Commit Graph

67 Commits

Author SHA1 Message Date
Hui Xiao
74cfe7db60 Refactor WriteBufferManager::CacheRep into CacheReservationManager (#8506)
Summary:
Context:
To help cap various memory usage by a single limit of the block cache capacity, we charge the memory usage through inserting/releasing dummy entries in the block cache. CacheReservationManager is such a class (non thread-safe) responsible for  inserting/removing dummy entries to reserve cache space for memory used by the class user.

- Refactored the inner private class CacheRep of WriteBufferManager into public CacheReservationManager class for reusability such as for https://github.com/facebook/rocksdb/pull/8428

- Encapsulated implementation details of cache key generation and dummy entries insertion/release in cache reservation as discussed in https://github.com/facebook/rocksdb/pull/8506#discussion_r666550838

- Consolidated increase/decrease cache reservation into one API - UpdateCacheReservation.

- Adjusted the previous dummy entry release algorithm in decreasing cache reservation to be loop-releasing dummy entries to stay symmetric to dummy entry insertion algorithm

- Made the previous dummy entry release algorithm in delayed decrease mode more aggressive for better decreasing cache reservation when memory used is less likely to increase back.

  Previously, the algorithms only release 1 dummy entries when new_mem_used < 3/4 * cache_allocated_size_ and cache_allocated_size_ - kSizeDummyEntry > new_mem_used.
Now, the algorithms loop-releases as many dummy entries as possible when new_mem_used < 3/4 * cache_allocated_size_.

- Updated WriteBufferManager's test cases to adapt to changes on the release algorithm mentioned above and left comment for some test cases for clarity

- Replaced the previous cache key prefix generation (utilizing object address related to the cache client) with one that utilizes Cache->NewID() to prevent cache-key collision among dummy entry clients sharing the same cache.

  The specific collision we are preventing happens when the object address is reused for a new cache-key prefix while the old cache-key using that same object address in its prefix still exists in the cache. This could happen due to that, under LRU cache policy, there is a possible delay in releasing a cache entry after the cache client object owning that cache entry get deallocated. In this case, the object address related to the cache client object can get reused for other client object to generate a new cache-key prefix.

  This prefix generation can be made obsolete after Peter's unification of all the code generating cache key, mentioned in https://github.com/facebook/rocksdb/pull/8506#discussion_r667265255

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8506

Test Plan:
- Passing the added unit tests cache_reservation_manager_test.cc
- Passing existing and adjusted write_buffer_manager_test.cc

Reviewed By: ajkr

Differential Revision: D29644135

Pulled By: hx235

fbshipit-source-id: 0fc93fbfe4a40bb41be85c314f8f2bafa8b741f7
2021-08-24 12:43:31 -07:00
Baptiste Lemaire
e51be2c5a1 Improve MemPurge sampling (#8656)
Summary:
Previously, the `MemPurge` sampling function was assessing whether a random entry from a memtable was garbage or not by simply querying the given memtable (see https://github.com/facebook/rocksdb/issues/8628 for more details).
In this diff, I am updating the sampling function by querying not only the memtable the entry was drawn from, but also all subsequent memtables that have a greater memtable ID.
I also added the size of the value for KV entries in the payload/useful payload estimates (which was also one of the reasons why sampling was not as good as mempurging all the time in terms of L0 SST files reduction).
Once these changes were made, I was able to clean obsolete objects and functions from the `MemtableList` struct, and did a bit of cleanup everywhere.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8656

Reviewed By: pdillinger

Differential Revision: D30288583

Pulled By: bjlemaire

fbshipit-source-id: 7646a545ec56f4715949daa59ab5eee74540feb3
2021-08-13 14:35:41 -07:00
Baptiste Lemaire
e3a96c4823 Memtable sampling for mempurge heuristic. (#8628)
Summary:
Changes the API of the MemPurge process: the `bool experimental_allow_mempurge` and `experimental_mempurge_policy` flags have been replaced by a `double experimental_mempurge_threshold` option.
This change of API reflects another major change introduced in this PR: the MemPurgeDecider() function now works by sampling the memtables being flushed to estimate the overall amount of useful payload (payload minus the garbage), and then compare this useful payload estimate with the `double experimental_mempurge_threshold` value.
Therefore, when the value of this flag is `0.0` (default value), mempurge is simply deactivated. On the other hand, a value of `DBL_MAX` would be equivalent to always going through a mempurge regardless of the garbage ratio estimate.
At the moment, a `double experimental_mempurge_threshold` value else than 0.0 or `DBL_MAX` is opnly supported`with the `SkipList` memtable representation.
Regarding the sampling, this PR includes the introduction of a `MemTable::UniqueRandomSample` function that collects (approximately) random entries from the memtable by using the new `SkipList::Iterator::RandomSeek()` under the hood, or by iterating through each memtable entry, depending on the target sample size and the total number of entries.
The unit tests have been readapted to support this new API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8628

