Summary:
In `FileMetaData`, we keep track of the lowest-numbered blob file
referenced by the SST file in question for the purposes of BlobDB's
garbage collection in the `oldest_blob_file_number` field, which is
updated in `UpdateBoundaries`. However, with the current code,
`BlobIndex` decoding errors (or invalid blob file numbers) are swallowed
in this method. The patch changes this by propagating these errors
and failing the corresponding flush/compaction. (Note that since blob
references are generated by the BlobDB code and also parsed by
`CompactionIterator`, in reality this can only happen in the case of
memory corruption.)
This change necessitated updating some unit tests that involved
fake/corrupt `BlobIndex` objects. Some of these just used a dummy string like
`"blob_index"` as a placeholder; these were replaced with real `BlobIndex`es.
Some were relying on the earlier behavior to simulate corruption; these
were replaced with `SyncPoint`-based test code that corrupts a valid
blob reference at read time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9851
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D35683671
Pulled By: ltamasi
fbshipit-source-id: f7387af9945c48e4d5c4cd864f1ba425c7ad51f6
Summary:
**This PR does not affect the functionality of `DB` and write-committed transactions.**
`CompactionIterator` uses `KeyCommitted(seq)` to determine if a key in the database is committed.
As the name 'write-committed' implies, if write-committed policy is used, a key exists in the database only if
it is committed. In fact, the implementation of `KeyCommitted()` is as follows:
```
inline bool KeyCommitted(SequenceNumber seq) {
// For non-txn-db and write-committed, snapshot_checker_ is always nullptr.
return snapshot_checker_ == nullptr ||
snapshot_checker_->CheckInSnapshot(seq, kMaxSequence) == SnapshotCheckerResult::kInSnapshot;
}
```
With that being said, we focus on write-prepared/write-unprepared transactions.
A few notes:
- A key can exist in the db even if it's uncommitted. Therefore, we rely on `snapshot_checker_` to determine data visibility. We also require that all writes go through transaction API instead of the raw `WriteBatch` + `Write`, thus at most one uncommitted version of one user key can exist in the database.
- `CompactionIterator` outputs a key as long as the key is uncommitted.
Due to the above reasons, it is possible that `CompactionIterator` decides to output an uncommitted key without
doing further checks on the key (`NextFromInput()`). By the time the key is being prepared for output, the key becomes
committed because the `snapshot_checker_(seq, kMaxSequence)` becomes true in the implementation of `KeyCommitted()`.
Then `CompactionIterator` will try to zero its sequence number and hit assertion error if the key is a tombstone.
To fix this issue, we should make the `CompactionIterator` see a consistent view of the input keys. Note that
for write-prepared/write-unprepared, the background flush/compaction jobs already take a "job snapshot" before starting
processing keys. The job snapshot is released only after the entire flush/compaction finishes. We can use this snapshot
to determine whether a key is committed or not with minor change to `KeyCommitted()`.
```
inline bool KeyCommitted(SequenceNumber sequence) {
// For non-txn-db and write-committed, snapshot_checker_ is always nullptr.
return snapshot_checker_ == nullptr ||
snapshot_checker_->CheckInSnapshot(sequence, job_snapshot_) ==
SnapshotCheckerResult::kInSnapshot;
}
```
As a result, whether a key is committed or not will remain a constant throughout compaction, causing no trouble
for `CompactionIterator`s assertions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9830
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D35561162
Pulled By: riversand963
fbshipit-source-id: 0e00d200c195240341cfe6d34cbc86798b315b9f
Summary:
Options `preserve_deletes` and `iter_start_seqnum` have been removed since 7.0.
This PR removes dead code related to these two removed options.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9825
Test Plan: make check
Reviewed By: akankshamahajan15
Differential Revision: D35517950
Pulled By: riversand963
fbshipit-source-id: 86282ce5ec4087acb94a06a42a1b6d55b1715482
Summary:
The patch replaces `std::map` with a sorted `std::vector` for
`VersionStorageInfo::blob_files_` and preallocates the space
for the `vector` before saving the `BlobFileMetaData` into the
new `VersionStorageInfo` in `VersionBuilder::Rep::SaveBlobFilesTo`.
