Summary:
This diff is addressing multiple things with a single goal -- to make RocksDB easier to use:
* Add some functions to Options that make RocksDB easier to tune.
* Add example code for both simple RocksDB and RocksDB with Column Families.
* Rewrite our README.md
Regarding Options, I took a stab at something we talked about for a long time:
* https://www.facebook.com/groups/rocksdb.dev/permalink/563169950448190/
I added functions:
* IncreaseParallelism() -- easy, increases the thread pool and max_background_compactions
* OptimizeLevelStyleCompaction(memtable_memory_budget) -- the easiest way to optimize rocksdb for less stalls with level style compaction. This is very likely not ideal configuration. Feel free to suggest improvements. I used some of Mark's suggestions from here: https://github.com/facebook/rocksdb/issues/54
* OptimizeUniversalStyleCompaction(memtable_memory_budget) -- optimize for universal compaction.
Test Plan: compiled rocksdb. ran examples.
Reviewers: dhruba, MarkCallaghan, haobo, sdong, yhchiang
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18621
Summary: This variable is not used. Remove it.
Test Plan: build.
Reviewers: haobo, igor, yhchiang
Reviewed By: haobo
CC: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18525
Summary:
TLB page allocation errors are now logged to info logs, instead of stderr.
In order to do that, mem table rep's factory functions take a info logger now.
Test Plan: make all check
Reviewers: haobo, igor, yhchiang
Reviewed By: yhchiang
CC: leveldb, yhchiang, dhruba
Differential Revision: https://reviews.facebook.net/D18471
Summary:
db_test includes Benchmark for LogAndApply. This diff removes it from db_test and puts it into a separate log_and_apply bench. I just wanted to play around with our new benchmark framework and figure out how it works.
I would also like to show you how great it is! I believe right set of microbenchmarks can speed up our productivity a lot and help catch early regressions.
Test Plan: no
Reviewers: dhruba, haobo, sdong, ljin, yhchiang
Reviewed By: yhchiang
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18261
Summary: Added a method that executes a callback on every cache entry.
Test Plan: added a unit test
Reviewers: haobo
Reviewed By: haobo
CC: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D18441
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: Add an option to allocate a piece of memory from huge page TLB. Add options to trigger it in dynamic bloom, plain table indexes andhash linked list hash table.
Test Plan: make all check
Reviewers: haobo, ljin
Reviewed By: haobo
CC: nkg-, dhruba, leveldb, igor, yhchiang
Differential Revision: https://reviews.facebook.net/D18357
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:
This enables user to add a TTL column family to normal DB.
Next step should be to expand StackableDB and create StackableColumnFamily, such that users can for example add geo-spatial column families to normal DB.
Test Plan: added a test
Reviewers: dhruba, haobo, ljin
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18201
Summary:
When TransactionLogIterator comes to EOF, it calls UnmarkEOF and continues reading. However, if glibc cached the EOF status of the file, it will get EOF again, even though the new data might have been written to it.
This has been causing errors in Mac OS.
Test Plan: test passes, was failing before
Reviewers: dhruba, haobo, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18381
Summary:
also add an override option total_order_iteration if you want to use full
iterator with prefix_extractor
Test Plan: make all check
Reviewers: igor, haobo, sdong, yhchiang
Reviewed By: haobo
CC: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D17805
Summary:
Now this gives us the real deal stack trace:
Assertion failed: (false), function GetProperty, file db/db_impl.cc, line 4072.
Received signal 6 (Abort trap: 6)
#0 0x7fff57ce39b9
#1 abort (in libsystem_c.dylib) + 125
#2 basename (in libsystem_c.dylib) + 0
#3 rocksdb::DBImpl::GetProperty(rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*) (in db_test) (db_impl.cc:4072)
#4 rocksdb::_Test_Empty::_Run() (in db_test) (testharness.h:68)
#5 rocksdb::_Test_Empty::_RunIt() (in db_test) (db_test.cc:1005)
#6 rocksdb::test::RunAllTests() (in db_test) (testharness.cc:60)
#7 main (in db_test) (db_test.cc:6697)
#8 start (in libdyld.dylib) + 1
Test Plan: added artificial assert, saw great stack trace
Reviewers: haobo, dhruba, ljin
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18309
Summary: Sometimes, our tests fail because of normal `assert` call. It would be helpful to see stack trace in that case, too.
Test Plan: Added `assert(false)` and verified it prints out stack trace
Reviewers: haobo, dhruba, sdong, ljin, yhchiang
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18291
Summary: While debugging Mac-only issue with ThreadLocalPtr, this was very useful. Let's print out stack trace in MAC OS, too.
