Summary:
If DB is not deleted, in concurrent test, the tests might fail because of the previously existing DB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6532

Test Plan:
make clean && make -j24 LITE=1  db_logical_block_size_cache_test && ./db_logical_block_size_cache_test
make clean && make -j24 db_logical_block_size_cache_test && ./db_logical_block_size_cache_test

Differential Revision: D20454734

Pulled By: cheng-chang

fbshipit-source-id: 8abede2ec1d79c1a4fe1bc95fbda489f8f7ee052

Summary:
Fix the build corruption caused by PR https://github.com/facebook/rocksdb/issues/6516

Testing plan: make make asan_check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6535

Differential Revision: D20448614

Pulled By: zhichao-cao

fbshipit-source-id: 4d2a3dae6cdd781fcfe8e28a84ac3f536db1b067

Summary:
After we had a lot of failures with maven.org downloads, we
wanted an alternative location for downloading binary dependencies.
Hosting them through github would have been good in terms of
organizational and network dependencies, but that approach seems to be
awkward (fake releases, so would need a 'rocksdb-deps' repo) and
strangely complicated for Facebook policy on open source repositories.

This commit moves the downloads (that are not officially hosted by
others on github) from my personal rocksdb fork to an S3 bucket owned
by the Facebook RocksDB AWS account. Facebook employees can access
this through an internal tool, and we should be able to grant permission
to outside collaborators.

Assuming this works out, I will back-port to older branches to stabilize
their CI testing as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6526

Test Plan: CI

Differential Revision: D20430130

Pulled By: pdillinger

fbshipit-source-id: df52394a65e0a57942db3039bdaade8a4d520cb2

Summary:
In some of the test, db_basic_test may cause time out due to its long running time. Separate the timestamp related test from db_basic_test to avoid the potential issue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6516

Test Plan: pass make asan_check

Differential Revision: D20423922

Pulled By: zhichao-cao

fbshipit-source-id: d6306f89a8de55b07bf57233e4554c09ef1fe23a

Summary:
block_based_table_reader.cc is a giant file, which makes it hard for users to navigate the code. Divide the files to multiple files.
Some class templates cannot be moved to .cc file. They are moved to .h files. It is still better than including them all in block_based_table_reader.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6527

Test Plan: "make all check" and "make release". Also build using cmake.

Differential Revision: D20428455

fbshipit-source-id: ca713c698469f07f35bc0c271358c0874ed4eb28

Summary:
This patch based on https://github.com/facebook/rocksdb/issues/5932 offers a better solution to add arm64 to TravisCI matrix.
Really thank adamretter for initiating Arm CI setup.

Difference comparing to amd64:
1. For CMake, as no official arm64 release ready on Kitware page,
a third party (conda-forge) released one is used instead of
building from source. The main reason is to save CI time.
2. Explicit export JAVA_HOME on arm64
3. Disable mingw test
Signed-off-by: NYuqi Gu <yuqi.gu@arm.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6436

Differential Revision: D20428505

Pulled By: pdillinger

fbshipit-source-id: 81ef02435e41480bb71710b783d85ebf452ce926

Summary:
tcc gtest runner need to know the location of the binary in order to collect coverage.  We can give them the location in an environment variable.

Note that all these tests will break in tpx currently, though this is a bug in rocksdb's wrapper script, not tpx.

Reviewed By: siying

Differential Revision: D20430043

fbshipit-source-id: c77d5f70bbc28f6011c6f91906bce2ceecc2f167

Summary:
Update example usage of closing column family.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6505

Test Plan: cd examples && make column_families_example && ./column_families_example

Differential Revision: D20362100

Pulled By: cheng-chang

fbshipit-source-id: 493c5e0068a40b4f237f8f8511cddd22dc15ea5c

Summary:
In DBLogicalBlockSizeCacheTest, do not test OpenForReadOnly in LITE mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6523

Test Plan: watch test for LITE mode

Differential Revision: D20420321

Pulled By: cheng-chang

fbshipit-source-id: e45bf6f2800206d6f8ce9af7308e76a08de80643

Summary:
In the `.travis.yml` file the `jdk: openjdk7` element is ignored when `language: cpp`. So whatever version of the JDK that was installed in the Travis container was used - typically JDK 11.

