Summary:
Add mid-point insertion functionality to LRU cache. Caller of `Cache::Insert()` can set an additional parameter to make a cache entry have higher priority. The LRU cache will reserve at most `capacity * high_pri_pool_pct` bytes for high-pri cache entries. If `high_pri_pool_pct` is zero, the cache degenerates to normal LRU cache.
Context: If we are to put index and filter blocks into RocksDB block cache, index/filter block can be swap out too early. We want to add an option to RocksDB to reserve some capacity in block cache just for index/filter blocks, to mitigate the issue.
In later diffs I'll update block based table reader to use the interface to cache index/filter blocks at high priority, and expose the option to `DBOptions` and make it dynamic changeable.
Test Plan: unit test.
Reviewers: IslamAbdelRahman, sdong, lightmark
Reviewed By: lightmark
Subscribers: andrewkr, dhruba, march, leveldb
Differential Revision: https://reviews.facebook.net/D61977
Summary:
This is a proof of concept of a RocksDB blob log file. The actual value of the Put() is appended to a blob log using normal data block format, and the handle of the block is written as the value of the key in RocksDB.
The prototype only supports Put() and Get(). It doesn't support DB restart, garbage collection, Write() call, iterator, snapshots, etc.
Test Plan: Add unit tests.
Reviewers: arahut
Reviewed By: arahut
Subscribers: kradhakrishnan, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61485
Summary: With read_options.background_purge_on_iterator_cleanup=true, File deletion and closing can still happen in forward iterator, or WAL file closing. Cover those cases too.
Test Plan: I am adding unit tests.
Reviewers: andrewkr, IslamAbdelRahman, yiwu
Reviewed By: yiwu
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61503
Summary:
compact_on_deletion_collector_test does not support --gtest_list_tests
since it isn't gtest, so the full program would run for the target
gen_parallel_tests. This caused gen_parallel_tests to take 8+ minutes for tsan
and prevented compact_on_deletion_collector_test from running during check_0
since no t/run-* script could be generated.
Test Plan:
run make check, verify generating t/run-* scripts is fast and
./compact_on_deletion_collector_test is now run
Reviewers: IslamAbdelRahman, wanning, lightmark, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D61695
Summary: Implement a time series database that supports DateTieredCompactionStrategy. It wraps a db object and separate SST files in different column families (time windows).
Test Plan: Add `date_tiered_test`.
Reviewers: dhruba, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D61653
Summary: Add a utility function that trigger necessary full compaction and put output to the correct level by looking at new options and old options.
Test Plan: Add unit tests for it.
Reviewers: andrewkr, igor, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: muthu, sumeet, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60783
Summary:
parallel tests are broken because gnu_parallel is reading deprecated options from `/etc/parallel/config`
Fix this by passing `--plain` to ignore `/etc/parallel/config`
Test Plan: make check -j64
Reviewers: kradhakrishnan, sdong, andrewkr, yiwu, arahut
Reviewed By: arahut
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61359
Summary:
Experiments on column-aware encodings. Supported features: 1) extract data blocks from SST file and encode with specified encodings; 2) Decode encoded data back into row format; 3) Directly extract data blocks and write in row format (without prefix encoding); 4) Get column distribution statistics for column format; 5) Dump data blocks separated by columns in human-readable format.
There is still on-going work on this diff. More refactoring is necessary.
Test Plan: Wrote tests in `column_aware_encoding_test.cc`. More tests should be added.
Reviewers: sdong
Reviewed By: sdong
Subscribers: arahut, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60027
Summary:
Removing moreutils from sandcastle and adding gnu parallel.
Then passing in J= nproc command
Test Plan: Testing on sandcastle
Reviewers: sdong, kradhakrishnan
Reviewed By: kradhakrishnan
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61017
Summary:
TickersNameMap is not consistent with Tickers enum.
this cause us to report wrong statistics and sometimes to access TickersNameMap outside it's boundary causing crashes (in Fb303 statistics)
Test Plan: added new unit test
Reviewers: sdong, kradhakrishnan
Reviewed By: kradhakrishnan
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61083
Summary:
Tsan crash white-box test was disabled because it never ends. Re-enable it with reduced killing odds.
