Summary:
util/ means for lower level libraries, so it's a good idea to move the files which requires knowledge to DB out. Create a file/ and move some files there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5375
Differential Revision: D15550935
Pulled By: siying
fbshipit-source-id: 61a9715dcde5386eebfb43e93f847bba1ae0d3f2
Summary:
This PR introduces a new MultiGet() API, with the underlying implementation grouping keys based on SST file and batching lookups in a file. The reason for the new API is twofold - the definition allows callers to allocate storage for status and values on stack instead of std::vector, as well as return values as PinnableSlices in order to avoid copying, and it keeps the original MultiGet() implementation intact while we experiment with batching.
Batching is useful when there is some spatial locality to the keys being queries, as well as larger batch sizes. The main benefits are due to -
1. Fewer function calls, especially to BlockBasedTableReader::MultiGet() and FullFilterBlockReader::KeysMayMatch()
2. Bloom filter cachelines can be prefetched, hiding the cache miss latency
The next step is to optimize the binary searches in the level_storage_info, index blocks and data blocks, since we could reduce the number of key comparisons if the keys are relatively close to each other. The batching optimizations also need to be extended to other formats, such as PlainTable and filter formats. This also needs to be added to db_stress.
Benchmark results from db_bench for various batch size/locality of reference combinations are given below. Locality was simulated by offsetting the keys in a batch by a stride length. Each SST file is about 8.6MB uncompressed and key/value size is 16/100 uncompressed. To focus on the cpu benefit of batching, the runs were single threaded and bound to the same cpu to eliminate interference from other system events. The results show a 10-25% improvement in micros/op from smaller to larger batch sizes (4 - 32).
Batch Sizes
1 | 2 | 4 | 8 | 16 | 32
Random pattern (Stride length 0)
4.158 | 4.109 | 4.026 | 4.05 | 4.1 | 4.074 - Get
4.438 | 4.302 | 4.165 | 4.122 | 4.096 | 4.075 - MultiGet (no batching)
4.461 | 4.256 | 4.277 | 4.11 | 4.182 | 4.14 - MultiGet (w/ batching)
Good locality (Stride length 16)
4.048 | 3.659 | 3.248 | 2.99 | 2.84 | 2.753
4.429 | 3.728 | 3.406 | 3.053 | 2.911 | 2.781
4.452 | 3.45 | 2.833 | 2.451 | 2.233 | 2.135
Good locality (Stride length 256)
4.066 | 3.786 | 3.581 | 3.447 | 3.415 | 3.232
4.406 | 4.005 | 3.644 | 3.49 | 3.381 | 3.268
4.393 | 3.649 | 3.186 | 2.882 | 2.676 | 2.62
Medium locality (Stride length 4096)
4.012 | 3.922 | 3.768 | 3.61 | 3.582 | 3.555
4.364 | 4.057 | 3.791 | 3.65 | 3.57 | 3.465
4.479 | 3.758 | 3.316 | 3.077 | 2.959 | 2.891
dbbench command used (on a DB with 4 levels, 12 million keys)-
TEST_TMPDIR=/dev/shm numactl -C 10 ./db_bench.tmp -use_existing_db=true -benchmarks="readseq,multireadrandom" -write_buffer_size=4194304 -target_file_size_base=4194304 -max_bytes_for_level_base=16777216 -num=12000000 -reads=12000000 -duration=90 -threads=1 -compression_type=none -cache_size=4194304000 -batch_size=32 -disable_auto_compactions=true -bloom_bits=10 -cache_index_and_filter_blocks=true -pin_l0_filter_and_index_blocks_in_cache=true -multiread_batched=true -multiread_stride=4
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5011
Differential Revision: D14348703
Pulled By: anand1976
fbshipit-source-id: 774406dab3776d979c809522a67bedac6c17f84b
Summary:
Annotate all of the logging functions to inform the compiler that these
use printf-style formatting arguments. This allows the compiler to emit
warnings if the format arguments are incorrect.
This also fixes many problems reported now that format string checking
is enabled. Many of these are simply mix-ups in the argument type (e.g,
int vs uint64_t), but in several cases the wrong number of arguments
were being passed in which can cause the code to crash.
The primary motivation for this was to fix the log message in
`DBImpl::SwitchMemtable()` which caused a segfault due to an extra %s
format parameter with no argument supplied.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5089
Differential Revision: D14574795
Pulled By: simpkins
fbshipit-source-id: 0921b03f0743652bf4ae21e414ff54b3bb65422a
Summary:
WAL files are currently not subject to deletion rate limiting by DeleteScheduler. If the size of the WAL files is significant, this can cause a high delete rate on SSDs that may affect other operations. To fix it, force WAL file deletions to go through the SstFileManager. Original PR for this is #2768
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5116
Differential Revision: D14669437
Pulled By: anand1976
fbshipit-source-id: c5f62d0640cebaa1574de841a1d01e4ce2faadf0
Summary:
The code convention we are following, Google C++ Style, discourage
alias in header files, especially public headers:
https://google.github.io/styleguide/cppguide.html#Aliases
Remove some of them. Might removed some from .cc files as well to be consistent.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5113
Differential Revision: D14633030
Pulled By: siying
fbshipit-source-id: b990edc919d5de60295992284f980195e501d424
Summary:
Right now, BlobDB::Open() fails to put all trash files to delete scheduler,
which causes some trash files permanently untracked.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5103
Differential Revision: D14606095
Pulled By: siying
fbshipit-source-id: 41a9437a2948abb235c0ed85f9a04612d0e50183
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
Summary:
Initialize magic_number to zero to avoid such failure.
