Commit Graph

277 Commits

Author SHA1 Message Date
Levi Tamasi
092f417037 Move the uncompression dictionary object out of the block cache (#5584)
Summary:
RocksDB has historically stored uncompression dictionary objects in the block
cache as opposed to storing just the block contents. This neccesitated
evicting the object upon table close. With the new code, only the raw blocks
are stored in the cache, eliminating the need for eviction.

In addition, the patch makes the following improvements:

1) Compression dictionary blocks are now prefetched/pinned similarly to
index/filter blocks.
2) A copy operation got eliminated when the uncompression dictionary is
retrieved.
3) Errors related to retrieving the uncompression dictionary are propagated as
opposed to silently ignored.

Note: the patch temporarily breaks the compression dictionary evicition stats.
They will be fixed in a separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5584

Test Plan: make asan_check

Differential Revision: D16344151

Pulled By: ltamasi

fbshipit-source-id: 2962b295f5b19628f9da88a3fcebbce5a5017a7b
2019-07-23 16:01:44 -07:00
haoyuhuang
8a008d4170 Block access tracing: Trace referenced key for Get on non-data blocks. (#5548)
Summary:
This PR traces the referenced key for Get for all types of blocks. This is useful when evaluating hybrid row-block caches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5548

Test Plan: make clean && USE_CLANG=1 make check -j32

Differential Revision: D16157979

Pulled By: HaoyuHuang

fbshipit-source-id: f6327411c9deb74e35e22a35f66cdbae09ab9d87
2019-07-17 13:05:58 -07:00
Levi Tamasi
3bde41b5a3 Move the filter readers out of the block cache (#5504)
Summary:
Currently, when the block cache is used for the filter block, it is not
really the block itself that is stored in the cache but a FilterBlockReader
object. Since this object is not pure data (it has, for instance, pointers that
might dangle, including in one case a back pointer to the TableReader), it's not
really sharable. To avoid the issues around this, the current code erases the
cache entries when the TableReader is closed (which, BTW, is not sufficient
since a concurrent TableReader might have picked up the object in the meantime).
Instead of doing this, the patch moves the FilterBlockReader out of the cache
altogether, and decouples the filter reader object from the filter block.
In particular, instead of the TableReader owning, or caching/pinning the
FilterBlockReader (based on the customer's settings), with the change the
TableReader unconditionally owns the FilterBlockReader, which in turn
owns/caches/pins the filter block. This change also enables us to reuse the code
paths historically used for data blocks for filters as well.

Note:
Eviction statistics for filter blocks are temporarily broken. We plan to fix this in a
separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5504

Test Plan: make asan_check

Differential Revision: D16036974

Pulled By: ltamasi

fbshipit-source-id: 770f543c5fb4ed126fd1e04bfd3809cf4ff9c091
2019-07-16 13:14:58 -07:00
haoyuhuang
6edc5d0719 Block cache tracing: Associate a unique id with Get and MultiGet (#5514)
Summary:
This PR associates a unique id with Get and MultiGet. This enables us to track how many blocks a Get/MultiGet request accesses. We can also measure the impact of row cache vs block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5514

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32

Differential Revision: D16032681

Pulled By: HaoyuHuang

fbshipit-source-id: 775b05f4440badd58de6667e3ec9f4fc87a0af4c
2019-07-03 19:35:41 -07:00
Mike Kolupaev
b4d7209428 Add an option to put first key of each sst block in the index (#5289)
Summary:
The first key is used to defer reading the data block until this file gets to the top of merging iterator's heap. For short range scans, most files never make it to the top of the heap, so this change can reduce read amplification by a lot sometimes.

Consider the following workload. There are a few data streams (we'll be calling them "logs"), each stream consisting of a sequence of blobs (we'll be calling them "records"). Each record is identified by log ID and a sequence number within the log. RocksDB key is concatenation of log ID and sequence number (big endian). Reads are mostly relatively short range scans, each within a single log. Writes are mostly sequential for each log, but writes to different logs are randomly interleaved. Compactions are disabled; instead, when we accumulate a few tens of sst files, we create a new column family and start writing to it.

So, a typical sst file consists of a few ranges of blocks, each range corresponding to one log ID (we use FlushBlockPolicy to cut blocks at log boundaries). A typical read would go like this. First, iterator Seek() reads one block from each sst file. Then a series of Next()s move through one sst file (since writes to each log are mostly sequential) until the subiterator reaches the end of this log in this sst file; then Next() switches to the next sst file and reads sequentially from that, and so on. Often a range scan will only return records from a small number of blocks in small number of sst files; in this case, the cost of initial Seek() reading one block from each file may be bigger than the cost of reading the actually useful blocks.

Neither iterate_upper_bound nor bloom filters can prevent reading one block from each file in Seek(). But this PR can: if the index contains first key from each block, we don't have to read the block until this block actually makes it to the top of merging iterator's heap, so for short range scans we won't read any blocks from most of the sst files.