Reviewed By: pdillinger

Differential Revision: D30149315

Pulled By: bjlemaire

fbshipit-source-id: 1feef5390c95db6f4480ab4434716533d3947f27
2021-08-10 18:09:03 -07:00
Andrew Kryczka
ed8eb436db Move slow valgrind tests behind -DROCKSDB_FULL_VALGRIND_RUN (#8475)
Summary:
Various tests had disabled valgrind due to it slowing down and timing
out (as is the case right now) the CI runs. Where a test was disabled with no comment,
I assumed slowness was the cause. For these tests that were slow under
valgrind, as well as the ones identified in https://github.com/facebook/rocksdb/issues/8352, this PR moves them
behind the compiler flag `-DROCKSDB_FULL_VALGRIND_RUN`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8475

Test Plan: running `make full_valgrind_test`, `make valgrind_test`, `make check`; will verify they appear working correctly

Reviewed By: jay-zhuang

Differential Revision: D29504843

Pulled By: ajkr

fbshipit-source-id: 2aac90749cfbd30d5ce11cb29a07a1b9314eeea7
2021-07-07 11:14:05 -07:00
Peter Dillinger
311a544c2a Use deleters to label cache entries and collect stats (#8297)
Summary:
This change gathers and publishes statistics about the
kinds of items in block cache. This is especially important for
profiling relative usage of cache by index vs. filter vs. data blocks.
It works by iterating over the cache during periodic stats dump
(InternalStats, stats_dump_period_sec) or on demand when
DB::Get(Map)Property(kBlockCacheEntryStats), except that for
efficiency and sharing among column families, saved data from
the last scan is used when the data is not considered too old.

The new information can be seen in info LOG, for example:

    Block cache LRUCache@0x7fca62229330 capacity: 95.37 MB collections: 8 last_copies: 0 last_secs: 0.00178 secs_since: 0
    Block cache entry stats(count,size,portion): DataBlock(7092,28.24 MB,29.6136%) FilterBlock(215,867.90 KB,0.888728%) FilterMetaBlock(2,5.31 KB,0.00544%) IndexBlock(217,180.11 KB,0.184432%) WriteBuffer(1,256.00 KB,0.262144%) Misc(1,0.00 KB,0%)

And also through DB::GetProperty and GetMapProperty (here using
ldb just for demonstration):

    $ ./ldb --db=/dev/shm/dbbench/ get_property rocksdb.block-cache-entry-stats
    rocksdb.block-cache-entry-stats.bytes.data-block: 0
    rocksdb.block-cache-entry-stats.bytes.deprecated-filter-block: 0
    rocksdb.block-cache-entry-stats.bytes.filter-block: 0
    rocksdb.block-cache-entry-stats.bytes.filter-meta-block: 0
    rocksdb.block-cache-entry-stats.bytes.index-block: 178992
    rocksdb.block-cache-entry-stats.bytes.misc: 0
    rocksdb.block-cache-entry-stats.bytes.other-block: 0
    rocksdb.block-cache-entry-stats.bytes.write-buffer: 0
    rocksdb.block-cache-entry-stats.capacity: 8388608
    rocksdb.block-cache-entry-stats.count.data-block: 0
    rocksdb.block-cache-entry-stats.count.deprecated-filter-block: 0
    rocksdb.block-cache-entry-stats.count.filter-block: 0
    rocksdb.block-cache-entry-stats.count.filter-meta-block: 0
    rocksdb.block-cache-entry-stats.count.index-block: 215
    rocksdb.block-cache-entry-stats.count.misc: 1
    rocksdb.block-cache-entry-stats.count.other-block: 0
    rocksdb.block-cache-entry-stats.count.write-buffer: 0
    rocksdb.block-cache-entry-stats.id: LRUCache@0x7f3636661290
    rocksdb.block-cache-entry-stats.percent.data-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.deprecated-filter-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.filter-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.filter-meta-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.index-block: 2.133751
    rocksdb.block-cache-entry-stats.percent.misc: 0.000000
    rocksdb.block-cache-entry-stats.percent.other-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.write-buffer: 0.000000
    rocksdb.block-cache-entry-stats.secs_for_last_collection: 0.000052
    rocksdb.block-cache-entry-stats.secs_since_last_collection: 0

Solution detail - We need some way to flag what kind of blocks each
entry belongs to, preferably without changing the Cache API.
One of the complications is that Cache is a general interface that could
have other users that don't adhere to whichever convention we decide
on for keys and values. Or we would pay for an extra field in the Handle
that would only be used for this purpose.

This change uses a back-door approach, the deleter, to indicate the
"role" of a Cache entry (in addition to the value type, implicitly).
This has the added benefit of ensuring proper code origin whenever we
recognize a particular role for a cache entry; if the entry came from
some other part of the code, it will use an unrecognized deleter, which
we simply attribute to the "Misc" role.

An internal API makes for simple instantiation and automatic
registration of Cache deleters for a given value type and "role".

Another internal API, CacheEntryStatsCollector, solves the problem of
caching the results of a scan and sharing them, to ensure scans are
neither excessive nor redundant so as not to harm Cache performance.

Because code is added to BlocklikeTraits, it is pulled out of
block_based_table_reader.cc into its own file.