utilities/blob_db/blob_log_format.cc:91:3: error: 'magic_number' may be used
uninitialized in this function [-Werror=maybe-uninitialized]
if (magic_number != kMagicNumber) {
^~
Signed-off-by: He Zhe <zhe.he@windriver.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5074
Differential Revision: D14505514
Pulled By: miasantreble
fbshipit-source-id: 4334462958c2b9c5a7c68c6ab24dadf94ad70902
Summary:
Statistics cost too much CPU for some use cases. Add two stats levels
so that people can choose to skip two types of expensive stats, timers and
histograms.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5027
Differential Revision: D14252765
Pulled By: siying
fbshipit-source-id: 75ecec9eaa44c06118229df4f80c366115346592
Summary:
When closing a BlobDB, it only waits for background tasks
to finish as the last thing, but the background task may access
some variables that are destroyed. The fix is to introduce a
shutdown function in the timer queue and call the function as
the first thing when destorying BlobDB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5005
Differential Revision: D14170342
Pulled By: siying
fbshipit-source-id: 081e6a2d99b9765d5956cf6cdfc290c07270c233
Summary:
Blob DB files are not tracked by the SFM, so they currently don't get
deleted in the background. Force them to be deleted in background so
rate limiting can be applied
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4928
Differential Revision: D13854649
Pulled By: anand1976
fbshipit-source-id: 8031ce66842ff0af440c715d886b377983dad7d8
Summary:
Right now, deleting blob files is not rate limited, even if SstFileManger is specified.
On the other hand, rate limiting blob deletion is not supported. With this change, Blob file
deletion will go through SstFileManager too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4904
Differential Revision: D13772545
Pulled By: siying
fbshipit-source-id: bd1b1d0beb26d5167385e00b7ecb8b94b879de84
Summary:
Remove unused blob WAL filter so that users are not confused.
I was initially under the impression that we have WAL Filter support in BlobDB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4896
Differential Revision: D13725709
Pulled By: sagar0
fbshipit-source-id: f997d7546e138a474036e88b957907cc714327f1
Summary:
This is essentially a re-submission of #4251 with a few improvements:
- Split `CompressionDict` into two separate classes: `CompressionDict` and `UncompressionDict`
- Eliminated `Init` functions. Instead do all initialization work in constructors.
- Added test case for parallel DB open, which is the scenario where #4251 failed under TSAN.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4849
Differential Revision: D13606039
Pulled By: ajkr
fbshipit-source-id: 08c236059798c710db9cbf545fce0f371232d447
Summary:
Remove `garbage_collection_deletion_size_threshold` as it is not used anywhere.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4888
Differential Revision: D13685982
Pulled By: sagar0
fbshipit-source-id: e08d3017b9a0c8fa99bc332b595ee4ed9db70c87
Summary:
- Corrected a comment asserting that the values "smaller" than a min_blob_size will be inlined in the base db.
- Also fixed the type of ttl_range_secs while dumping blobdb options.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4887
Differential Revision: D13680163
Pulled By: sagar0
fbshipit-source-id: 306c8cf2daa52210ffc334a6924ef44ffdedf887
Summary:
As pointed out in #4059, we miss use string as buffer for file read. Changing to use char array instead.
Closing #4059
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4662
Differential Revision: D13012998
Pulled By: yiwu-arbug
fbshipit-source-id: 41234ba17c0bccea65bd647e362a0e979152bd1e
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
Summary:
Ensure delete[] and not delete is called on buffer_, as it is reset with new char[buffer_size_].
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4647
Differential Revision: D12961327
Pulled By: ajkr
fbshipit-source-id: c1af373b98359edfdc291caebe4e0acdfb8afdd8
Summary:
A fix similar to #4410 but on the write path. On IO error on `SelectBlobFile()` we didn't return error code properly, but simply a nullptr of `BlobFile`. The `AppendBlob()` method didn't have null check for the pointer and caused crash. The fix make sure we properly return error code in this case.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4580
Differential Revision: D10513849
Pulled By: yiwu-arbug
fbshipit-source-id: 80bca920d1d7a3541149de981015ad83e0aa14b5
Summary:
- Fix DBImpl API race condition
The timeline of execution flow is as follow:
```
timeline user_thread1 user_thread2
t1 | cfh = GetColumnFamilyHandleUnlocked(0)
t2 | id1 = cfh->GetID()
t3 | GetColumnFamilyHandleUnlocked(1)
t4 | id2 = cfh->GetID()
V
```
The original implementation return a pointer to a stateful variable, so that the return `ColumnFamilyHandle` will be changed when another thread calls `GetColumnFamilyHandleUnlocked` with different `column family id`
- Expose ColumnFamily ID to compaction event listener
- Fix the return status of `DBImpl::GetLatestSequenceForKey`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4391
Differential Revision: D10221243
Pulled By: yiwu-arbug
fbshipit-source-id: dec60ee9ff0c8261a2f2413a8506ec1063991993
Summary:
Fix IO error on read not being handle and crashing the DB. With the fix we properly return the error.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4410
Differential Revision: D9979246
Pulled By: yiwu-arbug
fbshipit-source-id: 111a85675067a29c03cb60e9a34103f4ff636694
Summary:
Reverting is needed to unblock a user building against master, who is blocked for multiple days due to a thread-safety issue in `GetEmptyDict`. We haven't been able to fix it quickly, so reverting.
Simply ran `git revert 6c40806e51a89386d2b066fddf73d3fd03a36f65`. There were no merge conflicts.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4347
Differential Revision: D9668365
Pulled By: ajkr
fbshipit-source-id: 0c56334f0a23cf5ee0233d4e4679eae6709739cd
Summary:
As you know, almost all compilers support "pragma once" keyword instead of using include guards. To be keep consistency between header files, all header files are edited.
Besides this, try to fix some warnings about loss of data.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4339
Differential Revision: D9654990
Pulled By: ajkr
fbshipit-source-id: c2cf3d2d03a599847684bed81378c401920ca848
Summary:
`GetLiveFiles` and `GetLiveFilesMetadata` should return path relative to db path.