These changes reduce the time the DB mutex is held while
saving new `Version`s, and using a sorted `vector` also makes
lookups faster thanks to better memory locality.
In addition, the patch introduces helper methods
`VersionStorageInfo::GetBlobFileMetaData` and
`VersionStorageInfo::GetBlobFileMetaDataLB` that can be used by
clients to perform lookups in the `vector`, and does some general
cleanup in the parts of code where blob file metadata are used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9526
Test Plan:
Ran `make check` and the crash test script for a while.
Performance was tested using a load-optimized benchmark (`fillseq` with vector memtable, no WAL) and small file sizes so that a significant number of files are produced:
```
numactl --interleave=all ./db_bench --benchmarks=fillseq --allow_concurrent_memtable_write=false --level0_file_num_compaction_trigger=4 --level0_slowdown_writes_trigger=20 --level0_stop_writes_trigger=30 --max_background_jobs=8 --max_write_buffer_number=8 --db=/data/ltamasi-dbbench --wal_dir=/data/ltamasi-dbbench --num=800000000 --num_levels=8 --key_size=20 --value_size=400 --block_size=8192 --cache_size=51539607552 --cache_numshardbits=6 --compression_max_dict_bytes=0 --compression_ratio=0.5 --compression_type=lz4 --bytes_per_sync=8388608 --cache_index_and_filter_blocks=1 --cache_high_pri_pool_ratio=0.5 --benchmark_write_rate_limit=0 --write_buffer_size=16777216 --target_file_size_base=16777216 --max_bytes_for_level_base=67108864 --verify_checksum=1 --delete_obsolete_files_period_micros=62914560 --max_bytes_for_level_multiplier=8 --statistics=0 --stats_per_interval=1 --stats_interval_seconds=20 --histogram=1 --memtablerep=skip_list --bloom_bits=10 --open_files=-1 --subcompactions=1 --compaction_style=0 --min_level_to_compress=3 --level_compaction_dynamic_level_bytes=true --pin_l0_filter_and_index_blocks_in_cache=1 --soft_pending_compaction_bytes_limit=167503724544 --hard_pending_compaction_bytes_limit=335007449088 --min_level_to_compress=0 --use_existing_db=0 --sync=0 --threads=1 --memtablerep=vector --allow_concurrent_memtable_write=false --disable_wal=1 --enable_blob_files=1 --blob_file_size=16777216 --min_blob_size=0 --blob_compression_type=lz4 --enable_blob_garbage_collection=1 --seed=<some value>
```
Final statistics before the patch:
```
Cumulative writes: 0 writes, 700M keys, 0 commit groups, 0.0 writes per commit group, ingest: 284.62 GB, 121.27 MB/s
Interval writes: 0 writes, 334K keys, 0 commit groups, 0.0 writes per commit group, ingest: 139.28 MB, 72.46 MB/s
```
With the patch:
```
Cumulative writes: 0 writes, 760M keys, 0 commit groups, 0.0 writes per commit group, ingest: 308.66 GB, 131.52 MB/s
Interval writes: 0 writes, 445K keys, 0 commit groups, 0.0 writes per commit group, ingest: 185.35 MB, 93.15 MB/s
```
Total time to complete the benchmark is 2611 seconds with the patch, down from 2986 secs.
Reviewed By: riversand963
Differential Revision: D34082728
Pulled By: ltamasi
fbshipit-source-id: fc598abf676dce436734d06bb9d2d99a26a004fc
Summary:
The patch adds a new BlobDB configuration option `blob_compaction_readahead_size`
that can be used to enable prefetching data from blob files during compaction.
This is important when using storage with higher latencies like HDDs or remote filesystems.
If enabled, prefetching is used for all cases when blobs are read during compaction,
namely garbage collection, compaction filters (when the existing value has to be read from
a blob file), and `Merge` (when the value of the base `Put` is stored in a blob file).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9187
Test Plan: Ran `make check` and the stress/crash test.
