Commit Graph

70 Commits

Author SHA1 Message Date
yuzhangyu@fb.com 1cfdece85d Run internal cpp modernizer on RocksDB repo (#12398)
Summary:
When internal cpp modernizer attempts to format rocksdb code, it will replace macro `ROCKSDB_NAMESPACE`  with its default definition `rocksdb` when collapsing nested namespace. We filed a feedback for the tool T180254030 and the team filed a bug for this: https://github.com/llvm/llvm-project/issues/83452. At the same time, they suggested us to run the modernizer tool ourselves so future auto codemod attempts will be smaller. This diff contains:

Running
`xplat/scripts/codemod_service/cpp_modernizer.sh`
in fbcode/internal_repo_rocksdb/repo (excluding some directories in utilities/transactions/lock/range/range_tree/lib that has a non meta copyright comment)
without swapping out the namespace macro `ROCKSDB_NAMESPACE`

Followed by RocksDB's own
`make format`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12398

Test Plan: Auto tests

Reviewed By: hx235

Differential Revision: D54382532

Pulled By: jowlyzhang

fbshipit-source-id: e7d5b40f9b113b60e5a503558c181f080b9d02fa
2024-03-04 10:08:32 -08:00
Hui Xiao 06e593376c Group SST write in flush, compaction and db open with new stats (#11910)
Summary:
## Context/Summary
Similar to https://github.com/facebook/rocksdb/pull/11288, https://github.com/facebook/rocksdb/pull/11444, categorizing SST/blob file write according to different io activities allows more insight into the activity.

For that, this PR does the following:
- Tag different write IOs by passing down and converting WriteOptions to IOOptions
- Add new SST_WRITE_MICROS histogram in WritableFileWriter::Append() and breakdown FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS

Some related code refactory to make implementation cleaner:
- Blob stats
   - Replace high-level write measurement with low-level WritableFileWriter::Append() measurement for BLOB_DB_BLOB_FILE_WRITE_MICROS. This is to make FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS  include blob file. As a consequence, this introduces some behavioral changes on it, see HISTORY and db bench test plan below for more info.
   - Fix bugs where BLOB_DB_BLOB_FILE_SYNCED/BLOB_DB_BLOB_FILE_BYTES_WRITTEN include file failed to sync and bytes failed to write.
- Refactor WriteOptions constructor for easier construction with io_activity and rate_limiter_priority
- Refactor DBImpl::~DBImpl()/BlobDBImpl::Close() to bypass thread op verification
- Build table
   - TableBuilderOptions now includes Read/WriteOpitons so BuildTable() do not need to take these two variables
   - Replace the io_priority passed into BuildTable() with TableBuilderOptions::WriteOpitons::rate_limiter_priority. Similar for BlobFileBuilder.
This parameter is used for dynamically changing file io priority for flush, see  https://github.com/facebook/rocksdb/pull/9988?fbclid=IwAR1DtKel6c-bRJAdesGo0jsbztRtciByNlvokbxkV6h_L-AE9MACzqRTT5s for more
   - Update ThreadStatus::FLUSH_BYTES_WRITTEN to use io_activity to track flush IO in flush job and db open instead of io_priority

## Test
### db bench

Flush
```
./db_bench --statistics=1 --benchmarks=fillseq --num=100000 --write_buffer_size=100

rocksdb.sst.write.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.flush.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.compaction.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.db.open.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
```

compaction, db oopen
```
Setup: ./db_bench --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

Run:./db_bench --statistics=1 --benchmarks=compact  --db=../db_bench --use_existing_db=1

rocksdb.sst.write.micros P50 : 2.675325 P95 : 9.578788 P99 : 18.780000 P100 : 314.000000 COUNT : 638 SUM : 3279
rocksdb.file.write.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.compaction.micros P50 : 2.757353 P95 : 9.610687 P99 : 19.316667 P100 : 314.000000 COUNT : 615 SUM : 3213
rocksdb.file.write.db.open.micros P50 : 2.055556 P95 : 3.925000 P99 : 9.000000 P100 : 9.000000 COUNT : 23 SUM : 66
```

blob stats - just to make sure they aren't broken by this PR
```
Integrated Blob DB

Setup: ./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

Run:./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=compact  --db=../db_bench --use_existing_db=1

pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 7.298246 P95 : 9.771930 P99 : 9.991813 P100 : 16.000000 COUNT : 235 SUM : 1600
rocksdb.blobdb.blob.file.synced COUNT : 1
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842

post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 2.000000 P95 : 2.829360 P99 : 2.993779 P100 : 9.000000 COUNT : 707 SUM : 1614
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164

rocksdb.blobdb.blob.file.synced COUNT : 1 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 (stay the same)
```

```
Stacked Blob DB

Run: ./db_bench --use_blob_db=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 12.808042 P95 : 19.674497 P99 : 28.539683 P100 : 51.000000 COUNT : 10000 SUM : 140876
rocksdb.blobdb.blob.file.synced COUNT : 8
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445

post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 1.657370 P95 : 2.952175 P99 : 3.877519 P100 : 24.000000 COUNT : 30001 SUM : 67924
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164

rocksdb.blobdb.blob.file.synced COUNT : 8 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 (stay the same)
```

###  Rehearsal CI stress test
Trigger 3 full runs of all our CI stress tests

###  Performance

Flush
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=ManualFlush/key_num:524288/per_key_size:256 --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark; enable_statistics = true

Pre-pr: avg 507515519.3 ns
497686074,499444327,500862543,501389862,502994471,503744435,504142123,504224056,505724198,506610393,506837742,506955122,507695561,507929036,508307733,508312691,508999120,509963561,510142147,510698091,510743096,510769317,510957074,511053311,511371367,511409911,511432960,511642385,511691964,511730908,

Post-pr: avg 511971266.5 ns, regressed 0.88%
502744835,506502498,507735420,507929724,508313335,509548582,509994942,510107257,510715603,511046955,511352639,511458478,512117521,512317380,512766303,512972652,513059586,513804934,513808980,514059409,514187369,514389494,514447762,514616464,514622882,514641763,514666265,514716377,514990179,515502408,
```

Compaction
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_{pre|post}_pr --benchmark_filter=ManualCompaction/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1  --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark

Pre-pr: avg 495346098.30 ns
492118301,493203526,494201411,494336607,495269217,495404950,496402598,497012157,497358370,498153846

Post-pr: avg 504528077.20, regressed 1.85%. "ManualCompaction" include flush so the isolated regression for compaction should be around 1.85-0.88 = 0.97%
502465338,502485945,502541789,502909283,503438601,504143885,506113087,506629423,507160414,507393007
```

Put with WAL (in case passing WriteOptions slows down this path even without collecting SST write stats)
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=DBPut/comp_style:0/max_data:107374182400/per_key_size:256/enable_statistics:1/wal:1  --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark

Pre-pr: avg 3848.10 ns
3814,3838,3839,3848,3854,3854,3854,3860,3860,3860

Post-pr: avg 3874.20 ns, regressed 0.68%
3863,3867,3871,3874,3875,3877,3877,3877,3880,3881
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11910

Reviewed By: ajkr

Differential Revision: D49788060

Pulled By: hx235

fbshipit-source-id: 79e73699cda5be3b66461687e5147c2484fc5eff
2023-12-29 15:29:23 -08:00
anand76 269478ee46 Support compressed and local flash secondary cache stacking (#11812)
Summary:
This PR implements support for a three tier cache - primary block cache, compressed secondary cache, and a nvm (local flash) secondary cache. This allows more effective utilization of the nvm cache, and minimizes the number of reads from local flash by caching compressed blocks in the compressed secondary cache.

The basic design is as follows -
1. A new secondary cache implementation, ```TieredSecondaryCache```, is introduced. It keeps the compressed and nvm secondary caches and manages the movement of blocks between them and the primary block cache. To setup a three tier cache, we allocate a ```CacheWithSecondaryAdapter```, with a ```TieredSecondaryCache``` instance as the secondary cache.
2. The table reader passes both the uncompressed and compressed block to ```FullTypedCacheInterface::InsertFull```, allowing the block cache to optionally store the compressed block.
3. When there's a miss, the block object is constructed and inserted in the primary cache, and the compressed block is inserted into the nvm cache by calling ```InsertSaved```. This avoids the overhead of recompressing the block, as well as avoiding putting more memory pressure on the compressed secondary cache.
4. When there's a hit in the nvm cache, we attempt to insert the block in the compressed secondary cache and the primary cache, subject to the admission policy of those caches (i.e admit on second access). Blocks/items evicted from any tier are simply discarded.