This PR does the deferred block loading inside value() call. This is not ideal: there's no good way to report an IO error from inside value(). As discussed with siying offline, it would probably be better to change InternalIterator's interface to explicitly fetch deferred value and get status. I'll do it in a separate PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5289

Differential Revision: D15256423

Pulled By: al13n321

fbshipit-source-id: 750e4c39ce88e8d41662f701cf6275d9388ba46a
2019-06-24 20:54:04 -07:00
haoyuhuang
705b8eecb4 Add more callers for table reader. (#5454)
Summary:
This PR adds more callers for table readers. These information are only used for block cache analysis so that we can know which caller accesses a block.
1. It renames the BlockCacheLookupCaller to TableReaderCaller as passing the caller from upstream requires changes to table_reader.h and TableReaderCaller is a more appropriate name.
2. It adds more table reader callers in table/table_reader_caller.h, e.g., kCompactionRefill, kExternalSSTIngestion, and kBuildTable.

This PR is long as it requires modification of interfaces in table_reader.h, e.g., NewIterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5454

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32.

Differential Revision: D15819451

Pulled By: HaoyuHuang

fbshipit-source-id: b6caa704c8fb96ddd15b9a934b7e7ea87f88092d
2019-06-20 14:31:48 -07:00
Vijay Nadimpalli
24b118ad98 Combine the read-ahead logic for user reads and compaction reads (#5431)
Summary:
Currently the read-ahead logic for user reads and compaction reads go through different code paths where compaction reads create new table readers and use `ReadaheadRandomAccessFile`. This change is to unify read-ahead logic to use read-ahead in BlockBasedTableReader::InitDataBlock(). As a result of the change  `ReadAheadRandomAccessFile` class and `new_table_reader_for_compaction_inputs` option will no longer be used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5431

Test Plan:
make check

Here is the benchmarking - https://gist.github.com/vjnadimpalli/083cf423f7b6aa12dcdb14c858bc18a5

Differential Revision: D15772533

Pulled By: vjnadimpalli

fbshipit-source-id: b71dca710590471ede6fb37553388654e2e479b9
2019-06-19 14:10:46 -07:00
Levi Tamasi
5355e527d9 Make the 'block read count' performance counters consistent (#5484)
Summary:
The patch brings the semantics of per-block-type read performance
context counters in sync with the generic block_read_count by only
incrementing the counter if the block was actually read from the file.
It also fixes index_block_read_count, which fell victim to the
refactoring in PR https://github.com/facebook/rocksdb/issues/5298.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5484

Test Plan: Extended the unit tests.

Differential Revision: D15887431

Pulled By: ltamasi

fbshipit-source-id: a3889759d0ac5759d56625d692cd828d1b9207a6
2019-06-18 19:03:24 -07:00
Siying Dong
8843129ece Move some memory related files from util/ to memory/ (#5382)
Summary:
Move arena, allocator, and memory tools under util to a separate memory/ directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5382

Differential Revision: D15564655

Pulled By: siying

fbshipit-source-id: 9cd6b5d0d3d52b39606e19221fa154596e5852a5
2019-05-30 17:44:09 -07:00
Vijay Nadimpalli
50e470791d Organizing rocksdb/table directory by format
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5373

Differential Revision: D15559425

Pulled By: vjnadimpalli

fbshipit-source-id: 5d6d6d615582bedd96a4b879bb25d429a6de8b55
2019-05-30 14:51:11 -07:00
Levi Tamasi
1e35584251 Move the index readers out of the block cache (#5298)
Summary:
Currently, when the block cache is used for index blocks as well, it is
not really the index block that is stored in the cache but an
IndexReader object. Since this object is not pure data (it has, for
instance, pointers that might dangle), it's not really sharable. To
avoid the issues around this, the current code uses a dummy unique cache
key for each TableReader to store the IndexReader, and erases the
IndexReader entry when the TableReader is closed. Instead of doing this,
the new code moves the IndexReader out of the cache altogether. In
particular, instead of the TableReader owning, or caching/pinning the
IndexReader based on the customer's settings, the TableReader
unconditionally owns the IndexReader, which in turn owns/caches/pins
the index block (which is itself sharable and thus can be safely put in
the cache without any hacks).