This is a reformulation of https://github.com/facebook/rocksdb/issues/8276, without the type checking option
(could still be added), and with actual stat gathering.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8297

Test Plan: manual testing with db_bench, and a couple of basic unit tests

Reviewed By: ltamasi

Differential Revision: D28488721

Pulled By: pdillinger

fbshipit-source-id: 472f524a9691b5afb107934be2d41d84f2b129fb
2021-05-19 16:51:13 -07:00
Akanksha Mahajan
596e9008e4 Stall writes in WriteBufferManager when memory_usage exceeds buffer_size (#7898)
Summary:
When WriteBufferManager is shared across DBs and column families
to maintain memory usage under a limit, OOMs have been observed when flush cannot
finish but writes continuously insert to memtables.
In order to avoid OOMs, when memory usage goes beyond buffer_limit_ and DBs tries to write,
this change will stall incoming writers until flush is completed and memory_usage
drops.

Design: Stall condition: When total memory usage exceeds WriteBufferManager::buffer_size_
(memory_usage() >= buffer_size_) WriterBufferManager::ShouldStall() returns true.

DBImpl first block incoming/future writers by calling write_thread_.BeginWriteStall()
(which adds dummy stall object to the writer's queue).
Then DB is blocked on a state State::Blocked (current write doesn't go
through). WBStallInterface object maintained by every DB instance is added to the queue of
WriteBufferManager.

If multiple DBs tries to write during this stall, they will also be
blocked when check WriteBufferManager::ShouldStall() returns true.

End Stall condition: When flush is finished and memory usage goes down, stall will end only if memory
waiting to be flushed is less than buffer_size/2. This lower limit will give time for flush
to complete and avoid continous stalling if memory usage remains close to buffer_size.

WriterBufferManager::EndWriteStall() is called,
which removes all instances from its queue and signal them to continue.
Their state is changed to State::Running and they are unblocked. DBImpl
then signal all incoming writers of that DB to continue by calling
write_thread_.EndWriteStall() (which removes dummy stall object from the
queue).

DB instance creates WBMStallInterface which is an interface to block and
signal DBs during stall.
When DB needs to be blocked or signalled by WriteBufferManager,
state_for_wbm_ state is changed accordingly (RUNNING or BLOCKED).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7898

Test Plan: Added a new test db/db_write_buffer_manager_test.cc

Reviewed By: anand1976

Differential Revision: D26093227

Pulled By: akankshamahajan15

fbshipit-source-id: 2bbd982a3fb7033f6de6153aa92a221249861aae
2021-04-21 13:54:02 -07:00
mrambacher
3dff28cf9b Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033)
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
2021-03-15 04:34:11 -07:00
matthewvon
4126bdc0e1 Feature: add SetBufferSize() so that managed size can be dynamic (#7961)
Summary:
This PR adds SetBufferSize() to the WriteBufferManager object.  This enables user code to adjust the global budget for write_buffers based upon other memory conditions such as growth in table reader memory as the dataset grows.

The buffer_size_ member variable is now atomic to match design of other changeable size_t members within WriteBufferManager.

This change is useful as is.  However, this change is also essential if someone decides they wanted to enable db_write_buffer_size modifications through the DB::SetOptions() API, i.e. no waste taking this as is.

Any format / spacing changes are due to clang-format as required by check-in automation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7961

Reviewed By: ajkr

Differential Revision: D26639075

Pulled By: akankshamahajan15

fbshipit-source-id: 0604348caf092d35f44e85715331dc920e5c1033
2021-03-03 14:22:11 -08:00
mrambacher
12f1137355 Add a SystemClock class to capture the time functions of an Env (#7858)
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
2021-01-25 22:09:11 -08:00
Akanksha Mahajan
8ed680bdb0 Add new API to report dummy entries size in cache in WriteBufferManager (#7837)
Summary:
Add new API WriteBufferManager::dummy_entries_in_cache_usage() which reports the dummy entries size stored in cache to account for DataBlocks in WriteBufferManager.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7837

Test Plan: Updated test ./write_buffer_manager_test

Reviewed By: ajkr

Differential Revision: D25794312

Pulled By: akankshamahajan15

fbshipit-source-id: 197f5e8701e3dc57a7df72dab1735624f90daf4b
2021-01-08 13:26:24 -08:00
mrambacher
a8c89cc969 Test for LoadLatestOptions (#7554)
Summary:
Make LoadLatestOptions return PathNotFound if the options file does not exist.  Added tests for the LoadOptions related methods.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7554

Reviewed By: akankshamahajan15

Differential Revision: D24298985

Pulled By: zhichao-cao

fbshipit-source-id: c9ae3cb12fc4a5bbef07743e1c1300f98a2441b3
2020-10-14 22:28:55 -07:00
Peter Dillinger
08552b19d3 Genericize and clean up FastRange (#7436)
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
2020-09-28 11:35:00 -07:00
mrambacher
c7c7b07f06 More Makefile Cleanup (#7097)
Summary:
Cleans up some of the dependencies on test code in the Makefile while building tools:
- Moves the test::RandomString, DBBaseTest::RandomString into Random
- Moves the test::RandomHumanReadableString into Random
- Moves the DestroyDir method into file_utils
- Moves the SetupSyncPointsToMockDirectIO into sync_point.
- Moves the FaultInjection Env and FS classes under env

These changes allow all of the tools to build without dependencies on test_util, thereby simplifying the build dependencies.  By moving the FaultInjection code, the dependency in db_stress on different libraries for debug vs release was eliminated.

Tested both release and debug builds via Make and CMake for both static and shared libraries.