We can easily implement additional admission policies if desired.

Todo (In a subsequent PR):
1. Add to db_bench and run benchmarks
2. Add to db_stress

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11812

Reviewed By: pdillinger

Differential Revision: D49461842

Pulled By: anand1976

fbshipit-source-id: b40ac1330ef7cd8c12efa0a3ca75128e602e3a0b
2023-09-21 20:30:53 -07:00
Peter Dillinger 206fdea3d9 Change internal headers with duplicate names (#11408)
Summary:
In IDE navigation I find it annoying that there are two statistics.h files (etc.) and often land on the wrong one. Here I migrate several headers to use the blah.h <- blah_impl.h <- blah.cc idiom. Although clang-format wants "blah.h" to be the top include for "blah.cc", I think overall this is an improvement.

No public API changes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11408

Test Plan: existing tests

Reviewed By: ltamasi

Differential Revision: D45456696

Pulled By: pdillinger

fbshipit-source-id: 809d931253f3272c908cf5facf7e1d32fc507373
2023-05-17 11:27:09 -07:00
Peter Dillinger 204fcff751 HyperClockCache support for SecondaryCache, with refactoring (#11301)
Summary:
Internally refactors SecondaryCache integration out of LRUCache specifically and into a wrapper/adapter class that works with various Cache implementations. Notably, this relies on separating the notion of async lookup handles from other cache handles, so that HyperClockCache doesn't have to deal with the problem of allocating handles from the hash table for lookups that might fail anyway, and might be on the same key without support for coalescing. (LRUCache's hash table can incorporate previously allocated handles thanks to its pointer indirection.) Specifically, I'm worried about the case in which hundreds of threads try to access the same block and probing in the hash table degrades to linear search on the pile of entries with the same key.

This change is a big step in the direction of supporting stacked SecondaryCaches, but there are obstacles to completing that. Especially, there is no SecondaryCache hook for evictions to pass from one to the next. It has been proposed that evictions be transmitted simply as the persisted data (as in SaveToCallback), but given the current structure provided by the CacheItemHelpers, that would require an extra copy of the block data, because there's intentionally no way to ask for a contiguous Slice of the data (to allow for flexibility in storage). `AsyncLookupHandle` and the re-worked `WaitAll()` should be essentially prepared for stacked SecondaryCaches, but several "TODO with stacked secondaries" issues remain in various places.

It could be argued that the stacking instead be done as a SecondaryCache adapter that wraps two (or more) SecondaryCaches, but at least with the current API that would require an extra heap allocation on SecondaryCache Lookup for a wrapper SecondaryCacheResultHandle that can transfer a Lookup between secondaries. We could also consider trying to unify the Cache and SecondaryCache APIs, though that might be difficult if `AsyncLookupHandle` is kept a fixed struct.

## cache.h (public API)
Moves `secondary_cache` option from LRUCacheOptions to ShardedCacheOptions so that it is applicable to HyperClockCache.

## advanced_cache.h (advanced public API)
* Add `Cache::CreateStandalone()` so that the SecondaryCache support wrapper can use it.
* Add `SetEvictionCallback()` / `eviction_callback_` so that the SecondaryCache support wrapper can use it. Only a single callback is supported for efficiency. If there is ever a need for more than one, hopefully that can be handled with a broadcast callback wrapper.

These are essentially the two "extra" pieces of `Cache` for pulling out specific SecondaryCache support from the `Cache` implementation. I think it's a good trade-off as these are reasonable, limited, and reusable "cut points" into the `Cache` implementations.

* Remove async capability from standard `Lookup()` (getting rid of awkward restrictions on pending Handles) and add `AsyncLookupHandle` and `StartAsyncLookup()`. As noted in the comments, the full struct of `AsyncLookupHandle` is exposed so that it can be stack allocated, for efficiency, though more data is being copied around than before, which could impact performance. (Lookup info -> AsyncLookupHandle -> Handle vs. Lookup info -> Handle)

I could foresee a future in which a Cache internally saves a pointer to the AsyncLookupHandle, which means it's dangerous to allow it to be copyable or even movable. It also means it's not compatible with std::vector (which I don't like requiring as an API parameter anyway), so `WaitAll()` expects any contiguous array of AsyncLookupHandles. I believe this is best for common case efficiency, while behaving well in other cases also. For example, `WaitAll()` has no effect on default-constructed AsyncLookupHandles, which look like a completed cache miss.

## cacheable_entry.h
A couple of functions are obsolete because Cache::Handle can no longer be pending.

## cache.cc
Provides default implementations for new or revamped Cache functions, especially appropriate for non-blocking caches.

## secondary_cache_adapter.{h,cc}
The full details of the Cache wrapper adding SecondaryCache support. Essentially replicates the SecondaryCache handling that was in LRUCache, but obviously refactored. There is a bit of logic duplication, where Lookup() is essentially a manually optimized version of StartAsyncLookup() and Wait(), but it's roughly a dozen lines of code.

## sharded_cache.h, typed_cache.h, charged_cache.{h,cc}, sim_cache.cc
Simply updated for Cache API changes.

## lru_cache.{h,cc}
Carefully remove SecondaryCache logic, implement `CreateStandalone` and eviction handler functionality.

## clock_cache.{h,cc}
Expose existing `CreateStandalone` functionality, add eviction handler functionality. Light refactoring.

## block_based_table_reader*
Mostly re-worked the only usage of async Lookup, which is in BlockBasedTable::MultiGet. Used arrays in place of autovector in some places for efficiency. Simplified some logic by not trying to process some cache results before they're all ready.

Created new function `BlockBasedTable::GetCachePriority()` to reduce some pre-existing code duplication (and avoid making it worse).

Fixed at least one small bug from the prior confusing mixture of async and sync Lookups. In MaybeReadBlockAndLoadToCache(), called by RetrieveBlock(), called by MultiGet() with wait=false, is_cache_hit for the block_cache_tracer entry would not be set to true if the handle was pending after Lookup and before Wait.

## Intended follow-up work
* Figure out if there are any missing stats or block_cache_tracer work in refactored BlockBasedTable::MultiGet
* Stacked secondary caches (see above discussion)
* See if we can make up for the small MultiGet performance regression.
* Study more performance with SecondaryCache
* Items evicted from over-full LRUCache in Release were not being demoted to SecondaryCache, and still aren't to minimize unit test churn. Ideally they would be demoted, but it's an exceptional case so not a big deal.
* Use CreateStandalone for cache reservations (save unnecessary hash table operations). Not a big deal, but worthy cleanup.
* Somehow I got the contract for SecondaryCache::Insert wrong in #10945. (Doesn't take ownership!) That API comment needs to be fixed, but didn't want to mingle that in here.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11301

Test Plan:
## Unit tests
Generally updated to include HCC in SecondaryCache tests, though HyperClockCache has some different, less strict behaviors that leads to some tests not really being set up to work with it. Some of the tests remain disabled with it, but I think we have good coverage without them.

## Crash/stress test
Updated to use the new combination.

## Performance
First, let's check for regression on caches without secondary cache configured. Adding support for the eviction callback is likely to have a tiny effect, but it shouldn't be worrisome. LRUCache could benefit slightly from less logic around SecondaryCache handling. We can test with cache_bench default settings, built with DEBUG_LEVEL=0 and PORTABLE=0.

```
(while :; do base/cache_bench --cache_type=hyper_clock_cache | grep Rough; done) | awk '{ sum += $9; count++; print $0; print "Average: " int(sum / count) }'
```

**Before** this and #11299 (which could also have a small effect), running for about an hour, before & after running concurrently for each cache type:
HyperClockCache: 3168662 (average parallel ops/sec)
LRUCache: 2940127

**After** this and #11299, running for about an hour:
HyperClockCache: 3164862 (average parallel ops/sec) (0.12% slower)
LRUCache: 2940928 (0.03% faster)

This is an acceptable difference IMHO.

Next, let's consider essentially the worst case of new CPU overhead affecting overall performance. MultiGet uses the async lookup interface regardless of whether SecondaryCache or folly are used. We can configure a benchmark where all block cache queries are for data blocks, and all are hits.

