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:
This patch does the following improvement for regression_test.sh
* Allow regression_test.sh to specify OPTIONS_FILE.
* Add header comments that includes examples on how to run the script
  and introduce all configurable parameters.
* bug fix.

Test Plan: Run the example commands in the header comments of regression_test.sh

Reviewers: sdong, yiwu, gunnarku

Reviewed By: gunnarku

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59175

Summary:
Fix 2 issues that was breaking Windows build
1) double to size_t potential downcast warning
2) port_posix is not ready for windows, avoiding building hash_table_bench to
avoid build break

Test Plan: compile in Windoes and make check

Reviewers: sdong, andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59265

Summary: clang was removed from tp2 so change to llvm-fb.

Test Plan:
  USE_CLANG=1 make all -j64

Reviewers: yhchiang, andrewkr, kradhakrishnan, sdong, lightmark, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59259

Closes https://github.com/facebook/rocksdb/issues/835

Summary:
This diff provides the basic interface definitions of persistent read
cache system

PersistentCacheOptions captures the persistent read cache options used to
configure and control the system
PersistentCacheTier provides the basic building block for constructing tiered
cache
PersistentTieredCache provides a logical abstraction of tiers of cache layered
over one another

Test Plan: Compile

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57051

Summary: The path to g++ was outdated. Ran ./build_tools/update_dependencies.sh.

Test Plan: make -j64 all

Reviewers: sdong, lightmark, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59229

* stack_trace,cc: The current Stacktrace code does not compile for FreeBSD

So set it to generate empty routines

* stack_trace,cc: The current Stacktrace code does not compile for FreeBSD

Use the definition also used in other commits

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:
Rocksdb backup and restore rate limiting is currently done per backup/restore.
So, it is difficult to control rate across multiple backup/restores. With this
change, a throttler can be provided. If a throttler is provided, it is used.
Otherwise, a new throttler is created based on the actual rate limits specified
in the options.

Test Plan: Added unit tests

Reviewers: ldemailly, andrewkr, sdong

Reviewed By: andrewkr

Subscribers: igor, yiwu, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56265

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: With `table_options.cache_index_and_filter_blocks = true`, index and filter blocks are stored in block cache. Then people are curious how much of the block cache total size is used by indexes and bloom filters. It will be nice we have a way to report that. It can help people tune performance and plan for optimized hardware setting. We add several enum values for db Statistics. BLOCK_CACHE_INDEX/FILTER_BYTES_INSERT - BLOCK_CACHE_INDEX/FILTER_BYTES_ERASE = current INDEX/FILTER total block size in bytes.

Test Plan:
write a test case called `DBBlockCacheTest.IndexAndFilterBlocksStats`. The result is:
```
[gzh@dev9927.prn1 ~/local/rocksdb]  make db_block_cache_test -j64 && ./db_block_cache_test --gtest_filter=DBBlockCacheTest.IndexAndFilterBlocksStats
Makefile:101: Warning: Compiling in debug mode. Don't use the resulting binary in production
  GEN      util/build_version.cc
  make: `db_block_cache_test' is up to date.
  Note: Google Test filter = DBBlockCacheTest.IndexAndFilterBlocksStats
  [==========] Running 1 test from 1 test case.
  [----------] Global test environment set-up.
  [----------] 1 test from DBBlockCacheTest
  [ RUN      ] DBBlockCacheTest.IndexAndFilterBlocksStats
  [       OK ] DBBlockCacheTest.IndexAndFilterBlocksStats (689 ms)
  [----------] 1 test from DBBlockCacheTest (689 ms total)

  [----------] Global test environment tear-down
  [==========] 1 test from 1 test case ran. (689 ms total)
  [  PASSED  ] 1 test.
```

Reviewers: IslamAbdelRahman, andrewkr, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58677

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: fix flaky test

Test Plan: `make all check`

Reviewers: sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59157

Summary: Add hash table (under persistent cache) to CMake list

Test Plan: Run hash_test in windows and make check in Linux

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59151

Summary:
MemTableList::current_ could be written by background flush thread and
simultaneously read in the user thread (NumNotFlushed() is used in
SwitchMemtable()). Use the lock to prevent this case. Found the error from tsan.

Related: D58833

Test Plan:
  $ OPT=-g COMPILE_WITH_TSAN=1 make -j64 db_test
  $ TEST_TMPDIR=/dev/shm/rocksdb ./db_test --gtest_filter=DBTest.RepeatedWritesToSameKey

Reviewers: lightmark, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59139

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

* Create a callback for memtable becoming immutable

Create a callback for memtable becoming immutable

Create a callback for memtable becoming immutable

moved notification outside the lock

Move sealed notification to unlocked portion of SwitchMemtable

* fix lite build

Summary:
This patch does the following improvement on the regression_test.sh
* allows db_bench being executed at a remost host while storing the
  benchmark results locally.
* kills all db_bench related processes before running db_bench
* better error handling.