It is a separate issue when `path_relative` is false how can we return relative path. But `DBImpl::GetLiveFiles` don't handle it as well when there are multiple `db_paths`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4326
Differential Revision: D9545904
Pulled By: yiwu-arbug
fbshipit-source-id: 6762d879fcb561df2b612e6fdfb4a6b51db03f5d
Summary:
When reading an expired key using `Get(..., std::string* value)` API, BlobDB first read the index entry and decode expiration from it. In this case, although BlobDB reset the PinnableSlice, the index entry is stored in user provided string `value`. The value will be returned as a garbage value, despite status being NotFound. Fixing it by use a different PinnableSlice to read the index entry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4321
Differential Revision: D9519042
Pulled By: yiwu-arbug
fbshipit-source-id: f054c951a1fa98265228be94f931904ed7056677
Summary:
`DB::DiableFileDeletions` and `DB::EnableFileDeletions` are used for applications to stop RocksDB background jobs to delete files while they are doing replication. Implement these methods for BlobDB. `DeleteObsolteFiles` now needs to check `disable_file_deletions_` before starting, and will hold `delete_file_mutex_` the whole time while it is running. `DisableFileDeletions` needs to wait on `delete_file_mutex_` for running `DeleteObsolteFiles` job and set `disable_file_deletions_` flag.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4314
Differential Revision: D9501373
Pulled By: yiwu-arbug
fbshipit-source-id: 81064c1228f1724eff46da22b50ff765b16292cd
Summary:
In RocksDB, for a given SST file, all data blocks are compressed with the same dictionary. When we compress a block using the dictionary's raw bytes, the compression library first has to digest the dictionary to get it into a usable form. This digestion work is redundant and ideally should be done once per file.
ZSTD offers APIs for the caller to create and reuse a digested dictionary object (`ZSTD_CDict`). In this PR, we call `ZSTD_createCDict` once per file to digest the raw bytes. Then we use `ZSTD_compress_usingCDict` to compress each data block using the pre-digested dictionary. Once the file's created `ZSTD_freeCDict` releases the resources held by the digested dictionary.
There are a couple other changes included in this PR:
- Changed the parameter object for (un)compression functions from `CompressionContext`/`UncompressionContext` to `CompressionInfo`/`UncompressionInfo`. This avoids the previous pattern, where `CompressionContext`/`UncompressionContext` had to be mutated before calling a (un)compression function depending on whether dictionary should be used. I felt that mutation was error-prone so eliminated it.
- Added support for digested uncompression dictionaries (`ZSTD_DDict`) as well. However, this PR does not support reusing them across uncompression calls for the same file. That work is deferred to a later PR when we will store the `ZSTD_DDict` objects in block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4251
Differential Revision: D9257078
Pulled By: ajkr
fbshipit-source-id: 21b8cb6bbdd48e459f1c62343780ab66c0a64438
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
Summary:
Fix expired file not being evicted from the DB. We have a background task (previously called `CheckSeqFiles` and I rename it to `EvictExpiredFiles`) to scan and remove expired files, but it only close the files, not marking them as expired.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4294
Differential Revision: D9415984
Pulled By: yiwu-arbug
fbshipit-source-id: eff7bf0331c52a7ccdb02318602bff7f64f3ef3d
Summary:
Right now, `ldb idump` may have memory out of control if there is a big range of tombstones. Add an option to cut maxinum number of keys in GetAllKeyVersions(), and push down --max_num_ikeys from ldb.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4271
Differential Revision: D9369149
Pulled By: siying
fbshipit-source-id: 7cbb797b7d2fa16573495a7e84937456d3ff25bf
Summary:
Add API to allow fetching expiration of a key with `Get()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4227
Differential Revision: D9169897
Pulled By: yiwu-arbug
fbshipit-source-id: 2a6f216c493dc75731ddcef1daa689b517fab31b
Summary:
There are two issues with `VisibleToActiveSnapshot`:
1. If there are no snapshots, `oldest_snapshot` will be 0 and `VisibleToActiveSnapshot` will always return true. Since the method is used to decide whether it is safe to delete obsolete files, obsolete file won't be able to delete in this case.
2. The `auto` keyword of `auto snapshots = db_impl_->snapshots()` translate to a copy of `const SnapshotList` instead of a reference. Since copy constructor of `SnapshotList` is not defined, using the copy may yield unexpected result.
Issue 2 actually hide issue 1 from being catch by tests. During test `snapshots.empty()` can return false while it should actually be empty, and `snapshots.oldest()` return an invalid address, making `oldest_snapshot` being some random large number.
The issue was originally reported by BlobDB early adopter at Kuaishou.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4236
Differential Revision: D9188706
Pulled By: yiwu-arbug
fbshipit-source-id: a0f2624b927cf9bf28c1bb534784fee5d106f5ea
Summary:
Cleanup TTLExtractor interface. The original purpose of it is to allow our users keep using existing `Write()` interface but allow it to accept TTL via `TTLExtractor`. However the interface is confusing. Will replace it with something like `WriteWithTTL(batch, ttl)` in the future.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4229
Differential Revision: D9174390
Pulled By: yiwu-arbug
fbshipit-source-id: 68201703d784408b851336ab4dd9b84188245b2d
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
Summary:
Previously with is_fifo=true we only evict TTL file. Changing it to also evict non-TTL files from oldest to newest, after exhausted TTL files.
Closes https://github.com/facebook/rocksdb/pull/4049
Differential Revision: D8604597
Pulled By: yiwu-arbug
fbshipit-source-id: bc4209ee27c1528ce4b72833e6f1e1bff80082c1
Summary:
Enable readahead for blob DB garbage collection, which should improve GC performance a little bit.
Closes https://github.com/facebook/rocksdb/pull/3648
Differential Revision: D7383791
Pulled By: yiwu-arbug
fbshipit-source-id: 642b3327f7105eca85986d3fb2d8f960a3d83cf1
Summary:
We potentially need this information for tracing, profiling and diagnosis.