Create DB and test (before and after tests running simultaneously):
```
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=30000000 -disable_wal=1 -bloom_bits=16
TEST_TMPDIR=/dev/shm base/db_bench -benchmarks=multireadrandom[-X30] -readonly -multiread_batched -batch_size=32 -num=30000000 -bloom_bits=16 -cache_size=6789000000 -duration 20 -threads=16
```

**Before**:
multireadrandom [AVG    30 runs] : 3444202 (± 57049) ops/sec;  240.9 (± 4.0) MB/sec
multireadrandom [MEDIAN 30 runs] : 3514443 ops/sec;  245.8 MB/sec
**After**:
multireadrandom [AVG    30 runs] : 3291022 (± 58851) ops/sec;  230.2 (± 4.1) MB/sec
multireadrandom [MEDIAN 30 runs] : 3366179 ops/sec;  235.4 MB/sec

So that's roughly a 3% regression, on kind of a *worst case* test of MultiGet CPU. Similar story with HyperClockCache:

**Before**:
multireadrandom [AVG    30 runs] : 3933777 (± 41840) ops/sec;  275.1 (± 2.9) MB/sec
multireadrandom [MEDIAN 30 runs] : 3970667 ops/sec;  277.7 MB/sec
**After**:
multireadrandom [AVG    30 runs] : 3755338 (± 30391) ops/sec;  262.6 (± 2.1) MB/sec
multireadrandom [MEDIAN 30 runs] : 3785696 ops/sec;  264.8 MB/sec

Roughly a 4-5% regression. Not ideal, but not the whole story, fortunately.

Let's also look at Get() in db_bench:

```
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=readrandom[-X30] -readonly -num=30000000 -bloom_bits=16 -cache_size=6789000000 -duration 20 -threads=16
```

**Before**:
readrandom [AVG    30 runs] : 2198685 (± 13412) ops/sec;  153.8 (± 0.9) MB/sec
readrandom [MEDIAN 30 runs] : 2209498 ops/sec;  154.5 MB/sec
**After**:
readrandom [AVG    30 runs] : 2292814 (± 43508) ops/sec;  160.3 (± 3.0) MB/sec
readrandom [MEDIAN 30 runs] : 2365181 ops/sec;  165.4 MB/sec

That's showing roughly a 4% improvement, perhaps because of the secondary cache code that is no longer part of LRUCache. But weirdly, HyperClockCache is also showing 2-3% improvement:

**Before**:
readrandom [AVG    30 runs] : 2272333 (± 9992) ops/sec;  158.9 (± 0.7) MB/sec
readrandom [MEDIAN 30 runs] : 2273239 ops/sec;  159.0 MB/sec
**After**:
readrandom [AVG    30 runs] : 2332407 (± 11252) ops/sec;  163.1 (± 0.8) MB/sec
readrandom [MEDIAN 30 runs] : 2335329 ops/sec;  163.3 MB/sec

Reviewed By: ltamasi

Differential Revision: D44177044

Pulled By: pdillinger

fbshipit-source-id: e808e48ff3fe2f792a79841ba617be98e48689f5
2023-03-17 20:23:49 -07:00
Peter Dillinger 3cacd4b4ec Put Cache and CacheWrapper in new public header (#11192)
Summary:
The definition of the Cache class should not be needed by the vast majority of RocksDB users, so I think it is just distracting to include it in cache.h, which is primarily needed for configuring and creating caches. This change moves the class to a new header advanced_cache.h. It is just cut-and-paste except for modifying the class API comment.

In general, operations on shared_ptr<Cache> should continue to work when only a forward declaration of Cache is available, as long as all the Cache instances provided are already shared_ptr. See https://stackoverflow.com/a/17650101/454544

Also, the most common way to customize a Cache is by wrapping an existing implementation, so it makes sense to provide CacheWrapper in the public API. This was a cut-and-paste job except removing the implementation of Name() so that derived classes must provide it.

Intended follow-up: consolidate Release() into one function to reduce customization bugs / confusion

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11192

Test Plan: `make check`

Reviewed By: anand1976

Differential Revision: D43055487

Pulled By: pdillinger

fbshipit-source-id: 7b05492df35e0f30b581b4c24c579bc275b6d110
2023-02-09 12:12:02 -08:00
Peter Dillinger 9f7801c5f1 Major Cache refactoring, CPU efficiency improvement (#10975)
Summary:
This is several refactorings bundled into one to avoid having to incrementally re-modify uses of Cache several times. Overall, there are breaking changes to Cache class, and it becomes more of low-level interface for implementing caches, especially block cache. New internal APIs make using Cache cleaner than before, and more insulated from block cache evolution. Hopefully, this is the last really big block cache refactoring, because of rather effectively decoupling the implementations from the uses. This change also removes the EXPERIMENTAL designation on the SecondaryCache support in Cache. It seems reasonably mature at this point but still subject to change/evolution (as I warn in the API docs for Cache).

The high-level motivation for this refactoring is to minimize code duplication / compounding complexity in adding SecondaryCache support to HyperClockCache (in a later PR). Other benefits listed below.

* static_cast lines of code +29 -35 (net removed 6)
* reinterpret_cast lines of code +6 -32 (net removed 26)

## cache.h and secondary_cache.h
* Always use CacheItemHelper with entries instead of just a Deleter. There are several motivations / justifications:
  * Simpler for implementations to deal with just one Insert and one Lookup.
  * Simpler and more efficient implementation because we don't have to track which entries are using helpers and which are using deleters
  * Gets rid of hack to classify cache entries by their deleter. Instead, the CacheItemHelper includes a CacheEntryRole. This simplifies a lot of code (cache_entry_roles.h almost eliminated). Fixes https://github.com/facebook/rocksdb/issues/9428.
  * Makes it trivial to adjust SecondaryCache behavior based on kind of block (e.g. don't re-compress filter blocks).
  * It is arguably less convenient for many direct users of Cache, but direct users of Cache are now rare with introduction of typed_cache.h (below).
  * I considered and rejected an alternative approach in which we reduce customizability by assuming each secondary cache compatible value starts with a Slice referencing the uncompressed block contents (already true or mostly true), but we apparently intend to stack secondary caches. Saving an entry from a compressed secondary to a lower tier requires custom handling offered by SaveToCallback, etc.
* Make CreateCallback part of the helper and introduce CreateContext to work with it (alternative to https://github.com/facebook/rocksdb/issues/10562). This cleans up the interface while still allowing context to be provided for loading/parsing values into primary cache. This model works for async lookup in BlockBasedTable reader (reader owns a CreateContext) under the assumption that it always waits on secondary cache operations to finish. (Otherwise, the CreateContext could be destroyed while async operation depending on it continues.) This likely contributes most to the observed performance improvement because it saves an std::function backed by a heap allocation.
* Use char* for serialized data, e.g. in SaveToCallback, where void* was confusingly used. (We use `char*` for serialized byte data all over RocksDB, with many advantages over `void*`. `memcpy` etc. are legacy APIs that should not be mimicked.)
* Add a type alias Cache::ObjectPtr = void*, so that we can better indicate the intent of the void* when it is to be the object associated with a Cache entry. Related: started (but did not complete) a refactoring to move away from "value" of a cache entry toward "object" or "obj". (It is confusing to call Cache a key-value store (like DB) when it is really storing arbitrary in-memory objects, not byte strings.)
* Remove unnecessary key param from DeleterFn. This is good for efficiency in HyperClockCache, which does not directly store the cache key in memory. (Alternative to https://github.com/facebook/rocksdb/issues/10774)
* Add allocator to Cache DeleterFn. This is a kind of future-proofing change in case we get more serious about using the Cache allocator for memory tracked by the Cache. Right now, only the uncompressed block contents are allocated using the allocator, and a pointer to that allocator is saved as part of the cached object so that the deleter can use it. (See CacheAllocationPtr.) If in the future we are able to "flatten out" our Cache objects some more, it would be good not to have to track the allocator as part of each object.
* Removes legacy `ApplyToAllCacheEntries` and changes `ApplyToAllEntries` signature for Deleter->CacheItemHelper change.

## typed_cache.h
Adds various "typed" interfaces to the Cache as internal APIs, so that most uses of Cache can use simple type safe code without casting and without explicit deleters, etc. Almost all of the non-test, non-glue code uses of Cache have been migrated. (Follow-up work: CompressedSecondaryCache deserves deeper attention to migrate.) This change expands RocksDB's internal usage of metaprogramming and SFINAE (https://en.cppreference.com/w/cpp/language/sfinae).