Note: the change has two side effects:
1) Partitions of partitioned indexes no longer affect the read
amplification statistics.
2) Eviction statistics for index blocks are temporarily broken. We plan to fix
this in a separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5298

Differential Revision: D15303203

Pulled By: ltamasi

fbshipit-source-id: 935a69ba59d87d5e44f42e2310619b790c366e47
2019-05-30 11:53:27 -07:00
Siying Dong
e9e0101ca4 Move test related files under util/ to test_util/ (#5377)
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377

Differential Revision: D15551366

Pulled By: siying

fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
2019-05-30 11:25:51 -07:00
Mike Kolupaev
6a6aef25c1 Fix crash in BlockBasedTableIterator::Seek() (#5291)
Summary:
https://github.com/facebook/rocksdb/pull/5256 broke it: `block_iter_.user_key()` may not be valid even if `block_iter_points_to_real_block_` is true. E.g. if there was an IO error or Status::Incomplete.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5291

Differential Revision: D15273324

Pulled By: al13n321

fbshipit-source-id: 442e5b09f9884a58f92a6ac1ca93af719c219886
2019-05-10 12:40:57 -07:00
yiwu-arbug
f1239d5f10 Avoid per-key upper bound check in BlockBasedTableIterator (#5142)
Summary:
This is second attempt for #5101. Original commit message:
`BlockBasedTableIterator` avoid reading next block on `Next()` if it detects the iterator will be out of bound, by checking against index key. The optimization was added in #2239, and by the time it only check the bound per block. It seems later change make it a per-key check, which introduce unnecessary key comparisons.

This patch come with two fixes:

Fix 1: To optimize checking for bounds, we need comparing the bounds with index key as well. However BlockBasedTableIterator doesn't know whether its index iterator is internally using user keys or internal keys. The patch fixes that by extending InternalIterator with a user_key() function that is overridden by In IndexBlockIter.

Fix 2: In #5101 we return `IsOutOfBound()=true` when block index key is out of bound. But the index key can be larger than smallest key of the next file on the level. That file can be within upper bound and should not be filtered out.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5142

Differential Revision: D14907113

Pulled By: siying

fbshipit-source-id: ac95775c5b4e7b700f76ab43e39f45402c98fbfb
2019-04-16 11:37:47 -07:00
Levi Tamasi
59ef2ba559 Evict the uncompression dictionary from the block cache upon table close (#5150)
Summary:
The uncompression dictionary object has a Statistics pointer that might
dangle if the database closed. This patch evicts the dictionary from the
block cache when a table is closed, similarly to how index and filter
readers are handled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5150

Differential Revision: D14782422

Pulled By: ltamasi

fbshipit-source-id: 0cec9336c742c479aa92206e04521767f1aa9622
2019-04-04 16:21:12 -07:00
Siying Dong
ebcc8ae1d3 Revert "Avoid per-key upper bound check in BlockBasedTableIterator (#5101)" (#5132)
Summary:
This reverts commit f29dc1b906.

In BlockBasedTableIterator, index_iter_->key() is sometimes a user key, so it is wrong to call ExtractUserKey() against it. This is a bug introduced by #5101.
Temporarily revert the diff to keep the branch clean.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5132

Differential Revision: D14718584

Pulled By: siying

fbshipit-source-id: 0ac55dc9b5dbc18c7809092146bdf7eb9364b9ad
2019-04-02 10:00:38 -07:00
Yi Wu
f29dc1b906 Avoid per-key upper bound check in BlockBasedTableIterator (#5101)
Summary:
`BlockBasedTableIterator` avoid reading next block on `Next()` if it detects the iterator will be out of bound, by checking against index key. The optimization was added in #2239, and by the time it only check the bound per block. It seems later change make it a per-key check, which introduce unnecessary key comparisons.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5101

Differential Revision: D14678707

Pulled By: siying

fbshipit-source-id: 2372446116753c7892ea4cec7b4b49ef87ba463e
2019-03-29 13:11:46 -07:00
Shobhit Dayal
b45b1cde3e Feature for sampling and reporting compressibility (#4842)
Summary:
This is a feature to sample data-block compressibility and and report them as stats. 1 in N (tunable) blocks is sampled for compressibility using two algorithms:
1. lz4 or snappy for fast compression
2. zstd or zlib for slow but higher compression.

The stats are reported to the caller as raw-bytes and compressed-bytes. The block continues to be compressed for storage using the specified CompressionType.

The db_bench_tool how has a command line option for specifying the sampling rate. It's default value is 0 (no sampling). To test the overhead for a certain value, users can compare the performance of db_bench_tool, varying the sampling rate. It is unlikely to have a noticeable impact for high values like 20.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4842

Differential Revision: D13629011

Pulled By: shobhitdayal

fbshipit-source-id: 14ca668bcab6499b2a1734edf848eb62a4f4fafa
2019-03-18 12:15:34 -07:00
Siying Dong
aef763b6d6 Make statistics's stats_level change thread-safe (#5030)
Summary:
Right now, users can change statistics.stats_level while DB is running, but TSAN may report
data race. We make stats_level_ to be atomic, and access them using accessors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5030

Differential Revision: D14267519

Pulled By: siying

fbshipit-source-id: 37d7ebeff7a43a406230143422a16af899163f73
2019-03-01 10:42:09 -08:00
Michael Liu
ca89ac2ba9 Apply modernize-use-override (2nd iteration)
Summary:
Use C++11’s override and remove virtual where applicable.
Change are automatically generated.

