Commit Graph

303 Commits

Author SHA1 Message Date
Peter Dillinger
479eb1aad6 Hide deprecated, inefficient block-based filter from public API (#9535)
Summary:
This change removes the ability to configure the deprecated,
inefficient block-based filter in the public API. Options that would
have enabled it now use "full" (and optionally partitioned) filters.
Existing block-based filters can still be read and used, and a "back
door" way to build them still exists, for testing and in case of trouble.

About the only way this removal would cause an issue for users is if
temporary memory for filter construction greatly increases. In
HISTORY.md we suggest a few possible mitigations: partitioned filters,
smaller SST files, or setting reserve_table_builder_memory=true.

Or users who have customized a FilterPolicy using the
CreateFilter/KeyMayMatch mechanism removed in https://github.com/facebook/rocksdb/issues/9501 will have to upgrade
their code. (It's long past time for people to move to the new
builder/reader customization interface.)

This change also introduces some internal-use-only configuration strings
for testing specific filter implementations while bypassing some
compatibility / intelligence logic. This is intended to hint at a path
toward making FilterPolicy Customizable, but it also gives us a "back
door" way to configure block-based filter.

Aside: updated db_bench so that -readonly implies -use_existing_db

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9535

Test Plan:
Unit tests updated. Specifically,

* BlockBasedTableTest.BlockReadCountTest is tweaked to validate the back
door configuration interface and ignoring of `use_block_based_builder`.
* BlockBasedTableTest.TracingGetTest is migrated from testing
block-based filter access pattern to full filter access patter, by
re-ordering some things.
* Options test (pretty self-explanatory)

Performance test - create with `./db_bench -db=/dev/shm/rocksdb1 -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=fillrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0` with and without `-use_block_based_filter`, which creates a DB with 21 SST files in L0. Read with `./db_bench -db=/dev/shm/rocksdb1 -readonly -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=readrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -duration=30`

Without -use_block_based_filter: readrandom 464 ops/sec, 689280 KB DB
With -use_block_based_filter: readrandom 169 ops/sec, 690996 KB DB
No consistent difference with fillrandom

Reviewed By: jay-zhuang

Differential Revision: D34153871

Pulled By: pdillinger

fbshipit-source-id: 31f4a933c542f8f09aca47fa64aec67832a69738
2022-02-12 07:05:57 -08:00
Peter Dillinger
68a9c186d0 FilterPolicy API changes for 7.0 (#9501)
Summary:
* Inefficient block-based filter is no longer customizable in the public
API, though (for now) can still be enabled.
  * Removed deprecated FilterPolicy::CreateFilter() and
  FilterPolicy::KeyMayMatch()
  * Removed `rocksdb_filterpolicy_create()` from C API
* Change meaning of nullptr return from GetBuilderWithContext() from "use
block-based filter" to "generate no filter in this case." This is a
cleaner solution to the proposal in https://github.com/facebook/rocksdb/issues/8250.
  * Also, when user specifies bits_per_key < 0.5, we now round this down
  to "no filter" because we expect a filter with >= 80% FP rate is
  unlikely to be worth the CPU cost of accessing it (esp with
  cache_index_and_filter_blocks=1 or partition_filters=1).
  * bits_per_key >= 0.5 and < 1.0 is still rounded up to 1.0 (for 62% FP
  rate)
  * This also gives us some support for configuring filters from OPTIONS
  file as currently saved: `filter_policy=rocksdb.BuiltinBloomFilter`.
  Opening from such an options file will enable reading filters (an
  improvement) but not writing new ones. (See Customizable follow-up
  below.)
* Also removed deprecated functions
  * FilterBitsBuilder::CalculateNumEntry()
  * FilterPolicy::GetFilterBitsBuilder()
  * NewExperimentalRibbonFilterPolicy()
* Remove default implementations of
  * FilterBitsBuilder::EstimateEntriesAdded()
  * FilterBitsBuilder::ApproximateNumEntries()
  * FilterPolicy::GetBuilderWithContext()
* Remove support for "filter_policy=experimental_ribbon" configuration
string.
* Allow "filter_policy=bloomfilter:n" without bool to discourage use of
block-based filter.

Some pieces for https://github.com/facebook/rocksdb/issues/9389

Likely follow-up (later PRs):
* Refactoring toward FilterPolicy Customizable, so that we can generate
filters with same configuration as before when configuring from options
file.
* Remove support for user enabling block-based filter (ignore `bool
use_block_based_builder`)
  * Some months after this change, we could even remove read support for
  block-based filter, because it is not critical to DB data
  preservation.
* Make FilterBitsBuilder::FinishV2 to avoid `using
FilterBitsBuilder::Finish` mess and add support for specifying a
MemoryAllocator (for cache warming)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9501

Test Plan:
A number of obsolete tests deleted and new tests or test
cases added or updated.

Reviewed By: hx235

Differential Revision: D34008011

Pulled By: pdillinger

fbshipit-source-id: a39a720457c354e00d5b59166b686f7f59e392aa
2022-02-08 13:56:46 -08:00
Hui Xiao
920386f2b7 Detect (new) Bloom/Ribbon Filter construction corruption (#9342)
Summary:
Note: rebase on and merge after https://github.com/facebook/rocksdb/pull/9349, https://github.com/facebook/rocksdb/pull/9345, (optional) https://github.com/facebook/rocksdb/pull/9393
**Context:**
(Quoted from pdillinger) Layers of information during new Bloom/Ribbon Filter construction in building block-based tables includes the following:
a) set of keys to add to filter
b) set of hashes to add to filter (64-bit hash applied to each key)
c) set of Bloom indices to set in filter, with duplicates
d) set of Bloom indices to set in filter, deduplicated
e) final filter and its checksum

This PR aims to detect corruption (e.g, unexpected hardware/software corruption on data structures residing in the memory for a long time) from b) to e) and leave a) as future works for application level.
- b)'s corruption is detected by verifying the xor checksum of the hash entries calculated as the entries accumulate before being added to the filter. (i.e, `XXPH3FilterBitsBuilder::MaybeVerifyHashEntriesChecksum()`)
- c) - e)'s corruption is detected by verifying the hash entries indeed exists in the constructed filter by re-querying these hash entries in the filter (i.e, `FilterBitsBuilder::MaybePostVerify()`) after computing the block checksum (except for PartitionFilter, which is done right after each `FilterBitsBuilder::Finish` for impl simplicity - see code comment for more). For this stage of detection, we assume hash entries are not corrupted after checking on b) since the time interval from b) to c) is relatively short IMO.

Option to enable this feature of detection is `BlockBasedTableOptions::detect_filter_construct_corruption` which is false by default.

**Summary:**
- Implemented new functions `XXPH3FilterBitsBuilder::MaybeVerifyHashEntriesChecksum()` and `FilterBitsBuilder::MaybePostVerify()`
- Ensured hash entries, final filter and banding and their [cache reservation ](https://github.com/facebook/rocksdb/issues/9073) are released properly despite corruption
   - See [Filter.construction.artifacts.release.point.pdf ](https://github.com/facebook/rocksdb/files/7923487/Design.Filter.construction.artifacts.release.point.pdf) for high-level design
   -  Bundled and refactored hash entries's related artifact in XXPH3FilterBitsBuilder into `HashEntriesInfo` for better control on lifetime of these artifact during `SwapEntires`, `ResetEntries`
- Ensured RocksDB block-based table builder calls `FilterBitsBuilder::MaybePostVerify()` after constructing the filter by `FilterBitsBuilder::Finish()`
- When encountering such filter construction corruption, stop writing the filter content to files and mark such a block-based table building non-ok by storing the corruption status in the builder.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9342