Closes https://github.com/facebook/rocksdb/pull/4026
Differential Revision: D8555214
Pulled By: riversand963
fbshipit-source-id: 4263e06c00b6d5410b46aa46eb4e358ff2161dd2
Summary:
PR https://github.com/facebook/rocksdb/pull/3838 made some changes that triggers lint warnings.
Run `make format` to fix formatting as suggested by siying .
Also piggyback two changes:
1) fix singleton destruction order for windows and posix env
2) fix two clang warnings
Closes https://github.com/facebook/rocksdb/pull/3954
Differential Revision: D8272041
Pulled By: miasantreble
fbshipit-source-id: 7c4fd12bd17aac13534520de0c733328aa3c6c9f
Summary:
Windows does not have LD_PRELOAD mechanism to override all memory allocation functions and ZSTD makes use of C-tuntime calloc. During flushes and compactions default system allocator fragments and the system slows down considerably.
For builds with jemalloc we employ an advanced ZSTD context creation API that re-directs memory allocation to jemalloc. To reduce the cost of context creation on each block we cache ZSTD context within the block based table builder while a new SST file is being built, this will help all platform builds including those w/o jemalloc. This avoids system allocator fragmentation and improves the performance.
The change does not address random reads and currently on Windows reads with ZSTD regress as compared with SNAPPY compression.
Closes https://github.com/facebook/rocksdb/pull/3838
Differential Revision: D8229794
Pulled By: miasantreble
fbshipit-source-id: 719b622ab7bf4109819bc44f45ec66f0dd3ee80d
Summary:
Before this PR, Iterator/InternalIterator may simultaneously have non-ok status() and Valid() = true. That state means that the last operation failed, but the iterator is nevertheless positioned on some unspecified record. Likely intended uses of that are:
* If some sst files are corrupted, a normal iterator can be used to read the data from files that are not corrupted.
* When using read_tier = kBlockCacheTier, read the data that's in block cache, skipping over the data that is not.
However, this behavior wasn't documented well (and until recently the wiki on github had misleading incorrect information). In the code there's a lot of confusion about the relationship between status() and Valid(), and about whether Seek()/SeekToLast()/etc reset the status or not. There were a number of bugs caused by this confusion, both inside rocksdb and in the code that uses rocksdb (including ours).
This PR changes the convention to:
* If status() is not ok, Valid() always returns false.
* Any seek operation resets status. (Before the PR, it depended on iterator type and on particular error.)
This does sacrifice the two use cases listed above, but siying said it's ok.
Overview of the changes:
* A commit that adds missing status checks in MergingIterator. This fixes a bug that actually affects us, and we need it fixed. `DBIteratorTest.NonBlockingIterationBugRepro` explains the scenario.
* Changes to lots of iterator types to make all of them conform to the new convention. Some bug fixes along the way. By far the biggest changes are in DBIter, which is a big messy piece of code; I tried to make it less big and messy but mostly failed.
* A stress-test for DBIter, to gain some confidence that I didn't break it. It does a few million random operations on the iterator, while occasionally modifying the underlying data (like ForwardIterator does) and occasionally returning non-ok status from internal iterator.
To find the iterator types that needed changes I searched for "public .*Iterator" in the code. Here's an overview of all 27 iterator types:
Iterators that didn't need changes:
* status() is always ok(), or Valid() is always false: MemTableIterator, ModelIter, TestIterator, KVIter (2 classes with this name anonymous namespaces), LoggingForwardVectorIterator, VectorIterator, MockTableIterator, EmptyIterator, EmptyInternalIterator.
* Thin wrappers that always pass through Valid() and status(): ArenaWrappedDBIter, TtlIterator, InternalIteratorFromIterator.
Iterators with changes (see inline comments for details):
* DBIter - an overhaul:
- It used to silently skip corrupted keys (`FindParseableKey()`), which seems dangerous. This PR makes it just stop immediately after encountering a corrupted key, just like it would for other kinds of corruption. Let me know if there was actually some deeper meaning in this behavior and I should put it back.
- It had a few code paths silently discarding subiterator's status. The stress test caught a few.
- The backwards iteration code path was expecting the internal iterator's set of keys to be immutable. It's probably always true in practice at the moment, since ForwardIterator doesn't support backwards iteration, but this PR fixes it anyway. See added DBIteratorTest.ReverseToForwardBug for an example.
- Some parts of backwards iteration code path even did things like `assert(iter_->Valid())` after a seek, which is never a safe assumption.
- It used to not reset status on seek for some types of errors.
- Some simplifications and better comments.
- Some things got more complicated from the added error handling. I'm open to ideas for how to make it nicer.
* MergingIterator - check status after every operation on every subiterator, and in some places assert that valid subiterators have ok status.
* ForwardIterator - changed to the new convention, also slightly simplified.
* ForwardLevelIterator - fixed some bugs and simplified.
* LevelIterator - simplified.
* TwoLevelIterator - changed to the new convention. Also fixed a bug that would make SeekForPrev() sometimes silently ignore errors from first_level_iter_.
* BlockBasedTableIterator - minor changes.
* BlockIter - replaced `SetStatus()` with `Invalidate()` to make sure non-ok BlockIter is always invalid.
* PlainTableIterator - some seeks used to not reset status.
* CuckooTableIterator - tiny code cleanup.
* ManagedIterator - fixed some bugs.
* BaseDeltaIterator - changed to the new convention and fixed a bug.
* BlobDBIterator - seeks used to not reset status.
* KeyConvertingIterator - some small change.
Closes https://github.com/facebook/rocksdb/pull/3810
Differential Revision: D7888019
Pulled By: al13n321
fbshipit-source-id: 4aaf6d3421c545d16722a815b2fa2e7912bc851d
Summary:
this PR fixes a few failed contbuild:
1. ASAN memory leak in Block::NewIterator (table/block.cc:429). the proper destruction of first_level_iter_ and second_level_iter_ of two_level_iterator.cc is missing from the code after the refactoring in https://github.com/facebook/rocksdb/pull/3406
2. various unused param errors introduced by https://github.com/facebook/rocksdb/pull/3662
3. updated comment for `ForceReleaseCachedEntry` to emphasize the use of `force_erase` flag.