More work remains to clean up how the tools are built and remove some unnecessary dependencies.  There is also more work that should be done to get the Makefile and CMake to align in their builds -- what is in the libraries and the sizes of the executables are different.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7097

Reviewed By: riversand963

Differential Revision: D22463160

Pulled By: pdillinger

fbshipit-source-id: e19462b53324ab3f0b7c72459dbc73165cc382b2
2020-07-09 14:35:17 -07:00
Peter Dillinger
c7432cc3c0 Fix more defects reported by Coverity Scan (#6935)
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
2020-06-04 15:35:08 -07:00
Peter Dillinger
31da5e34c1 C++20 compatibility (#6697)
Summary:
Based on https://github.com/facebook/rocksdb/issues/6648 (CLA Signed), but heavily modified / extended:

* Implicit capture of this via [=] deprecated in C++20, and [=,this] not standard before C++20 -> now using explicit capture lists
* Implicit copy operator deprecated in gcc 9 -> add explicit '= default' definition
* std::random_shuffle deprecated in C++17 and removed in C++20 -> migrated to a replacement in RocksDB random.h API
* Add the ability to build with different std version though -DCMAKE_CXX_STANDARD=11/14/17/20 on the cmake command line
* Minimal rebuild flag of MSVC is deprecated and is forbidden with /std:c++latest (C++20)
* Added MSVC 2019 C++11 & MSVC 2019 C++20 in AppVeyor
* Added GCC 9 C++11 & GCC9 C++20 in Travis
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6697

Test Plan: make check and CI

Reviewed By: cheng-chang

Differential Revision: D21020318

Pulled By: pdillinger

fbshipit-source-id: 12311be5dbd8675a0e2c817f7ec50fa11c18ab91
2020-04-20 13:24:25 -07:00
sdong
57096ab13e Fix a bug that crashes the service when write buffer manager fails to insert to block cache (#6619)
Summary:
https://github.com/facebook/rocksdb/issues/6247 reports that when write buffer manager fails to insert the dummy entry to block cache, null pointer is still stored and used to release the handle and cause corruption. Fix the bug by not releasing it with null handle.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6619

Test Plan: Add a unit test that fails without the fix.

Reviewed By: ajkr

Differential Revision: D20776769

fbshipit-source-id: 4127fbd9f295a0a3e45774746ffcd91f939f6287
2020-04-01 11:27:40 -07:00
sdong
fdf882ded2 Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)
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
2020-02-20 12:09:57 -08:00
Peter Dillinger
ca7ccbe2ea Misc hashing updates / upgrades (#5909)
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
2019-10-24 17:16:46 -07:00
Maysam Yabandeh
638d239507 Charge block cache for cache internal usage (#5797)
Summary:
For our default block cache, each additional entry has extra memory overhead. It include LRUHandle (72 bytes currently) and the cache key (two varint64, file id and offset). The usage is not negligible. For example for block_size=4k, the overhead accounts for an extra 2% memory usage for the cache. The patch charging the cache for the extra usage, reducing untracked memory usage outside block cache. The feature is enabled by default and can be disabled by passing kDontChargeCacheMetadata to the cache constructor.
This PR builds up on https://github.com/facebook/rocksdb/issues/4258
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5797

Test Plan:
- Existing tests are updated to either disable the feature when the test has too much dependency on the old way of accounting the usage or increasing the cache capacity to account for the additional charge of metadata.
- The Usage tests in cache_test.cc are augmented to test the cache usage under kFullChargeCacheMetadata.

Differential Revision: D17396833

Pulled By: maysamyabandeh

fbshipit-source-id: 7684ccb9f8a40ca595e4f5efcdb03623afea0c6f
2019-09-16 15:26:21 -07:00
Lingjing You
1a928c22a0 Add insert hints for each writebatch (#5728)
Summary:
Add insert hints for each writebatch so that they can be used in concurrent write, and add write option to enable it.

Bench result (qps):

`./db_bench --benchmarks=fillseq -allow_concurrent_memtable_write=true -num=4000000 -batch-size=1 -threads=1 -db=/data3/ylj/tmp -write_buffer_size=536870912 -num_column_families=4`

master:

| batch size \ thread num | 1       | 2       | 4       | 8       |
| ----------------------- | ------- | ------- | ------- | ------- |
| 1                       | 387883  | 220790  | 308294  | 490998  |
| 10                      | 1397208 | 978911  | 1275684 | 1733395 |
| 100                     | 2045414 | 1589927 | 1798782 | 2681039 |
| 1000                    | 2228038 | 1698252 | 1839877 | 2863490 |

fillseq with writebatch hint:

| batch size \ thread num | 1       | 2       | 4       | 8       |
| ----------------------- | ------- | ------- | ------- | ------- |
| 1                       | 286005  | 223570  | 300024  | 466981  |
| 10                      | 970374  | 813308  | 1399299 | 1753588 |
| 100                     | 1962768 | 1983023 | 2676577 | 3086426 |
| 1000                    | 2195853 | 2676782 | 3231048 | 3638143 |
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5728

Differential Revision: D17297240

fbshipit-source-id: b053590a6d77871f1ef2f911a7bd013b3899b26c
2019-09-12 17:15:18 -07:00
Shylock Hg
9eb3e1f77d Use delete to disable automatic generated methods. (#5009)
Summary:
Use delete to disable automatic generated methods instead of private, and put the constructor together for more clear.This modification cause the unused field warning, so add unused attribute to disable this warning.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5009