Reviewed By: Orvid

Differential Revision: D14090024

fbshipit-source-id: 1e9432e87d2657e1ff0028e15370a85d1739ba2a
2019-02-14 14:41:36 -08:00
Andrew Kryczka
62f70f6d14 Reduce scope of compression dictionary to single SST (#4952)
Summary:
Our previous approach was to train one compression dictionary per compaction, using the first output SST to train a dictionary, and then applying it on subsequent SSTs in the same compaction. While this was great for minimizing CPU/memory/I/O overhead, it did not achieve good compression ratios in practice. In our most promising potential use case, moderate reductions in a dictionary's scope make a major difference on compression ratio.

So, this PR changes compression dictionary to be scoped per-SST. It accepts the tradeoff during table building to use more memory and CPU. Important changes include:

- The `BlockBasedTableBuilder` has a new state when dictionary compression is in-use: `kBuffered`. In that state it accumulates uncompressed data in-memory whenever `Add` is called.
- After accumulating target file size bytes or calling `BlockBasedTableBuilder::Finish`, a `BlockBasedTableBuilder` moves to the `kUnbuffered` state. The transition (`EnterUnbuffered()`) involves sampling the buffered data, training a dictionary, and compressing/writing out all buffered data. In the `kUnbuffered` state, a `BlockBasedTableBuilder` behaves the same as before -- blocks are compressed/written out as soon as they fill up.
- Samples are now whole uncompressed data blocks, except the final sample may be a partial data block so we don't breach the user's configured `max_dict_bytes` or `zstd_max_train_bytes`. The dictionary trainer is supposed to work better when we pass it real units of compression. Previously we were passing 64-byte KV samples which was not realistic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4952

Differential Revision: D13967980

Pulled By: ajkr

fbshipit-source-id: 82bea6f7537e1529c7a1a4cdee84585f5949300f
2019-02-11 19:47:32 -08:00
Andrew Kryczka
8ec3e72551 Cache dictionary used for decompressing data blocks (#4881)
Summary:
- If block cache disabled or not used for meta-blocks, `BlockBasedTableReader::Rep::uncompression_dict` owns the `UncompressionDict`. It is preloaded during `PrefetchIndexAndFilterBlocks`.
- If block cache is enabled and used for meta-blocks, block cache owns the `UncompressionDict`, which holds dictionary and digested dictionary when needed. It is never prefetched though there is a TODO for this in the code. The cache key is simply the compression dictionary block handle.
- New stats for compression dictionary accesses in block cache: "BLOCK_CACHE_COMPRESSION_DICT_*" and "compression_dict_block_read_count"
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4881

Differential Revision: D13663801

Pulled By: ajkr

fbshipit-source-id: bdcc54044e180855cdcc57639b493b0e016c9a3f
2019-01-23 18:15:47 -08:00
Yi Wu
512a5e3ef8 Fix BlockBasedTable not always using memory allocator if available (#4678)
Summary:
Fix block based table reader not using memory_allocator when allocating index blocks and compression dictionary blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4678

Differential Revision: D13054594

Pulled By: yiwu-arbug

fbshipit-source-id: 379f25bcc665395662511c4f873f4b7b55104ce2
2018-11-28 18:01:24 -08:00
Abhishek Madan
8fe1e06ca0 Clean up FragmentedRangeTombstoneList (#4692)
Summary:
Removed `one_time_use` flag, which removed the need for some
tests, and changed all `NewRangeTombstoneIterator` methods to return
`FragmentedRangeTombstoneIterators`.

These changes also led to removing `RangeDelAggregatorV2::AddUnfragmentedTombstones`
and one of the `MemTableListVersion::AddRangeTombstoneIterators` methods.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4692

Differential Revision: D13106570

Pulled By: abhimadan

fbshipit-source-id: cbab5432d7fc2d9cdfd8d9d40361a1bffaa8f845
2018-11-28 15:29:02 -08:00
Yi Wu
05d9d82181 Revert "Move MemoryAllocator option from Cache to BlockBasedTableOpti… (#4697)
Summary:
…ons (#4676)"

This reverts commit b32d087dbb.

`MemoryAllocator` needs to be with `Cache`, since cache entry can
outlive DB and block based table. The cache needs to hold reference to
memory allocator when deleting cache entry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4697

Differential Revision: D13133490

Pulled By: yiwu-arbug

fbshipit-source-id: 8ef7e8a51263bfd929f892fd062665ff4ce9ce5a
2018-11-21 11:29:57 -08:00
Siying Dong
b82e57d425 Remove two variables from BlockContents class and don't use class Block for compressed block (#4650)
Summary:
We carry compression type and "cachable" variables for every block in the block cache, while they take well-known values. 8-byte is wasted for each block (2-byte for useful information but it takes 8 bytes because of padding). With this change, these two variables are removed.

The cachable information is only useful in the process of reading the block. We use other information to infer from it. For compressed blocks, the compression type is a part of the block content itself so we can get it from there.