Test Plan:
- Added new unit test `DBFilterConstructionCorruptionTestWithParam.DetectCorruption`
- Included this new feature in `DBFilterConstructionReserveMemoryTestWithParam.ReserveMemory` as this feature heavily touch ReserveMemory's impl
   - For fallback case, I run `./filter_bench -impl=3 -detect_filter_construct_corruption=true -reserve_table_builder_memory=true -strict_capacity_limit=true  -quick -runs 10 | grep 'Build avg'` to make sure nothing break.
- Added to `filter_bench`: increased filter construction time by **30%**, mostly by `MaybePostVerify()`
   -  FastLocalBloom
       - Before change: `./filter_bench -impl=2 -quick -runs 10 | grep 'Build avg'`: **28.86643s**
       - After change:
          -  `./filter_bench -impl=2 -detect_filter_construct_corruption=false -quick -runs 10 | grep 'Build avg'` (expect a tiny increase due to MaybePostVerify is always called regardless): **27.6644s (-4% perf improvement might be due to now we don't drop bloom hash entry in `AddAllEntries` along iteration but in bulk later, same with the bypassing-MaybePostVerify case below)**
          - `./filter_bench -impl=2 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'` (expect acceptable increase): **34.41159s (+20%)**
          - `./filter_bench -impl=2 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'` (by-passing MaybePostVerify, expect minor increase): **27.13431s (-6%)**
    -  Standard128Ribbon
       - Before change: `./filter_bench -impl=3 -quick -runs 10 | grep 'Build avg'`: **122.5384s**
       - After change:
          - `./filter_bench -impl=3 -detect_filter_construct_corruption=false -quick -runs 10 | grep 'Build avg'` (expect a tiny increase due to MaybePostVerify is always called regardless - verified by removing MaybePostVerify under this case and found only +-1ns difference): **124.3588s (+2%)**
          - `./filter_bench -impl=3 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'`(expect acceptable increase): **159.4946s (+30%)**
          - `./filter_bench -impl=3 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'`(by-passing MaybePostVerify, expect minor increase) : **125.258s (+2%)**
- Added to `db_stress`: `make crash_test`, `./db_stress --detect_filter_construct_corruption=true`
- Manually smoke-tested: manually corrupted the filter construction in some db level tests with basic PUT and background flush. As expected, the error did get returned to users in subsequent PUT and Flush status.

Reviewed By: pdillinger

Differential Revision: D33746928

Pulled By: hx235

fbshipit-source-id: cb056426be5a7debc1cd16f23bc250f36a08ca57
2022-02-01 17:42:35 -08:00
Peter Dillinger
f6d7ec1d02 Ignore total_order_seek in DB::Get (#9427)
Summary:
Apparently setting total_order_seek=true for DB::Get was
intended to allow accurate read semantics if the current prefix
extractor doesn't match what was used to generate SST files on
disk. But since prefix_extractor was made a mutable option in 5.14.0, we
have been able to detect this case and provide the correct semantics
regardless of the total_order_seek option. Since that time, the option
has only made Get() slower in a reasonably common case: prefix_extractor
unchanged and whole_key_filtering=false.

So this change primarily removes unnecessary effect of
total_order_seek on Get. Also cleans up some related comments.

Also adds a -total_order_seek option to db_bench and canonicalizes
handling of ReadOptions in db_bench so that command line options have
the expected association with library features. (There is potential
for change in regression test behavior, but the old behavior is likely
indefensible, or some other inconsistency would need to be fixed.)

TODO in follow-up work: there should be no reason for Get() to depend on
current prefix extractor at all.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9427

Test Plan:
Unit tests updated.

Performance (using db_bench update)

Create DB with `TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=12 -whole_key_filtering=0`

Test with and without `-total_order_seek` on `TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -use_existing_db -readonly -benchmarks=readrandom -num=10000000 -duration=40 -disable_wal=1 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=12`

Before this change, total_order_seek=false: 25188 ops/sec
Before this change, total_order_seek=true:   1222 ops/sec (~20x slower)

After this change, total_order_seek=false: 24570 ops/sec
After this change, total_order_seek=true:  25012 ops/sec (indistinguishable)

Reviewed By: siying

Differential Revision: D33753458

Pulled By: pdillinger

fbshipit-source-id: bf892f34907a5e407d9c40bd4d42f0adbcbe0014
2022-01-31 19:46:42 -08:00
Hui Xiao
11d7329503 Clarify status-handling logic in BlockBasedTableBuilder::WriteRawBlock (#9393)
Summary:
**Context:**
Inside `BlockBasedTableBuilder::WriteRawBlock`, there are multiple places that change local variables `io_s` and `s` while
depend on them. This PR attempts to clarify the relevant logics so that it's easier to read and add places of changing these local variables later (like https://github.com/facebook/rocksdb/pull/9342.) without changing the current behavior.

**Summary:**
- Shorten the lifetime of local var `io_s` and `s` as much as possible to avoid if-else branches by early return

**Test**
- Reasoned against original behavior to verify new changes do not break existing behaviors.
- Rely on CI tests since we are not changing current behavior.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9393

Reviewed By: pdillinger

Differential Revision: D33626095

Pulled By: hx235

fbshipit-source-id: 6184d1e1d85d2650d16617c449971988d062ed3f
2022-01-26 10:24:16 -08:00
sdong
5d10a53b42 Not try to finish index builder after errors (#9426)
Summary:
Right now, when error happens in block based table reader, we still call index_builder->Finish(), this causes one assertion in one stress test:

db_stress: table/block_based/index_builder.cc:202: virtual rocksdb::Status rocksdb::PartitionedIndexBuilder::Finish(rocksdb::IndexBuilder::IndexBlocks*, const rocksdb::BlockHandle&): Assertion `sub_index_builder_ == nullptr' failed.

This unlikely causes any corruption as we would finally abandon the file, but the code is confusing and it is hard to understand what would happen. Changing the behavior.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9426

Test Plan: Run existing tests

Reviewed By: pdillinger

Differential Revision: D33751929

fbshipit-source-id: 3c916b9444a4171010fc53df40496570bef5ae7a
2022-01-25 10:22:32 -08:00
Peter Dillinger
fc9d4071f0 Fast path for detecting unchanged prefix_extractor (#9407)
Summary:
Fixes a major performance regression in 6.26, where
extra CPU is spent in SliceTransform::AsString when reads involve
a prefix_extractor (Get, MultiGet, Seek). Common case performance
is now better than 6.25.

This change creates a "fast path" for verifying that the current prefix
extractor is unchanged and compatible with what was used to
generate a table file. This fast path detects the common case by
pointer comparison on the current prefix_extractor and a "known
good" prefix extractor (if applicable) that is saved at the time the
table reader is opened. The "known good" prefix extractor is saved
as another shared_ptr copy (in an existing field, however) to ensure
the pointer is not recycled.

When the prefix_extractor has changed to a different instance but
same compatible configuration (rare, odd), performance is still a
regression compared to 6.25, but this is likely acceptable because
of the oddity of such a case. The performance of incompatible
prefix_extractor is essentially unchanged.

Also fixed a minor case (ForwardIterator) where a prefix_extractor
could be used via a raw pointer after being freed as a shared_ptr,
if replaced via SetOptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9407

Test Plan:
## Performance
Populate DB with `TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=12`

Running head-to-head comparisons simultaneously with `TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -use_existing_db -readonly -benchmarks=seekrandom -num=10000000 -duration=20 -disable_wal=1 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=12`

Below each is compared by ops/sec vs. baseline which is version 6.25 (multiple baseline runs because of variable machine load)

v6.26: 4833 vs. 6698 (<- major regression!)
v6.27: 4737 vs. 6397 (still)
New: 6704 vs. 6461 (better than baseline in common case)
Disabled fastpath: 4843 vs. 6389 (e.g. if prefix extractor instance changes but is still compatible)
Changed prefix size (no usable filter) in new: 787 vs. 5927
Changed prefix size (no usable filter) in new & baseline: 773 vs. 784

Reviewed By: mrambacher

Differential Revision: D33677812

Pulled By: pdillinger

fbshipit-source-id: 571d9711c461fb97f957378a061b7e7dbc4d6a76
2022-01-21 11:37:46 -08:00
Peter Dillinger
ffe1e4b820 Make some FilterPolicy deprecations more clear (#9403)
Summary:
The old block-based filter has been deprecated for years, but
this makes that more clear by marking the functions specific to it and
logging a warning when the feature is used.

