Summary:
Tracing the MultiGet information including timestamp, keys, and CF_IDs to the trace file for analyzing and replay.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8421
Test Plan: make check, add test to trace_analyzer_test
Reviewed By: anand1976
Differential Revision: D29221195
Pulled By: zhichao-cao
fbshipit-source-id: 30c677d6c39ab31ef4bbdf7e0d1fa1fd79f295ff
Summary:
Add request_id in IODebugContext which will be populated by
underlying FileSystem for IOTracing purposes. Update IOTracer to trace
request_id in the tracing records. Provided API
IODebugContext::SetRequestId which will set the request_id and enable
tracing for request_id. The API hides the implementation and underlying
file system needs to call this API directly.
Update DB::StartIOTrace API and remove redundant Env* from the
argument as its not used and DB already has Env that is passed down to
IOTracer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8045
Test Plan: Update unit test.
Differential Revision: D26899871
Pulled By: akankshamahajan15
fbshipit-source-id: 56adef52ee5af0fb3060b607c3af1ec01635fa2b
Summary:
For some branches, I see an error during analyze on this code. I do not know why it is not persistent, but this should address the error:
Logic error | Result of operation is garbage or undefined | trace_replay.cc | Replay | 436 | 30 | View Report
DecodeCFAndKey(trace.payload, &get_payload.cf_id, &get_payload.get_key);
--
433 | } else {
434 | TracerHelper::DecodeGetPayload(&trace, &get_payload);
| 25←Calling 'TracerHelper::DecodeGetPayload'→ | 25 | ← | Calling 'TracerHelper::DecodeGetPayload' | →
25 | ← | Calling 'TracerHelper::DecodeGetPayload' | →
| 29←Returning from 'TracerHelper::DecodeGetPayload'→ | 29 | ← | Returning from 'TracerHelper::DecodeGetPayload' | →
29 | ← | Returning from 'TracerHelper::DecodeGetPayload' | →
435 | }
436 | if (get_payload.cf_id > 0 &&
| 30←The left operand of '>' is a garbage value | 30 | ← | The left operand of '>' is a garbage value
30 | ← | The left operand of '>' is a garbage value
437 | cf_map_.find(get_payload.cf_id) == cf_map_.end()) {
438 | return Status::Corruption("Invalid Column Family ID.");
439 | }
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8121
Reviewed By: zhichao-cao
Differential Revision: D27366022
Pulled By: mrambacher
fbshipit-source-id: 309c05dbab08cd7ab7f15389e8456f09196f37f6
Summary:
For performance purposes, the lower level routines were changed to use a SystemClock* instead of a std::shared_ptr<SystemClock>. The shared ptr has some performance degradation on certain hardware classes.
For most of the system, there is no risk of the pointer being deleted/invalid because the shared_ptr will be stored elsewhere. For example, the ImmutableDBOptions stores the Env which has a std::shared_ptr<SystemClock> in it. The SystemClock* within the ImmutableDBOptions is essentially a "short cut" to gain access to this constant resource.
There were a few classes (PeriodicWorkScheduler?) where the "short cut" property did not hold. In those cases, the shared pointer was preserved.
Using db_bench readrandom perf_level=3 on my EC2 box, this change performed as well or better than 6.17:
6.17: readrandom : 28.046 micros/op 854902 ops/sec; 61.3 MB/s (355999 of 355999 found)
6.18: readrandom : 32.615 micros/op 735306 ops/sec; 52.7 MB/s (290999 of 290999 found)
PR: readrandom : 27.500 micros/op 871909 ops/sec; 62.5 MB/s (367999 of 367999 found)
(Note that the times for 6.18 are prior to revert of the SystemClock).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8033
Reviewed By: pdillinger
Differential Revision: D27014563
Pulled By: mrambacher
fbshipit-source-id: ad0459eba03182e454391b5926bf5cdd45657b67
Summary:
The trace file record and payload encode is fixed, which requires complex backward compatibility resolving. This PR introduce a new trace file format, which makes it easier to add new entries to the payload and does not have backward compatible issues. V 0.1 is still supported in this PR. Added the tracing for lower_bound and upper_bound for iterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7977
Test Plan: make check. tested with old trace file in replay and analyzing.