The existing usages of Cache are divided up at a high level into these new interfaces. See updated existing uses of Cache for examples of how these are used.
* PlaceholderCacheInterface - Used for making cache reservations, with entries that have a charge but no value.
* BasicTypedCacheInterface<TValue> - Used for primary cache storage of objects of type TValue, which can be cleaned up with std::default_delete<TValue>. The role is provided by TValue::kCacheEntryRole or given in an optional template parameter.
* FullTypedCacheInterface<TValue, TCreateContext> - Used for secondary cache compatible storage of objects of type TValue. In addition to BasicTypedCacheInterface constraints, we require TValue::ContentSlice() to return persistable data. This simplifies usage for the normal case of simple secondary cache compatibility (can give you a Slice to the data already in memory). In addition to TCreateContext performing the role of Cache::CreateContext, it is also expected to provide a factory function for creating TValue.
* For each of these, there's a "Shared" version (e.g. FullTypedSharedCacheInterface) that holds a shared_ptr to the Cache, rather than assuming external ownership by holding only a raw `Cache*`.

These interfaces introduce specific handle types for each interface instantiation, so that it's easy to see what kind of object is controlled by a handle. (Ultimately, this might not be worth the extra complexity, but it seems OK so far.)

Note: I attempted to make the cache 'charge' automatically inferred from the cache object type, such as by expecting an ApproximateMemoryUsage() function, but this is not so clean because there are cases where we need to compute the charge ahead of time and don't want to re-compute it.

## block_cache.h
This header is essentially the replacement for the old block_like_traits.h. It includes various things to support block cache access with typed_cache.h for block-based table.

## block_based_table_reader.cc
Before this change, accessing the block cache here was an awkward mix of static polymorphism (template TBlocklike) and switch-case on a dynamic BlockType value. This change mostly unifies on static polymorphism, relying on minor hacks in block_cache.h to distinguish variants of Block. We still check BlockType in some places (especially for stats, which could be improved in follow-up work) but at least the BlockType is a static constant from the template parameter. (No more awkward partial redundancy between static and dynamic info.) This likely contributes to the overall performance improvement, but hasn't been tested in isolation.

The other key source of simplification here is a more unified system of creating block cache objects: for directly populating from primary cache and for promotion from secondary cache. Both use BlockCreateContext, for context and for factory functions.

## block_based_table_builder.cc, cache_dump_load_impl.cc
Before this change, warming caches was super ugly code. Both of these source files had switch statements to basically transition from the dynamic BlockType world to the static TBlocklike world. None of that mess is needed anymore as there's a new, untyped WarmInCache function that handles all the details just as promotion from SecondaryCache would. (Fixes `TODO akanksha: Dedup below code` in block_based_table_builder.cc.)

## Everything else
Mostly just updating Cache users to use new typed APIs when reasonably possible, or changed Cache APIs when not.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10975

Test Plan:
tests updated

Performance test setup similar to https://github.com/facebook/rocksdb/issues/10626 (by cache size, LRUCache when not "hyper" for HyperClockCache):

34MB 1thread base.hyper -> kops/s: 0.745 io_bytes/op: 2.52504e+06 miss_ratio: 0.140906 max_rss_mb: 76.4844
34MB 1thread new.hyper -> kops/s: 0.751 io_bytes/op: 2.5123e+06 miss_ratio: 0.140161 max_rss_mb: 79.3594
34MB 1thread base -> kops/s: 0.254 io_bytes/op: 1.36073e+07 miss_ratio: 0.918818 max_rss_mb: 45.9297
34MB 1thread new -> kops/s: 0.252 io_bytes/op: 1.36157e+07 miss_ratio: 0.918999 max_rss_mb: 44.1523
34MB 32thread base.hyper -> kops/s: 7.272 io_bytes/op: 2.88323e+06 miss_ratio: 0.162532 max_rss_mb: 516.602
34MB 32thread new.hyper -> kops/s: 7.214 io_bytes/op: 2.99046e+06 miss_ratio: 0.168818 max_rss_mb: 518.293
34MB 32thread base -> kops/s: 3.528 io_bytes/op: 1.35722e+07 miss_ratio: 0.914691 max_rss_mb: 264.926
34MB 32thread new -> kops/s: 3.604 io_bytes/op: 1.35744e+07 miss_ratio: 0.915054 max_rss_mb: 264.488
233MB 1thread base.hyper -> kops/s: 53.909 io_bytes/op: 2552.35 miss_ratio: 0.0440566 max_rss_mb: 241.984
233MB 1thread new.hyper -> kops/s: 62.792 io_bytes/op: 2549.79 miss_ratio: 0.044043 max_rss_mb: 241.922
233MB 1thread base -> kops/s: 1.197 io_bytes/op: 2.75173e+06 miss_ratio: 0.103093 max_rss_mb: 241.559
233MB 1thread new -> kops/s: 1.199 io_bytes/op: 2.73723e+06 miss_ratio: 0.10305 max_rss_mb: 240.93
233MB 32thread base.hyper -> kops/s: 1298.69 io_bytes/op: 2539.12 miss_ratio: 0.0440307 max_rss_mb: 371.418
233MB 32thread new.hyper -> kops/s: 1421.35 io_bytes/op: 2538.75 miss_ratio: 0.0440307 max_rss_mb: 347.273
233MB 32thread base -> kops/s: 9.693 io_bytes/op: 2.77304e+06 miss_ratio: 0.103745 max_rss_mb: 569.691
233MB 32thread new -> kops/s: 9.75 io_bytes/op: 2.77559e+06 miss_ratio: 0.103798 max_rss_mb: 552.82
1597MB 1thread base.hyper -> kops/s: 58.607 io_bytes/op: 1449.14 miss_ratio: 0.0249324 max_rss_mb: 1583.55
1597MB 1thread new.hyper -> kops/s: 69.6 io_bytes/op: 1434.89 miss_ratio: 0.0247167 max_rss_mb: 1584.02
1597MB 1thread base -> kops/s: 60.478 io_bytes/op: 1421.28 miss_ratio: 0.024452 max_rss_mb: 1589.45
1597MB 1thread new -> kops/s: 63.973 io_bytes/op: 1416.07 miss_ratio: 0.0243766 max_rss_mb: 1589.24
1597MB 32thread base.hyper -> kops/s: 1436.2 io_bytes/op: 1357.93 miss_ratio: 0.0235353 max_rss_mb: 1692.92
1597MB 32thread new.hyper -> kops/s: 1605.03 io_bytes/op: 1358.04 miss_ratio: 0.023538 max_rss_mb: 1702.78
1597MB 32thread base -> kops/s: 280.059 io_bytes/op: 1350.34 miss_ratio: 0.023289 max_rss_mb: 1675.36
1597MB 32thread new -> kops/s: 283.125 io_bytes/op: 1351.05 miss_ratio: 0.0232797 max_rss_mb: 1703.83

Almost uniformly improving over base revision, especially for hot paths with HyperClockCache, up to 12% higher throughput seen (1597MB, 32thread, hyper). The improvement for that is likely coming from much simplified code for providing context for secondary cache promotion (CreateCallback/CreateContext), and possibly from less branching in block_based_table_reader. And likely a small improvement from not reconstituting key for DeleterFn.

Reviewed By: anand1976

Differential Revision: D42417818

Pulled By: pdillinger

fbshipit-source-id: f86bfdd584dce27c028b151ba56818ad14f7a432
2023-01-11 14:20:40 -08:00
akankshamahajan 0e7b27bfcf Refactor block cache tracing APIs (#10811)
Summary:
Refactor the classes, APIs and data structures for block cache tracing to allow a user provided trace writer to be used. Currently, only a TraceWriter is supported, with a default built-in implementation of FileTraceWriter. The TraceWriter, however, takes a flat trace record and is thus only suitable for file tracing. This PR introduces an abstract BlockCacheTraceWriter class that takes a structured BlockCacheTraceRecord. The BlockCacheTraceWriter implementation can then format and log the record in whatever way it sees fit. The default BlockCacheTraceWriterImpl does file tracing using a user provided TraceWriter.

`DB::StartBlockTrace` will internally redirect to changed `BlockCacheTrace::StartBlockCacheTrace`.
New API `DB::StartBlockTrace` is also added that directly takes `BlockCacheTraceWriter` pointer.