It is deprecated because of performance. In that old design, you have to
binary search through the full SST index before a bloom filter query, which
is much more expensive than a bloom query itself.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9403

Test Plan:
Used db_bench with and without -use_block_based_filter,
running at the same time

    TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom,readrandom -num=10000000 -duration=20 -disable_wal=1 -write_buffer_size=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0

No significant difference in construction time but 3x slower readrandom
with -use_block_based_filter:
readrandom   :     100.517 micros/op 9948 ops/sec;    1.1 MB/s
vs.
readrandom   :      33.368 micros/op 29968 ops/sec;    3.3 MB/s

Also saw deprecation message (just once) in LOG only with
-use_block_based_filter

Reviewed By: ajkr

Differential Revision: D33673202

Pulled By: pdillinger

fbshipit-source-id: 99f6f0eff619408d9e5f7ef546954ed0be6c7a5b
2022-01-19 18:12:10 -08:00
Si Ke
93b1de4f45 Enable db_test running in Centos 32 bit OS and Alpine 32 bit OS (#9294)
Summary:
Closes https://github.com/facebook/rocksdb/issues/9271

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9294

Reviewed By: riversand963, hx235

Differential Revision: D33586002

Pulled By: pdillinger

fbshipit-source-id: 3d1a2fa71023e108613ff03dbd37a5f954fc4920
2022-01-14 11:58:18 -08:00
mrambacher
1973fcba11 Restore Regex support for ObjectLibrary::Register, rename new APIs to allow old one to be deprecated in the future (#9362)
Summary:
In order to support old-style regex function registration, restored the original "Register<T>(string, Factory)" method using regular expressions.  The PatternEntry methods were left in place but renamed to AddFactory.  The goal is to allow for the deprecation of the original regex Registry method in an upcoming release.

Added modes to the PatternEntry kMatchZeroOrMore and kMatchAtLeastOne to match * or +, respectively (kMatchAtLeastOne was the original behavior).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9362

Reviewed By: pdillinger

Differential Revision: D33432562

Pulled By: mrambacher

fbshipit-source-id: ed88ab3f9a2ad0d525c7bd1692873f9bb3209d02
2022-01-11 06:33:48 -08:00
Hui Xiao
9110685e8c Release cache reservation of hash entries of the fall-back Ribbon Filter earlier (#9345)
Summary:
Note: rebase on and merge after https://github.com/facebook/rocksdb/pull/9349, as part of https://github.com/facebook/rocksdb/pull/9342
**Context:**
https://github.com/facebook/rocksdb/pull/9073 charged the hash entries' memory in block cache with `CacheReservationHandle`. However, in the edge case where Ribbon Filter falls back to Bloom Filter and swaps its hash entries to the embedded bloom filter object, the handles associated with those entries are not swapped and thus not released as soon as those entries are cleared during Bloom Filter's finish process.

Although this is a minor issue since RocksDB internal calls `FilterBitsBuilder->Reset()` right after `FilterBitsBuilder->Finish()` on the main path, which releases all the cache reservation related to both the Ribbon Filter and its embedded Bloom Filter, it still worths this fix to avoid confusion.

**Summary:**
- Swapped the `CacheReservationHandle` associated with the hash entries on Ribbon Filter's fallback

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9345

Test Plan: - Added a unit test to verify the number of cache reservation after clearing hash entries, which failed before the change and now succeeds

Reviewed By: pdillinger

Differential Revision: D33377225

Pulled By: hx235

fbshipit-source-id: 7487f4c40dfb6ee7928232021f93ef2c5329cffa
2022-01-07 11:25:21 -08:00
Hui Xiao
fb0a76a9e2 Always check previous conditionally unchecked status due to shortcut evaluation in BlockBasedTableBuilder::WriteIndexBlock (#9349)
Summary:
Note: part of https://github.com/facebook/rocksdb/pull/9342
**Context/Summary:**
Due to shortcut evaluation in `ok() && s.IsIncomplete()`, status `s` remains unchecked if `ok()==false`, which is the case in https://app.circleci.com/pipelines/github/facebook/rocksdb/10718/workflows/429f7ad4-6b9a-446b-b9b3-710d51b90409/jobs/265508 revealed by the change in the corresponding PR https://github.com/facebook/rocksdb/pull/9342.

As suggested by reviewers, separation and clarification of status checking for partitioned index building from general table building status is added.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9349

Test Plan:
- The newly added if-else code is an equivalent translation of the existing logic plus always checking the conditionally unchecked status so relying on existing tests should be fine
- https://github.com/facebook/rocksdb/pull/9342's `[build-linux-shared_lib-alt_namespace-status_checked](https://app.circleci.com/pipelines/github/facebook/rocksdb/10721/workflows/a200efe0-d545-4075-8c42-26dd3dc00f27/jobs/265625)` test should now pass after rebasing on this change

Reviewed By: pdillinger

Differential Revision: D33377223

Pulled By: hx235

fbshipit-source-id: cb81da9709ae9185e9cea89776e3012e915d6ef9
2022-01-06 10:10:44 -08:00
mrambacher
9a116ab4b4 Add NewMetaDataIterator method (#8692)
Summary:
Fixes a problem where the iterator for metadata was being treated as a non-user key when in fact it was a user key.  This led to a problem where the property keys could not be searched for correctly.

The main exposure of this problem was that the HashIndexReader could not get the "prefixes" property correctly, resulting in the failure of retrieval/creation of the BlockPrefixIndex.

Added BlockBasedTableTest.SeekMetaBlocks test to validate this condition.

Fixing this condition exposed two other tests (SeekWithPrefixLongerThanKey, MultiGetPrefixFilter) that passed incorrectly previously and now failed.  Updated those two tests to pass.  Not sure if the tests are functionally correct/still appropriate, but made them pass...

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8692

Reviewed By: riversand963

Differential Revision: D33119539

Pulled By: mrambacher

fbshipit-source-id: 658969fe9265f73dc184dab97cc3f4eaed2d881a
2021-12-21 11:32:49 -08:00
Peter Dillinger
0050a73a4f New stable, fixed-length cache keys (#9126)
Summary:
This change standardizes on a new 16-byte cache key format for
block cache (incl compressed and secondary) and persistent cache (but
not table cache and row cache).

The goal is a really fast cache key with practically ideal stability and
uniqueness properties without external dependencies (e.g. from FileSystem).
A fixed key size of 16 bytes should enable future optimizations to the
concurrent hash table for block cache, which is a heavy CPU user /
bottleneck, but there appears to be measurable performance improvement
even with no changes to LRUCache.

This change replaces a lot of disjointed and ugly code handling cache
keys with calls to a simple, clean new internal API (cache_key.h).
(Preserving the old cache key logic under an option would be very ugly
and likely negate the performance gain of the new approach. Complete
replacement carries some inherent risk, but I think that's acceptable
with sufficient analysis and testing.)

The scheme for encoding new cache keys is complicated but explained
in cache_key.cc.

Also: EndianSwapValue is moved to math.h to be next to other bit
operations. (Explains some new include "math.h".) ReverseBits operation
added and unit tests added to hash_test for both.

Fixes https://github.com/facebook/rocksdb/issues/7405 (presuming a root cause)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9126

Test Plan:
### Basic correctness
Several tests needed updates to work with the new functionality, mostly
because we are no longer relying on filesystem for stable cache keys
so table builders & readers need more context info to agree on cache
keys. This functionality is so core, a huge number of existing tests
exercise the cache key functionality.

### Performance
Create db with
`TEST_TMPDIR=/dev/shm ./db_bench -bloom_bits=10 -benchmarks=fillrandom -num=3000000 -partition_index_and_filters`
And test performance with
`TEST_TMPDIR=/dev/shm ./db_bench -readonly -use_existing_db -bloom_bits=10 -benchmarks=readrandom -num=3000000 -duration=30 -cache_index_and_filter_blocks -cache_size=250000 -threads=4`
using DEBUG_LEVEL=0 and simultaneous before & after runs.
Before ops/sec, avg over 100 runs: 121924
After ops/sec, avg over 100 runs: 125385 (+2.8%)

### Collision probability
I have built a tool, ./cache_bench -stress_cache_key to broadly simulate host-wide cache activity
over many months, by making some pessimistic simplifying assumptions:
* Every generated file has a cache entry for every byte offset in the file (contiguous range of cache keys)
* All of every file is cached for its entire lifetime

We use a simple table with skewed address assignment and replacement on address collision
to simulate files coming & going, with quite a variance (super-Poisson) in ages. Some output
with `./cache_bench -stress_cache_key -sck_keep_bits=40`:

```
Total cache or DBs size: 32TiB  Writing 925.926 MiB/s or 76.2939TiB/day
Multiply by 9.22337e+18 to correct for simulation losses (but still assume whole file cached)
```

These come from default settings of 2.5M files per day of 32 MB each, and
`-sck_keep_bits=40` means that to represent a single file, we are only keeping 40 bits of
the 128-bit cache key.  With file size of 2\*\*25 contiguous keys (pessimistic), our simulation
is about 2\*\*(128-40-25) or about 9 billion billion times more prone to collision than reality.