Reviewed By: anand1976
Differential Revision: D26529948
Pulled By: zhichao-cao
fbshipit-source-id: ebb75a127ce3c07c25a1ccc194c551f917896a76
Summary:
Introduces and uses a SystemClock class to RocksDB. This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.
Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead. There are likely more places that can be changed, but this is a start to show what can/should be done. Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.
There are several Env classes that implement these functions. Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR. It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).
Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858
Reviewed By: pdillinger
Differential Revision: D26006406
Pulled By: mrambacher
fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
Summary:
1. In IOTracing, add filename with each IOTrace record. Filename is stored in file object (Tracing Wrappers).
2. Change the logic of figuring out which additional information (file_size,
length, offset etc) needs to be store with each operation
which is different for different operations.
When new information will be added in future (depends on operation),
this change would make the future additions simple.
Logic: In IOTraceRecord, io_op_data is added and its
bitwise positions represent which additional information need
to added in the record from enum IOTraceOp. Values in IOTraceOp represent bitwise positions.
So if length and offset needs to be stored (IOTraceOp::kIOLen
is 1 and IOTraceOp::kIOOffset is 2), position 1 and 2 (from rightmost bit) will be set
and io_op_data will contain 110.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7885
Test Plan: Updated io_tracer_test and verified the trace file manually.
Reviewed By: anand1976
Differential Revision: D25982353
Pulled By: akankshamahajan15
fbshipit-source-id: ebfc5539cc0e231d7794a6b42b73f5403e360b22
Summary:
A generic algorithm in progress depends on a templatized
version of fastrange, so this change generalizes it and renames
it to fit our style guidelines, FastRange32, FastRange64, and now
FastRangeGeneric.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7436
Test Plan: added a few more test cases
Reviewed By: jay-zhuang
Differential Revision: D23958153
Pulled By: pdillinger
fbshipit-source-id: 8c3b76101653417804997e5f076623a25586f3e8
Summary:
Implement a parsing tool io_tracer_parser that takes IO trace file (binary file) with command line argument --io_trace_file and output file with --output_file and dumps the IO trace records in outputfile in human readable form.
Also added unit test cases that generates IO trace records and calls io_tracer_parse to parse those records.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7333
Test Plan:
make check -j64,
Add unit test cases.
Reviewed By: anand1976
Differential Revision: D23772360
Pulled By: akankshamahajan15
fbshipit-source-id: 9c20519c189362e6663352d08863326f3e496271
Summary:
More tests now pass. When in doubt, I added a TODO comment to check what should happen with an ignored error.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7305
Reviewed By: akankshamahajan15
Differential Revision: D23301262
Pulled By: ajkr
fbshipit-source-id: 5f120edc7393560aefc0633250277bbc7e8de9e6
Summary:
1. Add the wrapper classes FileSystemTracingWrapper, FSSequentialFileTracingWrapper, FSRandomAccessFileTracingWrapper, FSWritableFileTracingWrapper, FSRandomRWFileTracingWrapper that forward the calls to underlying storage system and then pass the file operation information to IOTracer. IOTracer dumps the record in binary format for tracing.
2. Add the wrapper classes FileSystemPtr, FSSequentialFilePtr, FSRandomAccessFilePtr, FSWritableFilePtr and FSRandomRWFilePtr that overload operator-> and return ptr to underlying storage system or Tracing wrapper class based on enabling/disabling of IO tracing. These classes are added to bypass Tracing Wrapper classes when we disable tracing.
3. Add enums in trace.h that distinguish which options need to be added for different file operations(Read, close, write etc) as part of tracing record.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7002
Test Plan: make check -j64
Reviewed By: anand1976
Differential Revision: D22127897
Pulled By: akankshamahajan15
fbshipit-source-id: 74cff58ce5661c9a3832dfaa52483f3b2d8565e0
Summary:
Fix the following error
"./trace_replay/io_tracer.h:20:20: error: redefinition of ‘const unsigned int rocksdb::{anonymous}::kCharSize’
const unsigned int kCharSize = 1;
^~~~~~~~~
In file included from unity.cc:177:
trace_replay/block_cache_tracer.cc:22:20: note: ‘const unsigned int rocksdb::{anonymous}::kCharSize’ previously defined here
const unsigned int kCharSize = 1;"
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7007
Reviewed By: akankshamahajan15
Differential Revision: D22142618
Pulled By: zhichao-cao
fbshipit-source-id: e6dcd51ccc21d1f58df52cdc7a1c88e54cf4f6e8
Summary:
1. As part of IOTracing project, Add a class IOTracer,
IOTraceReader and IOTracerWriter that writes the file operations
information in a binary file. IOTrace Record contains record information
and right now it contains access_timestamp, file_operation, file_name,
io_status, len, offset and later other options will be added when file
system APIs will be call IOTracer.