This same philosophy can be applied to KV and IO tracing as well.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10811

Test Plan:
existing unit tests
Old API DB::StartBlockTrace checked with db_bench tool
create database
```
./db_bench --benchmarks="fillseq" \
--key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 \
--cache_index_and_filter_blocks --cache_size=1048576 \
--disable_auto_compactions=1 --disable_wal=1 --compression_type=none \
--min_level_to_compress=-1 --compression_ratio=1 --num=10000000
```

To trace block cache accesses when running readrandom benchmark:
```
./db_bench --benchmarks="readrandom" --use_existing_db --duration=60 \
--key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 \
--cache_index_and_filter_blocks --cache_size=1048576 \
--disable_auto_compactions=1 --disable_wal=1 --compression_type=none \
--min_level_to_compress=-1 --compression_ratio=1 --num=10000000 \
--threads=16 \
-block_cache_trace_file="/tmp/binary_trace_test_example" \
-block_cache_trace_max_trace_file_size_in_bytes=1073741824 \
-block_cache_trace_sampling_frequency=1

```

Reviewed By: anand1976

Differential Revision: D40435289

Pulled By: akankshamahajan15

fbshipit-source-id: fa2755f4788185e19f4605e731641cfd21ab3282
2022-10-21 12:15:35 -07:00
Peter Dillinger e466173d5c Print stack traces on frozen tests in CI (#10828)
Summary:
Instead of existing calls to ps from gnu_parallel, call a new wrapper that does ps, looks for unit test like processes, and uses pstack or gdb to print thread stack traces. Also, using `ps -wwf` instead of `ps -wf` ensures output is not cut off.

For security, CircleCI runs with security restrictions on ptrace (/proc/sys/kernel/yama/ptrace_scope = 1), and this change adds a work-around to `InstallStackTraceHandler()` (only used by testing tools) to allow any process from the same user to debug it. (I've also touched >100 files to ensure all the unit tests call this function.)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10828

Test Plan: local manual + temporary infinite loop in a unit test to observe in CircleCI

Reviewed By: hx235

Differential Revision: D40447634

Pulled By: pdillinger

fbshipit-source-id: 718a4c4a5b54fa0f9af2d01a446162b45e5e84e1
2022-10-18 00:35:35 -07:00
Peter Dillinger e6c5e0ab9a Have Cache use Status::MemoryLimit (#10262)
Summary:
I noticed it would clean up some things to have Cache::Insert()
return our MemoryLimit Status instead of Incomplete for the case in
which the capacity limit is reached. I suspect this fixes some existing but
unknown bugs where this Incomplete could be confused with other uses
of Incomplete, especially no_io cases. This is the most suspicious case I
noticed, but was not able to reproduce a bug, in part because the existing
code is not covered by unit tests (FIXME added): 57adbf0e91/table/get_context.cc (L397)

I audited all the existing uses of IsIncomplete and updated those that
seemed relevant.

HISTORY updated with a clear warning to users of strict_capacity_limit=true
to update uses of `IsIncomplete()`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10262

Test Plan: updated unit tests

Reviewed By: hx235

Differential Revision: D37473155

Pulled By: pdillinger

fbshipit-source-id: 4bd9d9353ccddfe286b03ebd0652df8ce20f99cb
2022-07-06 14:41:46 -07:00
sdong 736a7b5433 Remove own ToString() (#9955)
Summary:
ToString() is created as some platform doesn't support std::to_string(). However, we've already used std::to_string() by mistake for 16 months (in db/db_info_dumper.cc). This commit just remove ToString().

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9955

Test Plan: Watch CI tests

Reviewed By: riversand963

Differential Revision: D36176799

fbshipit-source-id: bdb6dcd0e3a3ab96a1ac810f5d0188f684064471
2022-05-06 13:03:58 -07:00
gitbw95 8102690a52 Update Cache::Release param from force_erase to erase_if_last_ref (#9728)
Summary:
The param name force_erase may be misleading, since the handle is erased only if it has last reference even if the param is set true.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9728

Reviewed By: pdillinger

Differential Revision: D35038673

Pulled By: gitbw95

fbshipit-source-id: 0d16d1e8fed17b97eba7fb53207119332f659a5f
2022-03-22 10:22:18 -07:00
Jay Zhuang 6bab278291 Fix flaky SimCacheTest.SimCacheLogging (#9373)
Summary:
The random string may contain the string we're checking, e.g.:
```
ADD - 206FBC78E96BC4C6A2DDDDC0AD5D1ADD - 111
```
Only check the line starts-with "ADD -".

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9373

Test Plan: `gtest-parallel ./sim_cache_test --gtest_filter=SimCacheTest.SimCacheLogging -r 1000`

Reviewed By: riversand963

Differential Revision: D33519574

Pulled By: jay-zhuang

fbshipit-source-id: d0c1c9b0b489246d292e7da4133030edaa748099
2022-01-10 22:03:36 -08:00
Merlin Mao f58d276764 Make TraceRecord and Replayer public (#8611)
Summary:
New public interfaces:
`TraceRecord` and `TraceRecord::Handler`, available in "rocksdb/trace_record.h".
`Replayer`, available in `rocksdb/utilities/replayer.h`.

User can use `DB::NewDefaultReplayer()` to create a Replayer to auto/manual replay a trace file.

Unit tests:
- `./db_test2 --gtest_filter="DBTest2.TraceAndReplay"`: Updated with the internal API changes.
- `./db_test2 --gtest_filter="DBTest2.TraceAndManualReplay"`: New for manual replay.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8611

Reviewed By: ajkr

Differential Revision: D30266329

Pulled By: autopear

fbshipit-source-id: 1ecb3cbbedae0f6a67c18f0cc82e002b4d81b6f8
2021-08-11 19:32:46 -07:00
Drewryz 3b27725245 Fix a minor issue with initializing the test path (#8555)
Summary:
The PerThreadDBPath has already specified a slash. It does not need to be specified when initializing the test path.

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

Reviewed By: ajkr

Differential Revision: D29758399

Pulled By: jay-zhuang

fbshipit-source-id: 6d2b878523e3e8580536e2829cb25489844d9011
2021-07-23 08:38:45 -07:00
Peter Dillinger df5dc73bec Don't hold DB mutex for block cache entry stat scans (#8538)
Summary:
I previously didn't notice the DB mutex was being held during
block cache entry stat scans, probably because I primarily checked for
read performance regressions, because they require the block cache and
are traditionally latency-sensitive.

This change does some refactoring to avoid holding DB mutex and to
avoid triggering and waiting for a scan in GetProperty("rocksdb.cfstats").
Some tests have to be updated because now the stats collector is
populated in the Cache aggressively on DB startup rather than lazily.
(I hope to clean up some of this added complexity in the future.)

This change also ensures proper treatment of need_out_of_mutex for
non-int DB properties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8538

Test Plan:
Added unit test logic that uses sync points to fail if the DB mutex
is held during a scan, covering the various ways that a scan might be
triggered.

Performance test - the known impact to holding the DB mutex is on
TransactionDB, and the easiest way to see the impact is to hack the
scan code to almost always miss and take an artificially long time
scanning. Here I've injected an unconditional 5s sleep at the call to
ApplyToAllEntries.

Before (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     433.219 micros/op 2308 ops/sec;    0.1 MB/s ( transactions:78999 aborts:0)
    rocksdb.db.write.micros P50 : 16.135883 P95 : 36.622503 P99 : 66.036115 P100 : 5000614.000000 COUNT : 149677 SUM : 8364856
    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     448.802 micros/op 2228 ops/sec;    0.1 MB/s ( transactions:75999 aborts:0)
    rocksdb.db.write.micros P50 : 16.629221 P95 : 37.320607 P99 : 72.144341 P100 : 5000871.000000 COUNT : 143995 SUM : 13472323

Notice the 5s P100 write time.

After (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     303.645 micros/op 3293 ops/sec;    0.1 MB/s ( transactions:98999 aborts:0)
    rocksdb.db.write.micros P50 : 16.061871 P95 : 33.978834 P99 : 60.018017 P100 : 616315.000000 COUNT : 187619 SUM : 4097407
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     310.383 micros/op 3221 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.270026 P95 : 35.786844 P99 : 64.302878 P100 : 603088.000000 COUNT : 183819 SUM : 4095918

P100 write is now ~0.6s. Not good, but it's the same even if I completely bypass all the scanning code:

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     311.365 micros/op 3211 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.274362 P95 : 36.221184 P99 : 68.809783 P100 : 649808.000000 COUNT : 183819 SUM : 4156767
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     308.395 micros/op 3242 ops/sec;    0.1 MB/s ( transactions:97999 aborts:0)
    rocksdb.db.write.micros P50 : 16.106222 P95 : 37.202403 P99 : 67.081875 P100 : 598091.000000 COUNT : 185714 SUM : 4098832

No substantial difference.

Reviewed By: siying

Differential Revision: D29738847

Pulled By: pdillinger

fbshipit-source-id: 1c5c155f5a1b62e4fea0fd4eeb515a8b7474027b
2021-07-16 14:13:08 -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
anand76 feb06e83b2 Initial support for secondary cache in LRUCache (#8271)
Summary:
Defined the abstract interface for a secondary cache in include/rocksdb/secondary_cache.h, and updated LRUCacheOptions to take a std::shared_ptr<SecondaryCache>. An item is initially inserted into the LRU (primary) cache. When it ages out and evicted from memory, its inserted into the secondary cache. On a LRU cache miss and successful lookup in the secondary cache, the item is promoted to the LRU cache. Only support synchronous lookup currently. The secondary cache would be used to implement a persistent (flash cache) or compressed cache.