Reviewed By: riversand963
Differential Revision: D32565512
Pulled By: ltamasi
fbshipit-source-id: 87be9cebc3aa01cc227bec6b5f64d827b8164f5d
Summary:
For multiple versions (ts + seq) of the same user key, if they cross the boundary of `full_history_ts_low_`,
we should retain the version that is visible to the `full_history_ts_low_`. Namely, we keep the internal key
with the largest timestamp smaller than `full_history_ts_low`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9116
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D32261514
Pulled By: riversand963
fbshipit-source-id: e10f47c254c04c05261440051e4f50cb7d95474e
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9105
The user contract of SingleDelete is that: a SingleDelete can only be issued to
a key that exists and has NOT been updated. For example, application can insert
one key `key`, and uses a SingleDelete to delete it in the future. The `key`
cannot be updated or removed using Delete.
In reality, especially when write-prepared transaction is being used, things
can get tricky. For example, a prepared transaction already writes `key` to the
memtable after a successful Prepare(). Afterwards, should the transaction
rollback, it will insert a Delete into the memtable to cancel out the prior
Put. Consider the following sequence of operations.
```
// operation sequence 1
Begin txn
Put(key)
Prepare()
Flush()
Rollback txn
Flush()
```
There will be two SSTs resulting from above. One of the contains a PUT, while
the second one contains a Delete. It is also known that releasing a snapshot
can lead to an L0 containing only a SD for a particular key. Consider the
following operations following the above block.
```
// operation sequence 2
db->Put(key)
db->SingleDelete(key)
Flush()
```
The operation sequence 2 can result in an L0 with only the SD.
Should there be a snapshot for conflict checking created before operation
sequence 1, then an attempt to compact the db may hit the assertion failure
below, because ikey_.type is Delete (from a rollback).
```
else if (clear_and_output_next_key_) {
assert(ikey_.type == kTypeValue || ikey_.type == kTypeBlobIndex);
}
```
To fix the assertion failure, we can skip the SingleDelete if we detect an
earlier Delete in the same snapshot interval.
Reviewed By: ltamasi
Differential Revision: D32056848
fbshipit-source-id: 23620a91e28562d91c45cf7e95f414b54b729748
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9060
RocksDB bottommost level compaction may zero out an internal key's sequence if
the key's sequence is in the earliest_snapshot.
In write-prepared transaction, checking the visibility of a certain sequence in
a specific released snapshot may return a "snapshot released" result.
Therefore, it is possible, after a certain sequence of events, a PUT has its
sequence zeroed out, but a subsequent SingleDelete of the same key will still
be output with its original sequence. This violates the ascending order of
keys and leads to incorrect result.
The solution is to use an extra variable `last_key_seq_zeroed_` to track the
information about visibility in earliest snapshot. With this variable, we can
know for sure that a SingleDelete is in the earliest snapshot even if the said
snapshot is released during compaction before processing the SD.
Reviewed By: ltamasi
Differential Revision: D31813016
fbshipit-source-id: d8cff59d6f34e0bdf282614034aaea99be9174e1
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9061
In write-prepared txn, checking a sequence's visibility in a released (old)
snapshot may return "Snapshot released". Suppose we have two snapshots:
```
earliest_snap < earliest_write_conflict_snap
```
If we release `earliest_write_conflict_snap` but keep `earliest_snap` during
bottommost level compaction, then it is possible that certain sequence of
events can lead to a PUT being seq-zeroed followed by a SingleDelete of the
same key. This violates the ascending order of keys, and will cause data
inconsistency.
Reviewed By: ltamasi
Differential Revision: D31813017
fbshipit-source-id: dc68ba2541d1228489b93cf3edda5f37ed06f285
Summary:
This header file was including everything and the kitchen sink when it did not need to. This resulted in many places including this header when they needed other pieces instead.
Cleaned up this header to only include what was needed and fixed up the remaining code to include what was now missing.
Hopefully, this sort of code hygiene cleanup will speed up the builds...
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8930
Reviewed By: pdillinger
Differential Revision: D31142788
Pulled By: mrambacher
fbshipit-source-id: 6b45de3f300750c79f751f6227dece9cfd44085d
Summary:
Added support for SingleDelete for user-defined timestamps. Users can now Get and Iterate over keys deleted with SingleDelete. It also includes changes in CompactionIterator which preserves the same user key with different timestamps, unless the timestamp is below a certain threshold full_history_ts_low.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8921
Test Plan: Added new unit tests
Reviewed By: riversand963
Differential Revision: D31098191
Pulled By: akankshamahajan15
fbshipit-source-id: 78a59ef4b4884ae324fcd10f56e62a27d5ee2f49
Summary:
In debug mode, we are seeing assertion failure as follows
```
db/compaction/compaction_iterator.cc:980: void rocksdb::CompactionIterator::PrepareOutput(): \
Assertion `ikey_.type != kTypeDeletion && ikey_.type != kTypeSingleDeletion' failed.