Add a parameter in crash test script to allow we pass it through an environment variable.
Test Plan: Run it manually.
Reviewers: IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61053
Summary: Multiput atomiciy is broken across multiple column families if we don't sync WAL before flushing one column family. The WAL file may contain a write batch containing writes to a key to the CF to be flushed and a key to other CF. If we don't sync WAL before flushing, if machine crashes after flushing, the write batch will only be partial recovered. Data to other CFs are lost.
Test Plan: Add a new unit test which will fail without the diff.
Reviewers: yhchiang, IslamAbdelRahman, igor, yiwu
Reviewed By: yiwu
Subscribers: yiwu, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60915
Summary: RocksDB behavior is slightly different between data on tmpfs and normal file systems. Add a test case to run RocksDB on normal file system.
Test Plan: See the tests launched by Phabricator
Reviewers: kradhakrishnan, IslamAbdelRahman, gunnarku
Reviewed By: gunnarku
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60963
EnvLibrados is a customized RocksDB Env to use RADOS as the backend file system of RocksDB. It overrides all file system related API of default Env. The easiest way to use it is just like following:
std::string db_name = "test_db";
std::string config_path = "path/to/ceph/config";
DB* db;
Options options;
options.env = EnvLibrados(db_name, config_path);
Status s = DB::Open(options, kDBPath, &db);
Then EnvLibrados will forward all file read/write operation to the RADOS cluster assigned by config_path. Default pool is db_name+"_pool".
There are some options that users could set for EnvLibrados.
- write_buffer_size. This variable is the max buffer size for WritableFile. After reaching the buffer_max_size, EnvLibrados will sync buffer content to RADOS, then clear buffer.
- db_pool. Rather than using default pool, users could set their own db pool name
- wal_dir. The dir for WAL files. Because RocksDB only has 2-level structure (dir_name/file_name), the format of wal_dir is "/dir_name"(CAN'T be "/dir1/dir2"). Default wal_dir is "/wal".
- wal_pool. Corresponding pool name for WAL files. Default value is db_name+"_wal_pool"
The example of setting options looks like following:
db_name = "test_db";
db_pool = db_name+"_pool";
wal_dir = "/wal";
wal_pool = db_name+"_wal_pool";
write_buffer_size = 1 << 20;
env_ = new EnvLibrados(db_name, config, db_pool, wal_dir, wal_pool, write_buffer_size);
DB* db;
Options options;
options.env = env_;
// The last level dir name should match the dir name in prefix_pool_map
options.wal_dir = "/tmp/wal";
// open DB
Status s = DB::Open(options, kDBPath, &db);
Librados is required to compile EnvLibrados. Then use "$make LIBRADOS=1" to compile RocksDB. If you want to only compile EnvLibrados test, just run "$ make env_librados_test LIBRADOS=1". To run env_librados_test, you need to have a running RADOS cluster with the configure file located in "../ceph/src/ceph.conf" related to "rocksdb/".
Summary:
Fix flush not being commit while writing manifest, which is a recent bug introduced by D60075.
The issue:
# Options.max_background_flushes > 1
# Background thread A pick up a flush job, flush, then commit to manifest. (Note that mutex is released before writing manifest.)
# Background thread B pick up another flush job, flush. When it gets to `MemTableList::InstallMemtableFlushResults`, it notices another thread is commiting, so it quit.
# After the first commit, thread A doesn't double check if there are more flush result need to commit, leaving the second flush uncommitted.
Test Plan: run the test. Also verify the new test hit deadlock without the fix.
Reviewers: sdong, igor, lightmark
Reviewed By: lightmark
Subscribers: andrewkr, omegaga, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D60969
The tests run by `make check` require Bash. On Debian you'd need to run
the test as `make SHELL=/bin/bash check`. This commit makes it work on
all POSIX compatible shells (tested on Debian with `dash`).
Summary: As Title.
Test Plan: See how the diff works.
Reviewers: kradhakrishnan, andrewkr, gunnarku
Reviewed By: gunnarku
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60933
Summary:
When write stalls because of auto compaction is disabled, or stop write trigger is reached,
user may change these two options to unblock writes. Unfortunately we had issue where the write
thread will block the attempt to persist the options, thus creating a deadlock. This diff
fix the issue and add two test cases to detect such deadlock.
