flush
compaction nothing to do
wait for memtable flush
compaction nothing to do
This change eliminates that
Test Plan:
make check
Also:
icanadi@dev1440 ~ $ grep "nothing to do" /fast-rocksdb-tmp/rocksdb_test/column_family_test/LOG | wc -l
7435
icanadi@dev1440 ~ $ grep "nothing to do" /fast-rocksdb-tmp/rocksdb_test/column_family_test/LOG | wc -l
372
First version is before the change, second version is after the change.
Reviewers: dhruba, ljin, haobo, yhchiang, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D18855
Summary:
Forward iterator puts everything together in a flat structure instead of
a hierarchy of nested iterators. this should simplify the code and
provide better performance. It also enables more optimization since all
information are accessiable in one place.
Init evaluation shows about 6% improvement
Test Plan: db_test and db_bench
Reviewers: dhruba, igor, tnovak, sdong, haobo
Reviewed By: haobo
Subscribers: sdong, leveldb
Differential Revision: https://reviews.facebook.net/D18795
Summary:
Added a new option `max_total_wal_size`. Once the total WAL size goes over that, we make an attempt to flush all column families that still have data in the earliest WAL file.
By default, I calculate `max_total_wal_size` dynamically, that should be good-enough for non-advanced customers.
Test Plan: Added a test
Reviewers: dhruba, haobo, sdong, ljin, yhchiang
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18345
Summary:
= Major Changes =
* Add a new mem-table representation, HashCuckooRep, which is based cuckoo hash.
Cuckoo hash uses multiple hash functions. This allows each key to have multiple
possible locations in the mem-table.
- Put: When insert a key, it will try to find whether one of its possible
locations is vacant and store the key. If none of its possible
locations are available, then it will kick out a victim key and
store at that location. The kicked-out victim key will then be
stored at a vacant space of its possible locations or kick-out
another victim. In this diff, the kick-out path (known as
cuckoo-path) is found using BFS, which guarantees to be the shortest.
- Get: Simply tries all possible locations of a key --- this guarantees
worst-case constant time complexity.
- Time complexity: O(1) for Get, and average O(1) for Put if the
fullness of the mem-table is below 80%.
- Default using two hash functions, the number of hash functions used
by the cuckoo-hash may dynamically increase if it fails to find a
short-enough kick-out path.
- Currently, HashCuckooRep does not support iteration and snapshots,
as our current main purpose of this is to optimize point access.
= Minor Changes =
* Add IsSnapshotSupported() to DB to indicate whether the current DB
supports snapshots. If it returns false, then DB::GetSnapshot() will
always return nullptr.
Test Plan:
Run existing tests. Will develop a test specifically for cuckoo hash in
the next diff.
Reviewers: sdong, haobo
Reviewed By: sdong
CC: leveldb, dhruba, igor
Differential Revision: https://reviews.facebook.net/D16155
Summary:
ReadFirstRecord() reads the actual log file from disk on every call. This diff introduces a cache layer on top of ReadFirstRecord(), which should significantly speed up repeated calls to GetUpdatesSince().
I also cleaned up some stuff, but the whole TransactionLogIterator could use some refactoring, especially if we see increased usage.
Test Plan: make check
Reviewers: haobo, sdong, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18387
Summary: As summary. Add two autovectors that get filled up in MakeRoomForWrite and they get deleted outside of mutex
Test Plan: make check
Reviewers: dhruba, haobo, ljin, sdong
Reviewed By: ljin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18249
Summary:
Introducing RocksDBLite! Removes all the non-essential features and reduces the binary size. This effort should help our adoption on mobile.
Binary size when compiling for IOS (`TARGET_OS=IOS m static_lib`) is down to 9MB from 15MB (without stripping)
Test Plan: compiles :)
Reviewers: dhruba, haobo, ljin, sdong, yhchiang
Reviewed By: yhchiang
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17835
Summary:
With multiple column families, especially when manual Flush is executed, we might roll the log file, although the current log file is empty (no data has been written to the log).
After the diff, we won't create new log file if current is empty.
Next, I will write an algorithm that will flush column families that reference old log files (i.e., that weren't flushed in a while)
Test Plan: Added an unit test. Confirmed that unit test failes in master
Reviewers: dhruba, haobo, ljin, sdong
Reviewed By: ljin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17631
Summary:
replace the super version acquisision in tailing itrator with thread
local
Test Plan: will post results
Reviewers: igor, haobo, sdong, yhchiang, dhruba
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17757
Summary: Our measurement shows that sometimes new log::Write's constructor can take hundreds of milliseconds. It's unclear why but just simply move it out of DB mutex.
Test Plan: make all check
Reviewers: haobo, ljin, igor
Reviewed By: haobo
CC: nkg-, yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D17487
Summary: Move several some common logging still in DB mutex to log buffer.
Test Plan: make all check
Reviewers: haobo, igor, ljin, nkg-
Reviewed By: nkg-
CC: nkg-, yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D17439
Summary: This patch fixed a race condition where a log file is moved to archived dir in the middle of GetSortedWalFiles. Without the fix, the log file would be missed in the result, which leads to transaction log iterator gap. A test utility SyncPoint is added to help reproducing the race condition.
Test Plan: TransactionLogIteratorRace; make check
Reviewers: dhruba, ljin
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17121
