Commit graph

1230 commits

Author SHA1 Message Date
Akanksha Mahajan 8b2f60b668 Cache warming blocks during flush (#8561)
Summary:
Insert warm blocks  (data, uncompressed dict, index and filter blocks) during flush in Block cache which is enabled under option BlockBasedTableOptions.prepopulate_block_cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8561

Test Plan: Added unit test

Reviewed By: anand1976

Differential Revision: D29773411

Pulled By: akankshamahajan15

fbshipit-source-id: 6631123c10134340ef0bd7e90baafaa6deba0e66
2021-08-03 12:44:15 -07:00
hongrubb 870033291a Fix Get() return status when block cache is disabled (#8485)
Summary:
This PR is for https://github.com/facebook/rocksdb/issues/8453

We need to update `s = biter.status();`  when `biter.status().IsIncomplete()` is true. By doing this, can fix the problem in issue.
Besides, we still need to update `db_statistics`  in `get_context.ReportCounters()` before return back.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8485

Reviewed By: jay-zhuang

Differential Revision: D29604835

Pulled By: ajkr

fbshipit-source-id: c7f2f1cd058223ce1b507ec05d57cf264b9c9710
2021-07-13 18:13:24 -07:00
mrambacher c8665611bc Make FlushBlockPolicyFactory into a Customizable class (#8432)
Summary:
Add ability to treat FlushBlockPolicyFactory as a Customizable.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8432

Reviewed By: zhichao-cao

Differential Revision: D29558941

Pulled By: mrambacher

fbshipit-source-id: 4a791af941ea4a65fc2f1fdfb1d7a95f42ca6774
2021-07-12 09:04:59 -07:00
Andrew Kryczka ed8eb436db Move slow valgrind tests behind -DROCKSDB_FULL_VALGRIND_RUN (#8475)
Summary:
Various tests had disabled valgrind due to it slowing down and timing
out (as is the case right now) the CI runs. Where a test was disabled with no comment,
I assumed slowness was the cause. For these tests that were slow under
valgrind, as well as the ones identified in https://github.com/facebook/rocksdb/issues/8352, this PR moves them
behind the compiler flag `-DROCKSDB_FULL_VALGRIND_RUN`.

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

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

Reviewed By: jay-zhuang

Differential Revision: D29504843

Pulled By: ajkr

fbshipit-source-id: 2aac90749cfbd30d5ce11cb29a07a1b9314eeea7
2021-07-07 11:14:05 -07:00
Levi Tamasi 1ae026c400 Partially revert the "apply subrange of table property collectors" change (#8465)
Summary:
We ended up using a different approach for tracking the amount of
garbage in blob files (see e.g. https://github.com/facebook/rocksdb/pull/8450),
so the ability to apply only a range of table property collectors is
now unnecessary. The patch reverts this part of
https://github.com/facebook/rocksdb/pull/8298 while keeping the cleanup done
in that PR.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8465

Test Plan: `make check`

Reviewed By: jay-zhuang

Differential Revision: D29399921

Pulled By: ltamasi

fbshipit-source-id: af64816c357d0829b9d7ba8ca1477038138f6f0a
2021-07-06 10:14:32 -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
anand76 a50da404be Fix a tsan warning due to reading flags in LRUHandle without holding a mutex (#8433)
Summary:
Tsan complains due to a perceived race condition in accessing LRUHandle flags. One thread calls ```LRUHandle::SetHit()``` from ```LRUCacheShard::Lookup()```, while another thread calls ```LRUHandle::IsPending()``` from ```LRUCacheShard::IsReady()```. The latter call is from ```MultiGet```. It doesn't actually have to call ```IsReady``` since a null value indicates the cache handle is not ready, so its sufficient to check for a null value.

Also modify ```IsReady``` to acquire the LRU shard mutex.

Tests:
1. make check
2. Run tsan_crash

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8433

Reviewed By: zhichao-cao

Differential Revision: D29278030

Pulled By: anand1976

fbshipit-source-id: 0c9fed56d12eda853e72dadebe75038361bd257f
2021-06-21 21:23:56 -07:00
anand76 8ea0a2c1bd Parallelize secondary cache lookup in MultiGet (#8405)
Summary:
Implement the ```WaitAll()``` interface in ```LRUCache``` to allow callers to issue multiple lookups in parallel and wait for all of them to complete. Modify ```MultiGet``` to use this to parallelize the secondary cache lookups in order to reduce the overall latency. A call to ```cache->Lookup()``` returns a handle that has an incomplete value (nullptr), and the caller can call ```cache->IsReady()``` to check whether the lookup is complete, and pass a vector of handles to ```WaitAll``` to wait for completion. If any of the lookups fail, ```MultiGet``` will read the block from the SST file.