More default assumptions, relatively pessimistic:
* 100 DBs in same process (doesn't matter much)
* Re-open DB in same process (new session ID related to old session ID) on average
every 100 files generated
* Restart process (all new session IDs unrelated to old) 24 times per day

After enough data, we get a result at the end:

```
(keep 40 bits)  17 collisions after 2 x 90 days, est 10.5882 days between (9.76592e+19 corrected)
```

If we believe the (pessimistic) simulation and the mathematical generalization, we would need to run a billion machines all for 97 billion days to expect a cache key collision. To help verify that our generalization ("corrected") is robust, we can make our simulation more precise with `-sck_keep_bits=41` and `42`, which takes more running time to get enough data:

```
(keep 41 bits)  16 collisions after 4 x 90 days, est 22.5 days between (1.03763e+20 corrected)
(keep 42 bits)  19 collisions after 10 x 90 days, est 47.3684 days between (1.09224e+20 corrected)
```

The generalized prediction still holds. With the `-sck_randomize` option, we can see that we are beating "random" cache keys (except offsets still non-randomized) by a modest amount (roughly 20x less collision prone than random), which should make us reasonably comfortable even in "degenerate" cases:

```
197 collisions after 1 x 90 days, est 0.456853 days between (4.21372e+18 corrected)
```

I've run other tests to validate other conditions behave as expected, never behaving "worse than random" unless we start chopping off structured data.

Reviewed By: zhichao-cao

Differential Revision: D33171746

Pulled By: pdillinger

fbshipit-source-id: f16a57e369ed37be5e7e33525ace848d0537c88f
2021-12-16 17:15:13 -08:00
Akanksha Mahajan
96d0773a11 Update prepopulate_block_cache logic to support block-based filter (#9300)
Summary:
Update prepopulate_block_cache logic to support block-based
filter during insertion in block cache

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9300

Test Plan:
CircleCI tests,
make crash_test -j64

Reviewed By: pdillinger

Differential Revision: D33132018

Pulled By: akankshamahajan15

fbshipit-source-id: 241deabab8645bda704728e572d6de6354df18b2
2021-12-15 13:20:27 -08:00
Peter Dillinger
e92a0ed040 Optimize & clean up footer code (#9280)
Summary:
Again, ahead of planned changes in https://github.com/facebook/rocksdb/issues/9058. This change improves
performance (vs. pre-https://github.com/facebook/rocksdb/issues/9240 baseline) by separating a FooterBuilder from
Footer, where FooterBuilder includes (inline owns) the serialized data
so that it can be stack allocated.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9280

Test Plan:
existing tests + performance testing below

Extreme case performance testing as in https://github.com/facebook/rocksdb/issues/9240 with

    TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=30000000

(Each is ops/s averaged over 50 runs, run simultaneously with competing
configuration for load fairness)
Pre-https://github.com/facebook/rocksdb/issues/9240 baseline (f577458): 436389
With https://github.com/facebook/rocksdb/issues/9240 (653c392): 417946 (-4.2% vs. baseline)
This change: 443762 (+1.7% vs. baseline)

Reviewed By: ajkr

Differential Revision: D33077220

Pulled By: pdillinger

fbshipit-source-id: 7eaa6499589aac1693414a758e8c799216c5016c
2021-12-13 17:43:07 -08:00
Peter Dillinger
653c392e47 More refactoring ahead of footer & meta changes (#9240)
Summary:
I'm working on a new format_version=6 to support context
checksum (https://github.com/facebook/rocksdb/issues/9058) and this includes much of the refactoring and test
updates to support that change.

Test coverage data and manual inspection agree on dead code in
block_based_table_reader.cc (removed).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9240

Test Plan:
tests enhanced to cover more cases etc.

Extreme case performance testing indicates small % regression in fillseq (w/ compaction), though CPU profile etc. doesn't suggest any explanation. There is enhanced correctness checking in Footer::DecodeFrom, but this should be negligible.

TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=30000000 -checksum_type=1 --disable_wal={false,true}

(Each is ops/s averaged over 50 runs, run simultaneously with competing configuration for load fairness)
Before w/ wal: 454512
After w/ wal: 444820 (-2.1%)
Before w/o wal: 1004560
After w/o wal: 998897 (-0.6%)

Since this doesn't modify WAL code, one would expect real effects to be larger in w/o wal case.

This regression will be corrected in a follow-up PR.

Reviewed By: ajkr

Differential Revision: D32813769

Pulled By: pdillinger

fbshipit-source-id: 444a244eabf3825cd329b7d1b150cddce320862f
2021-12-10 08:13:26 -08:00
Akanksha Mahajan
9e4d56f2c9 Fix segmentation fault in table_options.prepopulate_block_cache when used with partition_filters (#9263)
Summary:
When table_options.prepopulate_block_cache is set to
BlockBasedTableOptions::PrepopulateBlockCache::kFlushOnly and
table_options.partition_filters is also set true, then there is
segmentation failure when top level filter is fetched because its
entered with wrong type in cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9263

Test Plan:
Updated unit tests;
Ran db_stress: make crash_test -j32

Reviewed By: pdillinger

Differential Revision: D32936566

Pulled By: akankshamahajan15

fbshipit-source-id: 8bd79e53830d3e3c1bb79787e1ffbc3cb46d4426
2021-12-08 12:44:38 -08:00
Akanksha Mahajan
04b2c16f9b Fix bug in rocksdb internal automatic prefetching (#9234)
Summary:
After introducing adaptive_readahead, the original flow got
broken. Readahead size was set to 0 because of which rocksdb wasn't be
able to do automatic prefetching which it enables after seeing
sequential reads. This PR fixes it.

----------------------------------------------------------------------------------------------------

Before this patch:
b_bench -use_existing_db=true -db=/tmp/prefix_scan -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 6.27
Date:       Tue Nov 30 11:56:50 2021
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/prefix_scan]

seekrandom   : 5356367.174 micros/op 0 ops/sec;   29.4 MB/s (23 of 23 found)

----------------------------------------------------------------------------------------------------

After the patch:
./db_bench -use_existing_db=true -db=/tmp/prefix_scan -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 6.27
Date:       Tue Nov 30 14:38:33 2021
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/prefix_scan]
seekrandom   :  456504.277 micros/op 2 ops/sec;  359.8 MB/s (264 of 264 found)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9234

Test Plan:
Ran ./db_bench -db=/data/mysql/rocksdb/prefix_scan
-benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_d
irect_io_for_flush_and_compaction=true -target_file_size_base=16777216
and then ./db_bench -use_existing_db=true
-db=/data/mysql/rocksdb/prefix_scan -benchmarks="seekrandom"
-key_size=32 -value_siz
e=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680
-duration=120 -ops_between_duration_checks=1
 and compared the results.

Reviewed By: anand1976

Differential Revision: D32743965

Pulled By: akankshamahajan15

fbshipit-source-id: b950fba68c91963b7deb5c20acdf471bc60251f5
2021-11-30 22:53:10 -08:00
Levi Tamasi
dc5de45af8 Support readahead during compaction for blob files (#9187)
Summary:
The patch adds a new BlobDB configuration option `blob_compaction_readahead_size`
that can be used to enable prefetching data from blob files during compaction.
This is important when using storage with higher latencies like HDDs or remote filesystems.
If enabled, prefetching is used for all cases when blobs are read during compaction,
namely garbage collection, compaction filters (when the existing value has to be read from
a blob file), and `Merge` (when the value of the base `Put` is stored in a blob file).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9187

Test Plan: Ran `make check` and the stress/crash test.

Reviewed By: riversand963

Differential Revision: D32565512

Pulled By: ltamasi

fbshipit-source-id: 87be9cebc3aa01cc227bec6b5f64d827b8164f5d
2021-11-19 17:53:47 -08:00
Peter Dillinger
cd4ea675e3 Fix backward compatibility with 2.5 through 2.7 (#9189)
Summary:
A bug in https://github.com/facebook/rocksdb/issues/9163 can cause checksum verification to fail if
parsing a properties block fails.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9189

Test Plan:
check_format_compatible.sh (never quite works locally but
this particular case seems fixed using variants of SHORT_TEST=1).
And added new unit test case.