```
It is caused by releasing earliest snapshot during compaction between the execution of
`NextFromInput()` and `PrepareOutput()`.
In one case, as demonstrated in unit test `WritePreparedTransaction.ReleaseEarliestSnapshotDuringCompaction_WithSD2`,
incorrect result may be returned by a following range scan if we disable assertion, as in opt compilation
level: the SingleDelete marker's sequence number is zeroed out, but the preceding PUT is also
outputted to the SST file after compaction. Due to the logic of DBIter, the PUT will not be
skipped and will be returned by iterator in range scan. https://github.com/facebook/rocksdb/issues/8661 illustrates what happened.
Fix by taking a more conservative approach: make compaction zero out sequence number only
if key is in the earliest snapshot when the compaction starts.
Another assertion failure is
```
Assertion `current_user_key_snapshot_ == last_snapshot' failed.
```
It's caused by releasing the snapshot between the PUT and SingleDelete during compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8608
Test Plan: make check
Reviewed By: jay-zhuang
Differential Revision: D30145645
Pulled By: riversand963
fbshipit-source-id: 699f58e66faf70732ad53810ccef43935d3bbe81
Summary:
The patch adds statistics support to the integrated BlobDB implementation,
namely the tickers `BLOB_DB_BLOB_FILE_BYTES_READ` and
`BLOB_DB_GC_{NUM_KEYS,BYTES}_RELOCATED`, and the histograms
`BLOB_DB_(DE)COMPRESSION_MICROS`. (Some other statistics, like
`BLOB_DB_BLOB_FILE_BYTES_WRITTEN`, `BLOB_DB_BLOB_FILE_SYNCED`,
`BLOB_DB_BLOB_FILE_{READ,WRITE,SYNC}_MICROS` were already supported.)
Note that the vast majority of the old BlobDB's tickers/histograms are not
really applicable to the new implementation, since they e.g. pertain to calling
dedicated BlobDB APIs (which the integrated BlobDB does not have) or are
tied to the legacy BlobDB's design of writing blob files synchronously when
a write API is called. Such statistics are marked "legacy BlobDB only" in
`statistics.h`.
Fixes https://github.com/facebook/rocksdb/issues/8645 .
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8667
Test Plan: Ran `make check` and tested the new statistics using `db_bench`.
Reviewed By: riversand963
Differential Revision: D30356884
Pulled By: ltamasi
fbshipit-source-id: 5f8a833faee60401c5643c2f0a6c0415488190a4
Summary:
Internal task T96186510.
Created new inline member functions in `CompactionIterator`,
`DefinitelyInSnapshot`, `DefinitelyNotInSnapshot`, and
`InEarliestSnapshot` to replace the macros at the top of
`compaction_iterator.cc`.
Placed the definitions in `compaction_iterator.h` in accordance with
Google's style guide for inline functions. Separated the declarations
and definitions, and only placed the `inline` keyword on the
definitions, in line with ISO CPP recommendations.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8592
Test Plan: Ran `make check`. Successful build and all tests appeared to pass.
Reviewed By: riversand963
Differential Revision: D29966782
Pulled By: jimmycFB
fbshipit-source-id: 3584290bbbabf862e9ab58852281f46d37f58be6
Summary:
Provide support for Merge operation with base values during
Compaction in IntegratedBlobDB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8445
Test Plan: Add new unit test
Reviewed By: ltamasi
Differential Revision: D29343949
Pulled By: akankshamahajan15
fbshipit-source-id: 844f6f02f93388a11e6e08bda7bb3a2a28e47c70
Summary:
The patch builds on `BlobGarbageMeter` and `BlobCountingIterator`
(introduced in https://github.com/facebook/rocksdb/issues/8426 and
https://github.com/facebook/rocksdb/issues/8443 respectively)
and ties it all together. It measures the amount of garbage
generated by a compaction and logs the corresponding `BlobFileGarbage`
records as part of the compaction job's `VersionEdit`. Note: in order
to have accurate results, `kRemoveAndSkipUntil` for compaction filters
is implemented using iteration.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8450
Test Plan: Ran `make check` and the crash test script.