Another change in this PR is to rename ```SecondaryCacheHandle``` to ```SecondaryCacheResultHandle``` as it more accurately describes the return result of the secondary cache lookup, which is more like a future.

Tests:
1. Add unit tests in lru_cache_test
2. Benchmark results with no secondary cache configured
Master -
```
readrandom   :      41.175 micros/op 388562 ops/sec;  106.7 MB/s (7277999 of 7277999 found)
readrandom   :      41.217 micros/op 388160 ops/sec;  106.6 MB/s (7274999 of 7274999 found)
multireadrandom :      10.309 micros/op 1552082 ops/sec; (28908992 of 28908992 found)
multireadrandom :      10.321 micros/op 1550218 ops/sec; (29081984 of 29081984 found)
```

This PR -
```
readrandom   :      41.158 micros/op 388723 ops/sec;  106.8 MB/s (7290999 of 7290999 found)
readrandom   :      41.185 micros/op 388463 ops/sec;  106.7 MB/s (7287999 of 7287999 found)
multireadrandom :      10.277 micros/op 1556801 ops/sec; (29346944 of 29346944 found)
multireadrandom :      10.253 micros/op 1560539 ops/sec; (29274944 of 29274944 found)
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8405

Reviewed By: zhichao-cao

Differential Revision: D29190509

Pulled By: anand1976

fbshipit-source-id: 6f8eff6246712af8a297cfe22ea0d1c3b2a01bb0
2021-06-18 09:35:59 -07:00
Akanksha Mahajan 5ba1b6e549 Cache warming data blocks during flush (#8242)
Summary:
This PR prepopulates warm/hot data blocks which are already in memory
into block cache at the time of flush. On a flush, the data block that is
in memory (in memtables) get flushed to the device. If using Direct IO,
additional IO is incurred to read this data back into memory again, which
is avoided by enabling newly added option.

 Right now, this is enabled only for flush for data blocks. We plan to
expand this option to cover compactions in the future and for other types
 of blocks.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8242

Test Plan: Add new unit test

Reviewed By: anand1976

Differential Revision: D28521703

Pulled By: akankshamahajan15

fbshipit-source-id: 7219d6958821cedce689a219c3963a6f1a9d5f05
2021-06-17 21:56:47 -07:00
Peter Dillinger 865a25101d Mark Ribbon filter and optimize_filters_for_memory as production (#8408)
Summary:
Marked the Ribbon filter and optimize_filters_for_memory features
as production-ready, each enabling memory savings for Bloom-like filters.
Use `NewRibbonFilterPolicy` in place of `NewBloomFilterPolicy` to use
Ribbon filters instead of Bloom, or `ribbonfilter` in place of
`bloomfilter` in configuration string.

Some small refactoring in db_stress.

Removed/refactored unused code in db_bench, in part preparing for future
default possibly being different from "disabled."

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8408

Test Plan:
Lots of prior automated, ad-hoc, and "real world" testing.
Updated tests for new API names. Quick db_bench test:

bloom fillrandom
77730 ops/sec
rocksdb.block.cache.filter.bytes.insert COUNT : 89929384

ribbon fillrandom
71492 ops/sec
rocksdb.block.cache.filter.bytes.insert COUNT : 64531384

Reviewed By: mrambacher

Differential Revision: D29140805

Pulled By: pdillinger

fbshipit-source-id: d742c922722421678f95ad85eeb0aaebc9f5e49a
2021-06-17 12:29:16 -07:00
mrambacher b788e3f497 Increase range for GeneralTableTest.ApproximateOffsetOfCompressed (#8387)
Summary:
Newer versions of Snappy (1.1 patch 8) were failing this test because the offsets were outside of the expected range.

In some experiments:
- On a RH machine with 1.1.0, the offset of "k04" and "xyy" were 3331 and 6665.
- On an Ubuntu machine with 1.1.8, the same keys were at 3501 and 7004.
- On a Mac with 1.1.8, the offsets were 3499 and 7001.

AFAICT, the test environments are either using an older version of Snappy or no Snappy at all.

This change increases the range to allow the tests to pass.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8387

Reviewed By: pdillinger

Differential Revision: D29064475

Pulled By: mrambacher

fbshipit-source-id: fac01927576765b8aff9f57e08a63a2ae210855f
2021-06-15 03:46:30 -07:00
mrambacher 281ac9c89e Add CreateFrom methods to Env/FileSystem (#8174)
Summary:
- Added CreateFromString method to Env and FilesSystem to replace LoadEnv/Load.  This method/signature is a precursor to making these classes extend Customizable.

- Added CreateFromSystem to Env.  This method standardizes creating an Env from the environment variables.  Previously, some places would check TEST_ENV_URI and others would also check TEST_FS_URI.  Now the code is more command/standardized.

- Added CreateFromFlags to Env.  These method allows Env to be create from string options (such as GFLAGS options) in a more standard way.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8174

Reviewed By: zhichao-cao

