Commit Graph

1950 Commits

Author SHA1 Message Date
mrambacher
6924869867 Make SystemClock into a Customizable Class (#8636)
Summary:
Made SystemClock into a Customizable class, complete with CreateFromString.

Cleaned up some of the existing SystemClock implementations that were redundant (NoSleep was the same as the internal one for MockEnv).

Changed MockEnv construction to allow Clock to be passed to the Memory/MockFileSystem.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8636

Reviewed By: zhichao-cao

Differential Revision: D30483360

Pulled By: mrambacher

fbshipit-source-id: cd0e3a876c39f8c98fe13374c06e8edbd5b9f2a1
2021-09-21 09:23:48 -07:00
Hui Xiao
65411b8d4e Improve rate_limiter_test.cc (#8904)
Summary:
- Fixed a bug in `RateLimiterTest.GeneratePriorityIterationOrder` that the callbacks in this test were not called starting from `i = 1`. Fix by increasing `rate_bytes_per_sec` and requested bytes.
   - The bug is due to the previous `rate_bytes_per_sec` was set too small, resulting in `refill_bytes_per_period`  less than  `kMinRefillBytesPerPeriod`. Hence the actual `refill_bytes_per_period` was equal to `kMinRefillBytesPerPeriod` due to the logic [here](https://github.com/facebook/rocksdb/blob/main/util/rate_limiter.cc#L302-L303)  and it ended up being greater than the previously set requested bytes. Therefore starting from `i = 1`, `RefillBytesAndGrantRequests()` and `GeneratePriorityIterationOrder` won't be called and the test callbacks was not triggered to execute the assertion.
- Added internal flag to assert callbacks are called in `RateLimiterTest.GeneratePriorityIterationOrder` to prevent any future changes defeat the purpose of the test [as suggested](https://github.com/facebook/rocksdb/pull/8890#discussion_r704915134)
- Increased `rate_bytes_per_sec` and bytes of each request in `RateLimiterTest.GetTotalBytesThrough`, `RateLimiterTest.GetTotalRequests`, `RateLimiterTest.GetTotalPendingRequests` to trigger the "long path" of execution (i.e, the one trigger RefillBytesAndGrantRequests()) to increase test coverage
   - This increased the running time of the three tests, see test plan for time difference running locally
- Cleared up sync point effects after each test by calling `SyncPoint::GetInstance()->DisableProcessing();` and `SyncPoint::GetInstance()->ClearAllCallBacks();` in `~RateLimiterTest()` [as suggested](https://github.com/facebook/rocksdb/pull/8595/files#r697534279)
  - It's fine to call these two methods even when `EnableProcessing()` or `SetCallBack()` is not called in the test or is already cleaned up. In those cases, calling these two functions in destructor is effectively no-op.
  - This will allow cleaning up sync point effects of previous test even when the previous test failed in assertion.
- Added missing `SyncPoint::GetInstance()->DisableProcessing();` and `SyncPoint::GetInstance()->ClearCallBacks(..);` in existing tests for completeness
- Called `SyncPoint::GetInstance()->DisableProcessing();` and `SyncPoint::GetInstance()->ClearCallBacks(..);` in loop in `RateLimiterTest.GeneratePriorityIterationOrder` for completeness

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8904

Test Plan:
- Passing existing tests
- To verify the 1st change, run `RateLimiterTest.GeneratePriorityIterationOrder` with assertions of callbacks are indeed called under original `rate_bytes_per_sec` and request byte and under updated `rate_bytes_per_sec` and request byte. The former will fail the assertion while the latter succeeds.
- Here is the increased test time due to the 3rd change mentioned above in the summary. The relevant 3 tests mentioned in total increase the test time by 6s (~6000/33848 = 17.7% of the original total test time), which IMO is acceptable for better test coverage through running the "long path".
   - current (run on branch rate_limiter_ut_improve locally)

   [ RUN      ] RateLimiterTest.GetTotalBytesThrough
   [       OK ] RateLimiterTest.GetTotalBytesThrough (3000 ms)
   [ RUN      ] RateLimiterTest.GetTotalRequests
   [       OK ] RateLimiterTest.GetTotalRequests (3001 ms)
   [ RUN      ] RateLimiterTest.GetTotalPendingRequests
   [       OK ] RateLimiterTest.GetTotalPendingRequests (0 ms)
   ...
   [----------] 10 tests from RateLimiterTest (43349 ms total)

   [----------] Global test environment tear-down
   [==========] 10 tests from 1 test case ran. (43349 ms total)
   [  PASSED  ] 10 tests.

   - previous (run on branch main locally)

   [ RUN      ] RateLimiterTest.GetTotalBytesThrough
   [       OK ] RateLimiterTest.GetTotalBytesThrough (0 ms)
   [ RUN      ] RateLimiterTest.GetTotalRequests
   [       OK ] RateLimiterTest.GetTotalRequests (0 ms)
   [ RUN      ] RateLimiterTest.GetTotalPendingRequests
   [       OK ] RateLimiterTest.GetTotalPendingRequests (0 ms)
   ...
   [----------] 10 tests from RateLimiterTest (33848 ms total)

  [----------] Global test environment tear-down
  [==========] 10 tests from 1 test case ran. (33848 ms total)
  [  PASSED  ] 10 tests.

Reviewed By: ajkr

Differential Revision: D30872544

Pulled By: hx235

fbshipit-source-id: ff894f5c1a4bef70e8e407d53b00be45f776b3e4
2021-09-17 09:23:31 -07:00
Peter Dillinger
bda8d93ba9 Fix and detect headers with missing dependencies (#8893)
Summary:
It's always annoying to find a header does not include its own
dependencies and only works when included after other includes. This
change adds `make check-headers` which validates that each header can
be included at the top of a file. Some headers are excluded e.g. because
of platform or external dependencies.

rocksdb_namespace.h had to be re-worked slightly to enable checking for
failure to include it. (ROCKSDB_NAMESPACE is a valid namespace name.)

Fixes mostly involve adding and cleaning up #includes, but for
FileTraceWriter, a constructor was out-of-lined to make a forward
declaration sufficient.

This check is not currently run with `make check` but is added to
CircleCI build-linux-unity since that one is already relatively fast.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8893

Test Plan: existing tests and resolving issues detected by new check

Reviewed By: mrambacher

Differential Revision: D30823300

Pulled By: pdillinger

fbshipit-source-id: 9fff223944994c83c105e2e6496d24845dc8e572
2021-09-10 10:00:26 -07:00
Hui Xiao
12542488ef Add public API RateLimiter::GetTotalPendingRequests() (#8890)
Summary:
Context/Summary:
As users requested, a public API RateLimiter::GetTotalPendingRequests() is added to expose the total number of pending requests for bytes in the rate limiter, which is the size of the request queue of that priority (or of all priorities, if IO_TOTAL is interested) at the time when this API is called.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8890

Test Plan:
- Passing added new unit tests
- Passing existing unit tests

Reviewed By: ajkr

Differential Revision: D30815500

Pulled By: hx235

fbshipit-source-id: 2dfa990f651c1c47378b6215c751ad76a5824300
2021-09-10 08:37:04 -07:00
Peter Dillinger
0ef88538c6 Improve support for using regexes (#8740)
Summary:
* Consolidate use of std::regex for testing to testharness.cc, to
minimize Facebook linters constantly flagging uses in non-production
code.
* Improve syntax and error messages for asserting some string matches a
regex in tests.
* Add a public Regex wrapper class to encapsulate existing usage in
ObjectRegistry.
* Remove unnecessary include <regex>
* Put warnings that use of Regex in production code could cause bad
performance or stack overflow.