Test Plan:
Run unit tests.
Also, revert db_impl.cc to master (but don't revert `DBImpl::BackgroundCompaction:Finish` sync point) and run db_options_test. Both tests should hit deadlock.
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D60627
Summary: In D33849 we updated Makefile to generate .d files for all .cc sources. Since we have more types of source files now, this needs to be updated so that this mechanism can work for new files.
Test Plan: change a dependent .h file, re-make and see if .o file is recompiled.
Reviewers: sdong, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D60591
Summary:
Update Makefile to show warnings when we have invalid paths in our make_config.mk file
sample output
```
$ make static_lib -j64
Makefile:150: Warning: /mnt/gvfs/third-party2/libgcc/53e0eac8911888a105aa98b9a35fe61cf1d8b278/4.9.x/gcc-4.9-glibc-2.20/024dbc3/libs dont exist
Makefile:150: Warning: /mnt/gvfs/third-party2/llvm-fb/b91de48a4974ec839946d824402b098d43454cef/stable/centos6-native/7aaccbe/../../src/clang/tools/scan-build/scan-build dont exist
GEN util/build_version.cc
```
Test Plan: check that warning is printed visually
Reviewers: sdong, yiwu, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59523
Summary:
This provides provides an implementation of PersistentCacheTier that is
specialized for RAM. This tier does not persist data though.
Why do we need this tier ?
This is ideal as tier 0. This tier can host data that is too hot.
Why can't we use Cache variants ?
Yes you can use them instead. This tier can potentially outperform BlockCache
in RAW mode by virtue of compression and compressed cache in block cache doesn't
seem very popular. Potentially this tier can be modified to under stand the
disadvantage of the tier below and retain data that the tier below is bad at
handling (for example index and bloom data that is huge in size)
Test Plan: Run unit tests added
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57069
Summary:
- Provide env_test as a static library. We will build it for future releases so internal Envs can use env_test by linking against this library.
- Add tests for CustomEnv, which is configurable via ENV_TEST_URI environment variable. It uses the URI-based Env lookup (depends on D58449).
- Refactor env_basic_test cases to use a unique/configurable directory for test files.
Test Plan:
built a test binary against librocksdb_env_test.a. It registered the
default Env with URI prefix "a://".
- verify runs all CustomEnv tests when URI with correct prefix is provided
```
$ ENV_TEST_URI="a://ok" ./tmp --gtest_filter="CustomEnv/*"
...
[ PASSED ] 12 tests.
```
- verify runs no CustomEnv tests when URI with non-matching prefix is provided
```
$ ENV_TEST_URI="b://ok" ./tmp --gtest_filter="CustomEnv/*"
...
[ PASSED ] 0 tests.
```
Reviewers: ldemailly, IslamAbdelRahman, lightmark, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D58485
Summary:
Extracted basic Env-related tests from mock_env_test and memenv_test into a
parameterized test for Envs: env_basic_test.
Depends on D58449. (The dependency is here only so I can keep this series of
diffs in a chain -- there is no dependency on that diff's code.)
Test Plan: ran tests
Reviewers: IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D58635
Summary:
This enables configurable Envs without recompiling. For example, my
next diff will make env_test test an Env created by NewEnvFromUri(). Then,
users can determine which Env is tested simply by providing the URI for
NewEnvFromUri() (e.g., through a CLI argument or environment variable).
The registration process allows us to register any Env that is linked with the
RocksDB library, so we can register our internal Envs as well.
The registration code is inspired by our internal InitRegistry.
Test Plan: new unit test
Reviewers: IslamAbdelRahman, lightmark, ldemailly, sdong
Reviewed By: sdong
Subscribers: leveldb, dhruba, andrewkr
Differential Revision: https://reviews.facebook.net/D58449
Summary:
This patch allows db_bench to initialize it's RocksDB Options via a
options file, specified by the --options_file flag. Note that if
--options_file flag is set, then it has higher priority than the
command-line argument.