Differential Revision: D28999603

Pulled By: mrambacher

fbshipit-source-id: 88e6911e7e91f908458a7fe10a20e93ecbc275fb
2021-06-15 03:43:48 -07:00
Akanksha Mahajan 3897ce3125 Support for Merge in Integrated BlobDB with base values (#8292)
Summary:
This PR add support for Merge operation in Integrated BlobDB with base values(i.e DB::Put). Merged values can be retrieved through  DB::Get, DB::MultiGet, DB::GetMergeOperands and Iterator operation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8292

Test Plan: Add new unit tests

Reviewed By: ltamasi

Differential Revision: D28415896

Pulled By: akankshamahajan15

fbshipit-source-id: e9b3478bef51d2f214fb88c31ed3c8d2f4a531ff
2021-06-10 12:58:37 -07:00
Zhichao Cao f44e69c64a Use DbSessionId as cache key prefix when secondary cache is enabled (#8360)
Summary:
Currently, we either use the file system inode or a monotonically incrementing runtime ID as the block cache key prefix. However, if we use a monotonically incrementing runtime ID (in the case that the file system does not support inode id generation), in some cases, it cannot ensure uniqueness (e.g., we have secondary cache migrated from host to host). We use DbSessionID (20 bytes) + current file number (at most 10 bytes) as the new cache block key prefix when the secondary cache is enabled. So can accommodate scenarios such as transfer of cache state across hosts.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8360

Test Plan: add the test to lru_cache_test

Reviewed By: pdillinger

Differential Revision: D29006215

Pulled By: zhichao-cao

fbshipit-source-id: 6cff686b38d83904667a2bd39923cd030df16814
2021-06-10 11:02:43 -07:00
Zhichao Cao a4405fd981 fix lru caching test and fix reference binding to null pointer (#8326)
Summary:
Fix for https://github.com/facebook/rocksdb/issues/8315. Inhe lru caching test, 5100 is not enough to hold meta block and first block in some random case, increase to 6100. Fix the reference binding to null pointer, use template.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8326

Test Plan: make check

Reviewed By: pdillinger

Differential Revision: D28625666

Pulled By: zhichao-cao

fbshipit-source-id: 97b85306ae3d09bfb74addc7c65e57fe55a976a5
2021-05-24 08:37:00 -07:00
Zhichao Cao 7303d02bdf Use new Insert and Lookup APIs in table reader to support secondary cache (#8315)
Summary:
Secondary cache is implemented to achieve the secondary cache tier for block cache. New Insert and Lookup APIs are introduced in https://github.com/facebook/rocksdb/issues/8271  . To support and use the secondary cache in block based table reader, this PR introduces the corresponding callback functions that will be used in secondary cache, and update the Insert and Lookup APIs accordingly.

benchmarking:
./db_bench --benchmarks="fillrandom" -num=1000000 -key_size=32 -value_size=256 -use_direct_io_for_flush_and_compaction=true -db=/tmp/rocks_t/db -partition_index_and_filters=true

./db_bench -db=/tmp/rocks_t/db -use_existing_db=true -benchmarks=readrandom -num=1000000 -key_size=32 -value_size=256 -use_direct_reads=true -cache_size=1073741824 -cache_numshardbits=5 -cache_index_and_filter_blocks=true -read_random_exp_range=17 -statistics -partition_index_and_filters=true -stats_dump_period_sec=30 -reads=50000000

master benchmarking results:
readrandom   :       3.923 micros/op 254881 ops/sec;   33.4 MB/s (23849796 of 50000000 found)
rocksdb.db.get.micros P50 : 2.820992 P95 : 5.636716 P99 : 16.450553 P100 : 8396.000000 COUNT : 50000000 SUM : 179947064

Current PR benchmarking results
readrandom   :       4.083 micros/op 244925 ops/sec;   32.1 MB/s (23849796 of 50000000 found)
rocksdb.db.get.micros P50 : 2.967687 P95 : 5.754916 P99 : 15.665912 P100 : 8213.000000 COUNT : 50000000 SUM : 187250053

About 3.8% throughput reduction.
P50: 5.2% increasing, P95, 2.09% increasing, P99 4.77% improvement

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8315

Test Plan: added the testing case

Reviewed By: anand1976

Differential Revision: D28599774

Pulled By: zhichao-cao

fbshipit-source-id: 098c4df0d7327d3a546df7604b2f1602f13044ed
2021-05-21 18:29:12 -07:00
Peter Dillinger 3469d60fcc Add table properties for number of entries added to filters (#8323)
Summary:
With Ribbon filter work and possible variance in actual bits
per key (or prefix; general term "entry") to achieve certain FP rates,
I've received a request to be able to track actual bits per key in
generated filters. This change adds a num_filter_entries table
property, which can be combined with filter_size to get bits per key
(entry).

This can vary from num_entries in at least these ways:
* Different versions of same key are only counted once in filters.
* With prefix filters, several user keys map to the same filter entry.