To ensure our RocksJava builds are working, we now instead install and use OpenJDK 8. Ideally we would use OpenJDK 7, as RocksJava supports Java 7, but many of the newer Travis containers don't support Java 7, so Java 8 is the next best thing.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6512

Differential Revision: D20388296

Pulled By: pdillinger

fbshipit-source-id: 8bbe6b59b70cfab7fe81ff63867d907fefdd2df1

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6519

Test Plan:
```
make all
make check
```

Differential Revision: D20400691

Pulled By: ltamasi

fbshipit-source-id: 20ef911cf1c2c92c7f71ef0b493f9be64f2eef94

Summary:
fix a few build warnings that are treated as failures with more strict MSVC warning settings
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6517

Differential Revision: D20401325

Pulled By: pdillinger

fbshipit-source-id: b44979dfaafdc7b3b8cb44a565400a99b331dd30

Summary:
Remove copy of pairs from the for range loop
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6514

Test Plan: make check

Differential Revision: D20389688

Pulled By: cheng-chang

fbshipit-source-id: 1c772091f955be33267514010f3596c61a6f46b5

Summary:
In Linux, when reopening DB with many SST files, profiling shows that 100% system cpu time spent for a couple of seconds for `GetLogicalBufferSize`. This slows down MyRocks' recovery time when site is down.

This PR introduces two new APIs:
1. `Env::RegisterDbPaths` and `Env::UnregisterDbPaths` lets `DB` tell the env when it starts or stops using its database directories . The `PosixFileSystem` takes this opportunity to set up a cache from database directories to the corresponding logical block sizes.
2. `LogicalBlockSizeCache` is defined only for OS_LINUX to cache the logical block sizes.

Other modifications:
1. rename `logical buffer size` to `logical block size` to be consistent with Linux terms.
2. declare `GetLogicalBlockSize` in `PosixHelper` to expose it to `PosixFileSystem`.
3. change the functions `IOError` and `IOStatus` in `env/io_posix.h` to have external linkage since they are used in other translation units too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6457

Test Plan:
1. A new unit test is added for `LogicalBlockSizeCache` in `env/io_posix_test.cc`.
2. A new integration test is added for `DB` operations related to the cache in `db/db_logical_block_size_cache_test.cc`.

`make check`

Differential Revision: D20131243

Pulled By: cheng-chang

fbshipit-source-id: 3077c50f8065c0bffb544d8f49fb10bba9408d04

Summary:
When users fail to open a DB with file lock failure, it is sometimes hard for users to debug. We now include the time the lock is acquired and the thread ID that acquired the lock, to help users debug problems like this. Default Env's thread ID is used.

Since type of lockedFiles is changed, rename it to follow naming convention too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6507

Test Plan: Add a unit test and improve an existing test to validate the case.

Differential Revision: D20378333

fbshipit-source-id: 312fe0e9733fd1d1e9969c321b90ce523cf4708a

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6513

Test Plan: `make unity_test`

Differential Revision: D20388919

Pulled By: ltamasi

fbshipit-source-id: 88dbceab0723a54ee3939e1644e13dc9a4c70420

Summary:
Let's see how this goes...
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6144

Differential Revision: D20387515

Pulled By: pdillinger

fbshipit-source-id: ba2669348c267141dfddff910b4c2224a22cbb38

Summary:
* **macOS version:** 10.15.2 (Catalina)
* **XCode/Clang version:** Apple clang version 11.0.0 (clang-1100.0.33.16)