Some code is slightly refactored so that the cachable information can flow better.

Another change is to only use class BlockContents for compressed block, and narrow the class Block to only be used for uncompressed blocks, including blocks in compressed block cache. This can make the Block class less confusing. It also saves tens of bytes for each block in compressed block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4650

Differential Revision: D12969070

Pulled By: siying

fbshipit-source-id: 548b62724e9eb66993026429fd9c7c3acd1f95ed
2018-11-13 17:02:55 -08:00
Yi Wu
b32d087dbb Move MemoryAllocator option from Cache to BlockBasedTableOptions (#4676)
Summary:
Per offline discussion with siying, `MemoryAllocator` and `Cache` should be decouple. The idea is that memory allocator handles memory allocation, while cache handle cache policy.

It is normal that external cache libraries pack couple the two components for better optimization. If we want to integrate with such library in the future, we can make a wrapper of the library implementing both `Cache` and `MemoryAllocator` interface.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4676

Differential Revision: D13047662

Pulled By: yiwu-arbug

fbshipit-source-id: cd42e246d80ab600b4de47d073f7d2db308ce6dd
2018-11-13 13:48:38 -08:00
Sagar Vemuri
dc3528077a Update all unique/shared_ptr instances to be qualified with namespace std (#4638)
Summary:
Ran the following commands to recursively change all the files under RocksDB:
```
find . -type f -name "*.cc" -exec sed -i 's/ unique_ptr/ std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<unique_ptr/<std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/ shared_ptr/ std::shared_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<shared_ptr/<std::shared_ptr/g' {} +
```
Running `make format` updated some formatting on the files touched.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4638

Differential Revision: D12934992

Pulled By: sagar0

fbshipit-source-id: 45a15d23c230cdd64c08f9c0243e5183934338a8
2018-11-09 11:19:58 -08:00
Siying Dong
566fc8b994 Black list some valgrind tests (#4642)
Summary:
valgrind tests with 1 thread run too long. To make it shorter, black list some long tests. These are already blacklisted in parallel valgrind tests, but they are not in non-parallel mode
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4642

Differential Revision: D12945237

Pulled By: siying

fbshipit-source-id: 04cf977d435996480fe87aa09f14b17975b74f7d
2018-11-06 14:22:36 -08:00
Bo Hou
cd9404bb77 xxhash 64 support
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/4607

Reviewed By: siying

Differential Revision: D12836696

Pulled By: jsjhoubo

fbshipit-source-id: 7122ccb712d0b0f1cd998aa4477e0da1401bd870
2018-11-01 15:44:06 -07:00
Yi Wu
f560c8f5c8 s/CacheAllocator/MemoryAllocator/g (#4590)
Summary:
Rename the interface, as it is mean to be a generic interface for memory allocation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4590

Differential Revision: D10866340

Pulled By: yiwu-arbug

fbshipit-source-id: 85cb753351a40cb856c046aeaa3f3b369eef3d16
2018-10-26 14:30:30 -07:00
Abhishek Madan
7528130e38 Cache fragmented range tombstones in BlockBasedTableReader (#4493)
Summary:
This allows tombstone fragmenting to only be performed when the table is opened, and cached for subsequent accesses.

On the same DB used in #4449, running `readrandom` results in the following:
```
readrandom   :       0.983 micros/op 1017076 ops/sec;   78.3 MB/s (63103 of 100000 found)
```

Now that Get performance in the presence of range tombstones is reasonable, I also compared the performance between a DB with range tombstones, "expanded" range tombstones (several point tombstones that cover the same keys the equivalent range tombstone would cover, a common workaround for DeleteRange), and no range tombstones. The created DBs had 5 million keys each, and DeleteRange was called at regular intervals (depending on the total number of range tombstones being written) after 4.5 million Puts. The table below summarizes the results of a `readwhilewriting` benchmark (in order to provide somewhat more realistic results):
```
   Tombstones?    | avg micros/op | stddev micros/op |  avg ops/s   | stddev ops/s
----------------- | ------------- | ---------------- | ------------ | ------------
None              |        0.6186 |          0.04637 | 1,625,252.90 | 124,679.41
500 Expanded      |        0.6019 |          0.03628 | 1,666,670.40 | 101,142.65
500 Unexpanded    |        0.6435 |          0.03994 | 1,559,979.40 | 104,090.52
1k Expanded       |        0.6034 |          0.04349 | 1,665,128.10 | 125,144.57
1k Unexpanded     |        0.6261 |          0.03093 | 1,600,457.50 |  79,024.94
5k Expanded       |        0.6163 |          0.05926 | 1,636,668.80 | 154,888.85
5k Unexpanded     |        0.6402 |          0.04002 | 1,567,804.70 | 100,965.55
10k Expanded      |        0.6036 |          0.05105 | 1,667,237.70 | 142,830.36
10k Unexpanded    |        0.6128 |          0.02598 | 1,634,633.40 |  72,161.82
25k Expanded      |        0.6198 |          0.04542 | 1,620,980.50 | 116,662.93
25k Unexpanded    |        0.5478 |          0.0362  | 1,833,059.10 | 121,233.81
50k Expanded      |        0.5104 |          0.04347 | 1,973,107.90 | 184,073.49
50k Unexpanded    |        0.4528 |          0.03387 | 2,219,034.50 | 170,984.32
```