Differential Revision: D17288733

fbshipit-source-id: 8a767ce096f185f1db01bd28fc88fef1cdd921f3
2019-09-11 18:09:00 -07:00
Zhongyi Xie
d68f9f4580 simplify include directive involving inttypes (#5402)
Summary:
When using `PRIu64` type of printf specifier, current code base does the following:
```
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
```
However, this can be simplified to
```
#include <cinttypes>
```
as long as flag `-std=c++11` is used.
This should solve issues like https://github.com/facebook/rocksdb/issues/5159
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5402

Differential Revision: D15701195

Pulled By: miasantreble

fbshipit-source-id: 6dac0a05f52aadb55e9728038599d3d2e4b59d03
2019-06-06 13:56:07 -07:00
Siying Dong
8843129ece Move some memory related files from util/ to memory/ (#5382)
Summary:
Move arena, allocator, and memory tools under util to a separate memory/ directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5382

Differential Revision: D15564655

Pulled By: siying

fbshipit-source-id: 9cd6b5d0d3d52b39606e19221fa154596e5852a5
2019-05-30 17:44:09 -07:00
Siying Dong
e9e0101ca4 Move test related files under util/ to test_util/ (#5377)
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377

Differential Revision: D15551366

Pulled By: siying

fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
2019-05-30 11:25:51 -07:00
Siying Dong
beb44ec3eb WriteBufferManager's dummy entry size to block cache 1MB -> 256KB (#5175)
Summary:
Dummy cache size of 1MB is too large for small block sizes. Our GetDefaultCacheShardBits() use min_shard_size = 512L * 1024L to determine number of shards, so 1MB will excceeds the size of the whole shard and make the cache excceeds the budget.
Change it to 256KB accordingly.
There shouldn't be obvious performance impact, since inserting a cache entry every 256KB of memtable inserts is still infrequently enough.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5175

Differential Revision: D14954289

Pulled By: siying

fbshipit-source-id: 2c275255c1ac3992174e06529e44c55538325c94
2019-04-16 12:03:07 -07:00
Siying Dong
0bb555630f Consolidate hash function used for non-persistent data in a new function (#5155)
Summary:
Create new function NPHash64() and GetSliceNPHash64(), which are currently
implemented using murmurhash.
Replace the current direct call of murmurhash() to use the new functions
if the hash results are not used in on-disk format.
This will make it easier to try out or switch to alternative functions
in the uses where data format compatibility doesn't need to be considered.
This part shouldn't have any performance impact.

Also, the sharded cache hash function is changed to the new format, because
it falls into this categoery. It doesn't show visible performance impact
in db_bench results. CPU showed by perf is increased from about 0.2% to 0.4%
in an extreme benchmark setting (4KB blocks, no-compression, everything
cached in block cache). We've known that the current hash function used,
our own Hash() has serious hash quality problem. It can generate a lots of
conflicts with similar input. In this use case, it means extra lock contention
for reads from the same file. This slight CPU regression is worthy to me
to counter the potential bad performance with hot keys. And hopefully this
will get further improved in the future with a better hash function.

cache_test's condition is relaxed a little bit to. The new hash is slightly
more skewed in this use case, but I manually checked the data and see
the hash results are still in a reasonable range.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5155

Differential Revision: D14834821

Pulled By: siying

fbshipit-source-id: ec9a2c0a2f8ae4b54d08b13a5c2e9cc97aa80cb5
2019-04-08 13:32:06 -07:00
Michael Liu
ca89ac2ba9 Apply modernize-use-override (2nd iteration)
Summary:
Use C++11’s override and remove virtual where applicable.
Change are automatically generated.

Reviewed By: Orvid

Differential Revision: D14090024

fbshipit-source-id: 1e9432e87d2657e1ff0028e15370a85d1739ba2a
2019-02-14 14:41:36 -08:00
Siying Dong
cf3a671733 Remove cuckoo hash memtable (#4953)
Summary:
Cuckoo Hash is less useful than we initially expected. Remove it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4953

Differential Revision: D13979264

Pulled By: siying

fbshipit-source-id: 2a60afdaa989f045357398b43a1cc5d46f4492ed
2019-02-07 16:15:27 -08:00
Siying Dong
13579e8c5a WriteBufferManger doens't cost to cache if no limit is set (#4695)
Summary:
WriteBufferManger is not invoked when allocating memory for memtable if the limit is not set even if a cache is passed. It is inconsistent from the comment syas. Fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4695

Differential Revision: D13112722

Pulled By: siying

fbshipit-source-id: 0b27eef63867f679cd06033ea56907c0569597f4
2018-11-18 16:55:43 -08:00
Sagar Vemuri
dc3528077a Update all unique/shared_ptr instances to be qualified with namespace std (#4638)
Summary:
Ran the following commands to recursively change all the files under RocksDB:
```
find . -type f -name "*.cc" -exec sed -i 's/ unique_ptr/ std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<unique_ptr/<std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/ shared_ptr/ std::shared_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<shared_ptr/<std::shared_ptr/g' {} +
```
Running `make format` updated some formatting on the files touched.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4638