Reviewed By: jay-zhuang
Differential Revision: D29338207
Pulled By: ltamasi
fbshipit-source-id: 4381c432ac215139439f6d6fb801a6c0e4d8c128
Summary:
Added the ability to cancel an in-progress range compaction by storing to an atomic "canceled" variable pointed to within the CompactRangeOptions structure.
Tested via two tests added to db_tests2.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8351
Reviewed By: ajkr
Differential Revision: D28808894
Pulled By: ddevec
fbshipit-source-id: cb321361c9e23b084b188bb203f11c375a22c2dd
Summary:
When a memtable is flushed, it will validate number of entries it reads, and compare the number with how many entries inserted into memtable. This serves as one sanity c\
heck against memory corruption. This change will also allow more counters to be added in the future for better validation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8288
Test Plan: Pass all existing tests
Reviewed By: ajkr
Differential Revision: D28369194
fbshipit-source-id: 7ff870380c41eab7f99eee508550dcdce32838ad
Summary:
From HISTORY.md release note:
- Allow `CompactionFilter`s to apply in more table file creation scenarios such as flush and recovery. For compatibility, `CompactionFilter`s by default apply during compaction. Users can customize this behavior by overriding `CompactionFilterFactory::ShouldFilterTableFileCreation()`.
- Removed unused structure `CompactionFilterContext`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8243
Test Plan: added unit tests
Reviewed By: pdillinger
Differential Revision: D28088089
Pulled By: ajkr
fbshipit-source-id: 0799be7908e3b39fea09fc3f1ab00e13ad817fae
Summary:
For performance purposes, the lower level routines were changed to use a SystemClock* instead of a std::shared_ptr<SystemClock>. The shared ptr has some performance degradation on certain hardware classes.
For most of the system, there is no risk of the pointer being deleted/invalid because the shared_ptr will be stored elsewhere. For example, the ImmutableDBOptions stores the Env which has a std::shared_ptr<SystemClock> in it. The SystemClock* within the ImmutableDBOptions is essentially a "short cut" to gain access to this constant resource.
There were a few classes (PeriodicWorkScheduler?) where the "short cut" property did not hold. In those cases, the shared pointer was preserved.
Using db_bench readrandom perf_level=3 on my EC2 box, this change performed as well or better than 6.17:
6.17: readrandom : 28.046 micros/op 854902 ops/sec; 61.3 MB/s (355999 of 355999 found)
6.18: readrandom : 32.615 micros/op 735306 ops/sec; 52.7 MB/s (290999 of 290999 found)
PR: readrandom : 27.500 micros/op 871909 ops/sec; 62.5 MB/s (367999 of 367999 found)
(Note that the times for 6.18 are prior to revert of the SystemClock).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8033
Reviewed By: pdillinger
Differential Revision: D27014563
Pulled By: mrambacher
fbshipit-source-id: ad0459eba03182e454391b5926bf5cdd45657b67
Summary:
The patch does the following:
1) Exposes the amount of data (number of bytes) read from blob files from
`BlobFileReader::GetBlob` / `Version::GetBlob`.
2) Tracks the total number and size of blobs read from blob files during a
compaction (due to garbage collection or compaction filter usage) in
`CompactionIterationStats` and propagates this data to
`InternalStats::CompactionStats` / `CompactionJobStats`.
3) Updates the formulae for write amplification calculations to include the
amount of data read from blob files.
4) Extends the compaction stats dump with a new column `Rblob(GB)` and
a new line containing the total number and size of blob files in the current
`Version` to complement the information about the shape and size of the LSM tree
that's already there.
5) Updates `CompactionJobStats` so that the number of files and amount of data
written by a compaction are broken down per file type (i.e. table/blob file).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8022
Test Plan: Ran `make check` and `db_bench`.
Reviewed By: riversand963
Differential Revision: D26801199
Pulled By: ltamasi
fbshipit-source-id: 28a5f072048a702643b28cb5971b4099acabbfb2
Summary:
Allow applications to implement a custom compaction filter and pass it to BlobDB.