Intended follow-up work:
* Replace std::regex with another underlying implementation like RE2
* Improve ObjectRegistry interface in terms of possibly confusing literal
string matching vs. regex and in terms of reporting invalid regex.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8740

Test Plan:
tests updated, basic unit test for public Regex, and some manual
testing of temporary changes to see example error messages:

utilities/backupable/backupable_db_test.cc:917: Failure
000010_1162373755_138626.blob (child.name)
does not match regex
[0-9]+_[0-9]+_[0-9]+[.]blobHAHAHA (pattern)

db/db_basic_test.cc:74: Failure
R3SHSBA8C4U0CIMV2ZB0 (sid3)
does not match regex [0-9A-Z]{20}HAHAHA

Reviewed By: mrambacher

Differential Revision: D30706246

Pulled By: pdillinger

fbshipit-source-id: ba845e8f563ccad39bdb58f44f04e9da8f78c3fd
2021-09-07 13:05:23 -07:00
Peter Dillinger
4750421ece Replace most typedef with using= (#8751)
Summary:
Old typedef syntax is confusing

Most but not all changes with

    perl -pi -e 's/typedef (.*) ([a-zA-Z0-9_]+);/using $2 = $1;/g' list_of_files
    make format

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8751

Test Plan: existing

Reviewed By: zhichao-cao

Differential Revision: D30745277

Pulled By: pdillinger

fbshipit-source-id: 6f65f0631c3563382d43347896020413cc2366d9
2021-09-07 11:31:59 -07:00
Peter Dillinger
c9cd5d25a8 Remove some unneeded code (#8736)
Summary:
* FullKey and ParseFullKey appear to serve no purpose in the public API
(or anything else) so removed. Only use in one test updated.
* NumberToString serves no purpose vs. ToString so removed, numerous
calls updated
* Remove unnecessary forward declarations in metadata.h by re-arranging
class definitions.
* Remove some unneeded semicolons

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8736

Test Plan: existing tests

Reviewed By: mrambacher

Differential Revision: D30700039

Pulled By: pdillinger

fbshipit-source-id: 1e436a576f511a6ed8b4d97af7cc8216bc729af2
2021-09-01 14:28:58 -07:00
Hui Xiao
240c4126fd Implement superior user & mid IO priority level in GenericRateLimiter (#8595)
Summary:
Context:
An extra IO_USER priority in rate limiter allows users to optionally charge WAL writes / SST reads to rate limiter at this priority level, which then has higher priority than IO_HIGH and IO_LOW. With an extra IO_USER priority, it allows users to better specify the relative urgency/importance among different requests in rate limiter. As a consequence, IO resource management can better prioritize and limit resource based on user's need.

The IO_USER is implemented as superior priority in GenericRateLimiter, in the sense that its request queue will always be iterated first without being constrained to fairness. The reason is that the notion of fairness is only meaningful in helping lower priorities in background IO (i.e, IO_HIGH/MID/LOW) to gain some fair chance to run so that it does not block foreground IO (i.e, the ones that are charged at the level of IO_USER). As we can see, the ultimate goal here is to not blocking foreground IO at IO_USER level, which justifies the superiority of IO_USER.

Similar benefits exist for IO_MID priority.
- Rewrote the logic of deciding the order of iterating request queues of high/low priorities to include the extra user/mid priority w/o affecting the existing behavior (see PR's [comment](https://github.com/facebook/rocksdb/pull/8595/files#r678749331))
- Included the request queue of user-pri/mid-pri in the code path of next-leader-candidate signaling and GenericRateLimiter's destructor
- Included the extra user/mid-pri in bookkeeping data structures: total_bytes_through_ and total_requests_
- Re-written the previous impl of explicitly iterating priorities with a loop from Env::IO_LOW to Env::IO_TOTAL

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8595

Test Plan:
- passed existing rate_limiter_test.cc
- passed added unit tests in rate_limiter_test.cc
- run performance test to verify performance with only high/low requests is not affected by this change
   - Set-up command:
   `TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=fillrandom --duration=5 --compression_type=none --num=100000000 --disable_auto_compactions=true --write_buffer_size=1048576 --writable_file_max_buffer_size=65536 --target_file_size_base=1048576 --max_bytes_for_level_base=4194304 --level0_slowdown_writes_trigger=$(((1 << 31) - 1)) --level0_stop_writes_trigger=$(((1 << 31) - 1))`

    - Test command:
   `TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=overwrite --use_existing_db=true --disable_wal=true --duration=30 --compression_type=none --num=100000000 --write_buffer_size=1048576 --writable_file_max_buffer_size=65536 --target_file_size_base=1048576 --max_bytes_for_level_base=4194304 --level0_slowdown_writes_trigger=$(((1 << 31) - 1)) --level0_stop_writes_trigger=$(((1 << 31) - 1)) --statistics=true --rate_limiter_bytes_per_sec=1048576 --rate_limiter_refill_period_us=1000  --threads=32 |& grep -E '(flush|compact)\.write\.bytes'`

   - Before (on branch upstream/master):
   `rocksdb.compact.write.bytes COUNT : 4014162`
   `rocksdb.flush.write.bytes COUNT : 26715832`
    rocksdb.flush.write.bytes/rocksdb.compact.write.bytes ~= 6.66

   - After (on branch rate_limiter_user_pri):
  `rocksdb.compact.write.bytes COUNT : 3807822`
  `rocksdb.flush.write.bytes COUNT : 26098659`
   rocksdb.flush.write.bytes/rocksdb.compact.write.bytes ~= 6.85

Reviewed By: ajkr

Differential Revision: D30577783

Pulled By: hx235

fbshipit-source-id: 0881f2705ffd13ecd331256bde7e8ec874a353f4
2021-08-31 11:24:27 -07:00
Peter Dillinger
13ded69484 Built-in support for generating unique IDs, bug fix (#8708)
Summary:
Env::GenerateUniqueId() works fine on Windows and on POSIX
where /proc/sys/kernel/random/uuid exists. Our other implementation is
flawed and easily produces collision in a new multi-threaded test.
As we rely more heavily on DB session ID uniqueness, this becomes a
serious issue.

This change combines several individually suitable entropy sources
for reliable generation of random unique IDs, with goal of uniqueness
and portability, not cryptographic strength nor maximum speed.

Specifically:
* Moves code for getting UUIDs from the OS to port::GenerateRfcUuid
rather than in Env implementation details. Callers are now told whether
the operation fails or succeeds.
* Adds an internal API GenerateRawUniqueId for generating high-quality
128-bit unique identifiers, by combining entropy from three "tracks":
  * Lots of info from default Env like time, process id, and hostname.
  * std::random_device
  * port::GenerateRfcUuid (when working)
* Built-in implementations of Env::GenerateUniqueId() will now always
produce an RFC 4122 UUID string, either from platform-specific API or
by converting the output of GenerateRawUniqueId.

DB session IDs now use GenerateRawUniqueId while DB IDs (not as
critical) try to use port::GenerateRfcUuid but fall back on
GenerateRawUniqueId with conversion to an RFC 4122 UUID.

GenerateRawUniqueId is declared and defined under env/ rather than util/
or even port/ because of the Env dependency.

Likely follow-up: enhance GenerateRawUniqueId to be faster after the
first call and to guarantee uniqueness within the lifetime of a single
process (imparting the same property onto DB session IDs).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8708

Test Plan:
A new mini-stress test in env_test checks the various public
and internal APIs for uniqueness, including each track of
GenerateRawUniqueId individually. We can't hope to verify anywhere close
to 128 bits of entropy, but it can at least detect flaws as bad as the
old code. Serial execution of the new tests takes about 350 ms on
my machine.

Reviewed By: zhichao-cao, mrambacher

Differential Revision: D30563780

Pulled By: pdillinger

fbshipit-source-id: de4c9ff4b2f581cf784fcedb5f39f16e5185c364
2021-08-30 15:20:41 -07:00
Peter Dillinger
22161b7547 Upgrade xxhash, add Hash128 (#8634)
Summary:
With expected use for a 128-bit hash, xxhash library is
upgraded to current dev (2c611a76f914828bed675f0f342d6c4199ffee1e)
as of Aug 6 so that we can use production version of XXH3_128bits
as new Hash128 function (added in hash128.h).