Differential Revision: D12934992

Pulled By: sagar0

fbshipit-source-id: 45a15d23c230cdd64c08f9c0243e5183934338a8
2018-11-09 11:19:58 -08:00
jsteemann
d1c0d3f358 Small issues (#4564)
Summary:
Couple of very minor improvements (typos in comments, full qualification of class name, reordering members of a struct to make it smaller)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4564

Differential Revision: D10510183

Pulled By: maysamyabandeh

fbshipit-source-id: c7ddf9bfbf2db08cd31896c3fd93789d3fa68c8b
2018-10-23 10:35:57 -07:00
Yi Wu
4f12d49daf Suppress clang analyzer error (#4299)
Summary:
Suppress multiple clang-analyzer error. All of them are clang false-positive.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4299

Differential Revision: D9430740

Pulled By: yiwu-arbug

fbshipit-source-id: fbdd575bdc214d124826d61d35a117995c509279
2018-08-21 16:43:05 -07:00
Siying Dong
4dd80debd0 Remove tests from ROCKSDB_VALGRIND_RUN
Summary:
In order to make valgrind check test to pass in a day, remove some tests that run prohibitively slow under valgrind.
Closes https://github.com/facebook/rocksdb/pull/3924

Differential Revision: D8210184

Pulled By: siying

fbshipit-source-id: 5b06fb08f3cf57571d422d05a0dbddc9f9376f7a
2018-05-30 16:15:16 -07:00
Xin Tong
aed7abbcca Reorder field based on esan data
Summary:
Running. TEST_TMPDIR=/dev/shm ./buck-out/gen/rocks/tools/rocks_db_bench --benchmarks=readwhilewriting --num=5000000 -benchmark_write_rate_limit=2000000 --threads=32

Collected esan data and reorder field. Accesses to 4th and 6th fields take majority of the access.  Group them. Overall, this struct takes 10%+ of the total accesses in the program. (637773011/6107964986)

==2433831==  class rocksdb::InlineSkipList
==2433831==   size = 48, count = 637773011, ratio = 112412, array access = 0
==2433831==   # 0: offset = 0,   size = 2,       count = 455137, type = i16
==2433831==   # 1: offset = 2,   size = 2,       count = 6,      type = i16
==2433831==   # 2: offset = 4,   size = 4,       count = 182303, type = i32
==2433831==   # 3: offset = 8,   size = 8,       count = 263953900, type = %"class.rocksdb::MemTableRep::KeyComparator"*
==2433831==   # 4: offset = 16,  size = 8,       count = 136409, type = %"class.rocksdb::Allocator"*
==2433831==   # 5: offset = 24,  size = 8,       count = 366628820, type = %"struct.rocksdb::InlineSkipList<const rocksdb::MemTableRep::KeyComparator &>::Node"*
==2433831==   # 6: offset = 32,  size = 4,       count = 6280031, type = %"struct.std::atomic" = type { %"struct.std::__atomic_base" }
==2433831==   # 7: offset = 40,  size = 8,       count = 136405, type = %"struct.rocksdb::InlineSkipList<const rocksdb::MemTableRep::KeyComparator &>::Splice"*
==2433831==EfficiencySanitizer: total struct field access count = 6107964986

Before re-ordering
[trentxintong@devbig460.frc2 ~/fbsource/fbcode]$ fgrep readwhilewriting
without-ro.log
readwhilewriting :       0.036 micros/op 27545605 ops/sec;   26.8 MB/s
(45954 of 5000000 found)
readwhilewriting :       0.036 micros/op 28024240 ops/sec;   27.2 MB/s
(43158 of 5000000 found)
readwhilewriting :       0.037 micros/op 27345145 ops/sec;   27.1 MB/s
(46725 of 5000000 found)
readwhilewriting :       0.037 micros/op 27072588 ops/sec;   27.3 MB/s
(42605 of 5000000 found)
readwhilewriting :       0.034 micros/op 29578781 ops/sec;   28.3 MB/s
(44294 of 5000000 found)
readwhilewriting :       0.035 micros/op 28528304 ops/sec;   27.7 MB/s
(44176 of 5000000 found)
readwhilewriting :       0.037 micros/op 27075497 ops/sec;   26.5 MB/s
(43763 of 5000000 found)
readwhilewriting :       0.036 micros/op 28024117 ops/sec;   27.1 MB/s
(40622 of 5000000 found)
readwhilewriting :       0.037 micros/op 27078709 ops/sec;   27.6 MB/s
(47774 of 5000000 found)
readwhilewriting :       0.034 micros/op 29020689 ops/sec;   28.1 MB/s
(45066 of 5000000 found)
AVERAGE()=27.37 MB/s

After re-ordering
[trentxintong@devbig460.frc2 ~/fbsource/fbcode]$ fgrep readwhilewriting
ro.log
readwhilewriting :       0.036 micros/op 27542409 ops/sec;   27.7 MB/s
(46163 of 5000000 found)
readwhilewriting :       0.036 micros/op 28021148 ops/sec;   28.2 MB/s
(46155 of 5000000 found)
readwhilewriting :       0.036 micros/op 28021035 ops/sec;   27.3 MB/s
(44039 of 5000000 found)
readwhilewriting :       0.036 micros/op 27538659 ops/sec;   27.5 MB/s
(46781 of 5000000 found)
readwhilewriting :       0.036 micros/op 28028604 ops/sec;   27.6 MB/s
(44689 of 5000000 found)
readwhilewriting :       0.036 micros/op 27541452 ops/sec;   27.3 MB/s
(43156 of 5000000 found)
readwhilewriting :       0.034 micros/op 29041338 ops/sec;   28.8 MB/s
(44895 of 5000000 found)
readwhilewriting :       0.036 micros/op 27784974 ops/sec;   26.3 MB/s
(39963 of 5000000 found)
readwhilewriting :       0.036 micros/op 27538892 ops/sec;   28.1 MB/s
(46570 of 5000000 found)
readwhilewriting :       0.038 micros/op 26622473 ops/sec;   27.0 MB/s
(43236 of 5000000 found)
AVERAGE()=27.58 MB/s
Closes https://github.com/facebook/rocksdb/pull/3855