* A single filter can include both prefixes and user keys.

Note that FilterBlockBuilder::NumAdded() didn't do anything useful
except distinguish empty from non-empty.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8323

Test Plan: basic unit test included, others updated

Reviewed By: jay-zhuang

Differential Revision: D28596210

Pulled By: pdillinger

fbshipit-source-id: 529a111f3c84501e5a470bc84705e436ee68c376
2021-05-21 17:11:32 -07:00
Peter Dillinger 311a544c2a Use deleters to label cache entries and collect stats (#8297)
Summary:
This change gathers and publishes statistics about the
kinds of items in block cache. This is especially important for
profiling relative usage of cache by index vs. filter vs. data blocks.
It works by iterating over the cache during periodic stats dump
(InternalStats, stats_dump_period_sec) or on demand when
DB::Get(Map)Property(kBlockCacheEntryStats), except that for
efficiency and sharing among column families, saved data from
the last scan is used when the data is not considered too old.

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

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

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

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

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

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

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

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

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

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

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

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

Reviewed By: ltamasi

Differential Revision: D28488721

Pulled By: pdillinger

fbshipit-source-id: 472f524a9691b5afb107934be2d41d84f2b129fb
2021-05-19 16:51:13 -07:00
Levi Tamasi d83542ca83 Make it possible to apply only a subrange of table property collectors (#8298)
Summary:
This patch does two things:
1) Introduces some aliases in order to eliminate/prevent long-winded type names
w/r/t the internal table property collectors (see e.g.
`std::vector<std::unique_ptr<IntTblPropCollectorFactory>>`).
2) Makes it possible to apply only a subrange of table property collectors during
table building by turning `TableBuilderOptions::int_tbl_prop_collector_factories`
from a pointer to a `vector` into a range (i.e. a pair of iterators).

Rationale: I plan to introduce a BlobDB related table property collector, which
should only be applied during table creation if blob storage is enabled at the moment
(which can be changed dynamically). This change will make it possible to include/
exclude the BlobDB related collector as needed without having to introduce
a second `vector` of collectors in `ColumnFamilyData` with pretty much the same
contents.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8298

Test Plan: `make check`

Reviewed By: jay-zhuang

Differential Revision: D28430910

Pulled By: ltamasi

fbshipit-source-id: a81d28f2c59495865300f43deb2257d2e6977c8e
2021-05-17 18:28:39 -07:00
Jay Zhuang d15fbae449 Refactor Option obj address from char* to void* (#8295)
Summary:
And replace `reinterpret_cast` with `static_cast` or no cast.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8295

Test Plan: `make check`

Reviewed By: mrambacher

Differential Revision: D28420303

Pulled By: jay-zhuang

fbshipit-source-id: 645be123a0df624dc2bea37cd54a35403fc494fa
2021-05-13 14:29:42 -07:00
mrambacher 8948dc8524 Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262)
Summary:
The ImmutableCFOptions contained a bunch of fields that belonged to the ImmutableDBOptions.  This change cleans that up by introducing an ImmutableOptions struct.  Following the pattern of Options struct, this class inherits from the DB and CFOption structs (of the Immutable form).

Only one structural change (the ImmutableCFOptions::fs was changed to a shared_ptr from a raw one) is in this PR.  All of the other changes involve moving the member variables from the ImmutableCFOptions into the ImmutableOptions and changing member variables or function parameters as required for compilation purposes.

Follow-on PRs may do a further clean-up of the code, such as renaming variables (such as "ImmutableOptions cf_options") and potentially eliminating un-needed function parameters (there is no longer a need to pass both an ImmutableDBOptions and an ImmutableOptions to a function).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8262

Reviewed By: pdillinger

Differential Revision: D28226540

Pulled By: mrambacher

fbshipit-source-id: 18ae71eadc879dedbe38b1eb8e6f9ff5c7147dbf
2021-05-05 14:00:17 -07:00
Peter Dillinger d2ca04e3ed Add more LSM info to FilterBuildingContext (#8246)
Summary:
Add `num_levels`, `is_bottommost`, and table file creation