After a large enough quantity of range tombstones are written, range tombstone Gets can become faster than reading from an equivalent DB with several point tombstones.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4493

Differential Revision: D10842844

Pulled By: abhimadan

fbshipit-source-id: a7d44534f8120e6aabb65779d26c6b9df954c509
2018-10-25 19:26:44 -07:00
Neil Mayhew
43dbd4411e Adapt three unit tests with newer compiler/libraries (#4562)
Summary:
This fixes three tests that fail with relatively recent tools and libraries:

The tests are:

* `spatial_db_test`
* `table_test`
* `db_universal_compaction_test`

I'm using:

* `gcc` 7.3.0
* `glibc` 2.27
* `snappy` 1.1.7
* `gflags` 2.2.1
* `zlib` 1.2.11
* `bzip2` 1.0.6.0.1
* `lz4` 1.8.2
* `jemalloc` 5.0.1

The versions used in the Travis environment (which is two Ubuntu LTS versions behind the current one and doesn't use `lz4` or `jemalloc`) don't seem to have a problem. However, to be safe, I verified that these tests pass with and without my changes in a trusty Docker container without `lz4` and `jemalloc`.

However, I do get an unrelated set of other failures when using a trusty Docker container that uses `lz4` and `jemalloc`:

```
db/db_universal_compaction_test.cc:506: Failure
Value of: num + 1
  Actual: 3
Expected: NumSortedRuns(1)
Which is: 4
[  FAILED  ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/0, where GetParam() = (1, false) (1189 ms)
[ RUN      ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/1
db/db_universal_compaction_test.cc:506: Failure
Value of: num + 1
  Actual: 3
Expected: NumSortedRuns(1)
Which is: 4
[  FAILED  ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/1, where GetParam() = (1, true) (1246 ms)
[ RUN      ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/2
db/db_universal_compaction_test.cc:506: Failure
Value of: num + 1
  Actual: 3
Expected: NumSortedRuns(1)
Which is: 4
[  FAILED  ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/2, where GetParam() = (3, false) (1237 ms)
[ RUN      ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/3
db/db_universal_compaction_test.cc:506: Failure
Value of: num + 1
  Actual: 3
Expected: NumSortedRuns(1)
Which is: 4
[  FAILED  ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/3, where GetParam() = (3, true) (1195 ms)
[ RUN      ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/4
db/db_universal_compaction_test.cc:506: Failure
Value of: num + 1
  Actual: 3
Expected: NumSortedRuns(1)
Which is: 4
[  FAILED  ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/4, where GetParam() = (5, false) (1161 ms)
[ RUN      ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/5
db/db_universal_compaction_test.cc:506: Failure
Value of: num + 1
  Actual: 3
Expected: NumSortedRuns(1)
Which is: 4
[  FAILED  ] UniversalCompactionNumLevels/DBTestUniversalCompaction.DynamicUniversalCompactionReadAmplification/5, where GetParam() = (5, true) (1229 ms)
```

I haven't attempted to fix these since I'm not using trusty and Travis doesn't use `lz4` and `jemalloc`. However, the final commit in this PR does at least fix the compilation errors that occur when using trusty's version of `lz4`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4562

Differential Revision: D10510917

Pulled By: maysamyabandeh

fbshipit-source-id: 59534042015ec339270e5fc2f6ac4d859370d189
2018-10-24 08:17:56 -07:00
Igor Canadi
1cf5deb8fd Introduce CacheAllocator, a custom allocator for cache blocks (#4437)
Summary:
This is a conceptually simple change, but it touches many files to
pass the allocator through function calls.

We introduce CacheAllocator, which can be used by clients to configure
custom allocator for cache blocks. Our motivation is to hook this up
with folly's `JemallocNodumpAllocator`
(f43ce6d686/folly/experimental/JemallocNodumpAllocator.h),
but there are many other possible use cases.

Additionally, this commit cleans up memory allocation in
`util/compression.h`, making sure that all allocations are wrapped in a
unique_ptr as soon as possible.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4437

Differential Revision: D10132814

Pulled By: yiwu-arbug

fbshipit-source-id: be1343a4b69f6048df127939fea9bbc96969f564
2018-10-02 17:24:58 -07:00
Yanqin Jin
bb5dcea98e Add path to WritableFileWriter. (#4039)
Summary:
We want to sample the file I/O issued by RocksDB and report the function calls. This requires us to include the file paths otherwise it's hard to tell what has been going on.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4039

Differential Revision: D8670178

Pulled By: riversand963

fbshipit-source-id: 97ee806d1c583a2983e28e213ee764dc6ac28f7a
2018-08-23 10:12:58 -07:00
Fenggang Wu
9d646a6311 Add db_bench options of data block hash index (#4281)
Summary:
Add `--data_block_index_type` and `--data_block_hash_table_util_ratio` option to `db_bench`.