Reviewed By: siying

Differential Revision: D8048781

Pulled By: trentxintong

fbshipit-source-id: bc9807a9845e2a92cb171ce1ecb5a2c8a51f1481
2018-05-17 17:57:48 -07:00
przemyslaw.skibinski@percona.com
dee95a1afc Fix GitHub issue #3716: gcc-8 warnings
Summary:
Fix the following gcc-8 warnings:
- conflicting C language linkage declaration [-Werror]
- writing to an object with no trivial copy-assignment [-Werror=class-memaccess]
- array subscript -1 is below array bounds [-Werror=array-bounds]

Solves https://github.com/facebook/rocksdb/issues/3716
Closes https://github.com/facebook/rocksdb/pull/3736

Differential Revision: D7684161

Pulled By: yiwu-arbug

fbshipit-source-id: 47c0423d26b74add251f1d3595211eee1e41e54a
2018-04-20 13:42:47 -07:00
David Lai
3be9b36453 comment unused parameters to turn on -Wunused-parameter flag
Summary:
This PR comments out the rest of the unused arguments which allow us to turn on the -Wunused-parameter flag. This is the second part of a codemod relating to https://github.com/facebook/rocksdb/pull/3557.
Closes https://github.com/facebook/rocksdb/pull/3662

Differential Revision: D7426121

Pulled By: Dayvedde

fbshipit-source-id: 223994923b42bd4953eb016a0129e47560f7e352
2018-04-12 17:59:16 -07:00
Radoslaw Zarzynski
09b6bf828a InlineSkiplist: don't decode keys unnecessarily during comparisons
Summary:
Summary
========
`InlineSkipList<>::Insert` takes the `key` parameter as a C-string. Then, it performs multiple comparisons with it requiring the `GetLengthPrefixedSlice()` to be spawn in `MemTable::KeyComparator::operator()(const char* prefix_len_key1, const char* prefix_len_key2)` on the same data over and over. The patch tries to optimize that.

Rough performance comparison
=====
Big keys, no compression.

```
$ ./db_bench --writes 20000000 --benchmarks="fillrandom" --compression_type none -key_size 256
(...)
fillrandom   :       4.222 micros/op 236836 ops/sec;   80.4 MB/s
```

```
$ ./db_bench --writes 20000000 --benchmarks="fillrandom" --compression_type none -key_size 256
(...)
fillrandom   :       4.064 micros/op 246059 ops/sec;   83.5 MB/s
```

TODO
======
In ~~a separated~~ this PR:
- [x] Go outside the write path. Maybe even eradicate the C-string-taking variant of `KeyIsAfterNode` entirely.
- [x] Try to cache the transformations applied by `KeyComparator` & friends in situations where we havy many comparisons with the same key.
Closes https://github.com/facebook/rocksdb/pull/3516

Differential Revision: D7059300

Pulled By: ajkr

fbshipit-source-id: 6f027dbb619a488129f79f79b5f7dbe566fb2dbb
2018-03-23 12:14:30 -07:00
Andrew Kryczka
5d68243e61 Comment out unused variables
Summary:
Submitting on behalf of another employee.
Closes https://github.com/facebook/rocksdb/pull/3557

Differential Revision: D7146025

Pulled By: ajkr

fbshipit-source-id: 495ca5db5beec3789e671e26f78170957704e77e
2018-03-05 13:13:41 -08:00
Igor Sugak
aba3409740 Back out "[codemod] - comment out unused parameters"
Reviewed By: igorsugak

fbshipit-source-id: 4a93675cc1931089ddd574cacdb15d228b1e5f37
2018-02-22 12:43:17 -08:00
David Lai
f4a030ce81 - comment out unused parameters
Reviewed By: everiq, igorsugak

Differential Revision: D7046710

fbshipit-source-id: 8e10b1f1e2aecebbfb229c742e214db887e5a461
2018-02-22 09:44:23 -08:00
Maysam Yabandeh
8eb1d445c3 Unbreak MemTableRep API change
Summary:
The MemTableRep API was broken by this commit: 813719e952
This patch reverts the changes and instead adds InsertKey (and etc.) overloads to extend the MemTableRep API without breaking the existing classes that inherit from it.
Closes https://github.com/facebook/rocksdb/pull/3513