2. Add few unit test cases that verify that reading and writing to a IO
Trace file is working properly and before start trace and after ending
trace nothing is added to the binary file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6958
Test Plan:
1. make check -j64
2. New testcases for IOTracer.
Reviewed By: anand1976
Differential Revision: D21943375
Pulled By: akankshamahajan15
fbshipit-source-id: 3532204e2a3eab0104bf411ab142e3fdd4fbce54
Summary:
Mostly uninitialized values: some probably written before use, but some seem like bugs. Also, destructor needs to be virtual, and possible use-after-free in test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6935
Test Plan: make check
Reviewed By: siying
Differential Revision: D21885484
Pulled By: pdillinger
fbshipit-source-id: e2e7cb0a0cf196f2b55edd16f0634e81f6cc8e08
Summary:
The multiple CF hash map is not passed to the multi-thread worker. When using multi-thread replay for multiple CFs, it will cause segment fault. Pass the cf_map to the argument.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6787
Test Plan: pass trace replay test.
Reviewed By: yhchiang
Differential Revision: D21339941
Pulled By: zhichao-cao
fbshipit-source-id: 434482b492287e6722c7cd5a706f057c5ec170ce
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433
Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.
Differential Revision: D19977691
fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
Summary:
- Updated our included xxhash implementation to version 0.7.2 (== the latest dev version as of 2019-10-09).
- Using XXH_NAMESPACE (like other fb projects) to avoid potential name collisions.
- Added fastrange64, and unit tests for it and fastrange32. These are faster alternatives to hash % range.
- Use preview version of XXH3 instead of MurmurHash64A for NPHash64
-- Had to update cache_test to increase probability of passing for any given hash function.
- Use fastrange64 instead of % with uses of NPHash64
-- Had to fix WritePreparedTransactionTest.CommitOfDelayedPrepared to avoid deadlock apparently caused by new hash collision.
- Set default seed for NPHash64 because specifying a seed rarely makes sense for it.
- Removed unnecessary include xxhash.h in a popular .h file
- Rename preview version of XXH3 to XXH3p for clarity and to ease backward compatibility in case final version of XXH3 is integrated.
Relying on existing unit tests for NPHash64-related changes. Each new implementation of fastrange64 passed unit tests when manipulating my local build to select it. I haven't done any integration performance tests, but I consider the improved performance of the pieces being swapped in to be well established.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5909
Differential Revision: D18125196
Pulled By: pdillinger
fbshipit-source-id: f6bf83d49d20cbb2549926adf454fd035f0ecc0d
Summary:
In the previous PR https://github.com/facebook/rocksdb/issues/5934 , in the while loop, if/else if is used without ending with else to free the object referenced by ra, it might cause potential memory leak (warning during compiling). Fix it by changing the last "else if" to "else".
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5955
Test Plan: pass make asan check, pass the USE_CLANG=1 TEST_TMPDIR=/dev/shm/rocksdb OPT=-g make -j64 analyze.
Differential Revision: D18071612
Pulled By: zhichao-cao
fbshipit-source-id: 51c00023d0c97c2921507254329aed55d56e1786
Summary:
The pointer ra needs to be freed the status s returns not OK. In the previous PR https://github.com/facebook/rocksdb/issues/5934 , the ra is not freed which might cause potential memory leak. Fix this issue by moving the clarification of ra inside the while loop and freeing it as desired.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5949
Test Plan: pass make asan check.
Differential Revision: D18045726
Pulled By: zhichao-cao
fbshipit-source-id: d5445b7b832c8bb1dafe008bafea7bfe9eb0b1ce
Summary:
In the current trace replay, all the queries are serialized and called by single threads. It may not simulate the original application query situations closely. The multi-threads replay is implemented in this PR. Users can set the number of threads to replay the trace. The queries generated according to the trace records are scheduled in the thread pool job queue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5934
Test Plan: test with make check and real trace replay.