Tests:
Results from cache_bench and db_bench don't show any regression due to these changes.

cache_bench results before and after this change -
Command
```./cache_bench -ops_per_thread=10000000 -threads=1```
Before
```Complete in 40.688 s; QPS = 245774```
```Complete in 40.486 s; QPS = 246996```
```Complete in 42.019 s; QPS = 237989```
After
```Complete in 40.672 s; QPS = 245869```
```Complete in 44.622 s; QPS = 224107```
```Complete in 42.445 s; QPS = 235599```

db_bench results before this change, and with this change + https://github.com/facebook/rocksdb/issues/8213 and https://github.com/facebook/rocksdb/issues/8191 -
Commands
```./db_bench  --benchmarks="fillseq,compact" -num=30000000 -key_size=32 -value_size=256 -use_direct_io_for_flush_and_compaction=true -db=/home/anand76/nvm_cache/db -partition_index_and_filters=true```

```./db_bench -db=/home/anand76/nvm_cache/db -use_existing_db=true -benchmarks=readrandom -num=30000000 -key_size=32 -value_size=256 -use_direct_reads=true -cache_size=1073741824 -cache_numshardbits=6 -cache_index_and_filter_blocks=true -read_random_exp_range=17 -statistics -partition_index_and_filters=true -threads=16 -duration=300```
Before
```
DB path: [/home/anand76/nvm_cache/db]
readrandom   :      80.702 micros/op 198104 ops/sec;   54.4 MB/s (3708999 of 3708999 found)
```
```
DB path: [/home/anand76/nvm_cache/db]
readrandom   :      87.124 micros/op 183625 ops/sec;   50.4 MB/s (3439999 of 3439999 found)
```
After
```
DB path: [/home/anand76/nvm_cache/db]
readrandom   :      77.653 micros/op 206025 ops/sec;   56.6 MB/s (3866999 of 3866999 found)
```
```
DB path: [/home/anand76/nvm_cache/db]
readrandom   :      84.962 micros/op 188299 ops/sec;   51.7 MB/s (3535999 of 3535999 found)
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8271

Reviewed By: zhichao-cao

Differential Revision: D28357511

Pulled By: anand1976

fbshipit-source-id: d1cfa236f00e649a18c53328be10a8062a4b6da2
2021-05-13 22:58:40 -07:00
Peter Dillinger 78a309bf86 New Cache API for gathering statistics (#8225)
Summary:
Adds a new Cache::ApplyToAllEntries API that we expect to use
(in follow-up PRs) for efficiently gathering block cache statistics.
Notable features vs. old ApplyToAllCacheEntries:

* Includes key and deleter (in addition to value and charge). We could
have passed in a Handle but then more virtual function calls would be
needed to get the "fields" of each entry. We expect to use the 'deleter'
to identify the origin of entries, perhaps even more.
* Heavily tuned to minimize latency impact on operating cache. It
does this by iterating over small sections of each cache shard while
cycling through the shards.
* Supports tuning roughly how many entries to operate on for each
lock acquire and release, to control the impact on the latency of other
operations without excessive lock acquire & release. The right balance
can depend on the cost of the callback. Good default seems to be
around 256.
* There should be no need to disable thread safety. (I would expect
uncontended locks to be sufficiently fast.)

I have enhanced cache_bench to validate this approach:

* Reports a histogram of ns per operation, so we can look at the
ditribution of times, not just throughput (average).
* Can add a thread for simulated "gather stats" which calls
ApplyToAllEntries at a specified interval. We also generate a histogram
of time to run ApplyToAllEntries.

To make the iteration over some entries of each shard work as cleanly as
possible, even with resize between next set of entries, I have
re-arranged which hash bits are used for sharding and which for indexing
within a shard.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8225

Test Plan:
A couple of unit tests are added, but primary validation is manual, as
the primary risk is to performance.

The primary validation is using cache_bench to ensure that neither
the minor hashing changes nor the simulated stats gathering
significantly impact QPS or latency distribution. Note that adding op
latency histogram seriously impacts the benchmark QPS, so for a
fair baseline, we need the cache_bench changes (except remove simulated
stat gathering to make it compile). In short, we don't see any
reproducible difference in ops/sec or op latency unless we are gathering
stats nearly continuously. Test uses 10GB block cache with
8KB values to be somewhat realistic in the number of items to iterate
over.

Baseline typical output:

```
Complete in 92.017 s; Rough parallel ops/sec = 869401
Thread ops/sec = 54662

Operation latency (ns):
Count: 80000000 Average: 11223.9494  StdDev: 29.61
Min: 0  Median: 7759.3973  Max: 9620500
Percentiles: P50: 7759.40 P75: 14190.73 P99: 46922.75 P99.9: 77509.84 P99.99: 217030.58
------------------------------------------------------
[       0,       1 ]       68   0.000%   0.000%
(    2900,    4400 ]       89   0.000%   0.000%
(    4400,    6600 ] 33630240  42.038%  42.038% ########
(    6600,    9900 ] 18129842  22.662%  64.700% #####
(    9900,   14000 ]  7877533   9.847%  74.547% ##
(   14000,   22000 ] 15193238  18.992%  93.539% ####
(   22000,   33000 ]  3037061   3.796%  97.335% #
(   33000,   50000 ]  1626316   2.033%  99.368%
(   50000,   75000 ]   421532   0.527%  99.895%
(   75000,  110000 ]    56910   0.071%  99.966%
(  110000,  170000 ]    16134   0.020%  99.986%
(  170000,  250000 ]     5166   0.006%  99.993%
(  250000,  380000 ]     3017   0.004%  99.996%
(  380000,  570000 ]     1337   0.002%  99.998%
(  570000,  860000 ]      805   0.001%  99.999%
(  860000, 1200000 ]      319   0.000% 100.000%
( 1200000, 1900000 ]      231   0.000% 100.000%
( 1900000, 2900000 ]      100   0.000% 100.000%
( 2900000, 4300000 ]       39   0.000% 100.000%
( 4300000, 6500000 ]       16   0.000% 100.000%
( 6500000, 9800000 ]        7   0.000% 100.000%
```

New, gather_stats=false. Median thread ops/sec of 5 runs:

```
Complete in 92.030 s; Rough parallel ops/sec = 869285
Thread ops/sec = 54458

Operation latency (ns):
Count: 80000000 Average: 11298.1027  StdDev: 42.18
Min: 0  Median: 7722.0822  Max: 6398720
Percentiles: P50: 7722.08 P75: 14294.68 P99: 47522.95 P99.9: 85292.16 P99.99: 228077.78
------------------------------------------------------
[       0,       1 ]      109   0.000%   0.000%
(    2900,    4400 ]      793   0.001%   0.001%
(    4400,    6600 ] 34054563  42.568%  42.569% #########
(    6600,    9900 ] 17482646  21.853%  64.423% ####
(    9900,   14000 ]  7908180   9.885%  74.308% ##
(   14000,   22000 ] 15032072  18.790%  93.098% ####
(   22000,   33000 ]  3237834   4.047%  97.145% #
(   33000,   50000 ]  1736882   2.171%  99.316%
(   50000,   75000 ]   446851   0.559%  99.875%
(   75000,  110000 ]    68251   0.085%  99.960%
(  110000,  170000 ]    18592   0.023%  99.983%
(  170000,  250000 ]     7200   0.009%  99.992%
(  250000,  380000 ]     3334   0.004%  99.997%
(  380000,  570000 ]     1393   0.002%  99.998%
(  570000,  860000 ]      700   0.001%  99.999%
(  860000, 1200000 ]      293   0.000% 100.000%
( 1200000, 1900000 ]      196   0.000% 100.000%
( 1900000, 2900000 ]       69   0.000% 100.000%
( 2900000, 4300000 ]       32   0.000% 100.000%
( 4300000, 6500000 ]       10   0.000% 100.000%
```