The compaction filter's custom logic can operate on blobs.
To do so, application needs to subclass `CompactionFilter` abstract class and implement `FilterV2()` method.
Optionally, a method called `ShouldFilterBlobByKey()` can be implemented if application's custom logic rely solely
on the key to make a decision without reading the blob, thus saving extra IO. Examples can be found in
db/blob/db_blob_compaction_test.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7974
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D26509280
Pulled By: riversand963
fbshipit-source-id: 59f9ae5614c4359de32f4f2b16684193cc537b39
Summary:
There is a small `SingleDelete` related optimization in the
`CompactionIterator` code: when a `SingleDelete`-`Put` pair is preserved
solely for the purposes of transaction conflict checking, the value
itself gets cleared. (This is referred to as "optimization 3" in the
`CompactionIterator` code.) Though the rest of the code got updated to
support `SingleDelete`'ing blob indexes, this chunk was apparently
missed, resulting in an assertion failure (or `ROCKS_LOG_FATAL` in release
builds) when triggered. Note: in addition to clearing the value, we also
need to update the type of the KV to regular value when dealing with
blob indexes here.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7904
Test Plan: `make check`
Reviewed By: ajkr
Differential Revision: D26118009
Pulled By: ltamasi
fbshipit-source-id: 6bf78043d20265e2b15c2e1ab8865025040c42ae
Summary:
Introduces and uses a SystemClock class to RocksDB. This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.
Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead. There are likely more places that can be changed, but this is a start to show what can/should be done. Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.
There are several Env classes that implement these functions. Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR. It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).
Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858
Reviewed By: pdillinger
Differential Revision: D26006406
Pulled By: mrambacher
fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
Summary:
The patch adds basic garbage collection support to the integrated BlobDB
implementation. Valid blobs residing in the oldest blob files are relocated
as they are encountered during compaction. The threshold that determines
which blob files qualify is computed based on the configuration option
`blob_garbage_collection_age_cutoff`, which was introduced in https://github.com/facebook/rocksdb/issues/7661 .
Once a blob is retrieved for the purposes of relocation, it passes through the
same logic that extracts large values to blob files in general. This means that
if, for instance, the size threshold for key-value separation (`min_blob_size`)
got changed or writing blob files got disabled altogether, it is possible for the
value to be moved back into the LSM tree. In particular, one way to re-inline
all blob values if needed would be to perform a full manual compaction with
`enable_blob_files` set to `false`, `enable_blob_garbage_collection` set to
`true`, and `blob_file_garbage_collection_age_cutoff` set to `1.0`.
Some TODOs that I plan to address in separate PRs:
1) We'll have to measure the amount of new garbage in each blob file and log
`BlobFileGarbage` entries as part of the compaction job's `VersionEdit`.
(For the time being, blob files are cleaned up solely based on the
`oldest_blob_file_number` relationships.)
2) When compression is used for blobs, the compression type hasn't changed,
and the blob still qualifies for being written to a blob file, we can simply copy
the compressed blob to the new file instead of going through decompression
and compression.
3) We need to update the formula for computing write amplification to account
for the amount of data read from blob files as part of GC.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7694
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D25069663
Pulled By: ltamasi
fbshipit-source-id: bdfa8feb09afcf5bca3b4eba2ba72ce2f15cd06a
Summary:
`CompactionProxy` is currently both a concrete class used for actual `Compaction`s
and a base class that `FakeCompaction` (which is used in `compaction_iterator_test`)
is derived from. This is bad from an OO design standpoint, and also results in
`FakeCompaction` containing an (uninitialized and unused) `Compaction*` member.
The patch fixes this by making `CompactionProxy` a pure interface and introducing
a separate concrete class `RealCompaction` for non-test/non-fake compactions. It
also removes an unused parameter from the virtual method `level`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7662
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D24907680
Pulled By: ltamasi
fbshipit-source-id: c100ecb1beef4b0ada35e799116c5bda71719ee7
Summary:
https://github.com/facebook/rocksdb/issues/7556 introduced support for compaction iterator to perform timestamp-aware garbage collection.