Differential Revision: D17998098
Pulled By: zhichao-cao
fbshipit-source-id: 87eecf6f7c17a9dc9d7ab29dd2af74f6f60212c8
Summary:
This PR adds support in block cache trace analyzer to read from human readable trace file. This is needed when a user does not have access to the binary trace file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5679
Test Plan: USE_CLANG=1 make check -j32
Differential Revision: D16697239
Pulled By: HaoyuHuang
fbshipit-source-id: f2e29d7995816c389b41458f234ec8e184a924db
Summary:
This PR adds four more eviction policies.
- OPT [1]
- Hyperbolic caching [2]
- ARC [3]
- GreedyDualSize [4]
[1] L. A. Belady. 1966. A Study of Replacement Algorithms for a Virtual-storage Computer. IBM Syst. J. 5, 2 (June 1966), 78-101. DOI=http://dx.doi.org/10.1147/sj.52.0078
[2] Aaron Blankstein, Siddhartha Sen, and Michael J. Freedman. 2017. Hyperbolic caching: flexible caching for web applications. In Proceedings of the 2017 USENIX Conference on Usenix Annual Technical Conference (USENIX ATC '17). USENIX Association, Berkeley, CA, USA, 499-511.
[3] Nimrod Megiddo and Dharmendra S. Modha. 2003. ARC: A Self-Tuning, Low Overhead Replacement Cache. In Proceedings of the 2nd USENIX Conference on File and Storage Technologies (FAST '03). USENIX Association, Berkeley, CA, USA, 115-130.
[4] N. Young. The k-server dual and loose competitiveness for paging. Algorithmica, June 1994, vol. 11,(no.6):525-41. Rewritten version of ''On-line caching as cache size varies'', in The 2nd Annual ACM-SIAM Symposium on Discrete Algorithms, 241-250, 1991.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5644
Differential Revision: D16548817
Pulled By: HaoyuHuang
fbshipit-source-id: 838f76db9179f07911abaab46c97e1c929cfcd63
Summary:
- Compute correlation between a few features and predictions, e.g., number of accesses since the last access vs number of accesses till the next access on a block.
- Output human readable trace file so python can consume it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5596
Test Plan: make clean && USE_CLANG=1 make check -j32
Differential Revision: D16373200
Pulled By: HaoyuHuang
fbshipit-source-id: c848d26bc2e9210461f317d7dbee42d55be5a0cc
Summary:
This PR traces the referenced key for Get for all types of blocks. This is useful when evaluating hybrid row-block caches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5548
Test Plan: make clean && USE_CLANG=1 make check -j32
Differential Revision: D16157979
Pulled By: HaoyuHuang
fbshipit-source-id: f6327411c9deb74e35e22a35f66cdbae09ab9d87
Summary:
This PR adds a ghost cache for admission control. Specifically, it admits an entry on its second access.
It also adds a hybrid row-block cache that caches the referenced key-value pairs of a Get/MultiGet request instead of its blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5534
Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32
Differential Revision: D16101124
Pulled By: HaoyuHuang
fbshipit-source-id: b99edda6418a888e94eb40f71ece45d375e234b1
Summary:
This PR associates a unique id with Get and MultiGet. This enables us to track how many blocks a Get/MultiGet request accesses. We can also measure the impact of row cache vs block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5514
Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32
Differential Revision: D16032681
Pulled By: HaoyuHuang
fbshipit-source-id: 775b05f4440badd58de6667e3ec9f4fc87a0af4c
Summary:
This PR is needed for integration into MyRocks. A second call on StartTrace returns Busy so that MyRocks may return an error to the user.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5519
Test Plan: make clean && USE_CLANG=1 make check -j32
Differential Revision: D16055476
Pulled By: HaoyuHuang
fbshipit-source-id: a51772fb0965c873922757eb470a332b1e02a91d
Summary:
This PR adds more callers for table readers. These information are only used for block cache analysis so that we can know which caller accesses a block.
1. It renames the BlockCacheLookupCaller to TableReaderCaller as passing the caller from upstream requires changes to table_reader.h and TableReaderCaller is a more appropriate name.
2. It adds more table reader callers in table/table_reader_caller.h, e.g., kCompactionRefill, kExternalSSTIngestion, and kBuildTable.