To make this work, however, we have to carve out the "preview" version
of XXH3 that is used in new SST Bloom and Ribbon filters, since that
will not get maintenance in xxhash releases. I have consolidated all the
relevant code into xxph3.h and made it "inline only" (no .cc file). The
working name for this hash function is changed from XXH3p to XXPH3
(XX Preview Hash) because the latter is easier to get working with no
symbol name conflicts between the headers.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8634

Test Plan:
no expected change in existing functionality. For Hash128,
added some unit tests based on those for Hash64 to ensure some basic
properties and that the values do not change accidentally.

Reviewed By: zhichao-cao

Differential Revision: D30173490

Pulled By: pdillinger

fbshipit-source-id: 06aa542a7a28b353bc2c865b9b2f8bdfe44158e4
2021-08-20 18:41:51 -07:00
Peter Dillinger
2a383f21f4 Add Bloom/Ribbon hybrid API support (#8679)
Summary:
This is essentially resurrection and fixing of the part of
https://github.com/facebook/rocksdb/issues/8198 that was reverted in https://github.com/facebook/rocksdb/issues/8212, using data added in https://github.com/facebook/rocksdb/issues/8246. Basically,
when configuring Ribbon filter, you can specify an LSM level before which
Bloom will be used instead of Ribbon. But Bloom is only considered for
Leveled and Universal compaction styles and file going into a known LSM
level. This way, SST file writer, FIFO compaction, etc. use Ribbon filter as
you would expect with NewRibbonFilterPolicy.

So that this can be controlled with a single int value and so that flushes
can be distinguished from intra-L0, we consider flush to go to level -1 for
the purposes of this option. (Explained in API comment.)

I also expect the most common and recommended Ribbon configuration to
use Bloom during flush, to minimize slowing down writes and because according
to my estimates, Ribbon only pays off if the structure lives in memory for
more than an hour. Thus, I have changed the default for NewRibbonFilterPolicy
to be this mild hybrid configuration. I don't really want to add something like
NewHybridFilterPolicy because at least the mild hybrid configuration (Bloom for
flush, Ribbon otherwise) should be considered a natural choice.

C APIs also updated, but because they don't support overloading,
rocksdb_filterpolicy_create_ribbon is kept pure ribbon for clarity and
rocksdb_filterpolicy_create_ribbon_hybrid must be called for a hybrid
configuration. While touching C API, I changed bits per key options from
int to double.

BuiltinFilterPolicy is needed so that LevelThresholdFilterPolicy doesn't inherit
unused fields from BloomFilterPolicy.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8679

Test Plan: new + updated tests, including crash test

Reviewed By: jay-zhuang

Differential Revision: D30445797

Pulled By: pdillinger

fbshipit-source-id: 6f5aeddfd6d79f7e55493b563c2d1d2d568892e1
2021-08-20 18:00:16 -07:00
Peter Dillinger
b6269b078a Stable cache keys on ingested SST files (#8669)
Summary:
Extends https://github.com/facebook/rocksdb/issues/8659 to work for ingested external SST files, even
the same file ingested into different DBs sharing a block cache.

Note: These new cache keys are currently only enabled when FileSystem
does not provide GetUniqueId. For now, they are typically larger,
so slightly less efficient.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8669

Test Plan: Extended unit test

Reviewed By: zhichao-cao

Differential Revision: D30398532

Pulled By: pdillinger

fbshipit-source-id: 1f13e2af4b8bfff5741953a69466e9589fbc23c7
2021-08-18 11:33:03 -07:00
Andrew Kryczka
82b81dc8b5 Simplify GenericRateLimiter algorithm (#8602)
Summary:
`GenericRateLimiter` slow path handles requests that cannot be satisfied
immediately.  Such requests enter a queue, and their thread stays in `Request()`
until they are granted or the rate limiter is stopped.  These threads are
responsible for unblocking themselves.  The work to do so is split into two main
duties.

(1) Waiting for the next refill time.
(2) Refilling the bytes and granting requests.

Prior to this PR, the slow path logic involved a leader election algorithm to
pick one thread to perform (1) followed by (2).  It elected the thread whose
request was at the front of the highest priority non-empty queue since that
request was most likely to be granted.  This algorithm was efficient in terms of
reducing intermediate wakeups, which is a thread waking up only to resume
waiting after finding its request is not granted.  However, the conceptual
complexity of this algorithm was too high.  It took me a long time to draw a
timeline to understand how it works for just one edge case yet there were so
many.

This PR drops the leader election to reduce conceptual complexity.  Now, the two
duties can be performed by whichever thread acquires the lock first.  The risk
of this change is increasing the number of intermediate wakeups, however, we
took steps to mitigate that.

- `wait_until_refill_pending_` flag ensures only one thread performs (1). This\
prevents the thundering herd problem at the next refill time. The remaining\
threads wait on their condition variable with an unbounded duration -- thus we\
must remember to notify them to ensure forward progress.
- (1) is typically done by a thread at the front of a queue. This is trivial\
when the queues are initially empty as the first choice that arrives must be\
the only entry in its queue. When queues are initially non-empty, we achieve\
this by having (2) notify a thread at the front of a queue (preferring higher\
priority) to perform the next duty.
- We do not require any additional wakeup for (2). Typically it will just be\
done by the thread that finished (1).

Combined, the second and third bullet points above suggest the refill/granting
will typically be done by a request at the front of its queue.  This is
important because one wakeup is saved when a granted request happens to be in an
already running thread.

Note there are a few cases that still lead to intermediate wakeup, however.  The
first two are existing issues that also apply to the old algorithm, however, the
third (including both subpoints) is new.

- No request may be granted (only possible when rate limit dynamically\
decreases).
- Requests from a different queue may be granted.
- (2) may be run by a non-front request thread causing it to not be granted even\
if some requests in that same queue are granted. It can happen for a couple\
(unlikely) reasons.
  - A new request may sneak in and grab the lock at the refill time, before the\
thread finishing (1) can wake up and grab it.
  - A new request may sneak in and grab the lock and execute (1) before (2)'s\
chosen candidate can wake up and grab the lock. Then that non-front request\
thread performing (1) can carry over to perform (2).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8602

Test Plan:
- Use existing tests. The edge cases listed in the comment are all performance\
related; I could not really think of any related to correctness. The logic\
looks the same whether a thread wakes up/finishes its work early/on-time/late,\
or whether the thread is chosen vs. "steals" the work.
- Verified write throughput and CPU overhead are basically the same with and\
  without this change, even in a rate limiter heavy workload:

Test command:
```
$ rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -benchmarks=fillrandom -num_multi_db=64 -num_low_pri_threads=64 -num_high_pri_threads=64 -write_buffer_size=262144 -target_file_size_base=262144 -max_bytes_for_level_base=1048576 -rate_limiter_bytes_per_sec=16777216 -key_size=24 -value_size=1000 -num=10000 -compression_type=none -rate_limiter_refill_period_us=1000
```

Results before this PR:

```
fillrandom   :     108.463 micros/op 9219 ops/sec;    9.0 MB/s
7.40user 8.84system 1:26.20elapsed 18%CPU (0avgtext+0avgdata 256140maxresident)k
```

Results after this PR:

```
fillrandom   :     108.108 micros/op 9250 ops/sec;    9.0 MB/s
7.45user 8.23system 1:26.68elapsed 18%CPU (0avgtext+0avgdata 255688maxresident)k
```

Reviewed By: hx235

Differential Revision: D30048013

Pulled By: ajkr

fbshipit-source-id: 6741bba9d9dfbccab359806d725105817fef818b
2021-08-09 16:47:15 -07:00
Lucian Grijincu
a756fb9c85 rocksdb: don't call LZ4_loadDictHC with null dictionary
Summary: UBSAN revealed a pointer underflow when `LZ4HC_init_internal` is called with a null `start`.