However, there was a bug. The comparison between `ikey_.user_key` and `current_user_key_` should happen
before `key_ = current_key_.SetInternalKey(key_, &ikey_);` (line 336 of compaction_iterator.cc).
Otherwise, after this line, `current_key_` is always the same as `ikey_.user_key`.
This PR also re-arranged the order of some data members because some of them are state variables of `CompactionIterator` while others are inputs from callers.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7645
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D24845028
Pulled By: riversand963
fbshipit-source-id: c7e79914832701462b86867e8463cd463b6c0c25
Summary:
Fixes Issue https://github.com/facebook/rocksdb/issues/7497
When allow_data_in_errors db_options is set, log error key details in `ParseInternalKey()`
Have fixed most of the calls. Have few TODOs still pending - because have to make more deeper changes to pass in the allow_data_in_errors flag. Will do those in a separate PR later.
Tests:
- make check
- some of the existing tests that exercise the "internal key too small" condition are: dbformat_test, cuckoo_table_builder_test
- some of the existing tests that exercise the corrupted key path are: corruption_test, merge_helper_test, compaction_iterator_test
Example of new status returns:
- Key too small - `Corrupted Key: Internal Key too small. Size=5`
- Corrupt key with allow_data_in_errors option set to false: `Corrupted Key: '<redacted>' seq:3, type:3`
- Corrupt key with allow_data_in_errors option set to true: `Corrupted Key: '61' seq:3, type:3`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7515
Reviewed By: ajkr
Differential Revision: D24240264
Pulled By: ramvadiv
fbshipit-source-id: bc48f5d4475ac19d7713e16df37505b31aac42e7
Summary:
Add a threshold timestamp, full_history_ts_low_ of type `std::string*` to
`CompactionIterator`, so that RocksDB can also perform garbage collection during
compaction.
* If full_history_ts_low_ is nullptr, then compaction iterator does not perform
GC, preserving all timestamp history for all keys. Compaction iterator will
treat user key with different timestamps as different user keys.
* If full_history_ts_low_ is not nullptr, then compaction iterator performs
GC. GC will look at keys older than `*full_history_ts_low_` and determine their
eligibility based on factors including snapshots.
Current rules of GC:
* If an internal key is in the same snapshot as a previous counterpart
with the same user key, and this key is eligible for GC, and the key is
not single-delete or merge operand, then this key can be dropped. Note
that the previous internal key cannot be a merge operand either.
* If a tombstone is the most recent one in the earliest snapshot and it
is eligible for GC, and keyNotExistsBeyondLevel() is true, then this
tombstone can be dropped.
* If a tombstone is the most recent one in a snapshot and it is eligible
for GC, and the compaction is at bottommost level, then all other older
internal keys of the same user key must also be eligible for GC, thus
can be dropped
* Single-delete, delete-range and merge are not currently supported.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7556
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D24507728
Pulled By: riversand963
fbshipit-source-id: 3c09c7301f41eed76dfcf4d1527e68cf6e0a8bb3
Summary:
Add a new Option "allow_data_in_errors". When it's set by users, it allows them to opt-in to get error messages containing corrupted keys/values. Corrupt keys, values will be logged in the messages, logs, status etc. that will help users with the useful information regarding affected data.
By default value is set false to prevent users data to be exposed in the messages.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7420
Test Plan:
1. make check -j64
2. Add a new test case
Reviewed By: ajkr
Differential Revision: D23835028
Pulled By: akankshamahajan15
fbshipit-source-id: 8d2eba8fb898e79fcf1fccc07295065a75eb59b1
Summary:
The patch adds support for writing blob files during flush by integrating
`BlobFileBuilder` with the flush logic, most importantly, `BuildTable` and
`CompactionIterator`. If `enable_blob_files` is set, large values are extracted
to blob files and replaced with references. The resulting blob files are then
logged to the MANIFEST as part of the flush job's `VersionEdit` and
added to the `Version`, similarly to table files. Errors related to writing
blob files fail the flush, and any blob files written by such jobs are immediately
deleted (again, similarly to how SST files are handled). In addition, the patch
extends the logging and statistics around flushes to account for the presence
of blob files (e.g. `InternalStats::CompactionStats::bytes_written`, which is
used for calculating write amplification, now considers the blob files as well).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7345
Test Plan: Tested using `make check` and `db_bench`.