This PR is long as it requires modification of interfaces in table_reader.h, e.g., NewIterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5454
Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32.
Differential Revision: D15819451
Pulled By: HaoyuHuang
fbshipit-source-id: b6caa704c8fb96ddd15b9a934b7e7ea87f88092d
Summary:
This PR integrates the block cache tracer into block based table reader. The tracer will write the block cache accesses using the trace_writer. The tracer is null in this PR so that nothing will be logged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5441
Differential Revision: D15772029
Pulled By: HaoyuHuang
fbshipit-source-id: a64adb92642cd23222e0ba8b10d86bf522b42f9b
Summary:
This PR integrates the block cache tracer class into db_impl.cc.
db_impl.cc contains a member variable of AtomicBlockCacheTraceWriter class and passes its reference to the block_based_table_reader.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5433
Differential Revision: D15728016
Pulled By: HaoyuHuang
fbshipit-source-id: 23d5659e8c82d556833dcc1a5558aac8c1f7db71
Summary:
This PR contains the first commit for block cache trace analyzer. It reads a block cache trace file and prints statistics of the traces.
We will extend this class to provide more functionalities.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5425
Differential Revision: D15709580
Pulled By: HaoyuHuang
fbshipit-source-id: 2f43bd2311f460ab569880819d95eeae217c20bb
Summary:
BlockCacheLookupContext only contains the caller for now.
We will trace block accesses at five places:
1. BlockBasedTable::GetFilter.
2. BlockBasedTable::GetUncompressedDict.
3. BlockBasedTable::MaybeReadAndLoadToCache. (To trace access on data, index, and range deletion block.)
4. BlockBasedTable::Get. (To trace the referenced key and whether the referenced key exists in a fetched data block.)
5. BlockBasedTable::MultiGet. (To trace the referenced key and whether the referenced key exists in a fetched data block.)
We create the context at:
1. BlockBasedTable::Get. (kUserGet)
2. BlockBasedTable::MultiGet. (kUserMGet)
3. BlockBasedTable::NewIterator. (either kUserIterator, kCompaction, or external SST ingestion calls this function.)
4. BlockBasedTable::Open. (kPrefetch)
5. Index/Filter::CacheDependencies. (kPrefetch)
6. BlockBasedTable::ApproximateOffsetOf. (kCompaction or kUserApproximateSize).
I loaded 1 million key-value pairs into the database and ran the readrandom benchmark with a single thread. I gave the block cache 10 GB to make sure all reads hit the block cache after warmup. The throughput is comparable.
Throughput of this PR: 231334 ops/s.
Throughput of the master branch: 238428 ops/s.
Experiment setup:
RocksDB: version 6.2
Date: Mon Jun 10 10:42:51 2019
CPU: 24 * Intel Core Processor (Skylake)
CPUCache: 16384 KB
Keys: 20 bytes each
Values: 100 bytes each (100 bytes after compression)
Entries: 1000000
Prefix: 20 bytes
Keys per prefix: 0
RawSize: 114.4 MB (estimated)
FileSize: 114.4 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: NoCompression
Compression sampling rate: 0
Memtablerep: skip_list
Perf Level: 1
Load command: ./db_bench --benchmarks="fillseq" --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000
Run command: ./db_bench --benchmarks="readrandom,stats" --use_existing_db --threads=1 --duration=120 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000 --duration=120
TODOs:
1. Create a caller for external SST file ingestion and differentiate the callers for iterator.
2. Integrate tracer to trace block cache accesses.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5421
Differential Revision: D15704258
Pulled By: HaoyuHuang
fbshipit-source-id: 4aa8a55f8cb1576ffb367bfa3186a91d8f06d93a
Summary:
This PR adds a help class block cache tracer to read/write block cache accesses. It uses the trace reader/writer to perform this task.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5410
Differential Revision: D15612843
Pulled By: HaoyuHuang
fbshipit-source-id: f30fd1e1524355ca87db5d533a5c086728b141ea
Summary:
util/ means for lower level libraries. trace_replay is highly integrated to DB and sometimes call DB. Move it out to a separate directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5376
Differential Revision: D15550938
Pulled By: siying
fbshipit-source-id: f46dce5ceffdc05a73f26379c7bb1b79ebe6c207