Reviewed By: ajkr

Differential Revision: D32574626

Pulled By: pdillinger

fbshipit-source-id: 6fa5c8595737b71a3c3d011a52daf6d6c08715d7
2021-11-19 17:31:01 -08:00
slk
e12753eb71 Track each SST's timestamp information as user properties (#9093)
Summary:
Track each SST's timestamp information as user properties https://github.com/facebook/rocksdb/issues/8959

Rockdb has supported user-defined timestamp feature. Application can specify a timestamp
when writing each k-v pair. When data flush from memory to disk file called SST files.
Each SST files consist of multiple data blocks and several metadata blocks. Among the metadata
blocks, there is one called Properties block that tracks some pre-defined properties of this SST file.

This PR is for collecting the properties of min and max timestamps of all keys in the file. With those
properties the SST file is more convenient to tell whether the keys in the SST have timestamps or not.

The changes involved are as follows:

1) Add a class TimestampTablePropertiesCollector to collect min/max timestamp when add keys to table,
   The way TimestampTablePropertiesCollector use to compare timestamp of key should defined by
   user by implementing the Comparator::CompareTimestamp function in the user defined comparator.
2) Add corresponding unit tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9093

Reviewed By: ltamasi

Differential Revision: D32406927

Pulled By: riversand963

fbshipit-source-id: 25922971b7e67bacf4d53a1fb67c4c5ddaa61573
2021-11-19 11:37:06 -08:00
Peter Dillinger
230660be73 Improve / clean up meta block code & integrity (#9163)
Summary:
* Checksums are now checked on meta blocks unless specifically
suppressed or not applicable (e.g. plain table). (Was other way around.)
This means a number of cases that were not checking checksums now are,
including direct read TableProperties in Version::GetTableProperties
(fixed in meta_blocks ReadTableProperties), reading any block from
PersistentCache (fixed in BlockFetcher), read TableProperties in
SstFileDumper (ldb/sst_dump/BackupEngine) before table reader open,
maybe more.
* For that to work, I moved the global_seqno+TableProperties checksum
logic to the shared table/ code, because that is used by many utilies
such as SstFileDumper.
* Also for that to work, we have to know when we're dealing with a block
that has a checksum (trailer), so added that capability to Footer based
on magic number, and from there BlockFetcher.
* Knowledge of trailer presence has also fixed a problem where other
table formats were reading blocks including bytes for a non-existant
trailer--and awkwardly kind-of not using them, e.g. no shared code
checking checksums. (BlockFetcher compression type was populated
incorrectly.) Now we only read what is needed.
* Minimized code duplication and differing/incompatible/awkward
abstractions in meta_blocks.{cc,h} (e.g. SeekTo in metaindex block
without parsing block handle)
* Moved some meta block handling code from table_properties*.*
* Moved some code specific to block-based table from shared table/ code
to BlockBasedTable class. The checksum stuff means we can't completely
separate it, but things that don't need to be in shared table/ code
should not be.
* Use unique_ptr rather than raw ptr in more places. (Note: you can
std::move from unique_ptr to shared_ptr.)

Without enhancements to GetPropertiesOfAllTablesTest (see below),
net reduction of roughly 100 lines of code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9163

Test Plan:
existing tests and
* Enhanced DBTablePropertiesTest.GetPropertiesOfAllTablesTest to verify that
checksums are now checked on direct read of table properties by TableCache
(new test would fail before this change)
* Also enhanced DBTablePropertiesTest.GetPropertiesOfAllTablesTest to test
putting table properties under old meta name
* Also generally enhanced that same test to actually test what it was
supposed to be testing already, by kicking things out of table cache when
we don't want them there.

Reviewed By: ajkr, mrambacher

Differential Revision: D32514757

Pulled By: pdillinger

fbshipit-source-id: 507964b9311d186ae8d1131182290cbd97a99fa9
2021-11-18 11:43:44 -08:00
Hui Xiao
74544d582f Account Bloom/Ribbon filter construction memory in global memory limit (#9073)
Summary:
Note: This PR is the 4th part of a bigger PR stack (https://github.com/facebook/rocksdb/pull/9073) and will rebase/merge only after the first three PRs (https://github.com/facebook/rocksdb/pull/9070, https://github.com/facebook/rocksdb/pull/9071, https://github.com/facebook/rocksdb/pull/9130) merge.

**Context:**
Similar to https://github.com/facebook/rocksdb/pull/8428, this PR is to track memory usage during (new) Bloom Filter (i.e,FastLocalBloom) and Ribbon Filter (i.e, Ribbon128) construction, moving toward the goal of [single global memory limit using block cache capacity](https://github.com/facebook/rocksdb/wiki/Projects-Being-Developed#improving-memory-efficiency). It also constrains the size of the banding portion of Ribbon Filter during construction by falling back to Bloom Filter if that banding is, at some point, larger than the available space in the cache under `LRUCacheOptions::strict_capacity_limit=true`.

The option to turn on this feature is `BlockBasedTableOptions::reserve_table_builder_memory = true` which by default is set to `false`. We [decided](https://github.com/facebook/rocksdb/pull/9073#discussion_r741548409) not to have separate option for separate memory user in table building therefore their memory accounting are all bundled under one general option.

**Summary:**
- Reserved/released cache for creation/destruction of three main memory users with the passed-in `FilterBuildingContext::cache_res_mgr` during filter construction:
   - hash entries (i.e`hash_entries`.size(), we bucket-charge hash entries during insertion for performance),
   - banding (Ribbon Filter only, `bytes_coeff_rows` +`bytes_result_rows` + `bytes_backtrack`),
   - final filter (i.e, `mutable_buf`'s size).
      - Implementation details: in order to use `CacheReservationManager::CacheReservationHandle` to account final filter's memory, we have to store the `CacheReservationManager` object and `CacheReservationHandle` for final filter in `XXPH3BitsFilterBuilder` as well as  explicitly delete the filter bits builder when done with the final filter in block based table.
- Added option fo run `filter_bench` with this memory reservation feature

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9073

Test Plan:
- Added new tests in `db_bloom_filter_test` to verify filter construction peak cache reservation under combination of  `BlockBasedTable::Rep::FilterType` (e.g, `kFullFilter`, `kPartitionedFilter`), `BloomFilterPolicy::Mode`(e.g, `kFastLocalBloom`, `kStandard128Ribbon`, `kDeprecatedBlock`) and `BlockBasedTableOptions::reserve_table_builder_memory`
  - To address the concern for slow test: tests with memory reservation under `kFullFilter` + `kStandard128Ribbon` and `kPartitionedFilter` take around **3000 - 6000 ms** and others take around **1500 - 2000 ms**, in total adding **20000 - 25000 ms** to the test suit running locally
- Added new test in `bloom_test` to verify Ribbon Filter fallback on large banding in FullFilter
- Added test in `filter_bench` to verify that this feature does not significantly slow down Bloom/Ribbon Filter construction speed. Local result averaged over **20** run as below:
   - FastLocalBloom
      - baseline `./filter_bench -impl=2 -quick -runs 20 | grep 'Build avg'`:
         - **Build avg ns/key: 29.56295** (DEBUG_LEVEL=1), **29.98153** (DEBUG_LEVEL=0)
      - new feature (expected to be similar as above)`./filter_bench -impl=2 -quick -runs 20 -reserve_table_builder_memory=true | grep 'Build avg'`:
         - **Build avg ns/key: 30.99046** (DEBUG_LEVEL=1), **30.48867** (DEBUG_LEVEL=0)
      - new feature of RibbonFilter with fallback  (expected to be similar as above) `./filter_bench -impl=2 -quick -runs 20 -reserve_table_builder_memory=true -strict_capacity_limit=true | grep 'Build avg'` :
         - **Build avg ns/key: 31.146975** (DEBUG_LEVEL=1), **30.08165** (DEBUG_LEVEL=0)

    - Ribbon128
       - baseline `./filter_bench -impl=3 -quick -runs 20 | grep 'Build avg'`:
           - **Build avg ns/key: 129.17585** (DEBUG_LEVEL=1), **130.5225** (DEBUG_LEVEL=0)
       - new feature  (expected to be similar as above) `./filter_bench -impl=3 -quick -runs 20 -reserve_table_builder_memory=true | grep 'Build avg' `:
           - **Build avg ns/key: 131.61645** (DEBUG_LEVEL=1), **132.98075** (DEBUG_LEVEL=0)
       - new feature of RibbonFilter with fallback (expected to be a lot faster than above due to fallback) `./filter_bench -impl=3 -quick -runs 20 -reserve_table_builder_memory=true -strict_capacity_limit=true | grep 'Build avg'` :
          - **Build avg ns/key: 52.032965** (DEBUG_LEVEL=1), **52.597825** (DEBUG_LEVEL=0)
          - And the warning message of `"Cache reservation for Ribbon filter banding failed due to cache full"` is indeed logged to console.