Before this bugfix the error generated is:

```
In file included from ./util/compression.h:23:
./snappy-1.1.7/snappy.h:76:59: error: unknown type name 'string'; did you mean 'std::string'?
  size_t Compress(const char* input, size_t input_length, string* output);
                                                          ^~~~~~
                                                          std::string
/Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/iosfwd:211:65: note: 'std::string' declared here
typedef basic_string<char, char_traits<char>, allocator<char> > string;
                                                                ^
In file included from db/builder.cc:10:
In file included from ./db/builder.h:12:
In file included from ./db/range_tombstone_fragmenter.h:15:
In file included from ./db/pinned_iterators_manager.h:12:
In file included from ./table/internal_iterator.h:13:
In file included from ./table/format.h:25:
In file included from ./options/cf_options.h:14:
In file included from ./util/compression.h:23:
./snappy-1.1.7/snappy.h:85:19: error: unknown type name 'string'; did you mean 'std::string'?
                  string* uncompressed);
                  ^~~~~~
                  std::string
/Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/iosfwd:211:65: note: 'std::string' declared here
typedef basic_string<char, char_traits<char>, allocator<char> > string;
                                                                ^
2 errors generated.
make: *** [jls/db/builder.o] Error 1
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6496

Differential Revision: D20389254

Pulled By: pdillinger

fbshipit-source-id: 2864245c8d0dba7b2ab81294241a62f2adf02e20

Summary:
This helps to diagnose errors in the CMake build where it tries to retrieve dependencies.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6511

Differential Revision: D20387392

Pulled By: pdillinger

fbshipit-source-id: 7028dfd62704bcc747f39ff864ea9c9bf51cd1be

Summary:
It's never too soon to refactor something. The patch splits the recently
introduced (`VersionEdit` related) `BlobFileState` into two classes
`BlobFileAddition` and `BlobFileGarbage`. The idea is that once blob files
are closed, they are immutable, and the only thing that changes is the
amount of garbage in them. In the new design, `BlobFileAddition` contains
the immutable attributes (currently, the count and total size of all blobs, checksum
method, and checksum value), while `BlobFileGarbage` contains the mutable
GC-related information elements (count and total size of garbage blobs). This is a
better fit for the GC logic and is more consistent with how SST files are handled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6502

Test Plan: `make check`

Differential Revision: D20348352

Pulled By: ltamasi

fbshipit-source-id: ff93f0121e80ab15e0e0a6525ba0d6af16a0e008

Summary:
Add sequence_number_ptr to the checkpoint interface to expose the sequence number during taking the checkpoint. The number will be consistent with the seq # in rocksdb log.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5528

Test Plan: make check -j64

Reviewed By: Winger1994

Differential Revision: D16080209

fbshipit-source-id: 6dc3c7680287ee97d673c5e61f89aae1f43e33df

Summary:
Allow user to specify options.max_open_files != -1 with FIFO compaction.
If max_open_files != -1, not all table files are kept open.
In the past, FIFO style compaction requires all table files to be open in order
to read file creation time from table properties. Later, we added file creation
time to MANIFEST, making it possible to read file creation time without opening
file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6503

Test Plan: make check

Differential Revision: D20353758

Pulled By: riversand963

fbshipit-source-id: ba5c61a648419e47e9ef6d74e0e280e3ee24f296

Summary:
Preliminary support for iterator with user timestamp. Current implementation does not consider merge operator and reverse iterator. Auto compaction is also disabled in unit tests.

Create an iterator with timestamp.
```
...
read_opts.timestamp = &ts;
auto* iter = db->NewIterator(read_opts);
// target is key without timestamp.
for (iter->Seek(target); iter->Valid(); iter->Next()) {}
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {}
delete iter;
read_opts.timestamp = &ts1;
// lower_bound and upper_bound are without timestamp.
read_opts.iterate_lower_bound = &lower_bound;
read_opts.iterate_upper_bound = &upper_bound;
auto* iter1 = db->NewIterator(read_opts);
// Do Seek or SeekToFirst()
delete iter1;
```

Test plan (dev server)
```
$make check
```

Simple benchmarking (dev server)