New, gather_stats=true, 1 second delay between scans. Scans take about
1 second here so it's spending about 50% time scanning. Still the effect on
ops/sec and latency seems to be in the noise. Median thread ops/sec of 5 runs:

```
Complete in 91.890 s; Rough parallel ops/sec = 870608
Thread ops/sec = 54551

Operation latency (ns):
Count: 80000000 Average: 11311.2629  StdDev: 45.28
Min: 0  Median: 7686.5458  Max: 10018340
Percentiles: P50: 7686.55 P75: 14481.95 P99: 47232.60 P99.9: 79230.18 P99.99: 232998.86
------------------------------------------------------
[       0,       1 ]       71   0.000%   0.000%
(    2900,    4400 ]      291   0.000%   0.000%
(    4400,    6600 ] 34492060  43.115%  43.116% #########
(    6600,    9900 ] 16727328  20.909%  64.025% ####
(    9900,   14000 ]  7845828   9.807%  73.832% ##
(   14000,   22000 ] 15510654  19.388%  93.220% ####
(   22000,   33000 ]  3216533   4.021%  97.241% #
(   33000,   50000 ]  1680859   2.101%  99.342%
(   50000,   75000 ]   439059   0.549%  99.891%
(   75000,  110000 ]    60540   0.076%  99.967%
(  110000,  170000 ]    14649   0.018%  99.985%
(  170000,  250000 ]     5242   0.007%  99.991%
(  250000,  380000 ]     3260   0.004%  99.995%
(  380000,  570000 ]     1599   0.002%  99.997%
(  570000,  860000 ]     1043   0.001%  99.999%
(  860000, 1200000 ]      471   0.001%  99.999%
( 1200000, 1900000 ]      275   0.000% 100.000%
( 1900000, 2900000 ]      143   0.000% 100.000%
( 2900000, 4300000 ]       60   0.000% 100.000%
( 4300000, 6500000 ]       27   0.000% 100.000%
( 6500000, 9800000 ]        7   0.000% 100.000%
( 9800000, 14000000 ]        1   0.000% 100.000%

Gather stats latency (us):
Count: 46 Average: 980387.5870  StdDev: 60911.18
Min: 879155  Median: 1033777.7778  Max: 1261431
Percentiles: P50: 1033777.78 P75: 1120666.67 P99: 1261431.00 P99.9: 1261431.00 P99.99: 1261431.00
------------------------------------------------------
(  860000, 1200000 ]       45  97.826%  97.826% ####################
( 1200000, 1900000 ]        1   2.174% 100.000%

Most recent cache entry stats:
Number of entries: 1295133
Total charge: 9.88 GB
Average key size: 23.4982
Average charge: 8.00 KB
Unique deleters: 3
```

Reviewed By: mrambacher

Differential Revision: D28295742

Pulled By: pdillinger

fbshipit-source-id: bbc4a552f91ba0fe10e5cc025c42cef5a81f2b95
2021-05-11 16:17:10 -07:00
mrambacher 4a09d632c4 Remove Legacy and Custom FileWrapper classes from header files (#7851)
Summary:
Removed the uses of the Legacy FileWrapper classes from the source code.  The wrappers were creating an additional layer of indirection/wrapping, as the Env already has a FileSystem.

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

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

Reviewed By: anand1976

Differential Revision: D26114816

Pulled By: mrambacher

fbshipit-source-id: db32840e58d969d3a0fa6c25aaf13d6dcdc74150
2021-01-28 22:10:32 -08:00
mrambacher 7d472accdc Bring the Configurable options together (#5753)
Summary:
This PR merges the functionality of making the ColumnFamilyOptions, TableFactory, and DBOptions into Configurable into a single PR, resolving any merge conflicts

Pull Request resolved: https://github.com/facebook/rocksdb/pull/5753

Reviewed By: ajkr

Differential Revision: D23385030

Pulled By: zhichao-cao

fbshipit-source-id: 8b977a7731556230b9b8c5a081b98e49ee4f160a
2020-09-14 17:01:01 -07:00
mrambacher b7e1c5213f Add some simulator cache and block tracer tests to ASSERT_STATUS_CHECKED (#7305)
Summary:
More tests now pass.  When in doubt, I added a TODO comment to check what should happen with an ignored error.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7305

Reviewed By: akankshamahajan15

Differential Revision: D23301262

Pulled By: ajkr

fbshipit-source-id: 5f120edc7393560aefc0633250277bbc7e8de9e6
2020-08-24 16:43:31 -07:00
sdong b194c21bba Whole DBTest to skip fsync (#7274)
Summary:
After https://github.com/facebook/rocksdb/pull/7036, we still see extra DBTest that can timeout when running 10 or 20 in parallel. Expand skip-fsync mode in whole DBTest. Still preserve other tests from doing this mode to be conservative.

This commit reinstates https://github.com/facebook/rocksdb/issues/7049, whose un-revert was lost in an automatic
infrastructure mis-merge.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7274

Test Plan: Run all existing files.

Reviewed By: pdillinger

Differential Revision: D23177444

fbshipit-source-id: 1f61690b2ac6333c3b2c87176fef6b2cba086b33
2020-08-17 18:42:25 -07:00
Peter Dillinger 52d59e0c93 Revert "Whole DBTest to skip fsync (#7049)" (#7070)
Summary:
This reverts commit 4f1534bdb0.

This commit caused failures and deadlocks in
MultiThreadedDBTest.MultiThreaded/69 and others.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7070

Reviewed By: riversand963

Differential Revision: D22358778

Pulled By: pdillinger

fbshipit-source-id: faf8f2cb469a7063a113921c8e9c64a9f7610dac
2020-07-02 10:22:43 -07:00
sdong 4f1534bdb0 Whole DBTest to skip fsync (#7049)
Summary:
After https://github.com/facebook/rocksdb/pull/7036, we still see extra DBTest that can timeout when running 10 or 20 in parallel. Expand skip-fsync mode in whole DBTest. Still preserve other tests from doing this mode to be conservative.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7049

Test Plan: Run all existing files.

Reviewed By: pdillinger

Differential Revision: D22301700

fbshipit-source-id: f9a9e3b3b26ce640665a47cb8bff33ba0c89b565
2020-07-01 19:37:56 -07:00
Peter Dillinger 45d2b4efca Fix tabs and lint-ignores (#6734)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6734

Reviewed By: cheng-chang

Differential Revision: D21134556

Pulled By: pdillinger

fbshipit-source-id: 3636cc1d1333137b70031f8277458781c21631fb
2020-04-20 11:39:31 -07:00
Levi Tamasi e6f86cfb36 Revert the recent cache deleter change (#6620)
Summary:
Revert "Use function objects as deleters in the block cache (https://github.com/facebook/rocksdb/issues/6545)"

    This reverts commit 6301dbe7a7.

    Revert "Call out the cache deleter related interface change in HISTORY.md (https://github.com/facebook/rocksdb/issues/6606)"

    This reverts commit 3a35542f86.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6620

Test Plan: `make check`

Reviewed By: zhichao-cao

Differential Revision: D20773311

Pulled By: ltamasi

fbshipit-source-id: 7637a761f718f323ef0e7da959462e8fb06e7a2b
2020-03-31 16:11:06 -07:00
Levi Tamasi 6301dbe7a7 Use function objects as deleters in the block cache (#6545)
Summary:
As the first step of reintroducing eviction statistics for the block
cache, the patch switches from using simple function pointers as deleters
to function objects implementing an interface. This will enable using
deleters that have state, like a smart pointer to the statistics object
that is to be updated when an entry is removed from the cache. For now,
the patch adds a deleter template class `SimpleDeleter`, which simply
casts the `value` pointer to its original type and calls `delete` or
`delete[]` on it as appropriate. Note: to prevent object lifecycle
issues, deleters must outlive the cache entries referring to them;
`SimpleDeleter` ensures this by using the ("leaky") Meyers singleton
pattern.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6545

Test Plan: `make asan_check`

Reviewed By: siying

Differential Revision: D20475823

Pulled By: ltamasi

fbshipit-source-id: fe354c33dd96d9bafc094605462352305449a22a
2020-03-26 16:19:58 -07:00
sdong fdf882ded2 Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433

Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.

Differential Revision: D19977691

fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
2020-02-20 12:09:57 -08:00
anand76 afa2420c2b Introduce a new storage specific Env API (#5761)
Summary:
The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc.

This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO.

The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before.

This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection.

The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761

Differential Revision: D18868376

Pulled By: anand1976

fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
2019-12-13 14:48:41 -08:00
sdong e8263dbdaa Apply formatter to recent 200+ commits. (#5830)
Summary:
Further apply formatter to more recent commits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830

Test Plan: Run all existing tests.