Reviewed By: pdillinger

Differential Revision: D31991348

Pulled By: hx235

fbshipit-source-id: 9336b2c60f44d530063da518ceaf56dac5f9df8e
2021-11-18 09:42:20 -08:00
Peter Dillinger
f8c685c4fc Check for and disallow shared key space in block caches (#9172)
Summary:
We have three layers of block cache that often use the same key
but map to different physical data:
* BlockBasedTableOptions::block_cache
* BlockBasedTableOptions::block_cache_compressed
* BlockBasedTableOptions::persistent_cache

If any two of these happen to share an underlying implementation and key
space (insertion into one shows up in another), then memory safety is
broken. The simplest case is block_cache == block_cache_compressed.
(Credit mrambacher for asking about this case in a review.)

With this change, we explicitly check for overlap and preemptively and
safely fail with a Status code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9172

Test Plan: test added. Crashes without new check

Reviewed By: anand1976

Differential Revision: D32465659

Pulled By: pdillinger

fbshipit-source-id: 3876b45b6dce6167e5a7a642725ddc86b96f8e40
2021-11-16 11:16:05 -08:00
Akanksha Mahajan
17ce1ca48b Reuse internal auto readhead_size at each Level (expect L0) for Iterations (#9056)
Summary:
RocksDB does auto-readahead for iterators on noticing more than two sequential reads for a table file if user doesn't provide readahead_size. The readahead starts at 8KB and doubles on every additional read up to max_auto_readahead_size. However at each level, if iterator moves over next file, readahead_size starts again from 8KB.

This PR introduces a new ReadOption "adaptive_readahead" which when set true will maintain readahead_size  at each level. So when iterator moves from one file to another, new file's readahead_size will continue from previous file's readahead_size instead of scratch. However if reads are not sequential it will fall back to 8KB (default) with no prefetching for that block.

1. If block is found in cache but it was eligible for prefetch (block wasn't in Rocksdb's prefetch buffer),  readahead_size will decrease by 8KB.
2. It maintains readahead_size for L1 - Ln levels.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9056

Test Plan:
Added new unit tests
Ran db_bench for "readseq, seekrandom, seekrandomwhilewriting, readrandom" with --adaptive_readahead=true and there was no regression if new feature is enabled.

Reviewed By: anand1976

Differential Revision: D31773640

Pulled By: akankshamahajan15

fbshipit-source-id: 7332d16258b846ae5cea773009195a5af58f8f98
2021-11-10 16:20:04 -08:00
Hui Xiao
3018a3e27e Minor improvement to CacheReservationManager/WriteBufferManager/CompressionDictBuilding (#9139)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9139

Reviewed By: zhichao-cao

Differential Revision: D32211415

Pulled By: hx235

fbshipit-source-id: 39ce036ba34e1fb4a1992a33ac6904a4a943301d
2021-11-05 16:13:47 -07:00
Hui Xiao
1ababeb76a Deallocate payload of BlockBasedTableBuilder::Rep::FilterBlockBuilder earlier for Full/PartitionedFilter (#9070)
Summary:
Note: This PR is the 1st part of a bigger PR stack (https://github.com/facebook/rocksdb/pull/9073).

Context:
Previously, the payload (i.e, filter data) within `BlockBasedTableBuilder::Rep::FilterBlockBuilder` object is not deallocated until `BlockBasedTableBuilder` is deallocated, despite it is no longer useful after its related `filter_content` being written.
- Transferred the payload (i.e, the filter data) out of `BlockBasedTableBuilder::Rep::FilterBlockBuilder` object
- For PartitionedFilter:
   - Unified `filters` and `filter_gc` lists into one `std::deque<FilterEntry> filters` by adding a new field `last_filter_entry_key` and storing the `std::unique_ptr filter_data` with the `Slice filter` in the same entry
   - Reset `last_filter_data` in the case where `filters` is empty, which should be as by then we would've finish using all the `Slice filter`
- Deallocated the payload by going out of scope as soon as we're done with using the `filter_content` associated with the payload
- This is an internal interface change at the level of `FilterBlockBuilder::Finish()`, which leads to touching the inherited interface in `BlockBasedFilterBlockBuilder`. But for that, the payload transferring is ignored.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9070

Test Plan: - The main focus is to catch segment fault error during `FilterBlockBuilder::Finish()` and `BlockBasedTableBuilder::Finish()` and interface mismatch. Relying on existing CI tests is enough as `assert(false)` was temporarily added to verify the new logic of transferring ownership indeed run

Reviewed By: pdillinger

Differential Revision: D31884933

Pulled By: hx235

fbshipit-source-id: f73ecfbea13788d4fc058013ace27230110b52f4
2021-11-04 13:35:38 -07:00
Peter Dillinger
dfedc74d82 Some checksum code refactoring (#9113)
Summary:
To prepare for adding checksum to footer and "context aware"
checksums. This also brings closely related code much closer together.

Recently added `BlockBasedTableBuilder::ComputeBlockTrailer` for testing
is made obsolete in the refactoring, as testing the checksums can happen
at a lower level of abstraction.

Also now checking for unrecognized checksum type on reading footer,
rather than later on use.

Also removed an obsolete function delcaration.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9113

Test Plan:
existing tests worked before refactoring to remove
`ComputeBlockTrailer`. And then refactored+improved tests using it.

Reviewed By: mrambacher

Differential Revision: D32090149

Pulled By: pdillinger

fbshipit-source-id: 2879da683c1498ea85a3b70dace9b6d9f6b47b6e
2021-11-04 09:09:34 -07:00
hx235
a5ec5e3ea0 Minor improvement to #8428 (Account for dictionary-building buffer in global memory limit) (#9032)
Summary:
Summary/Context:
- Renamed `cache_rev_mng` to `compression_dict_buffer_cache_res_mgr`
   - It is to distinguish with other potential `cache_res_mgr` in `BlockBasedTableBuilder` and to use correct short-hand for the words "reservation", "manager"
- Added `table_options.block_cache == nullptr` in additional to `table_options.no_block_cache == true` to be conditions where we don't create a `CacheReservationManager`
   - Theoretically `table_options.no_block_cache == true` is equivalent to `table_options.block_cache == nullptr` by API. But since segment fault will be generated by passing `nullptr` into `CacheReservationManager`'s constructor, it does not hurt to directly verify  `table_options.block_cache != nullptr` before passing in
- Renamed `is_cache_full` to `exceeds_global_block_cache_limit`
   - It is to hide implementation detail of cache reservation and to emphasize on the concept/design intent of caping memory within global block cache limit

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9032

Test Plan: - Passing existing tests

Reviewed By: ajkr

Differential Revision: D32005807

Pulled By: hx235

fbshipit-source-id: 619fd17bb924199de3db5924d8ab7dae53b1efa2
2021-11-01 14:28:09 -07:00
Peter Dillinger
a7d4bea43a Implement XXH3 block checksum type (#9069)
Summary:
XXH3 - latest hash function that is extremely fast on large
data, easily faster than crc32c on most any x86_64 hardware. In
integrating this hash function, I have handled the compression type byte
in a non-standard way to avoid using the streaming API (extra data
movement and active code size because of hash function complexity). This
approach got a thumbs-up from Yann Collet.

Existing functionality change:
* reject bad ChecksumType in options with InvalidArgument

This change split off from https://github.com/facebook/rocksdb/issues/9058 because context-aware checksum is
likely to be handled through different configuration than ChecksumType.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9069

Test Plan:
tests updated, and substantially expanded. Unit tests now check
that we don't accidentally change the values generated by the checksum
algorithms ("schema test") and that we properly handle
invalid/unrecognized checksum types in options or in file footer.

DBTestBase::ChangeOptions (etc.) updated from two to one configuration
changing from default CRC32c ChecksumType. The point of this test code
is to detect possible interactions among features, and the likelihood of
some bad interaction being detected by including configurations other
than XXH3 and CRC32c--and then not detected by stress/crash test--is
extremely low.

Stress/crash test also updated (manual run long enough to see it accepts
new checksum type). db_bench also updated for microbenchmarking
checksums.