Reviewed By: ajkr

Differential Revision: D30181874

fbshipit-source-id: ca9bbac1a85c58782871d7f153af733b000cc66c
2021-08-09 16:05:46 -07:00
Andrew Kryczka
23ffed9cb7 Prevent joining detached thread in ThreadPoolImpl (#8635)
Summary:
This draining mechanism should not be run during `JoinThreads()` because it can detach threads that will be joined. Joining detached threads would throw an exception.

With this PR, we skip draining when `JoinThreads()` has already decided what threads to `join()`, so the threads will exit naturally once the work queue empties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8635

Test Plan: verified it unblocked using `WaitForJobsAndJoinAllThreads()` in https://github.com/facebook/rocksdb/issues/8611.

Reviewed By: riversand963

Differential Revision: D30174587

Pulled By: ajkr

fbshipit-source-id: 144966398a607987e0763c7152a0f653fdbf3c8b
2021-08-06 19:06:02 -07:00
hx235
dbe3810c74 Improve rate limiter implementation's readability (#8596)
Summary:
Context:
As need for new feature of resource management using RocksDB's rate limiter like [https://github.com/facebook/rocksdb/issues/8595](https://github.com/facebook/rocksdb/pull/8595) arises, it is about time to re-learn our rate limiter and make this learning process easier for others by improving its readability. The comment/assertion/one extra else-branch are added based on my best understanding toward the rate_limiter.cc and rate_limiter_test.cc up to date after giving it a hard read.
- Add code comments/assertion/one extra else-branch (that is not affecting existing behavior, see PR comment) to describe how leader-election works under multi-thread settings in GenericRateLimiter::Request()
- Add code comments to describe a non-obvious trick during clean-up of rate limiter destructor
- Add code comments to explain more about the starvation being fixed in GenericRateLimiter::Refill() through partial byte-granting
- Add code comments to the rate limiter's setup in a complicated unit test in rate_limiter_test

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8596

Test Plan: - passed existing rate_limiter_test.cc

Reviewed By: ajkr

Differential Revision: D29982590

Pulled By: hx235

fbshipit-source-id: c3592986bb5b0c90d8229fe44f425251ec7e8a0a
2021-08-04 10:43:47 -07:00
Peter Dillinger
1d34cd797e Fix insecure internal API for GetImpl (#8590)
Summary:
Calling the GetImpl function could leave reference to a local
callback function in a field of a parameter struct. As this is
performance-critical code, I'm not going to attempt to sanitize this
code too much, but make the existing hack a bit cleaner by reverting
what it overwrites in the input struct.

Added SaveAndRestore utility class to make that easier.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8590

Test Plan:
added unit test for SaveAndRestore; existing tests for
GetImpl

Reviewed By: riversand963

Differential Revision: D29947983

Pulled By: pdillinger

fbshipit-source-id: 2f608853f970bc06724e834cc84dcc4b8599ddeb
2021-07-29 17:23:01 -07:00
Drewryz
3b27725245 Fix a minor issue with initializing the test path (#8555)
Summary:
The PerThreadDBPath has already specified a slash. It does not need to be specified when initializing the test path.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8555

Reviewed By: ajkr

Differential Revision: D29758399

Pulled By: jay-zhuang

fbshipit-source-id: 6d2b878523e3e8580536e2829cb25489844d9011
2021-07-23 08:38:45 -07:00
Peter Dillinger
84eef260de Remove TaskLimiterToken::ReleaseOnce for fix (#8567)
Summary:
Rare TSAN and valgrind failures are caused by unnecessary
reading of a field on the TaskLimiterToken::limiter_ for an assertion
after the token has been released and the limiter destroyed. To simplify
we can simply destroy the token before triggering DB shutdown
(potentially destroying the limiter). This makes the ReleaseOnce logic
unnecessary.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8567

Test Plan: watch for more failures in CI

Reviewed By: ajkr

Differential Revision: D29811795

Pulled By: pdillinger

fbshipit-source-id: 135549ebb98fe4f176d1542ed85d5bd6350a40b3
2021-07-21 17:37:53 -07:00
sherriiiliu
7b9ecd4067 fix several MSVC build errors (#8519)
Summary:
Fixed a few MSVC (VCToolsVersion=14.0) build errors and warnings
* `DEFINE_string` is a macro and VC compiler complains that it cannot put [ifdef-inside-define](https://stackoverflow.com/questions/5586429/ifdef-inside-define)
* `sleep()` is not a recognizable function. Use `FLAGS_env->SleepForMicroseconds` instead
* Define precise type in comparison to avoid mismatch warning

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8519

Reviewed By: jay-zhuang

Differential Revision: D29683086

fbshipit-source-id: 8c80941472089f8daba84ae29597e75e603850e4
2021-07-13 12:40:43 -07:00
mrambacher
89f66d4484 Add customizable_util.h to the public API (#8301)
Summary:
Useful for allowing new classes to create and manage Customizable objects without using internal APIs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8301

Reviewed By: zhichao-cao

Differential Revision: D29428303

Pulled By: mrambacher

fbshipit-source-id: 3d33d5197cc8379fe35b54d3d169f91f0dfe7a47
2021-06-29 09:08:57 -07:00
Zhichao Cao
a904c62d28 Using existing crc32c checksum in checksum handoff for Manifest and WAL (#8412)
Summary:
In PR https://github.com/facebook/rocksdb/issues/7523 , checksum handoff is introduced in RocksDB for WAL, Manifest, and SST files. When user enable checksum handoff for a certain type of file, before the data is written to the lower layer storage system, we calculate the checksum (crc32c) of each piece of data and pass the checksum down with the data, such that data verification can be down by the lower layer storage system if it has the capability. However, it cannot cover the whole lifetime of the data in the memory and also it potentially introduces extra checksum calculation overhead.

In this PR, we introduce a new interface in WritableFileWriter::Append, which allows the caller be able to pass the data and the checksum (crc32c) together. In this way, WritableFileWriter can directly use the pass-in checksum (crc32c) to generate the checksum of data being passed down to the storage system. It saves the calculation overhead and achieves higher protection coverage. When a new checksum is added with the data, we use Crc32cCombine https://github.com/facebook/rocksdb/issues/8305 to combine the existing checksum and the new checksum. To avoid the segmenting of data by rate-limiter before it is stored, rate-limiter is called enough times to accumulate enough credits for a certain write. This design only support Manifest and WAL which use log_writer in the current stage.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8412

Test Plan: make check, add new testing cases.

Reviewed By: anand1976

Differential Revision: D29151545

Pulled By: zhichao-cao

fbshipit-source-id: 75e2278c5126cfd58393c67b1efd18dcc7a30772
2021-06-25 00:47:17 -07:00
Zhichao Cao
ecccc63179 Implementation of Crc32c combine function (#8305)
Summary:
Implement a function to generate the crc32c of two combined strings. Suppose we have the string 1 (s1) with crc32c checksum crc32c_1 and string 2 (s2) with crc32c checksum crc32c_2, the new string is s1+s2 and its checksum is crc32c_new=Crc32cCombine(crc32c_1, crc32c_2, s2.size).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8305

Test Plan: make check, added new testing case

Reviewed By: pdillinger

Differential Revision: D28651665

Pulled By: zhichao-cao

fbshipit-source-id: c84116108388f11a81f6a217b49f99c70d4ffacf
2021-06-16 18:30:34 -07:00
mrambacher
6ad0810393 Make Comparator into a Customizable Object (#8336)
Summary:
Makes the Comparator class into a Customizable object.  Added/Updated the CreateFromString method to create Comparators.  Added test for using the ObjectRegistry to create one.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8336