1. The overhead introduced by this PR even when timestamp is disabled.
key size: 16 bytes
value size: 100 bytes
Entries: 1000000
Data reside in main memory, and try to stress iterator.
Repeated three times on master and this PR.
- Seek without next
```
./db_bench -db=/dev/shm/rocksdbtest-1000 -benchmarks=fillseq,seekrandom -enable_pipelined_write=false -disable_wal=true -format_version=3
```
master: 159047.0 ops/sec
this PR: 158922.3 ops/sec (2% drop in throughput)
- Seek and next 10 times
```
./db_bench -db=/dev/shm/rocksdbtest-1000 -benchmarks=fillseq,seekrandom -enable_pipelined_write=false -disable_wal=true -format_version=3 -seek_nexts=10
```
master: 109539.3 ops/sec
this PR: 107519.7 ops/sec (2% drop in throughput)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6255

Differential Revision: D19438227

Pulled By: riversand963

fbshipit-source-id: b66b4979486f8474619f4aa6bdd88598870b0746

Summary:
In direct IO mode, RandomAccessFileReader::Read allocates an internal aligned buffer, and then copies the result into the scratch buffer. If the result is only temporarily used inside a function, there is no need to do the memcpy and just let the result Slice refer to the internally allocated buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6455

Test Plan: make check

Differential Revision: D20106753

Pulled By: cheng-chang

fbshipit-source-id: 44f505843837bba47a56e3fa2c4dd3bd76486b58

Summary:
In most places in the code the variable names are spelled correctly as
COMMITTED but in a couple places not. This fixes them and ensures the
variable is always called COMMITTED everywhere.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6481

Differential Revision: D20306776

Pulled By: pdillinger

fbshipit-source-id: b6c1bfe41db559b4bc6955c530934460c07f7022

Summary:
`TruncateLastLogAfterRecoverWithoutFlush` case depends on fallocate support
of underlying file system.

On a file system which lacks of this feature, like zfs, it will fail to allocate predefined file size as this test case intends to do;

So a check block is added to detect fallocate support and skip test if not.
The related work is done by JunHe77. Thanks!
Signed-off-by: NYuqi Gu <yuqi.gu@arm.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6437

Differential Revision: D20145032

Pulled By: pdillinger

fbshipit-source-id: c8b691dc508e95acfa2a004ddbc07e2faa76680d

Summary:
In CompactRange, if there is no key in memtable falling in the specified range, then flush is skipped.
This PR extends this skipping logic to SST file levels: it starts compaction from the highest level (starting from L0) that has files with key falling in the specified range, instead of always starts from L0.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6482

Test Plan:
A new test ManualCompactionTest::SkipLevel is added.

Also updated a test related to statistics of index block cache hit in db_test2, the index cache hit is increased by 1 in this PR because when checking overlap for the key range in L0, OverlapWithLevelIterator will do a seek in the table cache iterator, which will read from the cached index.

Also updated db_compaction_test and db_test to use correct range for full compaction.

Differential Revision: D20251149

Pulled By: cheng-chang

fbshipit-source-id: f822157cf4796972bd5035d9d7178d8dfb7af08b

Summary:
In the current code base, we can use FaultInjectionTestEnv to simulate the env issue such as file write/read errors, which are used in most of the test. The PR https://github.com/facebook/rocksdb/issues/5761 introduce the File System as a new Env API. This PR implement the FaultInjectionTestFS, which can be used to simulate when File System has issues such as IO error. user can specify any IOStatus error as input, such that FS corresponding actions will return certain error to the caller.

A set of ErrorHandlerFSTests are introduced for testing
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6414

Test Plan: pass make asan_check, pass error_handler_fs_test.

Differential Revision: D20252421

Pulled By: zhichao-cao

fbshipit-source-id: e922038f8ce7e6d1da329fd0bba7283c4b779a21

Summary:
Check for sys/auxv.h and getauxval before using them as they are not
always available (for example on uclibc)
Signed-off-by: NFabrice Fontaine <fontaine.fabrice@gmail.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6359

Differential Revision: D20239797

fbshipit-source-id: 175a098094d81545628c2372e7c388e70a32fd48

Summary:
this silences following warning from clang-11
```
rocksdb/db/db_impl/db_impl_compaction_flush.cc:1040:21: warning: loop variable 'newf' of type 'const std::pair<int, rocksdb::FileMetaData>' creates a copy from type 'const
std::pair<int\