`--data_block_index_type` can be either of `binary` (default) or `binary_and_hash`;
`--data_block_hash_table_util_ratio` will be a double. The default value is `0.75`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4281

Differential Revision: D9361476

Pulled By: fgwu

fbshipit-source-id: dc53e01acef9db81b9eec5e8a96f3bc8ed718c10
2018-08-16 18:42:46 -07:00
Fenggang Wu
19ec44fd39 Improve point-lookup performance using a data block hash index (#4174)
Summary:
Add hash index support to data blocks, which helps to reduce the CPU utilization of point-lookup operations. This feature is backward compatible with the data block created without the hash index. It is disabled by default unless `BlockBasedTableOptions::data_block_index_type` is set to `data_block_index_type = kDataBlockBinaryAndHash.`

The DB size would be bigger with the hash index option as a hash table is added at the end of each data block. If the hash utilization ratio is 1:1, the space overhead is one byte per key. The hash table utilization ratio is adjustable using `BlockBasedTableOptions::data_block_hash_table_util_ratio`. A lower utilization ratio will improve more on the point-lookup efficiency, but take more space too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4174

Differential Revision: D8965914

Pulled By: fgwu

fbshipit-source-id: 1c6bae5d1fc39c80282d8890a72e9e67bc247198
2018-08-15 14:30:03 -07:00
Maysam Yabandeh
caf0f53a74 Index value delta encoding (#3983)
Summary:
Given that index value is a BlockHandle, which is basically an <offset, size> pair we can apply delta encoding on the values. The first value at each index restart interval encoded the full BlockHandle but the rest encode only the size. Refer to IndexBlockIter::DecodeCurrentValue for the detail of the encoding. This reduces the index size which helps using the  block cache more efficiently. The feature is enabled with using format_version 4.

The feature comes with a bit of cpu overhead which should be paid back by the higher cache hits due to smaller index block size.
Results with sysbench read-only using 4k blocks and using 16 index restart interval:
Format 2:
19585   rocksdb read-only range=100
Format 3:
19569   rocksdb read-only range=100
Format 4:
19352   rocksdb read-only range=100
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3983

Differential Revision: D8361343

Pulled By: maysamyabandeh

fbshipit-source-id: f882ee082322acac32b0072e2bdbb0b5f854e651
2018-08-09 16:58:40 -07:00
Yanqin Jin
54de56844d Remove random writes from SST file ingestion (#4172)
Summary:
RocksDB used to store global_seqno in external SST files written by
SstFileWriter. During file ingestion, RocksDB uses `pwrite` to update the
`global_seqno`. Since random write is not supported in some non-POSIX compliant
file systems, external SST file ingestion is not supported on these file
systems. To address this limitation, we no longer update `global_seqno` during
file ingestion. Later RocksDB uses the MANIFEST and other information in table
properties to deduce global seqno for externally-ingested SST files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4172

Differential Revision: D8961465

Pulled By: riversand963

fbshipit-source-id: 4382ec85270a96be5bc0cf33758ca2b167b05071
2018-07-27 16:12:23 -07:00
Siying Dong
a5e851e113 Reformatting some recent changes (#4161)
Summary:
Lint is not happy with some new code recently committed. Format them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4161

Differential Revision: D8940582

Pulled By: siying

fbshipit-source-id: c9b43b1ef8c88b5e923911058b44eb77234b36b7
2018-07-20 14:43:38 -07:00
Siying Dong
8425c8bd4d BlockBasedTableReader: automatically adjust tail prefetch size (#4156)
Summary:
Right now we use one hard-coded prefetch size to prefetch data from the tail of the SST files. However, this may introduce a waste for some use cases, while not efficient for others.
Introduce a way to adjust this prefetch size by tracking 32 recent times, and pick a value with which the wasted read is less than 10%
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4156

Differential Revision: D8916847

Pulled By: siying

fbshipit-source-id: 8413f9eb3987e0033ed0bd910f83fc2eeaaf5758
2018-07-20 14:43:37 -07:00
Andrew Kryczka
ab35505e21 Write properties metablock last in block-based tables (#4158)
Summary:
The properties meta-block should come at the end since we always need to
read it when opening a file, unlike index/filter/other meta-blocks, which
are sometimes read depending on the user's configuration. This ordering
will allow us to (in a future PR) do a small readahead on the end of the file
to read properties and meta-index blocks with one I/O.