Reviewed By: jay-zhuang

Differential Revision: D28999612

Pulled By: mrambacher

fbshipit-source-id: bff2cb2814eeb9fef6a00fddc61d6e34b6fbcf2e
2021-06-11 06:22:59 -07:00
Jay Zhuang
3786181a90 Add remote compaction public API (#8300)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8300

Reviewed By: ajkr

Differential Revision: D28464726

Pulled By: jay-zhuang

fbshipit-source-id: 49e9f4fb791808a6cbf39a7b1a331373f645fc5e
2021-05-19 21:41:31 -07:00
Glebanister
748e3acc11 Add StartThread type checking wrapper (#8303)
Summary:
- Add class `FunctorWrapper` to invoke the function with given parameters
- Implement `StartThreadTyped` which wraps `StartThread` with type checking cover
- Demonstrate `StartThreadTyped` in test `util/thread_local_test.cc`

https://github.com/facebook/rocksdb/issues/8285

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8303

Reviewed By: ajkr

Differential Revision: D28539318

Pulled By: pdillinger

fbshipit-source-id: 624789c236bde31163deda95c1e1471aee68933e
2021-05-19 16:51:13 -07:00
Jay Zhuang
a79b46c503 Add De/Serialization for CompactionInput/Result (#8247)
Summary:
The functions will be used for remote compaction parameter
input and result.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8247

Test Plan: `make check`

Reviewed By: ajkr

Differential Revision: D28104680

Pulled By: jay-zhuang

fbshipit-source-id: c0a5178e6277125118384278efea2acbf90aa6cb
2021-05-12 12:36:43 -07:00
Andrew Kryczka
c70bae1b05 Fix ConcurrentTaskLimiter token release for shutdown (#8253)
Summary:
Previously the shutdown process did not properly wait for all
`compaction_thread_limiter` tokens to be released before proceeding to
delete the DB's C++ objects. When this happened, we saw tests like
"DBCompactionTest.CompactionLimiter" flake with the following error:

```
virtual
rocksdb::ConcurrentTaskLimiterImpl::~ConcurrentTaskLimiterImpl():
Assertion `outstanding_tasks_ == 0' failed.
```

There is a case where a token can still be alive even after the shutdown
process has waited for BG work to complete. In particular, this happens
because the shutdown process only waits for flush/compaction scheduled/unscheduled counters to all
reach zero. These counters are decremented in `BackgroundCallCompaction()`
functions. However, tokens are released in `BGWork*Compaction()` functions, which
actually wrap the `BackgroundCallCompaction()` function.

A simple sleep could repro the race condition:

```
$ diff --git a/db/db_impl/db_impl_compaction_flush.cc
b/db/db_impl/db_impl_compaction_flush.cc
index 806bc548a..ba59efa89 100644
 --- a/db/db_impl/db_impl_compaction_flush.cc
+++ b/db/db_impl/db_impl_compaction_flush.cc
@@ -2442,6 +2442,7 @@ void DBImpl::BGWorkCompaction(void* arg) {
       static_cast<PrepickedCompaction*>(ca.prepicked_compaction);
   static_cast_with_check<DBImpl>(ca.db)->BackgroundCallCompaction(
       prepicked_compaction, Env::Priority::LOW);
+  sleep(1);
   delete prepicked_compaction;
 }

$ ./db_compaction_test --gtest_filter=DBCompactionTest.CompactionLimiter
db_compaction_test: util/concurrent_task_limiter_impl.cc:24: virtual rocksdb::ConcurrentTaskLimiterImpl::~ConcurrentTaskLimiterImpl(): Assertion `outstanding_tasks_ == 0' failed.
Received signal 6 (Aborted)
#0   /usr/local/fbcode/platform007/lib/libc.so.6(gsignal+0xcf) [0x7f02673c30ff] ??      ??:0
https://github.com/facebook/rocksdb/issues/1   /usr/local/fbcode/platform007/lib/libc.so.6(abort+0x134) [0x7f02673ac934] ??       ??:0
...
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8253

Test Plan: sleeps to expose race conditions

Reviewed By: akankshamahajan15

Differential Revision: D28168064

Pulled By: ajkr

fbshipit-source-id: 9e5167c74398d323e7975980c5cc00f450631160
2021-05-04 17:27:24 -07:00
mrambacher
0ca6d6297f Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)
Summary:
Renaming ImmutableCFOptions::info_log and statistics to logger and stats.  This is stage 2 in creating an ImmutableOptions class.  It is necessary because the names match those in ImmutableOptions and have different types.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8227

Reviewed By: jay-zhuang

Differential Revision: D28000967

Pulled By: mrambacher

fbshipit-source-id: 3bf2aa04e8f1e8724d825b7deacf41080c14420b
2021-04-26 12:43:45 -07:00
mrambacher
01e460d538 Make types of Immutable/Mutable Options fields match that of the underlying Option (#8176)
Summary:
This PR is a first step at attempting to clean up some of the Mutable/Immutable Options code.  With this change, a DBOption and a ColumnFamilyOption can be reconstructed from their Mutable and Immutable equivalents, respectively.

readrandom tests do not show any performance degradation versus master (though both are slightly slower than the current 6.19 release).

There are still fields in the ImmutableCFOptions that are not CF options but DB options.  Eventually, I would like to move those into an ImmutableOptions (= ImmutableDBOptions+ImmutableCFOptions).  But that will be part of a future PR to minimize changes and disruptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8176

Reviewed By: pdillinger

Differential Revision: D27954339

Pulled By: mrambacher

fbshipit-source-id: ec6b805ba9afe6e094bffdbd76246c2d99aa9fad
2021-04-22 20:43:54 -07:00
Peter Dillinger
95f6add746 Revert Ribbon starting level support from #8198 (#8212)
Summary:
This partially reverts commit 10196d7edc.

The problem with this change is because of important filter use cases:
FIFO compaction and SST writer. FIFO "compaction" always uses level 0 so
would only use Ribbon filters if specifically including level 0 for the
Ribbon filter policy. SST writer sets level_at_creation=-1 to indicate
unknown level, and this would be treated the same as level 0 unless
fixed.

We are keeping the part about committing to permanent schema, which is
only changes to API comments and HISTORY.md.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8212

Test Plan: CI

Reviewed By: jay-zhuang

Differential Revision: D27896468

Pulled By: pdillinger

fbshipit-source-id: 50a775f7cba5d64fb729d9b982e355864020596e
2021-04-20 19:46:40 -07:00
Peter Dillinger
10196d7edc Ribbon long-term support, starting level support (#8198)
Summary:
Since the Ribbon filter schema seems good (compatible back to
6.15.0), this change commits to long term support of the SST schema,
even though we expect the API for enabling Ribbon to change (still
called NewExperimentalRibbonFilterPolicy).

This also adds support for "hybrid" configuration in which some levels
use Bloom (higher levels, lower numbered) for speed and the rest use
Ribbon (lower levels, higher numbered) for memory space efficiency.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8198

Test Plan: unit test added, crash test support

Reviewed By: jay-zhuang

Differential Revision: D27831232

Pulled By: pdillinger

fbshipit-source-id: 90e528677689474d293ed6710b42ba89fbd5b5ab
2021-04-16 15:43:08 -07:00
Levi Tamasi
303cb23a0f Introduce a ThreadGuard class and use it in ExternalSSTFileTest.PickedLevelBug (#8112)
Summary:
The patch adds a resource management/RAII class called `ThreadGuard`,
which can be used to ensure that the managed thread is joined when the
`ThreadGuard` is destroyed, regardless of whether it is due to the
object going out of scope, an early return, an exception etc. This is
important because if an `std::thread` object is destroyed without having
been joined (or detached) first, the process is aborted (via
`std::terminate`).

For now, `ThreadGuard` is only used in the test case
`ExternalSSTFileTest.PickedLevelBug`; however, it could come in handy
elsewhere in the codebase as well (both in test code and "real" code).
Case in point: in the `PickedLevelBug` test case, with the earlier code we
could end up in the above situation when the following assertion (which is
before the threads are joined) is triggered:

```
ASSERT_FALSE(bg_compact_started.load());
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8112

Test Plan:
```
make check
gtest-parallel --repeat=10000 ./external_sst_file_test --gtest_filter="*PickedLevelBug"
```

Reviewed By: riversand963

Differential Revision: D27343185

Pulled By: ltamasi

fbshipit-source-id: 2a8c3aa68bc78cc03ec0dbae909fb25c2cd15c69
2021-03-25 22:08:58 -07:00
Jay Zhuang
45c65d6dcf Use thread-safe strerror_r() to get error message (#8087)
Summary:
`strerror()` is not thread-safe, using `strerror_r()` instead. The API could be different on the different platforms, used the code from 0deef031cb/folly/String.cpp (L457)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8087

Reviewed By: mrambacher

Differential Revision: D27267151

Pulled By: jay-zhuang

fbshipit-source-id: 4b8856d1ec069d5f239b764750682c56e5be9ddb
2021-03-24 23:07:27 -07:00
Peter Dillinger
da6b90ab48 Improve bloom_test bits_per_key flag (#8093)
Summary:
Improved handling of -bits_per_key other than 10, but at least
the OptimizeForMemory test is simply not designed for generally handling
other settings. (ribbon_test does have a statistical framework for this
kind of testing, but it's not important to do that same for Bloom right
now.)

Closes https://github.com/facebook/rocksdb/issues/7019

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8093

Test Plan: for I in `seq 1 20`; do ./bloom_test --gtest_filter=-*OptimizeForMemory* --bits_per_key=$I &> /dev/null || echo FAILED; done

Reviewed By: mrambacher

Differential Revision: D27275875

Pulled By: pdillinger

fbshipit-source-id: 7362e8ac2c41ea11f639412e4f30c8b375f04388
2021-03-23 21:42:40 -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
Peter Dillinger
01c2ec3fcb Add ROCKSDB_GTEST_BYPASS (#8048)
Summary:
This is for cases that do not meet the Facebook criteria for
SKIP (see new comments). Also made ROCKSDB_GTEST_{SKIP,BYPASS} print the
message because gtest doesn't ever seem to.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8048

Test Plan: manual inspection of ./ribbon_test output, CI

Reviewed By: mrambacher

Differential Revision: D26953688

Pulled By: pdillinger

fbshipit-source-id: c914eaffe7d419db6ab90a193d474531e23582e5
2021-03-12 16:02:06 -08:00
Yanqin Jin
82b3888433 Enable backward iterator for keys with user-defined timestamp (#8035)
Summary:
This PR does the following:

- Enable backward iteration for keys with user-defined timestamp. Note that merge, single delete, range delete are not supported yet.
- Introduces a new helper API `Comparator::EqualWithoutTimestamp()`.
- Fix a typo in `SetTimestamp()`.
- Add/update unit tests

Run db_bench (built with DEBUG_LEVEL=0) to demonstrate that no overhead is introduced for CPU-intensive workloads with a lot of `Prev()`. Also provided results of iterating keys with timestamps.

1. Disable timestamp, run:
```
./db_bench -db=/dev/shm/rocksdb -disable_wal=1 -benchmarks=fillseq,seekrandom[-W1-X6] -reverse_iterator=1 -seek_nexts=5
```
Results:
> Baseline
> - seekrandom [AVG    6 runs] : 96115 ops/sec;   53.2 MB/sec
> - seekrandom [MEDIAN 6 runs] : 98075 ops/sec;   54.2 MB/sec
>
> This PR
> - seekrandom [AVG    6 runs] : 95521 ops/sec;   52.8 MB/sec
> - seekrandom [MEDIAN 6 runs] : 96338 ops/sec;   53.3 MB/sec

2. Enable timestamp, run:
```
./db_bench -user_timestamp_size=8  -db=/dev/shm/rocksdb -disable_wal=1 -benchmarks=fillseq,seekrandom[-W1-X6] -reverse_iterator=1 -seek_nexts=5
```
Result:
> Baseline: not supported
>
> This PR
> - seekrandom [AVG    6 runs] : 90514 ops/sec;   50.1 MB/sec
> - seekrandom [MEDIAN 6 runs] : 90834 ops/sec;   50.2 MB/sec

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8035

Reviewed By: ltamasi

Differential Revision: D26926668

Pulled By: riversand963

fbshipit-source-id: 95330cc2242397c03e09d29e5417dfb0adc98ef5
2021-03-10 11:15:46 -08:00
David CARLIER
7a3444bf1f Mac M1 crc32 intrinsics ARM64 check support proposal (#7893)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/7893

Reviewed By: ajkr

Differential Revision: D26050966

Pulled By: jay-zhuang

fbshipit-source-id: 9df2bb65d82defd7fad49d5369979b03e22d39c2
2021-03-10 09:05:56 -08:00
Peter Dillinger
4b18c46d10 Refactor: add LineFileReader and Status::MustCheck (#8026)
Summary:
Removed confusing, awkward, and undocumented internal API
ReadOneLine and replaced with very simple LineFileReader.

In refactoring backupable_db.cc, this has the side benefit of
removing the arbitrary cap on the size of backup metadata files.

Also added Status::MustCheck to make it easy to mark a Status as
"must check." Using this, I can ensure that after
LineFileReader::ReadLine returns false the caller checks GetStatus().

Also removed some excessive conditional compilation in status.h

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8026

Test Plan: added unit test, and running tests with ASSERT_STATUS_CHECKED

Reviewed By: mrambacher

Differential Revision: D26831687

Pulled By: pdillinger

fbshipit-source-id: ef749c265a7a26bb13cd44f6f0f97db2955f6f0f
2021-03-09 20:12:38 -08:00
Levi Tamasi
cb25bc1128 Update compaction statistics to include the amount of data read from blob files (#8022)
Summary:
The patch does the following:
1) Exposes the amount of data (number of bytes) read from blob files from
`BlobFileReader::GetBlob` / `Version::GetBlob`.
2) Tracks the total number and size of blobs read from blob files during a
compaction (due to garbage collection or compaction filter usage) in
`CompactionIterationStats` and propagates this data to
`InternalStats::CompactionStats` / `CompactionJobStats`.
3) Updates the formulae for write amplification calculations to include the
amount of data read from blob files.
4) Extends the compaction stats dump with a new column `Rblob(GB)` and
a new line containing the total number and size of blob files in the current
`Version` to complement the information about the shape and size of the LSM tree
that's already there.
5) Updates `CompactionJobStats` so that the number of files and amount of data
written by a compaction are broken down per file type (i.e. table/blob file).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8022

Test Plan: Ran `make check` and `db_bench`.

Reviewed By: riversand963

Differential Revision: D26801199

Pulled By: ltamasi

fbshipit-source-id: 28a5f072048a702643b28cb5971b4099acabbfb2
2021-03-04 00:43:48 -08:00
Peter Dillinger
a8b3b9a20c Refine Ribbon configuration, improve testing, add Homogeneous (#7879)
Summary:
This change only affects non-schema-critical aspects of the production candidate Ribbon filter. Specifically, it refines choice of internal configuration parameters based on inputs. The changes are minor enough that the schema tests in bloom_test, some of which depend on this, are unaffected. There are also some minor optimizations and refactorings.

This would be a schema change for "smash" Ribbon, to fix some known issues with small filters, but "smash" Ribbon is not accessible in public APIs. Unit test CompactnessAndBacktrackAndFpRate updated to test small and medium-large filters. Run with --thoroughness=100 or so for much better detection power (not appropriate for continuous regression testing).