Test Plan: Verified that somewhat useful stack trace was generated on mac. Will run PrintStack() on linux, too.
Reviewers: ljin, haobo
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18189
Summary:
make singleton a static member instead of dynamic object. This should
also avoid the race on unique_ptr
Test Plan: make all check
Reviewers: igor, haobo, sdong
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18177
Summary:
Using ThreadLocalPtr as a flag to determine if a mutex is locked or not enables us to implement AssertNotHeld(). It also makes AssertHeld() actually correct.
I had to remove port::Mutex as a dependency for util/thread_local.h, but that's fine since we can just use std::mutex :)
Test Plan: make check
Reviewers: ljin, dhruba, haobo, sdong, yhchiang
Reviewed By: ljin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18171
Summary: Calling Fsync()/Sync() on a file should give the guarantee that whatever you written to the file is now persisted. This is currently not the case, since we might have some data left in application cache as we do Fsync()/Sync(). For example, BuildTable() calls Fsync() without the flush, assuming all sst data is now persisted, but it's actually not. This may result in big inconsistencies.
Test Plan: no test
Reviewers: sdong, dhruba, haobo, ljin, yhchiang
Reviewed By: sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18159
Summary: Added benchmark functionality on the lines of folly/Benchmark.h
Test Plan: Added unit tests
Reviewers: igor, haobo, sdong, ljin, yhchiang, dhruba
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17973
Summary: For some reason, on a subset of our continuous build machines, preallocation is allocating 8 block more than it should be. Let's relax the test a little bit -- now we require the test to allocate *at least* the number of blocks as we told them to.
Test Plan: no
Reviewers: ljin, haobo, sdong
Reviewed By: ljin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18141
Summary:
We don't really need sync_point.o if we're compiling with NDEBUG.
This diff depends on D17823
Test Plan: compiles
Reviewers: haobo, ljin, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17829
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:
This is first step of my effort to reduce size of librocksdb.a for use in mobile.
ldb object files are huge and are ment to be used as a command line tool. I moved them to `tools/` directory and include them only when compiling `ldb`
This diff reduced librocksdb.a from 42MB to 39MB on my mac (not stripped).
Test Plan: ran ldb
Reviewers: dhruba, haobo, sdong, ljin, yhchiang
Reviewed By: yhchiang
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17823
Summary: XCode for some reason injects `#define DEBUG 1` into our code, which makes compile fail because we use `DEBUG` keyword for other stuff. This diff fixes the issue by renaming `DEBUG` to `DEBUG_LEVEL`.
Test Plan: compiles
Reviewers: dhruba, haobo, sdong, yhchiang, ljin
Reviewed By: yhchiang
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17709
Summary: Compiling for iOS has by default turned on -Wmissing-prototypes, which causes rocksdb to fail compiling. This diff turns on -Wmissing-prototypes in our compile options and cleans up all functions with missing prototypes.
Test Plan: compiles
Reviewers: dhruba, haobo, ljin, sdong
Reviewed By: ljin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17649
Summary:
filluniquerandom is painfully slow due to the naive bitmap check to find
out if a key has been seen before. Majority of time is spent on searching
the last few keys. Split a giant BitSet to smaller ones so that we can
quickly check if a BitSet is full and thus can skip quickly.
It used to take over one hour to filluniquerandom for 100M keys, now it
takes about 10 mins.
Test Plan:
unit test
also verified correctness in db_bench and make sure all keys are
generated
Reviewers: igor, haobo, yhchiang
Reviewed By: igor
CC: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D17607
Summary: When opening DB in read-only mode, client can choose to only specify a subset of column families ("default" column family can't be omitted, though)
Test Plan: added a unit test in column_family_test
Reviewers: haobo, sdong, ljin, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17565
Summary: This will allow us to disable them completely for iOS or for better performance
Test Plan: will run make all check
Reviewers: igor, haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17511
Summary: I think this issue was caused by bad merge. We have to initialize bloom_locality, otherwise valgrind complains: "Use of uninitialised value of size 8"
Test Plan: Run valgrind ./prefix_test
Reviewers: ljin
Reviewed By: ljin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17553
Summary: per sdong's request, this will help processor prefetch on n->key case.
Test Plan: make all check
Reviewers: sdong, haobo, igor
Reviewed By: sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17415
Summary: Otherwise, if we compile on machine with SSE4.2 support and run it on machine without the support, we will fail.
Test Plan: compiles, verified that isSse42() gets called.
Reviewers: dhruba
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17505
Summary:
I had to make number of changes to the code and Makefile:
* Add `make lib`, that will create static library without debug info. We need this to avoid growing binary too much. Currently it's 14MB.