Test Plan: db_bench_tool_test
Reviewers: sdong, IslamAbdelRahman, kradhakrishnan, yiwu, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D58533
Summary:
Currently all the tools are included in librocksdb.a (db_bench is not). With
this separate library, we can access db_bench functionality from our internal
repo and eventually move tools out of librocksdb.a.
Test Plan: built a simple binary against this library that invokes db_bench_tool().
Reviewers: IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D58977
Summary: Deprecate this one option and delete code and tests that are now superfluous.
Test Plan: all tests pass
Reviewers: igor, yhchiang, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: msalib, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D55317
Summary:
Introduce MaxOperator a simple merge operator that return the max of all operands.
This merge operand help me in benchmarking
Test Plan: Add new unitttests
Reviewers: sdong, andrewkr, yhchiang
Reviewed By: yhchiang
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D57873
Summary:
This is a part of effort to reduce the size of db_test.cc. We move the following tests to a separate file `db_io_failure_test.cc`:
* DropWrites
* DropWritesFlush
* NoSpaceCompactRange
* NonWritableFileSystem
* ManifestWriteError
* PutFailsParanoid
Test Plan: Run `make check` to see if the tests are working properly.
Reviewers: sdong, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D58341
Summary:
We expect the persistent read cache to perform at speeds upto 8 GB/s. In order
to accomplish that, we need build a index mechanism which operate in the order
of multiple millions per sec rate.
This patch provide the basic data structure to accomplish that:
(1) Hash table implementation with lock contention spread
It is based on the StripedHashSet<T> implementation in
The Art of multiprocessor programming by Maurice Henry & Nir Shavit
(2) LRU implementation
Place holder algorithm for further optimizing
(3) Evictable Hash Table implementation
Building block for building index data structure that evicts data like files
etc
TODO:
(1) Figure if the sharded hash table and LRU can be used instead
(2) Figure if we need to support configurable eviction algorithm for
EvictableHashTable
Test Plan: Run unit tests
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D55785
Summary:
Introduced option to dump malloc statistics using new option flag.
Added new command line option to db_bench tool to enable this
funtionality.
Also extended build to support environments with/without jemalloc.
Test Plan:
1) Build rocksdb using `make` command. Launch the following command
`./db_bench --benchmarks=fillrandom --dump_malloc_stats=true
--num=10000000` end verified that jemalloc dump is present in LOG file.
2) Build rocksdb using `DISABLE_JEMALLOC=1 make db_bench -j32` and ran
the same db_bench tool and found the following message in LOG file:
"Please compile with jemalloc to enable malloc dump".
3) Also built rocksdb using `make` command on MacOS to verify behavior
in non-FB environment.
Also to debug build configuration change temporary changed
AM_DEFAULT_VERBOSITY = 1 in Makefile to see compiler and build
tools output. For case 1) -DROCKSDB_JEMALLOC was present in compiler
command line. For both 2) and 3) this flag was not present.
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D57321
* Musl libc does not provide adaptive mutex. Added feature test for PTHREAD_MUTEX_ADAPTIVE_NP.
* Musl libc does not provide backtrace(3). Added a feature check for backtrace(3).
* Fixed compiler error.
* Musl libc does not implement backtrace(3). Added platform check for libexecinfo.
* Alpine does not appear to support gcc -pg option. By default (gcc has PIE option enabled) it fails with:
gcc: error: -pie and -pg|p|profile are incompatible when linking
When -fno-PIE and -nopie are used it fails with:
/usr/lib/gcc/x86_64-alpine-linux-musl/5.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: cannot find gcrt1.o: No such file or directory
Added gcc -pg platform test and output PROFILING_FLAGS accordingly. Replaced pg var in Makefile with PROFILING_FLAGS.
* fix segfault when TEST_IOCTL_FRIENDLY_TMPDIR is undefined and default candidates are not suitable
* use ASSERT_DOUBLE_EQ instead of ASSERT_EQ
* When compiled with ROCKSDB_MALLOC_USABLE_SIZE UniversalCompactionFourPaths and UniversalCompactionSecondPathRatio tests fail due to premature memtable flushes on systems with 16-byte alignment. Arena runs out of block space before GenerateNewFile() completes.
Increased options.write_buffer_size.