`reason` to `FilterBuildingContext`, in anticipation of more powerful
Bloom-like filter support.

To support this, added `is_bottommost` and `reason` to
`TableBuilderOptions`, which allowed removing `reason` parameter from
`rocksdb::BuildTable`.

I attempted to remove `skip_filters` from `TableBuilderOptions`, because
filter construction decisions should arise from options, not one-off
parameters. I could not completely remove it because the public API for
SstFileWriter takes a `skip_filters` parameter, and translating this
into an option change would mean awkwardly replacing the table_factory
if it is BlockBasedTableFactory with new filter_policy=nullptr option.
I marked this public skip_filters option as deprecated because of this
oddity. (skip_filters on the read side probably makes sense.)

At least `skip_filters` is now largely hidden for users of
`TableBuilderOptions` and is no longer used for implementing the
optimize_filters_for_hits option. Bringing the logic for that option
closer to handling of FilterBuildingContext makes it more obvious that
hese two are using the same notion of "bottommost." (Planned:
configuration options for Bloom-like filters that generalize
`optimize_filters_for_hits`)

Recommended follow-up: Try to get away from "bottommost level" naming of
things, which is inaccurate (see
VersionStorageInfo::RangeMightExistAfterSortedRun), and move to
"bottommost run" or just "bottommost."

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8246

Test Plan:
extended an existing unit test to exercise and check various
filter building contexts. Also, existing tests for
optimize_filters_for_hits validate some of the "bottommost" handling,
which is now closely connected to FilterBuildingContext::is_bottommost
through TableBuilderOptions::is_bottommost

Reviewed By: mrambacher

Differential Revision: D28099346

Pulled By: pdillinger

fbshipit-source-id: 2c1072e29c24d4ac404c761a7b7663292372600a
2021-04-30 13:50:13 -07:00
Peter Dillinger 85becd94c1 Refactor: use TableBuilderOptions to reduce parameter lists (#8240)
Summary:
Greatly reduced the not-quite-copy-paste giant parameter lists
of rocksdb::NewTableBuilder, rocksdb::BuildTable,
BlockBasedTableBuilder::Rep ctor, and BlockBasedTableBuilder ctor.

Moved weird separate parameter `uint32_t column_family_id` of
TableFactory::NewTableBuilder into TableBuilderOptions.

Re-ordered parameters to TableBuilderOptions ctor, so that `uint64_t
target_file_size` is not randomly placed between uint64_t timestamps
(was easy to mix up).

Replaced a couple of fields of BlockBasedTableBuilder::Rep with a
FilterBuildingContext. The motivation for this change is making it
easier to pass along more data into new fields in FilterBuildingContext
(follow-up PR).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8240

Test Plan: ASAN make check

Reviewed By: mrambacher

Differential Revision: D28075891

Pulled By: pdillinger

fbshipit-source-id: fddb3dbb8260a0e8bdcbb51b877ebabf9a690d4f
2021-04-29 07:00:50 -07:00
Akanksha Mahajan a0e0feca62 Improve BlockPrefetcher to prefetch only for sequential scans (#7394)
Summary:
BlockPrefetcher is used by iterators to prefetch data if they
anticipate more data to be used in future and this is valid for forward sequential
scans. But BlockPrefetcher tracks only num_file_reads_ and not if reads
are sequential. This presents problem for MultiGet with large number of
keys when it reseeks index iterator and data block. FilePrefetchBuffer
can end up doing large readahead for reseeks as readahead size
increases exponentially once readahead is enabled. Same issue is with
BlockBasedTableIterator.

Add previous length and offset read as well in BlockPrefetcher (creates
FilePrefetchBuffer) and FilePrefetchBuffer (does prefetching of data) to
determine if reads are sequential and then  prefetch.

Update the last block read after cache hit to take reads from cache also
in account.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7394

Test Plan: Add new unit test case

Reviewed By: anand1976

Differential Revision: D23737617

Pulled By: akankshamahajan15

fbshipit-source-id: 8e6917c25ed87b285ee495d1b68dc623d71205a3
2021-04-28 12:53:46 -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 6bab3a34e9 Move RegisterOptions into the Configurable API (#8223)
Summary:
As previously coded, a Configurable extension would need access to code not in the public API.  This change moves RegisterOptions into the Configurable class and therefore available to public extensions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8223

Reviewed By: anand1976

Differential Revision: D27960188

Pulled By: mrambacher

fbshipit-source-id: ac88b19397183df633902def5b5701b9b65fbf40
2021-04-26 03:13:24 -07:00