* Remove cpuinfo() function and use __SSE4_2__ macro. We actually used the macro as part of Fast_CRC32() function.
As a result, I also accidentally fixed this issue: https://www.facebook.com/groups/rocksdb.dev/permalink/549700778461774/?stream_ref=2
* Remove __thread locals in OS_MACOSX
Test Plan: `make lib PLATFORM=IOS`
Reviewers: ljin, haobo, dhruba, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17475
Summary: Fix some signed and unsigned comparisons to make some other build script happy.
Test Plan: Build and run those changed tests
Reviewers: ljin, igor, haobo
Reviewed By: igor
CC: yhchiang, dhruba, kailiu, leveldb
Differential Revision: https://reviews.facebook.net/D17463
Summary: as title, make it easy to turn on/off profiling at per thread level.
Test Plan: make check
Reviewers: sdong, ljin
Reviewed By: ljin
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17469
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
Disassembling the Extend function shows something that looks
much more healthy now. The SSE 4.2 instructions are right
there in the body of the function.
Intel(R) Core(TM) i7-3540M CPU @ 3.00GHz
Before:
crc32c: 1.305 micros/op 766260 ops/sec; 2993.2 MB/s (4K per op)
After:
crc32c: 0.442 micros/op 2263843 ops/sec; 8843.1 MB/s (4K per op)
Summary: to make it less CPU intensive
Test Plan: ran it
Reviewers: igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17403
Summary:
Fixed a compile error which tries to check whether a size_t < 0 in env_posix.cc
util/env_posix.cc:180:16: error: comparison of unsigned expression < 0 is always false [-Werror,-Wtautological-compare]
} while (r < 0 && errno == EINTR);
~ ^ ~
1 error generated.
Test Plan: make check all
Reviewers: igor, haobo
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17379
Summary:
If auto roll logger can't create a new LOG file on roll (if, for example, somebody deletes rocksdb directory while rocksdb is running, khm), we'll try to call Logv on invalid address and get a SIGSEGV. This diff will fix the issue
Here's the paste of the stack trace: https://phabricator.fb.com/P8276386 (fb-only)
Test Plan: make check is fine, although not really testing error condition
Reviewers: haobo, ljin, yhchiang
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17367
Summary: EINTR means 'please retry'. We don't do that currenty. We should.
Test Plan: make check, although it doesn't really test the new code. we'll just have to believe in the code!
Reviewers: haobo, ljin
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17349
Summary: this causes overflow and asan failure
Test Plan: make asan_check
Reviewers: igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17301
Summary: Since we are optimizing for server workloads, some default values are not optimized any more. We change some of those values that I feel it's less prone to regression bugs.
Test Plan: make all check
Reviewers: dhruba, haobo, ljin, igor, yhchiang
Reviewed By: igor
CC: leveldb, MarkCallaghan
Differential Revision: https://reviews.facebook.net/D16995
Summary: int -> uint64_t
Test Plan:
it think it is pretty obvious
will run asan_check before committing
Reviewers: igor, haobo
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17241
Summary:
By constraining the probes within cache line(s), we can improve the
cache miss rate thus performance. This probably only makes sense for
in-memory workload so defaults the option to off.
Numbers and comparision can be found in wiki:
https://our.intern.facebook.com/intern/wiki/index.php/Ljin/rocksdb_perf/2014_03_17#Bloom_Filter_Study
Test Plan: benchmarked this change substantially. Will run make all check as well
Reviewers: haobo, igor, dhruba, sdong, yhchiang
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17133
Summary:
NewFixedPrefixTransform is leaked in default options. Broken by b47812fba6
Also included in the diff some code cleanup
Test Plan:
valgrind env_test
also make check
Reviewers: haobo, danguo, yhchiang
Reviewed By: danguo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17211
Summary:
This diff adds a new CompactionFilterV2 API that roll up the
decisions of kv pairs during compactions. These kv pairs must share the
same key prefix. They are buffered inside the db.
typedef std::vector<Slice> SliceVector;
virtual std::vector<bool> Filter(int level,
const SliceVector& keys,
const SliceVector& existing_values,
std::vector<std::string>* new_values,
std::vector<bool>* values_changed
) const = 0;
Application can override the Filter() function to operate
on the buffered kv pairs. More details in the inline documentation.
Test Plan:
make check. Added unit tests to make sure Keep, Delete,
Change all works.
Reviewers: haobo
CCs: leveldb
Differential Revision: https://reviews.facebook.net/D15087
Summary:
* PartialMerge api now takes a list of operands instead of two operands.