Closes https://github.com/facebook/rocksdb/pull/3718
Reviewed By: maysamyabandeh
Differential Revision: D7621192
Pulled By: miasantreble
fbshipit-source-id: 476c94264083a0730ded957c29de7807e4f5b146
Summary:
Make blob_dump tool able to show uncompressed values if the blob file is compressed. Also show total compressed vs. raw size at the end if --show_summary is provided.
Closes https://github.com/facebook/rocksdb/pull/3633
Differential Revision: D7348926
Pulled By: yiwu-arbug
fbshipit-source-id: ca709cb4ed5cf6a550ff2987df8033df81516f8e
Summary:
* Fix BlobDBImpl::GCFileAndUpdateLSM doesn't close the new file, and the new file will not be able to be garbage collected later.
* Fix BlobDBImpl::GCFileAndUpdateLSM doesn't copy over metadata from old file to new file.
Closes https://github.com/facebook/rocksdb/pull/3639
Differential Revision: D7355092
Pulled By: yiwu-arbug
fbshipit-source-id: 4fa3594ac5ce376bed1af04a545c532cfc0088c4
Summary:
Improving blob db FIFO eviction with the following changes,
* Change blob_dir_size to max_db_size. Take into account SST file size when computing DB size.
* FIFO now only take into account live sst files and live blob files. It is normal for disk usage to go over max_db_size because there are obsolete sst files and blob files pending deletion.
* FIFO eviction now also evict TTL blob files that's still open. It doesn't evict non-TTL blob files.
* If FIFO is triggered, it will pass an expiration and the current sequence number to compaction filter. Compaction filter will then filter inlined keys to evict those with an earlier expiration and smaller sequence number. So call LSM FIFO.
* Compaction filter also filter those blob indexes where corresponding blob file is gone.
* Add an event listener to listen compaction/flush event and update sst file size.
* Implement DB::Close() to make sure base db, as well as event listener and compaction filter, destruct before blob db.
* More blob db statistics around FIFO.
* Fix some locking issue when accessing a blob file.
Closes https://github.com/facebook/rocksdb/pull/3556
Differential Revision: D7139328
Pulled By: yiwu-arbug
fbshipit-source-id: ea5edb07b33dfceacb2682f4789bea61de28bbfa
Summary:
Red diff to remove existing implementation of garbage collection. The current approach is reference counting kind of approach and require a lot of effort to get the size counter right on compaction and deletion. I'm going to go with a simple mark-sweep kind of approach and will send another PR for that.
CompactionEventListener was added solely for blob db and it adds complexity and overhead to compaction iterator. Removing it as well.
Closes https://github.com/facebook/rocksdb/pull/3551
Differential Revision: D7130190
Pulled By: yiwu-arbug
fbshipit-source-id: c3a375ad2639a3f6ed179df6eda602372cc5b8df
Summary:
When blob_files is empty, std::min_element will return blobfiles.end(), which cannot be dereference. Fixing it.
Closes https://github.com/facebook/rocksdb/pull/3387
Differential Revision: D6764927
Pulled By: yiwu-arbug
fbshipit-source-id: 86f78700132be95760d35ac63480dfd3a8bbe17a
Summary:
Previously on a blob db read, we are making a read of the blob value, and then make another read to get CRC checksum. I'm combining the two read into one.
readrandom db_bench with 1G database with base db size of 13M, value size 1k:
`./db_bench --db=/home/yiwu/tmp/db_bench --use_blob_db --value_size=1024 --num=1000000 --benchmarks=readrandom --use_existing_db --cache_size=32000000`
master: throughput 234MB/s, get micros p50 5.984 p95 9.998 p99 20.817 p100 787
this PR: throughput 261MB/s, get micros p50 5.157 p95 9.928 p99 20.724 p100 190
Closes https://github.com/facebook/rocksdb/pull/3301
Differential Revision: D6615950
Pulled By: yiwu-arbug
fbshipit-source-id: 052410c6d8539ec0cc305d53793bbc8f3616baa3
Summary:
We dump blob db options on blob db open, but it was removed by mistake in #3246. Adding it back.
Closes https://github.com/facebook/rocksdb/pull/3298
Differential Revision: D6607177
Pulled By: yiwu-arbug
fbshipit-source-id: 2a4aacbfa52fd8f1878dc9e1fbb95fe48faf80c0
Summary:
Previously, if blob_db_options.bytes_per_sync, there is a background job to call fsync() for every bytes_per_sync bytes written to a blob file. With the change we simply pass bytes_per_sync as env_options_ to blob files so that sync_file_range() will be used instead.
Closes https://github.com/facebook/rocksdb/pull/3297
Differential Revision: D6606994
Pulled By: yiwu-arbug
fbshipit-source-id: 452424be52e32ba92f5ea603b564e9b88929af47
Summary:
Previously we store sequence number range of each blob files, and use the sequence number range to check if the file can be possibly visible by a snapshot. But it adds complexity to the code, since the sequence number is only available after a write. (The current implementation get sequence number by calling GetLatestSequenceNumber(), which is wrong.) With the patch, we are not storing sequence number range, and check if snapshot_sequence < obsolete_sequence to decide if the file is visible by a snapshot (previously we check if first_sequence <= snapshot_sequence < obsolete_sequence).
Closes https://github.com/facebook/rocksdb/pull/3274
Differential Revision: D6571497
Pulled By: yiwu-arbug
fbshipit-source-id: ca06479dc1fcd8782f6525b62b7762cd47d61909
Summary:
Refactor BlobDB open logic. List of changes:
Major:
* On reopen, mark blob files found as immutable, do not use them for writing new keys.
* Not to scan the whole file to find file footer. Instead just seek to the end of the file and try to read footer.
Minor:
* Move most of the real logic from blob_db.cc to blob_db_impl.cc.