, rocksdb::FileMetaData>' [-Wrange-loop-analysis]
    for (const auto newf : c->edit()->GetNewFiles()) {
                    ^
rocksdb/db/db_impl/db_impl_compaction_flush.cc:1040:10: note: use reference type 'const std::pair<int, rocksdb::FileMetaData> &' to prevent copying
    for (const auto newf : c->edit()->GetNewFiles()) {
         ^~~~~~~~~~~~~~~~~
                    &
```
Signed-off-by: NKefu Chai <tchaikov@gmail.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6477

Differential Revision: D20211850

Pulled By: ltamasi

fbshipit-source-id: 3e89e13a12bba79f1b934d46b7c4c0576cdafb01

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6474

Differential Revision: D20205109

Pulled By: ltamasi

fbshipit-source-id: ec136005c63740f5b713ff537b5671ea9b8e217a

Summary:
When DBImpl::GetCreationTimeOfOldestFile() calls Version::GetCreationTimeOfOldestFile(), the version is not directly or indirectly referenced, so an event like compaction can race with the operation and cause DBImpl::GetCreationTimeOfOldestFile() to access delocated data. This was caught by an ASAN run:

==268==ERROR: AddressSanitizer: heap-use-after-free on address 0x612000b7d198 at pc 0x000018332913 bp 0x7f391510d310 sp 0x7f391510d308
READ of size 8 at 0x612000b7d198 thread T845 (store_load-33)
SCARINESS: 51 (8-byte-read-heap-use-after-free)
    #0 0x18332912 in rocksdb::Version::GetCreationTimeOfOldestFile(unsigned long*) rocksdb/src/db/version_set.cc:1488
    https://github.com/facebook/rocksdb/issues/1 0x1803ddaa in rocksdb::DBImpl::GetCreationTimeOfOldestFile(unsigned long*) rocksdb/src/db/db_impl/db_impl.cc:4499
    https://github.com/facebook/rocksdb/issues/2 0xe24ca09 in rocksdb::StackableDB::GetCreationTimeOfOldestFile(unsigned long*) rocksdb/utilities/stackable_db.h:392
    ......
0x612000b7d198 is located 216 bytes inside of 296-byte region [0x612000b7d0c0,0x612000b7d1e8)
freed by thread T28 here:
    ......
    https://github.com/facebook/rocksdb/issues/5 0x1832c73f in std::vector<rocksdb::FileMetaData*, std::allocator<rocksdb::FileMetaData*> >::~vector() third-party-buck/platform007/build/libgcc/include/c++/trunk/bits/stl_vector.h:435
    https://github.com/facebook/rocksdb/issues/6 0x1832c73f in rocksdb::VersionStorageInfo::~VersionStorageInfo() rocksdb/src/db/version_set.cc:734
    https://github.com/facebook/rocksdb/issues/7 0x1832cf42 in rocksdb::Version::~Version() rocksdb/src/db/version_set.cc:758
    https://github.com/facebook/rocksdb/issues/8 0x9d1bb5 in rocksdb::Version::Unref() rocksdb/src/db/version_set.cc:2869
    https://github.com/facebook/rocksdb/issues/9 0x183e7631 in rocksdb::Compaction::~Compaction() rocksdb/src/db/compaction/compaction.cc:275
    https://github.com/facebook/rocksdb/issues/10 0x9e6de6 in std::default_delete<rocksdb::Compaction>::operator()(rocksdb::Compaction*) const third-party-buck/platform007/build/libgcc/include/c++/trunk/bits/unique_ptr.h:78
    https://github.com/facebook/rocksdb/issues/11 0x9e6de6 in std::unique_ptr<rocksdb::Compaction, std::default_delete<rocksdb::Compaction> >::reset(rocksdb::Compaction*) third-party-buck/platform007/build/libgcc/include/c++/trunk/bits/unique_ptr.h:376
    https://github.com/facebook/rocksdb/issues/12 0x9e6de6 in rocksdb::DBImpl::BackgroundCompaction(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::DBImpl::PrepickedCompaction*, rocksdb::Env::Priority) rocksdb/src/db/db_impl/db_impl_compaction_flush.cc:2826
    https://github.com/facebook/rocksdb/issues/13 0x9ac3b8 in rocksdb::DBImpl::BackgroundCallCompaction(rocksdb::DBImpl::PrepickedCompaction*, rocksdb::Env::Priority) rocksdb/src/db/db_impl/db_impl_compaction_flush.cc:2320
    https://github.com/facebook/rocksdb/issues/14 0x9abff7 in rocksdb::DBImpl::BGWorkCompaction(void*) rocksdb/src/db/db_impl/db_impl_compaction_flush.cc:2096
    ......

Fix the issue by reference the super version and use the referenced version from it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6473

Test Plan: Run ASAN for all existing tests.

Differential Revision: D20196416

fbshipit-source-id: 5f4a7918110fc7b8dd7841932d376bc9d1e59d6f

Summary:
In the current code base, we can use Directory from Env to manage directory (e.g, Fsync()). The PR https://github.com/facebook/rocksdb/issues/5761  introduce the File System as a new Env API. So we further replace the Directory class in DB with FSDirectory such that we can have more IO information from IOStatus returned by FSDirectory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6468

Test Plan: pass make asan_check

Differential Revision: D20195261

Pulled By: zhichao-cao

fbshipit-source-id: 93962cb9436852bfcfb76e086d9e7babd461cbe1

Summary:
Added new Get() methods that return timestamp. Dummy implementation is given so that classes derived from DB don't need to be touched to provide their implementation. MultiGet is not included.

ReadRandom perf test (10 minutes) on the same development machine ram drive with the same DB data shows no regression (within marge of error). The test is adapted from https://github.com/facebook/rocksdb/wiki/RocksDB-In-Memory-Workload-Performance-Benchmarks.
    base line (commit 72ee067b):
        101.712 micros/op 314602 ops/sec;   36.0 MB/s (5658999 of 5658999 found)
    This PR:
        100.288 micros/op 319071 ops/sec;   36.5 MB/s (5674999 of 5674999 found)

./db_bench --db=r:\rocksdb.github --num_levels=6 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --cache_size=2147483648 --cache_numshardbits=6 --compression_type=none --compression_ratio=1 --min_level_to_compress=-1 --disable_seek_compaction=1 --hard_rate_limit=2 --write_buffer_size=134217728 --max_write_buffer_number=2 --level0_file_num_compaction_trigger=8 --target_file_size_base=134217728 --max_bytes_for_level_base=1073741824 --disable_wal=0 --wal_dir=r:\rocksdb.github\WAL_LOG --sync=0 --verify_checksum=1 --delete_obsolete_files_period_micros=314572800 --max_background_compactions=4 --max_background_flushes=0 --level0_slowdown_writes_trigger=16 --level0_stop_writes_trigger=24 --statistics=0 --stats_per_interval=0 --stats_interval=1048576 --histogram=0 --use_plain_table=1 --open_files=-1 --mmap_read=1 --mmap_write=0 --memtablerep=prefix_hash --bloom_bits=10 --bloom_locality=1 --duration=600 --benchmarks=readrandom --use_existing_db=1 --num=25000000 --threads=32
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6409

Differential Revision: D20200086

Pulled By: riversand963

fbshipit-source-id: 490edd74d924f62bd8ae9c29c2a6bbbb8410ca50

Summary:
As reported in https://github.com/facebook/rocksdb/issues/6467, the
description of the `unordered_write` switch of `db_bench` was incorrect.
(Note: the new description is based on
https://rocksdb.org/blog/2019/08/15/unordered-write.html).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6476

Test Plan: `db_bench --help`

Differential Revision: D20200653

Pulled By: ltamasi

fbshipit-source-id: 4c3683fcfa6a069164167af5aaff9974a810c16a

Summary:
Both clangd and cquery-language-server requires a compile_commands.json file to
index the project. This file can be ignored by git.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6472

Differential Revision: D20194899

Pulled By: riversand963

fbshipit-source-id: ea1587f2e5d10b7591147073b61efe262a1cf747

Summary:
Some combinatino of --index_with_first_key and --index_shortening_mode can signifcantly improve performance for large values. Expose them in db_bench.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5859

Test Plan: Run them with the new options and observe the behavior.

Differential Revision: D20104434

fbshipit-source-id: 21d48a732a9caf20b82312c7d7557d747ea3c304

Summary:
MultiRead tests in env_test cannot simulate the io_uring case when queries need to be submitted in multiple rounds. Add a new unit test to cover up more requests per MultiRead
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6452

Test Plan: Run it and see it pass when liburing is enabled or not enabled.

Differential Revision: D20078924

fbshipit-source-id: 6cff7fe345a4c5aa47135186e6181bf00df02b68

Summary:
Found from Debian's "Lintian" program
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6464

Differential Revision: D20162862

Pulled By: zhichao-cao

fbshipit-source-id: 06941ee2437b038b2b8045becbe9d2c6fbff3e12

Summary:
Today `WriteUnpreparedTxn::RollbackInternal` will write the rollback batch assuming that there is only a single subbatch. However, because untracked_keys_ are currently not deduplicated, it's possible for duplicate keys to exist, and thus split the batch. Also, tracked_keys_ also does not support compators outside of the bytewise comparators, so it's possible for duplicates to occur there as well.

To solve this, just pass in the correct subbatch count.

Also, removed `WriteUnpreparedRollbackPreReleaseCallback` to unify the Commit/Rollback codepaths some more.

Also, fixed a bug in `CommitInternal` where if 1. two_write_queue is true and 2. include_data is true, then `WriteUnpreparedCommitEntryPreReleaseCallback` ends up calling `AddCommitted` on the commit time write batch a second time on the second write. To fix, `WriteUnpreparedCommitEntryPreReleaseCallback` is re-initialized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6463

Differential Revision: D20150153

Pulled By: lth

fbshipit-source-id: df0b42d39406c75af73df995aa1138f0db539cd1