Saketh Are cc1c3ee54e Eliminate double-buffering of keys in block_based_table_builder (#8219)
Summary:
The block_based_table_builder buffers some blocks in memory to construct a good compression dictionary. Before this commit, the keys from each block were buffered separately for convenience. However, the buffered block data implicitly contains all keys. This commit eliminates the redundant key buffers and reduces memory usage.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8219

Reviewed By: ajkr

Differential Revision: D27945851

Pulled By: saketh-are

fbshipit-source-id: caf3cac1217201e080a1e24b542bedf20973afee
2021-04-23 12:45:02 -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
Yanqin Jin 09528f9fa1 Fix a bug for SeekForPrev with partitioned filter and prefix (#8137)
Summary:
According to https://github.com/facebook/rocksdb/issues/5907, each filter partition "should include the bloom of the prefix of the last
key in the previous partition" so that SeekForPrev() in prefix mode can return correct result.
The prefix of the last key in the previous partition does not necessarily have the same prefix
as the first key in the current partition. Regardless of the first key in current partition, the
prefix of the last key in the previous partition should be added. The existing code, however,
does not follow this. Furthermore, there is another issue: when finishing current filter partition,
`FullFilterBlockBuilder::AddPrefix()` is called for the first key in next filter partition, which effectively
overwrites `last_prefix_str_` prematurely. Consequently, when the filter block builder proceeds
to the next partition, `last_prefix_str_` will be the prefix of its first key, leaving no way of adding
the bloom of the prefix of the last key of the previous partition.

Prefix extractor is FixedLength.2.
```
[  filter part 1   ]    [  filter part 2    ]
                  abc    d
```
When SeekForPrev("abcd"), checking the filter partition will land on filter part 2 because "abcd" > "abc"
but smaller than "d".
If the filter in filter part 2 happens to return false for the test for "ab", then SeekForPrev("abcd") will build
incorrect iterator tree in non-total-order mode.

Also fix a unit test which starts to fail following this PR. `InDomain` should not fail due to assertion
error when checking on an arbitrary key.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8137

Test Plan:
```
make check
```

Without this fix, the following command will fail pretty soon.
```
./db_stress --acquire_snapshot_one_in=10000 --avoid_flush_during_recovery=0 \
--avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=0 \
--batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=17 \
--bottommost_compression_type=disable --cache_index_and_filter_blocks=1 --cache_size=1048576 \
--checkpoint_one_in=0 --checksum_type=kxxHash64 --clear_column_family_one_in=0 \
--compact_files_one_in=1000000 --compact_range_one_in=1000000 --compaction_ttl=0 \
--compression_max_dict_buffer_bytes=0 --compression_max_dict_bytes=0 \
--compression_parallel_threads=1 --compression_type=zstd --compression_zstd_max_train_bytes=0 \
--continuous_verification_interval=0 --db=/dev/shm/rocksdb/rocksdb_crashtest_whitebox \
--db_write_buffer_size=8388608 --delpercent=5 --delrangepercent=0 --destroy_db_initially=0 --enable_blob_files=0 \
--enable_compaction_filter=0 --enable_pipelined_write=1 --file_checksum_impl=big --flush_one_in=1000000 \
--format_version=5 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 \
--get_sorted_wal_files_one_in=0 --index_block_restart_interval=4 --index_type=2 --ingest_external_file_one_in=0 \
--iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True \
--log2_keys_per_lock=10 --long_running_snapshots=1 --mark_for_compaction_one_file_in=0 \
--max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=100000000 --max_key_len=3 \
--max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=16777216 --max_write_buffer_number=3 \
--max_write_buffer_size_to_maintain=8388608 --memtablerep=skip_list --mmap_read=1 --mock_direct_io=False \
--nooverwritepercent=0 --open_files=500000 --ops_per_thread=20000000 --optimize_filters_for_memory=0 --paranoid_file_checks=1 --partition_filters=1 --partition_pinning=0 --pause_background_one_in=1000000 \
--periodic_compaction_seconds=0 --prefixpercent=5 --progress_reports=0 --read_fault_one_in=0 --read_only=0 \
--readpercent=45 --recycle_log_file_num=0 --reopen=20 --secondary_catch_up_one_in=0 \
--snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=104857600 \
--sst_file_manager_bytes_per_truncate=0 --subcompactions=2 --sync=0 --sync_fault_injection=False \
--target_file_size_base=2097152 --target_file_size_multiplier=2 --test_batches_snapshots=0 --test_cf_consistency=0 \
--top_level_index_pinning=0 --unpartitioned_pinning=1 --use_blob_db=0 --use_block_based_filter=0 \