Homogenous Ribbon:
This change adds internally a Ribbon filter variant we call Homogeneous Ribbon, in collaboration with Stefan Walzer. The expected "result" value for every key is zero, instead of computed from a hash. Entropy for queries not to be false positives comes from free variables ("overhead") in the solution structure, which are populated pseudorandomly. Construction is slightly faster for not tracking result values, and never fails. Instead, FP rate can jump up whenever and whereever entries are packed too tightly. For small structures, we can choose overhead to make this FP rate jump unlikely, as seen in updated unit test CompactnessAndBacktrackAndFpRate.

Unlike standard Ribbon, Homogeneous Ribbon seems to scale to arbitrary number of keys when accepting an FP rate penalty for small pockets of high FP rate in the structure. For example, 64-bit ribbon with 8 solution columns and 10% allocated space overhead for slots seems to achieve about 10.5% space overhead vs. information-theoretic minimum based on its observed FP rate with expected pockets of degradation. (FP rate is close to 1/256.) If targeting a higher FP rate with fewer solution columns, Homogeneous Ribbon can be even more space efficient, because the penalty from degradation is relatively smaller. If targeting a lower FP rate, Homogeneous Ribbon is less space efficient, as more allocated overhead is needed to keep the FP rate impact of degradation relatively under control. The new OptimizeHomogAtScale tool in ribbon_test helps to find these optimal allocation overheads for different numbers of solution columns. And Ribbon widths, with 128-bit Ribbon apparently cutting space overheads in half vs. 64-bit.

Other misc item specifics:
* Ribbon APIs in util/ribbon_config.h now provide configuration data for not just 5% construction failure rate (95% success), but also 50% and 0.1%.
  * Note that the Ribbon structure does not exhibit "threshold" behavior as standard Xor filter does, so there is a roughly fixed space penalty to cut construction failure rate in half. Thus, there isn't really an "almost sure" setting.
  * Although we can extrapolate settings for large filters, we don't have a good formula for configuring smaller filters (< 2^17 slots or so), and efforts to summarize with a formula have failed. Thus, small data is hard-coded from updated FindOccupancy tool.
* Enhances ApproximateNumEntries for public API Ribbon using more precise data (new API GetNumToAdd), thus a more accurate but not perfect reversal of CalculateSpace. (bloom_test updated to expect the greater precision)
* Move EndianSwapValue from coding.h to coding_lean.h to keep Ribbon code easily transferable from RocksDB
* Add some missing 'const' to member functions
* Small optimization to 128-bit BitParity
* Small refactoring of BandingStorage in ribbon_alg.h to support Homogeneous Ribbon
* CompactnessAndBacktrackAndFpRate now has an "expand" test: on construction failure, a possible alternative to re-seeding hash functions is simply to increase the number of slots (allocated space overhead) and try again with essentially the same hash values. (Start locations will be different roundings of the same scaled hash values--because fastrange not mod.) This seems to be as effective or more effective than re-seeding, as long as we increase the number of slots (m) by roughly m += m/w where w is the Ribbon width. This way, there is effectively an expansion by one slot for each ribbon-width window in the banding. (This approach assumes that getting "bad data" from your hash function is as unlikely as it naturally should be, e.g. no adversary.)
* 32-bit and 16-bit Ribbon configurations are added to ribbon_test for understanding their behavior, e.g. with FindOccupancy. They are not considered useful at this time and not tested with CompactnessAndBacktrackAndFpRate.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7879

Test Plan: unit test updates included

Reviewed By: jay-zhuang

Differential Revision: D26371245

Pulled By: pdillinger

fbshipit-source-id: da6600d90a3785b99ad17a88b2a3027710b4ea3a
2021-02-26 08:50:42 -08:00
sherriiiliu
e017af15c1 Fix testcase failures on windows (#7992)
Summary:
Fixed 5 test case failures found on Windows 10/Windows Server 2016
1. In `flush_job_test`, the DestroyDir function fails in deconstructor because some file handles are still being held by VersionSet. This happens on Windows Server 2016, so need to manually reset versions_ pointer to release all file handles.
2. In `StatsHistoryTest.InMemoryStatsHistoryPurging` test, the capping memory cost of stats_history_size on Windows becomes 14000 bytes with latest changes, not just 13000 bytes.
3. In `SSTDumpToolTest.RawOutput` test, the output file handle is not closed at the end.
4. In `FullBloomTest.OptimizeForMemory` test, ROCKSDB_MALLOC_USABLE_SIZE is undefined on windows so `total_mem` is always equal to `total_size`. The internal memory fragmentation assertion does not apply in this case.
5. In `BlockFetcherTest.FetchAndUncompressCompressedDataBlock` test, XPRESS cannot reach 87.5% compression ratio with original CreateTable method, so I append extra zeros to the string value to enhance compression ratio. Beside, since XPRESS allocates memory internally, thus does not support for custom allocator verification, we will skip the allocator verification for XPRESS

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7992

Reviewed By: jay-zhuang

Differential Revision: D26615283

Pulled By: ajkr

fbshipit-source-id: 3632612f84b99e2b9c77c403b112b6bedf3b125d
2021-02-23 14:35:06 -08:00
Andrew Kryczka
d904233d2f Limit buffering for collecting samples for compression dictionary (#7970)
Summary:
For dictionary compression, we need to collect some representative samples of the data to be compressed, which we use to either generate or train (when `CompressionOptions::zstd_max_train_bytes > 0`) a dictionary. Previously, the strategy was to buffer all the data blocks during flush, and up to the target file size during compaction. That strategy allowed us to randomly pick samples from as wide a range as possible that'd be guaranteed to land in a single output file.

However, some users try to make huge files in memory-constrained environments, where this strategy can cause OOM. This PR introduces an option, `CompressionOptions::max_dict_buffer_bytes`, that limits how much data blocks are buffered before we switch to unbuffered mode (which means creating the per-SST dictionary, writing out the buffered data, and compressing/writing new blocks as soon as they are built). It is not strict as we currently buffer more than just data blocks -- also keys are buffered. But it does make a step towards giving users predictable memory usage.

Related changes include:

- Changed sampling for dictionary compression to select unique data blocks when there is limited availability of data blocks
- Made use of `BlockBuilder::SwapAndReset()` to save an allocation+memcpy when buffering data blocks for building a dictionary
- Changed `ParseBoolean()` to accept an input containing characters after the boolean. This is necessary since, with this PR, a value for `CompressionOptions::enabled` is no longer necessarily the final component in the `CompressionOptions` string.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7970

Test Plan:
- updated `CompressionOptions` unit tests to verify limit is respected (to the extent expected in the current implementation) in various scenarios of flush/compaction to bottommost/non-bottommost level
- looked at jemalloc heap profiles right before and after switching to unbuffered mode during flush/compaction. Verified memory usage in buffering is proportional to the limit set.

Reviewed By: pdillinger

Differential Revision: D26467994

Pulled By: ajkr

fbshipit-source-id: 3da4ef9fba59974e4ef40e40c01611002c861465
2021-02-19 14:09:54 -08:00
Max Neunhoeffer
cf14cb3e29 Avoid self-move-assign in pop operation of binary heap. (#7942)
Summary:
The current implementation of a binary heap in `util/heap.h` does a move-assign in the `pop` method. In the case that there is exactly one element stored in the heap, this ends up being a self-move-assign. This can cause trouble with certain classes, which are not prepared for this. Furthermore, it trips up the glibc STL debugger (`-D_GLIBCXX_DEBUG`), which produces an assertion failure in this case.