Summary:
Generate t/run-* scripts to run tests in $PARALLEL_TEST separately, then make check_0 rule execute all of them.
Run `time make check` after running `make all`.
master: 71 sec
with this diff: 63 sec.
It seems moving more tests to $PARALLEL_TEST doesn't help improve test time though.
Test Plan:
Run the following
make check
J=16 make check
J=1 make check
make valgrind_check
J=1 make valgrind_check
J=16 make_valgrind_check
Reviewers: IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: leveldb, kradhakrishnan, dhruba, andrewkr, yhchiang
Differential Revision: https://reviews.facebook.net/D56805
Summary:
Before
{F1131675}
After
{F1131681}
This will have no effect on normal make check
Test Plan: make watch-log
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56847
Summary:
Extend "J=<parallel>" to valgrind_check.
For DBTest, modify the script to run valgrind. For other tests, prefix launch command with valgrind.
Test Plan: Run valgrind_check with J=1 and J>1 and make sure tests run under valgrind. Manually change codes to introduce memory leak and make sure "make watch-log" correctly report it.
Reviewers: yhchiang, yiwu, andrewkr, kradhakrishnan, IslamAbdelRahman
Reviewed By: kradhakrishnan, IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56727
Summary:
- Update Makefile check_some command to run a subset of the tests
- Update travis config to split the unittests job into 2 jobs
-- job testing db_test, db_test2
-- job testing the rest of the unittests
Test Plan:
Run the new travis.yml on my own branch
https://travis-ci.org/facebook/rocksdb/builds/122691453
Reviewers: kradhakrishnan, yhchiang, sdong, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56673
Summary: Test DBOptionsAllFieldsSettable sometimes fails under valgrind. Move option settable tests to a separate test file and disable it in valgrind..
Test Plan: Run valgrind test and make sure the test doesn't run.
Reviewers: andrewkr, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: kradhakrishnan, yiwu, yhchiang, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56529
Summary:
Undefined Behavior Sanitizer (ubsan) is //a good thing// which will help us to find sneaky bugs with low cost. Please see http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ for more details and official GCC documentation for more context: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html.
Changes itself are quite simple and pretty much imitating whatever is implemented for ASan.
Hooking the UBsan validation build to Sandcastle is a separate step and will be dealt as separate diff because code is in internal repository.
Test Plan: Make sure that that there no regressions when it comes to builds and test pass rate.
Reviewers: leveldb, sdong, IslamAbdelRahman, yhchiang
Reviewed By: yhchiang
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56049
Summary:
Basic test cases:
- Manifest is lost or corrupt
- Manifest refers to too many or too few SST files
- SST file is corrupt
- Unflushed data is present when RepairDB is called
Depends on D55065 for its CreateFile() function in file_utils
Test Plan: Ran the tests.
Reviewers: IslamAbdelRahman, yhchiang, yoshinorim, sdong
Reviewed By: sdong
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D55485
Summary:
Cache to have an option to fail Cache::Insert() when full. Update call sites to check status and handle error.
I totally have no idea what's correct behavior of all the call sites when they encounter error. Please let me know if you see something wrong or more unit test is needed.
Test Plan: make check -j32, see tests pass.
Reviewers: anthony, yhchiang, andrewkr, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D54705
Summary: We want to provide a way to detect whether an iterator is stale and needs to be recreated. Add a iterator property to return version number.
Test Plan: Add two unit tests for it.
Reviewers: IslamAbdelRahman, yhchiang, anthony, kradhakrishnan, andrewkr
Reviewed By: andrewkr
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54921
Summary: similar to D52809 add option to exclude zero counters.
Test Plan:
[yiwu@dev4504.prn1 ~/rocksdb] ./iostats_context_test
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from IOStatsContextTest
[ RUN ] IOStatsContextTest.ToString
[ OK ] IOStatsContextTest.ToString (0 ms)
[----------] 1 test from IOStatsContextTest (0 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (0 ms total)
[ PASSED ] 1 test.
Reviewers: anthony, yhchiang, andrewkr, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54591
Summary:
Users are confused on how to get the parallel compilation going. This
can help wire the parallelism.
Test Plan: Run manually
Reviewers: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53931