--use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --use_full_merge_v1=0 --use_merge=0 \
--use_multiget=0 --use_ribbon_filter=0 --use_txn=0 --user_timestamp_size=8 --verify_checksum=1 \
--verify_checksum_one_in=1000000 --verify_db_one_in=100000 --write_buffer_size=4194304 \
--write_dbid_to_manifest=1 --writepercent=35
```

Reviewed By: pdillinger

Differential Revision: D27553054

Pulled By: riversand963

fbshipit-source-id: 60e391e4a2d8d98a9a3172ec5d6176b90ec3de98
2021-04-06 12:14:08 -07:00
sunby c4d0e66d65 Remove check for status returned by InvalidatePageCache (#8156)
Summary:
Failures in `InvalidatePageCache` will change the API contract. So we remove the status check for `InvalidatePageCache` in `SstFileWriter::Add()`, `SstFileWriter::Finish` and `Rep::DeleteRange`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8156

Reviewed By: riversand963

Differential Revision: D27597012

Pulled By: ajkr

fbshipit-source-id: 2872051695d50cc47ed0f2848dc582464c00076f
2021-04-06 11:55:14 -07:00
Zhichao Cao 17002365c1 Replace Status with IOStatus for block fetcher IO function (#8130)
Summary:
To propagate the IOStatus from file reads to RocksDB read logic, some of the existing status needs to be replaced by IOStatus.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8130

Test Plan: make check

Reviewed By: anand1976

Differential Revision: D27440188

Pulled By: zhichao-cao

fbshipit-source-id: bbe7622c2106fe4e46871d60f7c26944e5030d78
2021-04-01 10:07:55 -07:00
Andrew Kryczka c43a37a922 Fix compression dictionary sampling with dedicated range tombstone SSTs (#8141)
Summary:
Return early in case there are zero data blocks when
`BlockBasedTableBuilder::EnterUnbuffered()` is called. This crash can
only be triggered by applying dictionary compression to SST files that
contain only range tombstones. It cannot be triggered by a low buffer
limit alone since we only consider entering unbuffered mode after
buffering a data block causing the limit to be breached, or `Finish()`ing the file. It also cannot
be triggered by a totally empty file because those go through
`Abandon()` rather than `Finish()` so unbuffered mode is never entered.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8141

Test Plan: added a unit test that repro'd the "Floating point exception"

Reviewed By: riversand963

Differential Revision: D27495640

Pulled By: ajkr

fbshipit-source-id: a463cfba476919dc5c5c380800a75a86c31ffa23
2021-04-01 05:08:17 -07:00
Andrew Kryczka 1ba2b8a568 Add sample_for_compression results to table properties (#8139)
Summary:
Added `TableProperties::{fast,slow}_compression_estimated_data_size`.
These properties are present in block-based tables when
`ColumnFamilyOptions::sample_for_compression > 0` and the necessary
compression library is supported when the file is generated. They
contain estimates of what `TableProperties::data_size` would be if the
"fast"/"slow" compression library had been used instead. One
limitation is we do not record exactly which "fast" (ZSTD or Zlib)
or "slow" (LZ4 or Snappy) compression library produced the result.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8139

Test Plan:
- new unit test
- ran `db_bench` with `sample_for_compression=1`; verified the `data_size` property matches the `{slow,fast}_compression_estimated_data_size` when the same compression type is used for the output file compression and the sampled compression

Reviewed By: riversand963

Differential Revision: D27454338

Pulled By: ajkr

fbshipit-source-id: 9529293de93ddac7f03b2e149d746e9f634abac4
2021-03-31 18:21:50 -07:00
Andrew Kryczka c20a7cd6c7 Apply sample_for_compression to all block-based tables (#8105)
Summary:
Previously it only applied to block-based tables generated by flush. This restriction
was undocumented and blocked a new use case. Now compression sampling
applies to all block-based tables we generate when it is enabled.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8105

Test Plan: new unit test

Reviewed By: riversand963

Differential Revision: D27317275

Pulled By: ajkr

fbshipit-source-id: cd9fcc5178d6515e8cb59c6facb5ac01893cb5b0
2021-03-25 15:00:45 -07:00
Yanqin Jin 0304352882 Fix a bug in key comparison when index type is kBinarySearchWithFirstKey (#8062)
Summary:
When timestamp is enabled, key comparison should take this into account.
In `BlockBasedTableReader::Get()`, `BlockBasedTableReader::MultiGet()`,
assume the target key is `key`, and the timestamp upper bound is `ts`.
The highest key in current block is (key, ts1), while the lowest key in next
block is (key, ts2).
If
```
ts1 > ts > ts2
```
then
```
(key, ts1) < (key, ts) < (key, ts2)
```
It can be shown that if `Compare()` is used, then we will mistakenly skip the next