Test Plan:
1. Run regression_test.sh both locally and remotely
2. Run multiple regression_test.sh at the same time and make sure
   i. Only one runs successfully.
   ii. The one that runs successfully will kill all other db_bench
       processes before it runs any benchmark.

Reviewers: sdong, yiwu, gunnarku

Reviewed By: gunnarku

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58611

Summary:
Direct IO checkin breaks Windows build. Fixing the code to work for
Windows.

Test Plan: Run env_test in Windows 10 and make check in Linux

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59073

Summary:
We see some write stalls because of number of unflushed memtables. With existing logging I couldn't figure out what's happening exactly. See internal task t11446054 for details if interested. This diff adds:
- logging of memtable creation at info level; I wanted it on multiple occasions for different reasons; also include number of immutable memtables,
- logging of number of remaining immutable memtables after a flush.

Test Plan: ran tests

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58833

Summary: Add asserts around PerfLevel enum

Test Plan: make all check -j32

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D59007

Summary: The function wrapper for LDBCommand::SelectCommand is too long so that Windows build fails with warning "decorated name length exceeded, name was truncated". Shrink the length by using a struct.

Test Plan: Build on both of Linux and Windows and make sure the warning doesn't show in either platform.

Reviewers: andrewkr, adsharma, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58965

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: When rate_bytes_per_sec * refill_period_us_ overflows, the actual limited rate is very low. Handle this case so the rate will be large.

Test Plan: Add a unit test for it.

Reviewers: IslamAbdelRahman, andrewkr

Reviewed By: andrewkr

Subscribers: yiwu, lightmark, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58929

Summary:
Made it consistent with posix Env, which uses pread() that returns 0
(success) when an offset is given beyond EOF. The purpose of making these Envs
behave consistently is I am repurposing the in-memory Envs' tests for the basic
Env tests in D58635.

Test Plan: ran mock_env_test and memenv_test

Reviewers: IslamAbdelRahman, lightmark, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58845

Summary:
Build failure with some compiler setting with

tools/reduce_levels_test.cc:97: undefined reference to `rocksdb::LDBCommand* rocksdb::LDBCommand::InitFromCmdLineArgs<rocksdb::LDBCommand* (*)(std::string const&, std::vector<std::string, std::allocator<std::string> > const&, std::map<std::string, std::string, std::less<std::string>, std::allocator<std::pair<std::string const, std::string> > > const&, std::vector<std::string, std::allocator<std::string> > const&)>(std::vector<std::string, std::allocator<std::string> > const&, rocksdb::Options const&, rocksdb::LDBOptions const&, std::vector<rocksdb::ColumnFamilyDescriptor, std::allocator<rocksdb::ColumnFamilyDescriptor> > const*, rocksdb::LDBCommand* (*)(std::string const&, std::vector<std::string, std::allocator<std::string> > const&, std::map<std::string, std::string, std::less<std::string>, std::allocator<std::pair<std::string const, std::string> > > const&, std::vector<std::string, std::allocator<std::string> > const&))'

Fix it by changing to function pointer instead

Test Plan: Run all existing tests

Reviewers: andrewkr, kradhakrishnan, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: adsharma, lightmark, yiwu, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58905

Summary:
Add under and over limits for rocksdb::PerfLevel enum
to allow us to do boundary checks before casting ints or unints
to this enum.

Test Plan: make all check -j32

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58521

Summary: util/threadpool.cc's function name is the same as a well-known class name. It breaks unity build. Rename it.

Test Plan: Run all existing test.

Reviewers: yiwu, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58881

Summary: I don't think util/mutable_cf_options.h is needed inside include/rocksdb/sst_file_writer.h and it is not allowed. Remove it.

Test Plan: Run all tests

Reviewers: IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: lightmark, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58827

Summary: We added more table properties for each SST file, so when using 2KB SST file size, the estimated size of SST files is off by almost half, causing the LSM tree structure not as expected. Fix it by making file size 4x as previously, as well as LSM base size. Also avoid the sleeping based synchronization and turn to use sync points.

Test Plan: Run paralell unit tests multiple times and make sure they always pass.

Reviewers: IslamAbdelRahman, kradhakrishnan

Reviewed By: kradhakrishnan

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58749

Summary: Fix simple issue with FLAGS_simcache_size condition

Test Plan: run db_bench

Reviewers: lightmark

Reviewed By: lightmark

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58743