This PR addresses this problem by not doing the (unnecessary in this case) move-assign if there is only one element in the heap.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7942

Reviewed By: jay-zhuang

Differential Revision: D26528739

Pulled By: ajkr

fbshipit-source-id: 5ca570e0c4168f086b10308ad766dff84e6e2d03
2021-02-19 13:47:25 -08:00
Wilfried Goesgens
8a05c21e32 add string separation while composing error message (#7919)
Summary:
This will fix a missing string separation between `msg[n]` and `state_`.
Example of an error message how its looking now:
```
IO error: No space left on deviceWhile appending to file: /home/willi/src/stable-3.7/tmp/arangosh_CL6EFQ/shell_client/single1/data/engine-rocksdb/126426.sst: No space left on device
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7919

Reviewed By: ajkr

Differential Revision: D26242246

Pulled By: jay-zhuang

fbshipit-source-id: 5d9a0997a410aecfb3781478e57395d3d937bb84
2021-02-18 12:25:35 -08:00
Zhichao Cao
d1c510baec Handoff checksum Implementation (#7523)
Summary:
in PR https://github.com/facebook/rocksdb/issues/7419 , we introduce the new Append and PositionedAppend APIs to WritableFile at File System, which enable RocksDB to pass the data verification information (e.g., checksum of the data) to the lower layer. In this PR, we use the new API in WritableFileWriter, such that the file created via WritableFileWrite can pass the checksum to the storage layer. To control which types file should apply the checksum handoff, we add checksum_handoff_file_types to DBOptions. User can use this option to control which file types (Currently supported file tyes: kLogFile, kTableFile, kDescriptorFile.) should use the new Append and PositionedAppend APIs to handoff the verification information.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7523

Test Plan: add new unit test, pass make check/ make asan_check

Reviewed By: pdillinger

Differential Revision: D24313271

Pulled By: zhichao-cao

fbshipit-source-id: aafd69091ae85c3318e3e17cbb96fe7338da11d0
2021-02-10 22:20:32 -08:00
Peter Dillinger
e4f1e64c30 Add prefetching (batched MultiGet) for experimental Ribbon filter (#7889)
Summary:
Adds support for prefetching data in Ribbon queries,
which especially optimizes batched Ribbon queries for MultiGet
(~222ns/key to ~97ns/key) but also single key queries on cold memory
(~333ns to ~226ns) because many queries span more than one cache line.

This required some refactoring of the query algorithm, and there
does not appear to be a noticeable regression in "hot memory" query
times (perhaps from 48ns to 50ns).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7889

Test Plan:
existing unit tests, plus performance validation with
filter_bench:

Each data point is the best of two runs. I saturated the machine
CPUs with other filter_bench runs in the background.

Before:

    $ ./filter_bench -impl=3 -m_keys_total_max=200 -average_keys_per_filter=100000 -m_queries=50
    WARNING: Assertions are enabled; benchmarks unnecessarily slow
    Building...
    Build avg ns/key: 125.86
    Number of filters: 1993
    Total size (MB): 168.166
    Reported total allocated memory (MB): 183.211
    Reported internal fragmentation: 8.94626%
    Bits/key stored: 7.05341
    Prelim FP rate %: 0.951827
    ----------------------------
    Mixed inside/outside queries...
      Single filter net ns/op: 48.0111
      Batched, prepared net ns/op: 222.384
      Batched, unprepared net ns/op: 343.908
      Skewed 50% in 1% net ns/op: 252.916
      Skewed 80% in 20% net ns/op: 320.579
      Random filter net ns/op: 332.957

After:

    $ ./filter_bench -impl=3 -m_keys_total_max=200 -average_keys_per_filter=100000 -m_queries=50
    WARNING: Assertions are enabled; benchmarks unnecessarily slow
    Building...
    Build avg ns/key: 128.117
    Number of filters: 1993
    Total size (MB): 168.166
    Reported total allocated memory (MB): 183.211
    Reported internal fragmentation: 8.94626%
    Bits/key stored: 7.05341
    Prelim FP rate %: 0.951827
    ----------------------------
    Mixed inside/outside queries...
      Single filter net ns/op: 49.8812
      Batched, prepared net ns/op: 97.1514
      Batched, unprepared net ns/op: 222.025
      Skewed 50% in 1% net ns/op: 197.48
      Skewed 80% in 20% net ns/op: 212.457
      Random filter net ns/op: 226.464

Bloom comparison, for reference:

    $ ./filter_bench -impl=2 -m_keys_total_max=200 -average_keys_per_filter=100000 -m_queries=50
    WARNING: Assertions are enabled; benchmarks unnecessarily slow
    Building...
    Build avg ns/key: 35.3042
    Number of filters: 1993
    Total size (MB): 238.488
    Reported total allocated memory (MB): 262.875
    Reported internal fragmentation: 10.2255%
    Bits/key stored: 10.0029
    Prelim FP rate %: 0.965327
    ----------------------------
    Mixed inside/outside queries...
      Single filter net ns/op: 9.09931
      Batched, prepared net ns/op: 34.21
      Batched, unprepared net ns/op: 88.8564
      Skewed 50% in 1% net ns/op: 139.75
      Skewed 80% in 20% net ns/op: 181.264
      Random filter net ns/op: 173.88

Reviewed By: jay-zhuang

Differential Revision: D26378710

Pulled By: pdillinger

fbshipit-source-id: 058428967c55ed763698284cd3b4bbe3351b6e69
2021-02-10 21:04:56 -08:00
Andrew Kryczka
78ee8564ad Integrity protection for live updates to WriteBatch (#7748)
Summary:
This PR adds the foundation classes for key-value integrity protection and the first use case: protecting live updates from the source buffers added to `WriteBatch` through the destination buffer in `MemTable`. The width of the protection info is not yet configurable -- only eight bytes per key is supported. This PR allows users to enable protection by constructing `WriteBatch` with `protection_bytes_per_key == 8`. It does not yet expose a way for users to get integrity protection via other write APIs (e.g., `Put()`, `Merge()`, `Delete()`, etc.).

The foundation classes (`ProtectionInfo.*`) embed the coverage info in their type, and provide `Protect.*()` and `Strip.*()` functions to navigate between types with different coverage. For making bytes per key configurable (for powers of two up to eight) in the future, these classes are templated on the unsigned integer type used to store the protection info. That integer contains the XOR'd result of hashes with independent seeds for all covered fields. For integer fields, the hash is computed on the raw unadjusted bytes, so the result is endian-dependent. The most significant bytes are truncated when the hash value (8 bytes) is wider than the protection integer.

When `WriteBatch` is constructed with `protection_bytes_per_key == 8`, we hold a `ProtectionInfoKVOTC` (i.e., one that covers key, value, optype aka `ValueType`, timestamp, and CF ID) for each entry added to the batch. The protection info is generated from the original buffers passed by the user, as well as the original metadata generated internally. When writing to memtable, each entry is transformed to a `ProtectionInfoKVOTS` (i.e., dropping coverage of CF ID and adding coverage of sequence number), since at that point we know the sequence number, and have already selected a memtable corresponding to a particular CF. This protection info is verified once the entry is encoded in the `MemTable` buffer.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7748

Test Plan:
- an integration test to verify a wide variety of single-byte changes to the encoded `MemTable` buffer are caught
- add to stress/crash test to verify it works in variety of configs/operations without intentional corruption
- [deferred] unit tests for `ProtectionInfo.*` classes for edge cases like KV swap, `SliceParts` and `Slice` APIs are interchangeable, etc.

Reviewed By: pdillinger

Differential Revision: D25754492

Pulled By: ajkr

fbshipit-source-id: e481bac6c03c2ab268be41359730f1ceb9964866
2021-01-29 12:18:58 -08:00
mrambacher
4a09d632c4 Remove Legacy and Custom FileWrapper classes from header files (#7851)
Summary:
Removed the uses of the Legacy FileWrapper classes from the source code.  The wrappers were creating an additional layer of indirection/wrapping, as the Env already has a FileSystem.

Moved the Custom FileWrapper classes into the CustomEnv, as these classes are really for the private use the the CustomEnv class.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7851

Reviewed By: anand1976

Differential Revision: D26114816

Pulled By: mrambacher

fbshipit-source-id: db32840e58d969d3a0fa6c25aaf13d6dcdc74150
2021-01-28 22:10:32 -08:00