Summary: Add two parameters of hash linked list to log distribution of number of entries across all buckets, and a sample row when there are too many entries in one single bucket.
Test Plan: Turn it on in plain_table_db_test and see the logs.
Reviewers: haobo, ljin
Reviewed By: ljin
Subscribers: leveldb, nkg-, dhruba, yhchiang
Differential Revision: https://reviews.facebook.net/D19095
Some platforms, particularly Windows, do not have a single method that can
release both a held reader lock and a held writer lock; instead, a
separate method (ReleaseSRWLockShared or ReleaseSRWLockExclusive) must be
called in each case.
This may also be necessary to back MutexRW with a shared_mutex in C++14;
the current language proposal includes both an unlock() and a
shared_unlock() method.
Summary:
Fix a bug causing LOG is not created when max_log_file_size is set.
This bug is reported in issue #174.
Test Plan:
Add TEST(AutoRollLoggerTest, LogFileExistence).
make auto_roll_logger_test
./auto_roll_logger_test
Reviewers: haobo, sdong, ljin, igor, igor2
Reviewed By: igor2
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D19053
Summary: as title
Test Plan:
db_bench
the initial result is very promising. I will post results of complete
runs
Reviewers: dhruba, haobo, sdong, igor
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D18867
Summary:
Clean PlainTableReader's data structures:
(1) inline bloom_ (in order to do this, change DynamicBloom to allow lazy initialization)
(2) remove some variables only used when initialization from the class
(3) put variables not used in normal read code paths to the end of the class and reference prefix_extractor directly
(4) make Options a reference.
Test Plan: make all check
Reviewers: haobo, ljin
Reviewed By: ljin
Subscribers: igor, yhchiang, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18891
Summary: Provide an convenience option to create column families if they are missing from the DB. Task #4460490
Test Plan: added unit test. also, stress test for some time
Reviewers: sdong, haobo, dhruba, ljin, yhchiang
Reviewed By: yhchiang
Subscribers: yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D18951
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:
This patch changes meaning of options.bloom_locality: 0 means disable cache line optimization and any positive number means use CACHE_LINE_SIZE as block size (the previous behavior is the block size will be CACHE_LINE_SIZE*options.bloom_locality). By doing it, the divide operations inside a block can be replaced by a shift.
Performance is improved:
https://reviews.facebook.net/P471
Also, improve the basic algorithm in two ways:
(1) make sure num of blocks is an odd number
(2) rotate bytes after every probe in locality mode. Since the divider is 2^n, unless doing it, we are never able to use all the bits.
Improvements of false positive: https://reviews.facebook.net/P459
Test Plan: make all check
Reviewers: ljin, haobo
Reviewed By: haobo
Subscribers: dhruba, yhchiang, igor, leveldb
Differential Revision: https://reviews.facebook.net/D18843
Summary: 220132b65e correctly fixed the issue of thread ID printing when terminating a thread. Nothing wrong with it. This diff prints the ID in the same way as in PosixLogger::logv() so that users can be more easily to correlates them.
Test Plan: run env_test and make sure it prints correctly.
Reviewers: igor, haobo, ljin, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18819
Summary:
Introducing new compaction style -- FIFO.
FIFO compaction style has write amplification of 1 (+1 for WAL) and it deletes the oldest files when the total DB size exceeds pre-configured values.
FIFO compaction style is suited for storing high-frequency event logs.
Test Plan: Added a unit test
Reviewers: dhruba, haobo, sdong
Reviewed By: dhruba
Subscribers: alberts, leveldb
Differential Revision: https://reviews.facebook.net/D18765
Summary: Per request from @nkg-, temporarily print thread ID when a thread terminates. It is a temp solution as we try to minimized stderr messages.
Test Plan: env_test
Reviewers: haobo, igor, dhruba
Reviewed By: igor
CC: nkg-, leveldb
Differential Revision: https://reviews.facebook.net/D18753
Summary:
Add a feature to decrease the number of threads in thread pool.
Also instantly schedule more threads if number of threads is increased.
Here is the way it is implemented: each background thread needs its thread ID. After decreasing number of threads, all threads are woken up. The thread with the largest thread ID will terminate. If there are more threads to terminate, the thread will wake up all threads again.
Another change is made so that when number of threads is increased, more threads are created and all previous excessive threads are woken up to do the work.
Test Plan: Add a unit test.
Reviewers: haobo, dhruba
Reviewed By: haobo
CC: yhchiang, igor, nkg-, leveldb
Differential Revision: https://reviews.facebook.net/D18675
Summary: Copy improvements from fbcode's version of EnvHdfs to our open-source version. Some very important bug fixes in there.
Test Plan: compiles
Reviewers: dhruba, haobo, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18711
Summary: Cleaned up compaction logging a little bit. Now file sizes are easier to read. Also, removed the trailing space.
Test Plan:
verified that i'm happy with logging output:
files_size[#33(seq=101,sz=98KB,0) #31(seq=81,sz=159KB,0) #26(seq=0,sz=637KB,0)]
Reviewers: sdong, haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18549
Summary:
In order to use arena to a use case that the total allocation size might be small (LogBuffer is already such a case), inline 1KB of data in it, so that it can be mostly in stack or inline in another class.
If always inlining 2KB is a concern, I could make it a template to determine what to inline. However, dependents need to changes. Doesn't go with it for now
Test Plan: make all check.
Reviewers: haobo, igor, yhchiang, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18609
Summary: As title
Test Plan: make all check.
Reviewers: haobo, igor, yhchiang
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18705
Summary:
This diff addresses task #4296714 and rethinks how users provide us with TablePropertiesCollectors as part of Options.
Here's description of task #4296714:
I'm debugging #4295529 and noticed that our count of user properties kDeletedKeys is wrong. We're sharing one single InternalKeyPropertiesCollector with all Table Builders. In LOG Files, we're outputting number of kDeletedKeys as connected with a single table, while it's actually the total count of deleted keys since creation of the DB.
For example, this table has 3155 entries and 1391828 deleted keys.
The problem with current approach that we call methods on a single TablePropertiesCollector for all the tables we create. Even worse, we could do it from multiple threads at the same time and TablePropertiesCollector has no way of knowing which table we're calling it for.
Good part: Looks like nobody inside Facebook is using Options::table_properties_collectors. This means we should be able to painfully change the API.
In this change, I introduce TablePropertiesCollectorFactory. For every table we create, we call `CreateTablePropertiesCollector`, which creates a TablePropertiesCollector for a single table. We then use it sequentially from a single thread, which means it doesn't have to be thread-safe.
Test Plan:
Added a test in table_properties_collector_test that fails on master (build two tables, assert that kDeletedKeys count is correct for the second one).
Also, all other tests
Reviewers: sdong, dhruba, haobo, kailiu
Reviewed By: kailiu
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18579
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