 ### Performance microbenchmark (PORTABLE=0 DEBUG_LEVEL=0, Broadwell processor)

./db_bench -benchmarks=crc32c,xxhash,xxhash64,xxh3,crc32c,xxhash,xxhash64,xxh3,crc32c,xxhash,xxhash64,xxh3
crc32c       :       0.200 micros/op 5005220 ops/sec; 19551.6 MB/s (4096 per op)
xxhash       :       0.807 micros/op 1238408 ops/sec; 4837.5 MB/s (4096 per op)
xxhash64     :       0.421 micros/op 2376514 ops/sec; 9283.3 MB/s (4096 per op)
xxh3         :       0.171 micros/op 5858391 ops/sec; 22884.3 MB/s (4096 per op)
crc32c       :       0.206 micros/op 4859566 ops/sec; 18982.7 MB/s (4096 per op)
xxhash       :       0.793 micros/op 1260850 ops/sec; 4925.2 MB/s (4096 per op)
xxhash64     :       0.410 micros/op 2439182 ops/sec; 9528.1 MB/s (4096 per op)
xxh3         :       0.161 micros/op 6202872 ops/sec; 24230.0 MB/s (4096 per op)
crc32c       :       0.203 micros/op 4924686 ops/sec; 19237.1 MB/s (4096 per op)
xxhash       :       0.839 micros/op 1192388 ops/sec; 4657.8 MB/s (4096 per op)
xxhash64     :       0.424 micros/op 2357391 ops/sec; 9208.6 MB/s (4096 per op)
xxh3         :       0.162 micros/op 6182678 ops/sec; 24151.1 MB/s (4096 per op)

As you can see, especially once warmed up, xxh3 is fastest.

 ### Performance macrobenchmark (PORTABLE=0 DEBUG_LEVEL=0, Broadwell processor)

Test

    for I in `seq 1 50`; do for CHK in 0 1 2 3 4; do TEST_TMPDIR=/dev/shm/rocksdb$CHK ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=30000000 -checksum_type=$CHK 2>&1 | grep 'micros/op' | tee -a results-$CHK & done; wait; done

Results (ops/sec)

    for FILE in results*; do echo -n "$FILE "; awk '{ s += $5; c++; } END { print 1.0 * s / c; }' < $FILE; done

results-0 252118 # kNoChecksum
results-1 251588 # kCRC32c
results-2 251863 # kxxHash
results-3 252016 # kxxHash64
results-4 252038 # kXXH3

Reviewed By: mrambacher

Differential Revision: D31905249

Pulled By: pdillinger

fbshipit-source-id: cb9b998ebe2523fc7c400eedf62124a78bf4b4d1
2021-10-28 22:15:17 -07:00
Peter Dillinger
5bf9a7d5ee Clarify caching behavior for index and filter partitions (#9068)
Summary:
Somewhat confusingly, index and filter partition blocks are
never owned by table readers, even with
cache_index_and_filter_blocks=false. They still go into block cache
(possibly pinned by table reader) if there is a block cache. If no block
cache, they are only loaded transiently on demand.

This PR primarily clarifies the options APIs and some internal code
comments.

Also, this closes a hypothetical data corruption vulnerability where
some but not all index partitions are pinned. I haven't been able to
reproduce a case where it can happen (the failure seems to propagate
to abort table open) but it's worth patching nonetheless.

Fixes https://github.com/facebook/rocksdb/issues/8979

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9068

Test Plan:
existing tests :-/  I could cover the new code using sync
points, but then I'd have to very carefully relax my `assert(false)`

Reviewed By: ajkr

Differential Revision: D31898284

Pulled By: pdillinger

fbshipit-source-id: f2511a7d3a36bc04b627935d8e6cfea6422f98be
2021-10-27 17:23:04 -07:00
Zhichao Cao
6d93b87588 Add lowest_used_cache_tier to ImmutableDBOptions to enable or disable Secondary Cache (#9050)
Summary:
Currently, if Secondary Cache is provided to the lru cache, it is used by default. We add CacheTier to advanced_options.h to describe the cache tier we used. Add a `lowest_used_cache_tier` option to `DBOptions` (immutable) and pass it to BlockBasedTableReader to decide if secondary cache will be used or not. By default it is `CacheTier::kNonVolatileTier`, which means, we always use both block cache (kVolatileTier) and secondary cache (kNonVolatileTier). By set it to `CacheTier::kVolatileTier`, the DB will not use the secondary cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9050

Test Plan: added new tests

Reviewed By: anand1976

Differential Revision: D31744769

Pulled By: zhichao-cao

fbshipit-source-id: a0575ebd23e1c6dfcfc2b4c8578764e73b15bce6
2021-10-19 15:54:23 -07:00
Peter Dillinger
b234a3f569 Improve data block construction performance (#9040)
Summary:
... by bypassing tracking of last_key in BlockBuilder when
last_key is already known (for BlockBasedTableBuilder::data_block).

I tried extracting a base class of BlockBuilder without the last_key
tracking at all, but that became complicated by NewFlushBlockPolicy() in
the public API referencing BlockBuilder, which would need to be the base
class, and I don't want to replace nearly all the internal references to
BlockBuilder.

Possible follow-up:
* Investigate / consider using AddWithLastKey in more places

This improvement should stack with https://github.com/facebook/rocksdb/issues/9039

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9040

Test Plan:
TEST_TMPDIR=/dev/shm/rocksdb1 ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=50000000
Compiled with DEBUG_LEVEL=0
Test vs. control runs simulaneous for better accuracy, units = ops/sec

Run 1: 278929 vs. 267799 (+4.2%)
Run 2: 281836 vs. 267432 (+5.4%)
Run 3: 278279 vs. 270454 (+2.9%)

(This benchmark is chosen to have detectable signal-to-noise, not to
represent expected improvement percent on real workloads.)

Reviewed By: mrambacher

Differential Revision: D31706033

Pulled By: pdillinger

fbshipit-source-id: 8a50fe6fefdd67b6d7665ffa687bbdcf5ad0d5ec
2021-10-19 12:36:21 -07:00
Peter Dillinger
9d66d6d13e Two performance improvements in BlockBuilder (#9039)
Summary:
Primarily, this change reserves space in the std::string for building
the next block once a block is finished, using `block_size` as
reservation size. Note: also tried reusing same std::string in the
common "unbuffered" path but that showed no benefit or regression.

Secondarily, this slightly reduces the work in resetting `restarts_`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9039

Test Plan:
TEST_TMPDIR=/dev/shm/rocksdb1 ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=50000000
Compiled with DEBUG_LEVEL=0
Test vs. control runs simulaneous for better accuracy, units = ops/sec

Run 1, Primary change only: 292697 vs. 280267 (+4.4%)
Run 2, Primary change only: 288763 vs. 279621 (+3.3%)
Run 1, Secondary change only: 260065 vs. 254232 (+2.3%)
Run 2, Secondary change only: 275925 vs. 272248 (+1.4%)
Run 1, Both changes: 284890 vs. 270372 (+5.3%)
Run 2, Both changes: 263511 vs. 258188 (+2.0%)

Reviewed By: zhichao-cao

Differential Revision: D31701253

Pulled By: pdillinger

fbshipit-source-id: 7e40810afbb98e6b6446955e77bda59e69b19ffd
2021-10-18 08:35:38 -07:00
mrambacher
13ae16c315 Cleanup includes in dbformat.h (#8930)
Summary:
This header file was including everything and the kitchen sink when it did not need to.  This resulted in many places including this header when they needed other pieces instead.

Cleaned up this header to only include what was needed and fixed up the remaining code to include what was now missing.

Hopefully, this sort of code hygiene cleanup will speed up the builds...