* Not to hold shared_ptr of event listeners in global maps in blob_db.cc
* Some changes to BlobFile interface.
* Improve logging and error handling.
Closes https://github.com/facebook/rocksdb/pull/3246
Differential Revision: D6526147
Pulled By: yiwu-arbug
fbshipit-source-id: 9dc4cdd63359a2f9b696af817086949da8d06952
Summary:
utilities/blob_db/blob_db_impl.cc
265 : bdb_options_.blob_dir;
3. uninit_member: Non-static class member env_ is not initialized in this constructor nor in any functions that it calls.
5. uninit_member: Non-static class member ttl_extractor_ is not initialized in this constructor nor in any functions that it calls.
7. uninit_member: Non-static class member open_p1_done_ is not initialized in this constructor nor in any functions that it calls.
CID 1418245 (#1 of 1): Uninitialized pointer field (UNINIT_CTOR)
9. uninit_member: Non-static class member debug_level_ is not initialized in this constructor nor in any functions that it calls.
266}
4. past_the_end: Function end creates an iterator.
CID 1418258 (#1 of 1): Using invalid iterator (INVALIDATE_ITERATOR)
5. deref_iterator: Dereferencing iterator file_nums.end() though it is already past the end of its container.
utilities/col_buf_decoder.h:
nullable_(nullable),
2. uninit_member: Non-static class member remain_runs_ is not initialized in this constructor nor in any functions that it calls.
4. uninit_member: Non-static class member run_val_ is not initialized in this constructor nor in any functions that it calls.
CID 1396134 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
6. uninit_member: Non-static class member last_val_ is not initialized in this constructor nor in any functions that it calls.
46 big_endian_(big_endian) {}
Closes https://github.com/facebook/rocksdb/pull/3134
Differential Revision: D6340607
Pulled By: sagar0
fbshipit-source-id: 25c52566e2ff979fe6c7abb0f40c27fc16597054
Summary:
Adding a list of blob db counters.
Also remove WaStats() which doesn't expose the stats and can be substitute by (BLOB_DB_BYTES_WRITTEN / BLOB_DB_BLOB_FILE_BYTES_WRITTEN).
Closes https://github.com/facebook/rocksdb/pull/3193
Differential Revision: D6394216
Pulled By: yiwu-arbug
fbshipit-source-id: 017508c8ff3fcd7ea7403c64d0f9834b24816803
Summary:
Garbage collection checks if the offset in blob index matches the offset of the blob value in the file. If it is a mismatch, the value is the current version. However it failed to check if the blob index is an inlined type, which don't even have an offset. Fixing it.
Closes https://github.com/facebook/rocksdb/pull/3194
Differential Revision: D6394270
Pulled By: yiwu-arbug
fbshipit-source-id: 7c2b9d795f1116f55f4d728086980f9b6e88ea78
Summary:
Saw some redundant log lines when trying to benchmark blob db. So, removed the lines from blob_file.cc, and let the lines in blob_db_impl.cc take the lead.
Closes https://github.com/facebook/rocksdb/pull/3189
Differential Revision: D6381726
Pulled By: sagar0
fbshipit-source-id: 5f0b1e56fe4bc3b715d89ea9b5749bd935cd0606
Summary:
The current implementation of PinnableSlice move assignment have an issue #3163. We are moving away from it instead of try to get the move assignment right, since it is too tricky.
Closes https://github.com/facebook/rocksdb/pull/3164
Differential Revision: D6319201
Pulled By: yiwu-arbug
fbshipit-source-id: 8f3279021f3710da4a4caa14fd238ed2df902c48
Summary:
Add per-exe execution capability
Add fix parsing of groups/tests
Add timer test exclusion
Fix unit tests
Ifdef threadpool specific tests that do not pass on Vista threadpool.
Remove spurious outout from prefix_test so test case listing works
properly.
Fix not using standard test directories results in file creation errors
in sst_dump_test.
BlobDb fixes:
In C++ end() iterators can not be dereferenced. They are not valid.
When deleting blob_db_ set it to nullptr before any other code executes.
Not fixed:. On Windows you can not delete a file while it is open.
[ RUN ] BlobDBTest.ReadWhileGC
d:\dev\rocksdb\rocksdb\utilities\blob_db\blob_db_test.cc(75): error: DestroyBlobDB(dbname_, options, bdb_options)
IO error: Failed to delete: d:/mnt/db\testrocksdb-17444/blob_db_test/blob_dir/000001.blob: Permission denied
d:\dev\rocksdb\rocksdb\utilities\blob_db\blob_db_test.cc(75): error: DestroyBlobDB(dbname_, options, bdb_options)
IO error: Failed to delete: d:/mnt/db\testrocksdb-17444/blob_db_test/blob_dir/000001.blob: Permission denied
write_batch
Should not call front() if there is a chance the container is empty
Closes https://github.com/facebook/rocksdb/pull/3152
Differential Revision: D6293274
Pulled By: sagar0
fbshipit-source-id: 318c3717c22087fae13b18715dffb24565dbd956
Summary:
A race condition will happen when:
* a user thread writes a value, but it hits the write stop condition because there are too many un-flushed memtables, while holding blob_db_impl.write_mutex_.
* Flush is triggered and call flush begin listener and try to acquire blob_db_impl.write_mutex_.
Fixing it.
Closes https://github.com/facebook/rocksdb/pull/3149
Differential Revision: D6279805
Pulled By: yiwu-arbug
fbshipit-source-id: 0e3c58afb78795ebe3360a2c69e05651e3908c40
Summary:
`compression` shadow the method name in `BlobFile`. Rename it.
Closes https://github.com/facebook/rocksdb/pull/3148
Differential Revision: D6274498
Pulled By: yiwu-arbug
fbshipit-source-id: 7d293596530998b23b6b8a8940f983f9b6343a98
Summary:
To fix the issue of failing to decompress existing value after reopen DB with a different compression settings.