Differential Revision: D7004134

Pulled By: maysamyabandeh

fbshipit-source-id: e568d91fe1e17dd76c0c1f6c7dd51a18633b1c4f
2018-02-15 17:27:24 -08:00
Maysam Yabandeh
813719e952 WritePrepared Txn: Duplicate Keys, Memtable part
Summary:
Currently DB does not accept duplicate keys (keys with the same user key and the same sequence number). If Memtable returns false when receiving such keys, we can benefit from this signal to properly increase the sequence number in the rare cases when we have a duplicate key in the write batch written to DB under WritePrepared transactions.
Closes https://github.com/facebook/rocksdb/pull/3418

Differential Revision: D6822412

Pulled By: maysamyabandeh

fbshipit-source-id: adea3ce5073131cd38ed52b16bea0673b1a19e77
2018-01-31 18:57:07 -08:00
Andrew Kryczka
63f1c0a57d fix gflags namespace
Summary:
I started adding gflags support for cmake on linux and got frustrated that I'd need to duplicate the build_detect_platform logic, which determines namespace based on attempting compilation. We can do it differently -- use the GFLAGS_NAMESPACE macro if available, and if not, that indicates it's an old gflags version without configurable namespace so we can simply hardcode "google".
Closes https://github.com/facebook/rocksdb/pull/3212

Differential Revision: D6456973

Pulled By: ajkr

fbshipit-source-id: 3e6d5bde3ca00d4496a120a7caf4687399f5d656
2017-12-01 10:42:05 -08:00
Dmitri Smirnov
ebab2e2d42 Enable MSVC W4 with a few exceptions. Fix warnings and bugs
Summary: Closes https://github.com/facebook/rocksdb/pull/3018

Differential Revision: D6079011

Pulled By: yiwu-arbug

fbshipit-source-id: 988a721e7e7617967859dba71d660fc69f4dff57
2017-10-19 10:57:12 -07:00
Adam Kupczyk
75f7f42d41 Added CPU prefetch for skiplist
Summary:
This change causes following changes result of test:
./db_bench --writes 10000000 --benchmarks="fillrandom" --compression_type none
from
fillrandom   :       3.177 micros/op 314804 ops/sec;   34.8 MB/s
to
fillrandom   :       2.777 micros/op 360087 ops/sec;   39.8 MB/s
Closes https://github.com/facebook/rocksdb/pull/2961

Differential Revision: D5977822

Pulled By: yiwu-arbug

fbshipit-source-id: 1ea77707bffa978b1592b0c5d0fe76bfa1930f8d
2017-10-04 18:12:52 -07:00
Siying Dong
0e99323ac2 Fix CLANG Analyze
Summary:
clang analyze shows warnings after we upgrade the CLANG version. Fix them.
Closes https://github.com/facebook/rocksdb/pull/2839

Differential Revision: D5769060

Pulled By: siying

fbshipit-source-id: 3f8e4df715590d8984f6564b608fa08cfdfa5f14
2017-09-07 14:28:06 -07:00
Andrew Kryczka
cc01985db0 Introduce bottom-pri thread pool for large universal compactions
Summary:
When we had a single thread pool for compactions, a thread could be busy for a long time (minutes) executing a compaction involving the bottom level. In multi-instance setups, the entire thread pool could be consumed by such bottom-level compactions. Then, top-level compactions (e.g., a few L0 files) would be blocked for a long time ("head-of-line blocking"). Such top-level compactions are critical to prevent compaction stalls as they can quickly reduce number of L0 files / sorted runs.

This diff introduces a bottom-priority queue for universal compactions including the bottom level. This alleviates the head-of-line blocking situation for fast, top-level compactions.

- Added `Env::Priority::BOTTOM` thread pool. This feature is only enabled if user explicitly configures it to have a positive number of threads.
- Changed `ThreadPoolImpl`'s default thread limit from one to zero. This change is invisible to users as we call `IncBackgroundThreadsIfNeeded` on the low-pri/high-pri pools during `DB::Open` with values of at least one. It is necessary, though, for bottom-pri to start with zero threads so the feature is disabled by default.
- Separated `ManualCompaction` into two parts in `PrepickedCompaction`. `PrepickedCompaction` is used for any compaction that's picked outside of its execution thread, either manual or automatic.
- Forward universal compactions involving last level to the bottom pool (worker thread's entry point is `BGWorkBottomCompaction`).
- Track `bg_bottom_compaction_scheduled_` so we can wait for bottom-level compactions to finish. We don't count them against the background jobs limits. So users of this feature will get an extra compaction for free.
Closes https://github.com/facebook/rocksdb/pull/2580

Differential Revision: D5422916

Pulled By: ajkr

fbshipit-source-id: a74bd11f1ea4933df3739b16808bb21fcd512333
2017-08-03 15:43:29 -07:00
Sagar Vemuri
72502cf227 Revert "comment out unused parameters"
Summary:
This reverts the previous commit 1d7048c598, which broke the build.

Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627

Differential Revision: D5476473

Pulled By: sagar0

fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
2017-07-21 18:26:26 -07:00
Victor Gao
1d7048c598 comment out unused parameters
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.

Reviewed By: igorsugak

Differential Revision: D5454343

fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
2017-07-21 14:57:44 -07:00
Siying Dong
3c327ac2d0 Change RocksDB License
Summary: Closes https://github.com/facebook/rocksdb/pull/2589

Differential Revision: D5431502

Pulled By: siying

fbshipit-source-id: 8ebf8c87883daa9daa54b2303d11ce01ab1f6f75
2017-07-15 16:11:23 -07:00