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8930

Reviewed By: pdillinger

Differential Revision: D31142788

Pulled By: mrambacher

fbshipit-source-id: 6b45de3f300750c79f751f6227dece9cfd44085d
2021-09-29 04:04:40 -07:00
Hui Xiao
d6bd1a0291 Support "level_at_creation" in TablePropertiesCollectorFactory::Context (#8919)
Summary:
Context:
Exposing the level of the sst file (i.e, table) where it is created in `TablePropertiesCollectorFactory::Context` allows users of `TablePropertiesCollectorFactory` to customize some implementation details of `TablePropertiesCollectorFactory` and `TablePropertiesCollector` based on the level of creation. For example, `TablePropertiesCollector::NeedCompact()` can return different values based on level of creation.
- Declared an extra field `level_at_creation` in `TablePropertiesCollectorFactory::Context`
- Allowed `level_at_creation` to be passed in as an argument in `IntTblPropCollectorFactory::CreateIntTblPropCollector()` and `UserKeyTablePropertiesCollectorFactory::CreateIntTblPropCollector()`, the latter of which is an internal wrapper of user's passed-in `TablePropertiesCollectorFactory::CreateTablePropertiesCollector()` used in table-building process
- Called `IntTblPropCollectorFactory::CreateIntTblPropCollector()` with `level_at_creation` passed into both `BlockBasedTableBuilder` and `PlainTableBuilder`
  -  `PlainTableBuilder` previously did not capture `level_at_creation` from `TableBuilderOptions` in `PlainTableFactory`. In order for it to call the method with this parameter, this PR also made `PlainTableBuilder` capture `level_at_creation` as a required parameter
- Called `IntTblPropCollectorFactory::CreateIntTblPropCollector()` with `level_at_creation` its overridden functions in its derived classes, including `RegularKeysStartWithAFactory::CreateIntTblPropCollector()` in `table_properties_collector_test.cc`, `SstFileWriterPropertiesCollectorFactory::CreateIntTblPropCollector()` in `sst_file_writer_collectors.h`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8919

Test Plan:
- Passed the added assertion for `context.level_at_creation`
- Passed existing tests
- Run `Make` to make sure adding a required parameter to `PlainTableBuilder`'s constructor does not break anything

Reviewed By: anand1976

Differential Revision: D30951729

Pulled By: hx235

fbshipit-source-id: c4a0173b0d9344a4cf47e1b987d759c1c73cb474
2021-09-28 12:35:24 -07:00
mrambacher
e0f697d2bd Make SliceTransform into a Customizable class (#8641)
Summary:
Made SliceTransform into a Customizable class.

Would be nice to write a test that stored and used a custom transform  in an SST table.

There are a set of tests (DBBlockFliterTest.PrefixExtractor*, SamePrefixTest.InDomainTest, PrefixTest.PrefixAndWholeKeyTest that run the same with or without a SliceTransform/PrefixFilter.  Is this expected?

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8641

Reviewed By: zhichao-cao

Differential Revision: D31142793

Pulled By: mrambacher

fbshipit-source-id: bb08672fccbfdc263dcae21f25a62307e1facda1
2021-09-27 07:43:47 -07:00
Peter Dillinger
2819c7840e Fix PrepopulateBlockCache::kFlushOnly (#8750)
Summary:
kFlushOnly currently means "always" except in the case of
remote compaction. This makes it flushes only.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8750

Test Plan: test updated

Reviewed By: akankshamahajan15

Differential Revision: D30968034

Pulled By: pdillinger

fbshipit-source-id: 5dbd24dde18852a0e937a540995fba9bfbe89037
2021-09-15 15:33:20 -07:00
anand76
7743f033b1 More robust checking of IO uring completion data (#8894)
Summary:
Potential bugs in the IO uring implementation can cause bad data to be returned in the completion queue. Add some checks in the PosixRandomAccessFile::MultiRead completion handling code to catch such errors and fail the entire MultiRead. Also log some diagnostic messages and stack trace.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8894

Reviewed By: siying, pdillinger

Differential Revision: D30826982

Pulled By: anand1976

fbshipit-source-id: af91815ac760e095d6cc0466cf8bd5c10167fd15
2021-09-15 12:44:43 -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
Levi Tamasi
7e78d7c540 Support timestamps in SstFileWriter (#8899)
Summary:
As a first step of supporting user-defined timestamps with ingestion, the
patch adds timestamp support to `SstFileWriter`; namely, it adds new
versions of the `Put` and `Delete` APIs that take timestamps. (`Merge`
and `DeleteRange` are currently not supported with user-defined timestamps
in general but once those features are implemented, we can handle them
in `SstFileWriter` in a similar fashion.) The new APIs validate the size of
the timestamp provided by the client. Similarly, calls to the pre-existing
timestamp-less APIs are now disallowed when user-defined timestamps are
in use according to the comparator.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8899

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D30850699

Pulled By: ltamasi

fbshipit-source-id: 779154373618f19b8f0797976bb7286783c57b67
2021-09-09 18:58:01 -07:00
Hui Xiao
91b95cadee Account for dictionary-building buffer in global memory limit (#8428)
Summary:
Context:
Some data blocks are temporarily buffered in memory in BlockBasedTableBuilder for building compression dictionary used in data block compression. Currently this memory usage is not counted toward our global memory usage utilizing block cache capacity. To improve that, this PR charges that memory usage into the block cache to achieve better memory tracking and limiting.

- Reserve memory in block cache for buffered data blocks that are used to build a compression dictionary
- Release all the memory associated with buffering the data blocks mentioned above in EnterUnbuffered(), which is called when (a) buffer limit is exceeded after buffering OR (b) the block cache becomes full after reservation OR (c) BlockBasedTableBuilder calls Finish()

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8428

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

Reviewed By: ajkr

Differential Revision: D30755305

Pulled By: hx235

fbshipit-source-id: 6e66665020b775154a94c4c5e0f2adaeaff13981
2021-09-08 12:35:46 -07:00
Peter Dillinger
cb5b851ff8 Add (& fix) some simple source code checks (#8821)
Summary:
* Don't hardcode namespace rocksdb (use ROCKSDB_NAMESPACE)
* Don't #include <rocksdb/...> (use double quotes)
* Support putting NOCOMMIT (any case) in source code that should not be
committed/pushed in current state.

These will be run with `make check` and in GitHub actions

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8821

Test Plan: existing tests, manually try out new checks

Reviewed By: zhichao-cao

Differential Revision: D30791726

Pulled By: pdillinger

fbshipit-source-id: 399c883f312be24d9e55c58951d4013e18429d92
2021-09-07 21:19:27 -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
1a5eb33d91 Allow intentionally swallowed errors in BlockBasedFilterBlockReader (#8695)
Summary:
To avoid getting "Didn't get expected error from Get" from
crash test by enabling block-based filter in crash test in https://github.com/facebook/rocksdb/issues/8679.
Basically, this applies the pattern of IGNORE_STATUS_IF_ERROR in
full_filter_block.cc to block_based_filter_block.cc

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8695

Test Plan: watch for resolution of crash test runs

Reviewed By: ltamasi

Differential Revision: D30496748

Pulled By: pdillinger

fbshipit-source-id: f7808fcf14c0e787fe81da03fa8303244590d273
2021-08-23 15:50:27 -07:00
Peter Dillinger
04db764831 Embed original file number in SST table properties (#8686)
Summary:
I very recently realized that with https://github.com/facebook/rocksdb/issues/8669 we cannot later add
file numbers to external SST files (so that more can share db session
ids for better uniqueness properties), because of forward compatibility.
We would have a version of RocksDB that assumes session IDs are unique
on external SST files and therefore can't really break that invariant in
future files.

This change adds a table property for "orig_file_number" which is
populated by normal SST files and also external SST files generated by
SstFileWriter. SstFileWriter now keeps a db_session_id for life of the
object and increments its own file numbers for embedding in table
properties. (They are arguably "fake" file numbers because these numbers
and not embedded in the file name.)

While updating block_based_table_builder, I removed several unnecessary
fields from Rep, because following the pattern would have created
another unnecessary field.

This change also updates block_based_table_reader to use this new
property when available, which means that for newer SST files, we can
determine the stable/original <db_session_id,file_number> unique
identifier using just the file contents, not the file name. (It's a bit
complicated; detailed comments in block_based_table_reader.)

Also added DB host id to properties listing by sst_dump, which could be
useful in debugging.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8686

Test Plan: majorly overhauled StableCacheKeys test for this change

Reviewed By: zhichao-cao

Differential Revision: D30457742

Pulled By: pdillinger

fbshipit-source-id: 2e5ae7dddeb94fb9d8eac8a928486aed8b8cd445
2021-08-20 20:40:48 -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
anand76
22f2936b35 Update the block_read_count/block_read_byte counters in MultiGet (#8676)
Summary:
MultiGet in block based table reader doesn't use BlockFetcher. As a result, the block_read_count and block_read_byte PerfContext counters were not being updated. This fixes that by updating them in MultiRead.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8676

Reviewed By: zhichao-cao

Differential Revision: D30428680

Pulled By: anand1976

fbshipit-source-id: 21846efe92588fc17123665dd06733693a40126d
2021-08-20 11:50:42 -07:00