* Add min_pertial_merge_operands to Options, indicating the minimum
number of operands to trigger partial merge.
* This diff is based on Schalk's previous diff (D14601), but it also
includes necessary changes such as updating the pure C api for
partial merge.
Test Plan:
* make check all
* develop tests for cases where partial merge takes more than two
operands.
TODOs (from Schalk):
* Add test with min_partial_merge_operands > 2.
* Perform benchmarks to measure the performance improvements (can probably
use results of task #2837810.)
* Add description of problem to doc/index.html.
* Change wiki pages to reflect the interface changes.
Reviewers: haobo, igor, vamsi
Reviewed By: haobo
CC: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D16815
Summary: LogBuffer::AddLogToBuffer() uses vsnprintf() in the wrong way, which might cause buffer overflow when log line is too line. Fix it.
Test Plan: Add a unit test to cover most LogBuffer's most logic.
Reviewers: igor, haobo, dhruba
Reviewed By: igor
CC: ljin, yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D17103
Summary:
Everytime a client opens a DB, we do a sanity check that:
* checks the existance of all the necessary files
* verifies that file sizes are correct
Some of the code was stolen from https://reviews.facebook.net/D16935
Test Plan: added a unit test
Reviewers: dhruba, haobo, sdong
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17097
Summary: Added a function/command to check the consistency of live files' meta data
Test Plan:
Manual test (size mismatch, file not exist).
Command test script.
Reviewers: haobo
Reviewed By: haobo
CC: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D16935
Summary:
Based on my recent findings (posted in our internal group), if we use fallocate without KEEP_SIZE flag, we get superior performance of fdatasync() in append-only workloads.
This diff provides an option for user to not use KEEP_SIZE flag, thus optimizing his sync performance by up to 2x-3x.
At one point we also just called posix_fallocate instead of fallocate, which isn't very fast: http://code.woboq.org/userspace/glibc/sysdeps/posix/posix_fallocate.c.html (tl;dr it manually writes out zero bytes to allocate storage). This diff also fixes that, by first calling fallocate and then posix_fallocate if fallocate is not supported.
Test Plan: make check
Reviewers: dhruba, sdong, haobo, ljin
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16761
Summary:
Original Summary:
Yesterday, @ljin and I were debugging various db_stress issues. We suspected one of them happens when we concurrently call NewIterator without prefix_seek on HashSkipList. This test demonstrates it.
Update:
Arena is not thread-safe!! When creating a new full iterator, we *have* to create a new arena, otherwise we're doomed.
Test Plan: SIGSEGV and assertion-throwing test now works!
Reviewers: ljin, haobo, sdong
Reviewed By: sdong
CC: leveldb, ljin
Differential Revision: https://reviews.facebook.net/D16857
Summary:
This is is based on https://reviews.facebook.net/D15027. It's not finished but I would like to give a prototype to avoid arena over-allocation while making better use of the already allocated memory blocks.
Instead of check approximate memtable size, we will take a deeper look at the arena, which incorporate essential idea that @sdong suggests: flush when arena has allocated its last and the last is "almost full"
Test Plan: N/A
Reviewers: haobo, sdong
Reviewed By: sdong
CC: leveldb, sdong
Differential Revision: https://reviews.facebook.net/D15051
Summary:
@igor pointed out that there is a potential data race because of the way we use the newly introduced LogBuffer. After "bg_compaction_scheduled_--" or "bg_flush_scheduled_--", they can both become 0. As soon as the lock is released after that, DBImpl's deconstructor can go ahead and deconstruct all the states inside DB, including the info_log object hold in a shared pointer of the options object it keeps. At that point it is not safe anymore to continue using the info logger to write the delayed logs.
With the patch, lock is released temporarily for log buffer to be flushed before "bg_compaction_scheduled_--" or "bg_flush_scheduled_--". In order to make sure we don't miss any pending flush or compaction, a new flag bg_schedule_needed_ is added, which is set to be true if there is a pending flush or compaction but not scheduled because of the max thread limit. If the flag is set to be true, the scheduling function will be called before compaction or flush thread finishes.
Thanks @igor for this finding!
Test Plan: make all check
Reviewers: haobo, igor
Reviewed By: haobo
CC: dhruba, ljin, yhchiang, igor, leveldb
Differential Revision: https://reviews.facebook.net/D16767
Summary: Add a function to Env so that users can query the waiting queue length of each thread pool
Test Plan: add a test in env_test
Reviewers: haobo
Reviewed By: haobo
CC: dhruba, igor, yhchiang, ljin, nkg-, leveldb
Differential Revision: https://reviews.facebook.net/D16755