Differential Revision: D17488031

fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab
2019-09-20 12:04:26 -07:00
Maysam Yabandeh 638d239507 Charge block cache for cache internal usage (#5797)
Summary:
For our default block cache, each additional entry has extra memory overhead. It include LRUHandle (72 bytes currently) and the cache key (two varint64, file id and offset). The usage is not negligible. For example for block_size=4k, the overhead accounts for an extra 2% memory usage for the cache. The patch charging the cache for the extra usage, reducing untracked memory usage outside block cache. The feature is enabled by default and can be disabled by passing kDontChargeCacheMetadata to the cache constructor.
This PR builds up on https://github.com/facebook/rocksdb/issues/4258
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5797

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

Differential Revision: D17396833

Pulled By: maysamyabandeh

fbshipit-source-id: 7684ccb9f8a40ca595e4f5efcdb03623afea0c6f
2019-09-16 15:26:21 -07:00
sdong b931f84e56 Divide file_reader_writer.h and .cc (#5803)
Summary:
file_reader_writer.h and .cc contain several files and helper function, and it's hard to navigate. Separate it to multiple files and put them under file/
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5803

Test Plan: Build whole project using make and cmake.

Differential Revision: D17374550

fbshipit-source-id: 10efca907721e7a78ed25bbf74dc5410dea05987
2019-09-16 10:33:51 -07:00
haoyuhuang 6e78fe3c8d Pysim more algorithms (#5644)
Summary:
This PR adds four more eviction policies.
- OPT [1]
- Hyperbolic caching [2]
- ARC [3]
- GreedyDualSize [4]

[1] L. A. Belady. 1966. A Study of Replacement Algorithms for a Virtual-storage Computer. IBM Syst. J. 5, 2 (June 1966), 78-101. DOI=http://dx.doi.org/10.1147/sj.52.0078
[2] Aaron Blankstein, Siddhartha Sen, and Michael J. Freedman. 2017. Hyperbolic caching: flexible caching for web applications. In Proceedings of the 2017 USENIX Conference on Usenix Annual Technical Conference (USENIX ATC '17). USENIX Association, Berkeley, CA, USA, 499-511.
[3] Nimrod Megiddo and Dharmendra S. Modha. 2003. ARC: A Self-Tuning, Low Overhead Replacement Cache. In Proceedings of the 2nd USENIX Conference on File and Storage Technologies (FAST '03). USENIX Association, Berkeley, CA, USA, 115-130.
[4] N. Young. The k-server dual and loose competitiveness for paging. Algorithmica, June 1994, vol. 11,(no.6):525-41. Rewritten version of ''On-line caching as cache size varies'', in The 2nd Annual ACM-SIAM Symposium on Discrete Algorithms, 241-250, 1991.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5644

Differential Revision: D16548817

Pulled By: HaoyuHuang

fbshipit-source-id: 838f76db9179f07911abaab46c97e1c929cfcd63
2019-08-06 18:50:59 -07:00
haoyuhuang e648c1d9eb Cache simulator: Optimize hybrid row-block cache. (#5616)
Summary:
This PR optimizes the hybrid row-block cache simulator. If a Get request hits the cache, we treat all its future accesses as hits.

Consider a Get request (no snapshot) accesses multiple files, e.g, file1, file2, file3. We construct the row key as "fdnumber_key_0". Before this PR, if it hits the cache when searching the key in file1, we continue to process its accesses in file2 and file3 which is unnecessary.

With this PR, if "file1_key_0" is in the cache, we treat all future accesses of this Get request as hits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5616

Differential Revision: D16453187

Pulled By: HaoyuHuang

fbshipit-source-id: 56f3169cc322322305baaf5543226a0824fae19f
2019-07-29 10:58:15 -07:00
haoyuhuang 3778470061 Block cache analyzer: Compute correlation of features and human readable trace file. (#5596)
Summary:
- Compute correlation between a few features and predictions, e.g., number of accesses since the last access vs number of accesses till the next access on a block.
- Output human readable trace file so python can consume it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5596

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

Differential Revision: D16373200

Pulled By: HaoyuHuang

fbshipit-source-id: c848d26bc2e9210461f317d7dbee42d55be5a0cc
2019-07-22 17:51:34 -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
haoyuhuang 1a59b6e2a9 Cache simulator: Add a ghost cache for admission control and a hybrid row-block cache. (#5534)
Summary:
This PR adds a ghost cache for admission control. Specifically, it admits an entry on its second access.
It also adds a hybrid row-block cache that caches the referenced key-value pairs of a Get/MultiGet request instead of its blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5534

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

Differential Revision: D16101124

Pulled By: HaoyuHuang

fbshipit-source-id: b99edda6418a888e94eb40f71ece45d375e234b1
2019-07-11 12:43:29 -07:00
haoyuhuang 6ca3feed5c Fix -Werror=shadow (#5546)
Summary:
This PR fixes shadow errors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5546

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

Differential Revision: D16147841

Pulled By: HaoyuHuang

fbshipit-source-id: 1043500d70c134185f537ab4c3900452752f1534
2019-07-08 00:12:43 -07:00
haoyuhuang 66464d1fde Remove multiple declarations o kMicrosInSecond.
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5526

Test Plan:
OPT=-g V=1 make J=1 unity_test -j32
make clean && make -j32

Differential Revision: D16079315

Pulled By: HaoyuHuang

fbshipit-source-id: 294ab439cf0db8dd5da44e30eabf0cbb2bb8c4f6
2019-07-01 15:15:12 -07:00
haoyuhuang 9f0bd56889 Cache simulator: Refactor the cache simulator so that we can add alternative policies easily (#5517)
Summary:
This PR creates cache_simulator.h file. It contains a CacheSimulator that runs against a block cache trace record. We can add alternative cache simulators derived from CacheSimulator later. For example, this PR adds a PrioritizedCacheSimulator that inserts filter/index/uncompressed dictionary blocks with high priority.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5517

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

Differential Revision: D16043689

Pulled By: HaoyuHuang

fbshipit-source-id: 65f28ed52b866ffb0e6eceffd7f9ca7c45bb680d
2019-07-01 12:46:32 -07:00
Vaibhav Gogte f46a2a0375 Export Cache::GetCharge (#5476)
Summary:
Exporting GetCharge to cache.hh
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5476

Differential Revision: D15881882

Pulled By: riversand963

fbshipit-source-id: 3d99084d10059b4fcaaaba240606ed50bc23351c
2019-06-18 17:35:41 -07:00
haoyuhuang 2d1dd5bce7 Support computing miss ratio curves using sim_cache. (#5449)
Summary:
This PR adds a BlockCacheTraceSimulator that reports the miss ratios given different cache configurations. A cache configuration contains "cache_name,num_shard_bits,cache_capacities". For example, "lru, 1, 1K, 2K, 4M, 4G".

When we replay the trace, we also perform lookups and inserts on the simulated caches.
In the end, it reports the miss ratio for each tuple <cache_name, num_shard_bits, cache_capacity> in a output file.

This PR also adds a main source block_cache_trace_analyzer so that we can run the analyzer in command line.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5449

Test Plan:
Added tests for block_cache_trace_analyzer.
COMPILE_WITH_ASAN=1 make check -j32.

Differential Revision: D15797073

Pulled By: HaoyuHuang

fbshipit-source-id: aef0c5c2e7938f3e8b6a10d4a6a50e6928ecf408
2019-06-17 16:41:12 -07:00
Michael Liu ca89ac2ba9 Apply modernize-use-override (2nd iteration)
Summary:
Use C++11’s override and remove virtual where applicable.
Change are automatically generated.

Reviewed By: Orvid

Differential Revision: D14090024

fbshipit-source-id: 1e9432e87d2657e1ff0028e15370a85d1739ba2a
2019-02-14 14:41:36 -08:00
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
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
David Lai 3be9b36453 comment unused parameters to turn on -Wunused-parameter flag
Summary:
This PR comments out the rest of the unused arguments which allow us to turn on the -Wunused-parameter flag. This is the second part of a codemod relating to https://github.com/facebook/rocksdb/pull/3557.
Closes https://github.com/facebook/rocksdb/pull/3662

Differential Revision: D7426121

Pulled By: Dayvedde

fbshipit-source-id: 223994923b42bd4953eb016a0129e47560f7e352
2018-04-12 17:59:16 -07:00
Andrew Kryczka 5d68243e61 Comment out unused variables
Summary:
Submitting on behalf of another employee.
Closes https://github.com/facebook/rocksdb/pull/3557

Differential Revision: D7146025

Pulled By: ajkr

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

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

Differential Revision: D7046710

fbshipit-source-id: 8e10b1f1e2aecebbfb229c742e214db887e5a461
2018-02-22 09:44:23 -08:00