The bulk of this PR is a refactoring of the `BlockBasedTableBuilder::Finish`
function. It was previously too large with inconsistent error handling, which
made it difficult to change. So I broke it up into one function per meta-block
write, and tried to make error handling consistent within those functions.
Then reordering the metablocks was trivial -- just reorder the calls to these
helper functions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4158

Differential Revision: D8921705

Pulled By: ajkr

fbshipit-source-id: 96c9cc3182eb1adf11af46adab79dbeba7b12fcc
2018-07-20 09:11:59 -07:00
Siying Dong
8f06b4fa01 Separate some IndexBlockIter logic from BlockIter (#4136)
Summary:
Some logic only related to IndexBlockIter is separated from BlockIter to IndexBlockIter. This is done by writing an exclusive Seek() and SeekForPrev() for DataBlockIter, and all metadata block iter and tombstone block iter now use data block iter. Dealing with the BinarySeek() sharing problem by passing in the comparator to use.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4136

Reviewed By: maysamyabandeh

Differential Revision: D8859673

Pulled By: siying

fbshipit-source-id: 703e5e6824b82b7cbf4721f3594b94127797ca9e
2018-07-16 10:13:18 -07:00
Maysam Yabandeh
8581a93a6b Per-thread unique test db names (#4135)
Summary:
The patch makes sure that two parallel test threads will operate on different db paths. This enables using open source tools such as gtest-parallel to run the tests of a file in parallel.
Example: ``` ~/gtest-parallel/gtest-parallel ./table_test```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4135

Differential Revision: D8846653

Pulled By: maysamyabandeh

fbshipit-source-id: 799bad1abb260e3d346bcb680d2ae207a852ba84
2018-07-13 17:27:39 -07:00
Tamir Duberstein
7bee48bdbd Add GCC 8 to Travis (#3433)
Summary:
- Avoid `strdup` to use jemalloc on Windows
- Use `size_t` for consistency
- Add GCC 8 to Travis
- Add CMAKE_BUILD_TYPE=Release to Travis
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3433

Differential Revision: D6837948

Pulled By: sagar0

fbshipit-source-id: b8543c3a4da9cd07ee9a33f9f4623188e233261f
2018-07-13 10:58:06 -07:00
Maysam Yabandeh
d4ad32d7bd Refactor BlockIter (#4121)
Summary:
BlockIter is getting crowded including details that specific only to either index or data blocks. The patch moves down such details to DataBlockIter and IndexBlockIter, both inheriting from BlockIter.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4121

Differential Revision: D8816832

Pulled By: maysamyabandeh

fbshipit-source-id: d492e74155c11d8a0c1c85cd7ee33d24c7456197
2018-07-12 17:27:31 -07:00
Yanqin Jin
39218a72a4 Increase the size of LRU cache. (#4090)
Summary:
Increase the size of each shard so that the number of cache hit/miss match
expectation. Otherwise FilterBlockInBlockCache test will fail.
Closes https://github.com/facebook/rocksdb/pull/4090

Differential Revision: D8736158

Pulled By: riversand963

fbshipit-source-id: 5cdbc06b02390389fd5b72a6d251d88949ad3d91
2018-07-05 11:45:11 -07:00
Maysam Yabandeh
29ffbb8a50 Charging block cache more accurately (#4073)
Summary:
Currently the block cache is charged only by the size of the raw data block and excludes the overhead of the c++ objects that contain the raw data block. The patch improves the accuracy of the charge by including the c++ object overhead into it.
Closes https://github.com/facebook/rocksdb/pull/4073

Differential Revision: D8686552

Pulled By: maysamyabandeh

fbshipit-source-id: 8472f7fc163c0644533bc6942e20cdd5725f520f
2018-06-29 08:57:20 -07:00
Maysam Yabandeh
235ab9dd32 Pin mmap files in ReadOnlyDB (#4053)
Summary:
https://github.com/facebook/rocksdb/pull/3881 fixed a bug where PinnableSlice pin mmap files which could be deleted with background compaction. This is however a non-issue for ReadOnlyDB when there is no compaction running and max_open_files is -1. This patch reenables the pinning feature for that case.
Closes https://github.com/facebook/rocksdb/pull/4053

Differential Revision: D8662546

Pulled By: maysamyabandeh

fbshipit-source-id: 402962602eb0f644e17822748332999c3af029fd
2018-06-27 17:13:34 -07:00
Zhongyi Xie
408205a36b use user_key and iterate_upper_bound to determine compatibility of bloom filters (#3899)
Summary:
Previously in https://github.com/facebook/rocksdb/pull/3601 bloom filter will only be checked if `prefix_extractor` in the mutable_cf_options matches the one found in the SST file.
This PR relaxes the requirement by checking if all keys in the range [user_key, iterate_upper_bound) all share the same prefix after transforming using the BF in the SST file. If so, the bloom filter is considered compatible and will continue to be looked at.
Closes https://github.com/facebook/rocksdb/pull/3899

Differential Revision: D8157459

Pulled By: miasantreble

fbshipit-source-id: 18d17cba56a1005162f8d5db7a27aba277089c41
2018-06-26 15:57:26 -07:00