Closes https://github.com/facebook/rocksdb/pull/3142
Differential Revision: D6267260
Pulled By: yiwu-arbug
fbshipit-source-id: c7cf7f3e33b0cd25520abf4771cdf9180cc02a5f
Summary:
After move assignment, we need to re-initialized the moved PinnableSlice.
Also update blob_db_impl.cc to not reuse the moved PinnableSlice since it is supposed to be in an undefined state after move.
Closes https://github.com/facebook/rocksdb/pull/3127
Differential Revision: D6238585
Pulled By: yiwu-arbug
fbshipit-source-id: bd99f2e37406c4f7de160c7dee6a2e8126bc224e
Summary:
Fix unreleased snapshot at the end of the test.
Closes https://github.com/facebook/rocksdb/pull/3126
Differential Revision: D6232867
Pulled By: yiwu-arbug
fbshipit-source-id: 651ca3144fc573ea2ab0ab20f0a752fb4a101d26
Summary:
After adding expiration to blob index in #3066, we are now able to add a compaction filter to cleanup expired blob index entries.
Closes https://github.com/facebook/rocksdb/pull/3090
Differential Revision: D6183812
Pulled By: yiwu-arbug
fbshipit-source-id: 9cb03267a9702975290e758c9c176a2c03530b83
Summary:
Blob db will keep blob file if data in the file is visible to an active snapshot. Before this patch it checks whether there is an active snapshot has sequence number greater than the earliest sequence in the file. This is problematic since we take snapshot on every read, if it keep having reads, old blob files will not be cleanup. Change to check if there is an active snapshot falls in the range of [earliest_sequence, obsolete_sequence) where obsolete sequence is
1. if data is relocated to another file by garbage collection, it is the latest sequence at the time garbage collection finish
2. otherwise, it is the latest sequence of the file
Closes https://github.com/facebook/rocksdb/pull/3087
Differential Revision: D6182519
Pulled By: yiwu-arbug
fbshipit-source-id: cdf4c35281f782eb2a9ad6a87b6727bbdff27a45
Summary:
Add an option to enable/disable auto garbage collection, where we keep counting how many keys have been evicted by either deletion or compaction and decide whether to garbage collect a blob file.
Default disable auto garbage collection for now since the whole logic is not fully tested and we plan to make major change to it.
Closes https://github.com/facebook/rocksdb/pull/3117
Differential Revision: D6224756
Pulled By: yiwu-arbug
fbshipit-source-id: cdf53bdccec96a4580a2b3a342110ad9e8864dfe
Summary:
The test intent to wait until key being overwritten until proceed with garbage collection. It failed to wait for `PutUntil` finally finish. Fixing it.
Closes https://github.com/facebook/rocksdb/pull/3116
Differential Revision: D6222833
Pulled By: yiwu-arbug
fbshipit-source-id: fa9b57a772b92a66cf250b44e7975c43f62f45c5
Summary:
Evict oldest blob file and put it in obsolete_files list when close to blob db size limit. The file will be delete when the `DeleteObsoleteFiles` background job runs next time.
For now I set `kEvictOldestFileAtSize` constant, which controls when to evict the oldest file, at 90%. It could be tweaked or made into an option if really needed; I didn't want to expose it as an option pre-maturely as there are already too many :) .
Closes https://github.com/facebook/rocksdb/pull/3094
Differential Revision: D6187340
Pulled By: sagar0
fbshipit-source-id: 687f8262101b9301bf964b94025a2fe9d8573421
Summary:
* cleanup num_concurrent_simple_blobs. We don't do concurrent writes (by taking write_mutex_) so it doesn't make sense to have multiple non TTL files open. We can revisit later when we want to improve writes.
* cleanup eviction callback. we don't have plan to use it now.
* rename s/open_simple_blob_files_/open_non_ttl_file_/ and s/open_blob_files_/open_ttl_files_/ to avoid confusion.
Closes https://github.com/facebook/rocksdb/pull/3088
Differential Revision: D6182598
Pulled By: yiwu-arbug
fbshipit-source-id: 99e6f5e01fa66d31309cdb06ce48502464bac6ad
Summary:
Changing blob file format and some code cleanup around the change. The change with blob log format are:
* Remove timestamp field in blob file header, blob file footer and blob records. The field is not being use and often confuse with expiration field.
* Blob file header now come with column family id, which always equal to default column family id. It leaves room for future support of column family.
* Compression field in blob file header now is a standalone byte (instead of compact encode with flags field)
* Blob file footer now come with its own crc.
* Key length now being uint64_t instead of uint32_t
* Blob CRC now checksum both key and value (instead of value only).
* Some reordering of the fields.
The list of cleanups:
* Better inline comments in blob_log_format.h
* rename ttlrange_t and snrange_t to ExpirationRange and SequenceRange respectively.
* simplify blob_db::Reader
* Move crc checking logic to inside blob_log_format.cc
Closes https://github.com/facebook/rocksdb/pull/3081
Differential Revision: D6171304
Pulled By: yiwu-arbug
fbshipit-source-id: e4373e0d39264441b7e2fbd0caba93ddd99ea2af
Summary:
Adding the `min_blob_size` option to allow storing small values in base db (in LSM tree) together with the key. The goal is to improve performance for small values, while taking advantage of blob db's low write amplification for large values.
Also adding expiration timestamp to blob index. It will be useful to evict stale blob indexes in base db by adding a compaction filter. I'll work on the compaction filter in future patches.
See blob_index.h for the new blob index format. There are 4 cases when writing a new key:
* small value w/o TTL: put in base db as normal value (i.e. ValueType::kTypeValue)
* small value w/ TTL: put (type, expiration, value) to base db.
* large value w/o TTL: write value to blob log and put (type, file, offset, size, compression) to base db.
* large value w/TTL: write value to blob log and put (type, expiration, file, offset, size, compression) to base db.