block. Instead, we should use `CompareWithoutTimestamp()`.

The majority of this PR makes some existing tests in `db_with_timestamp_basic_test.cc`
parameterized so that different index types can be tested. A new unit test is
also added for more coverage.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8062

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D27057557

Pulled By: riversand963

fbshipit-source-id: c1062fa7c159ed600a1ad7e461531d52265021f1
2021-03-15 17:44:52 -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
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
Peter Dillinger 0028e3398b Make format_version=5 new default (#8017)
Summary:
Haven't seen any production issues with new Bloom filter and
it's now > 1 year old (added in 6.6.0).

Updated check_format_compatible.sh and HISTORY.md

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8017

Test Plan: tests updated (or prior bugs fixed)

Reviewed By: ajkr

Differential Revision: D26762197

Pulled By: pdillinger

fbshipit-source-id: 0e755c46b443087c1544da0fd545beb9c403d1c2
2021-03-09 12:42:53 -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
xinyuliu b085ee13e0 Append all characters not captured by xsputn() in overflow() function (#7991)
Summary:
In the adapter class `WritableFileStringStreamAdapter`, which wraps WritableFile to be used for std::ostream, previouly only `std::endl` is considered a special case because `endl` is written by `os.put()` directly without going through `xsputn()`. `os.put()` will call `sputc()` and if we further check the internal implementation of `sputc()`, we will see it is
```
int_type __CLR_OR_THIS_CALL sputc(_Elem _Ch) {  // put a character
    return 0 < _Pnavail() ? _Traits::to_int_type(*_Pninc() = _Ch) : overflow(_Traits::to_int_type(_Ch));
```
As we explicitly disabled buffering, _Pnavail() is always 0. Thus every write, not captured by xsputn, becomes an overflow.

When I run tests on Windows, I found not only `std::endl` will drop into this case, writing an unsigned long long will also call `os.put()` then followed by `sputc()` and eventually call `overflow()`. Therefore, instead of only checking `std::endl`, we should try to append other characters as well unless the appending operation fails.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7991

Reviewed By: jay-zhuang

Differential Revision: D26615692

Pulled By: ajkr

fbshipit-source-id: 4c0003de1645b9531545b23df69b000e07014468
2021-02-23 21:44:48 -08:00
Akanksha Mahajan cd79a00903 Make BlockBasedTable::kMaxAutoReadAheadSize configurable (#7951)
Summary:
RocksDB does auto-readahead for iterators on noticing more
than two reads for a table file. The readahead starts at 8KB and doubles on every
additional read upto BlockBasedTable::kMaxAutoReadAheadSize which is
256*1024.
This PR adds a new option BlockBasedTableOptions::max_auto_readahead_size which
replaces BlockBasedTable::kMaxAutoReadAheadSize and the new option can be
configured.
If max_auto_readahead_size is set 0 then no implicit auto prefetching will
be done. If max_auto_readahead_size provided is less than
8KB (which is initial readahead size used by rocksdb in case of
auto-readahead), readahead size will remain same as max_auto_readahead_size.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7951

Test Plan: Add new unit test case.

Reviewed By: anand1976

Differential Revision: D26568085

Pulled By: akankshamahajan15

fbshipit-source-id: b6543520fc74e97d859f2002328d4c5254d417af
2021-02-23 16:54:08 -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 daca92c17a Pick samples for compression dictionary using prime number (#7987)
Summary:
The sample selection technique taken in https://github.com/facebook/rocksdb/issues/7970 was problematic
because it had two code paths for sample selection depending on the
number of data blocks, and one of those code paths involved an
allocation. Using prime numbers, we can consolidate into one code path
without allocation. The downside is there will be values of N (number of
data blocks buffered) that suffer from poor spread in the selected
samples.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7987

Test Plan: `make check -j48`

Reviewed By: pdillinger

Differential Revision: D26586147

Pulled By: ajkr

fbshipit-source-id: 62028e54336fadb6e2c7a7fe6747daa05a263d32
2021-02-22 17:43:03 -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
Ziyue Yang 0c2d71edba Fix typo: replace readadhead with readahead (#7953)
Summary:
This PR replaces several "readadhead" typos with "readahead".

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7953

Reviewed By: ajkr

Differential Revision: D26518903

Pulled By: jay-zhuang

fbshipit-source-id: 6f7dece0e39ec4f71c4a936399bcb2e02574f42a
2021-02-18 14:31:20 -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