Closes https://github.com/facebook/rocksdb/pull/3066
Differential Revision: D6142115
Pulled By: yiwu-arbug
fbshipit-source-id: 9526e76e19f0839310a3f5f2a43772a4ad182cd0
Summary:
I found that we continue accepting writes even when the blob db goes beyond the configured blob directory size limit. Now, we return an error for writes on reaching `blob_dir_size` limit and if `is_fifo` is set to false. (We cannot just drop any file when `is_fifo` is true.)
Deleting the oldest file when `is_fifo` is true will be handled in a later PR.
Closes https://github.com/facebook/rocksdb/pull/3060
Differential Revision: D6136156
Pulled By: sagar0
fbshipit-source-id: 2f11cb3f2eedfa94524fbfa2613dd64bfad7a23c
Summary:
With FIFO compaction we would like to get the oldest data time for monitoring. The problem is we don't have timestamp for each key in the DB. As an approximation, we expose the earliest of sst file "creation_time" property.
My plan is to override the property with a more accurate value with blob db, where we actually have timestamp.
Closes https://github.com/facebook/rocksdb/pull/2842
Differential Revision: D5770600
Pulled By: yiwu-arbug
fbshipit-source-id: 03833c8f10bbfbee62f8ea5c0d03c0cafb5d853a
Summary:
MSVC does not support unused attribute at this time. A separate assignment line fixes the issue probably by being counted as usage for MSVC and it no longer complains about unused var.
Closes https://github.com/facebook/rocksdb/pull/3048
Differential Revision: D6126272
Pulled By: maysamyabandeh
fbshipit-source-id: 4907865db45fd75a39a15725c0695aaa17509c1f
Summary:
Blob db insert blob index to base db as kTypeBlobIndex type, to tell apart values written by plain rocksdb or blob db. This is to make it possible to migrate from existing rocksdb to blob db.
Also with the patch blob db garbage collection get away from OptimisticTransaction. Instead it use a custom write callback to achieve similar behavior as OptimisticTransaction. This is because we need to pass the is_blob_index flag to DBImpl::Get but OptimisticTransaction don't support it.
Closes https://github.com/facebook/rocksdb/pull/3000
Differential Revision: D6050044
Pulled By: yiwu-arbug
fbshipit-source-id: 61dc72ab9977625e75f78cd968e7d8a3976e3632
Summary:
Previously each time we write a blob we write blog_record_header + key + value + blob_record_footer to blob log. The footer only contains a sequence and a crc for the sequence number. The sequence number was used in garbage collection to verify the value is recent. After #2703 we moved to use optimistic transaction and no longer use sequence number from the footer. Remove the footer altogether.
There's another usage of sequence number and we are keeping it: Each blob log file keep track of sequence number range of keys in it, and use it to check if it is reference by a snapshot, before being deleted.
Closes https://github.com/facebook/rocksdb/pull/3005
Differential Revision: D6057585
Pulled By: yiwu-arbug
fbshipit-source-id: d6da53c457a316e9723f359a1b47facfc3ffe090
Summary:
Enabled WAL, during GC, for blob index which is stored on regular RocksDB.
Closes https://github.com/facebook/rocksdb/pull/2975
Differential Revision: D5997384
Pulled By: sagar0
fbshipit-source-id: b76c1487d8b5be0e36c55e8d77ffe3d37d63d85b
Summary:
Fixing flaky blob_db_test.
To close a blob file, blob db used to add a CloseSeqWrite job to the background thread to close it. Changing file close to be synchronous in order to simplify logic, and fix flaky blob_db_test.
Closes https://github.com/facebook/rocksdb/pull/2787
Differential Revision: D5699387
Pulled By: yiwu-arbug
fbshipit-source-id: dd07a945cd435cd3808fce7ee4ea57817409474a
Summary:
If GC kicks in between
* A Get() reads index entry from base db.
* The Get() read from a blob file
The GC can delete the corresponding blob file, making the key not found. Fortunately we have existing logic to avoid deleting a blob file if it is referenced by a snapshot. So the fix is to explicitly create a snapshot before reading index entry from base db.
Closes https://github.com/facebook/rocksdb/pull/2754
Differential Revision: D5655956
Pulled By: yiwu-arbug
fbshipit-source-id: e4ccbc51331362542e7343175bbcbdea5830f544
Summary:
When out of space, blob db should GC the oldest file. The current implementation GC the newest one instead. Fixing it.
Closes https://github.com/facebook/rocksdb/pull/2757
Differential Revision: D5657611
Pulled By: yiwu-arbug
fbshipit-source-id: 56c30a4c52e6ab04551dda8c5c46006d4070b28d
Summary:
On initial call to BlobDBImpl::WaStats() `all_periods_write_` would be empty, so it will crash when we call pop_front() at line 1627. Apparently it is mean to pop only when `all_periods_write_.size() > kWriteAmplificationStatsPeriods`.
The whole write amp calculation doesn't seems to be correct and it is not being exposed. Will work on it later.
Test Plan
Change kWriteAmplificationStatsPeriodMillisecs to 1000 (1 second) and run db_bench --use_blob_db for 5 minutes.
Closes https://github.com/facebook/rocksdb/pull/2751
Differential Revision: D5648269
Pulled By: yiwu-arbug
fbshipit-source-id: b843d9a09bb5f9e1b713d101ec7b87e54b5115a4
Summary:
Implement the main body of WritePrepared pseudo code. This includes PrepareInternal and CommitInternal, as well as AddCommitted which updates the commit map. It also provides a IsInSnapshot method that could be later called form the read path to decide if a version is in the read snapshot or it should other be skipped.
This patch lacks unit tests and does not attempt to offer an efficient implementation. The idea is that to have the API specified so that we can work on related tasks in parallel.
Closes https://github.com/facebook/rocksdb/pull/2713
Differential Revision: D5640021
Pulled By: maysamyabandeh
fbshipit-source-id: bfa7a05e8d8498811fab714ce4b9c21530514e1c