Reviewed By: riversand963
Differential Revision: D23506369
Pulled By: ltamasi
fbshipit-source-id: 646885f22dfbe063f650d38a1fedc132f499a159
Summary:
During bottommost compaction, RocksDB cannot simply drop a tombstone if
this tombstone is not in the earliest snapshot. The current behavior is: RocksDB
skips other internal keys (of the same user key) in the same snapshot range. In
the meantime, RocksDB should check for the `shutting_down` flag. Otherwise, it
is possible for a bottommost compaction that has already started running to take
a long time to finish, even if the application has tried to cancel all background jobs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7356
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D23663241
Pulled By: riversand963
fbshipit-source-id: 25f8e9b51bc3bfa3353cdf87557800f9d90ee0b5
Summary:
- Closes https://github.com/facebook/rocksdb/issues/6490
- Currently MERGEs are converted to PUTs at bottom or compaction has reached the beginning of the key, this can wrongly cover a PUT future base case.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7166
Test Plan:
- Automated: `make all check`
- Manual: With `allow_ingest_behind = true`, add Merge operations to a key then run compaction. Then run ingesting external files to make sure the base case is probably compacted with existing Merges.
Reviewed By: cheng-chang
Differential Revision: D23325425
Pulled By: ajkr
fbshipit-source-id: 3eb415eb7b381b5453e45245393566153b1abb68
Summary:
Manual compaction with `CompactRangeOptions::change_levels` set could
refit to a level targeted by another manual compaction. If
force_consistency_checks were disabled, it could be possible for
overlapping files to be written at that target level.
This PR prevents the possibility by calling `DisableManualCompaction()`
prior to `ReFitLevel()`. It also improves the manual compaction disabling
mechanism to wait for pending manual compactions to complete before
returning, and support disabling from multiple threads.
Fixes https://github.com/facebook/rocksdb/issues/6432.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7250
Test Plan:
crash test command that repro'd the bug reliably:
```
$ TEST_TMPDIR=/dev/shm python tools/db_crashtest.py blackbox --simple -target_file_size_base=524288 -write_buffer_size=1048576 -clear_column_family_one_in=0 -reopen=0 -max_key=10000000 -column_families=1 -max_background_compactions=8 -compact_range_one_in=100000 -compression_type=none -compaction_style=1 -num_levels=5 -universal_min_merge_width=4 -universal_max_merge_width=8 -level0_file_num_compaction_trigger=12 -rate_limiter_bytes_per_sec=1048576000 -universal_max_size_amplification_percent=100 --duration=3600 --interval=60 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --enable_compaction_filter=0
```
Reviewed By: ltamasi
Differential Revision: D23090800
Pulled By: ajkr
fbshipit-source-id: afcbcd51b42ce76789fdb907d8b9ada790709c13
Summary:
Currently, RocksDB lets compaction to go through even in case of
corrupted keys, the number of which is reported in CompactionJobStats.
However, RocksDB does not check this value. We should let compaction run
in a stricter mode.
Temporarily disable two tests that allow corrupted keys in compaction.
With this PR, the two tests will assert(false) and terminate. Still need
to investigate what is the recommended google-test way of doing it.
Death test (EXPECT_DEATH) in gtest has warnings now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7124
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D22530722
Pulled By: riversand963
fbshipit-source-id: 6a5a6a992028c6d4f92cb74693c92db462ae4ad6
Summary:
Added compaction filter support for BlobDB non-TTL values. Same as vanilla RocksDB, user compaction filter applies to all k/v pairs of the compaction for non-TTL values. It honors `min_blob_size`, which potentially results value transitions between inlined data and stored-in-blob data when size of value is changed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6850
Reviewed By: siying
Differential Revision: D22263487
Pulled By: ltamasi
fbshipit-source-id: 8fc03f8cde2a5c831e63b436b3dbf1b7f90939e8
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
Summary:
With https://github.com/facebook/rocksdb/pull/6121, errors returned by `PrepareBlobValue`
result in `CompactionIterator::status_` being set to `Corruption` or `IOError`
as appropriate, however, `valid_` is not set to `false`. The error is eventually propagated in
`CompactionJob::ProcessKeyValueCompaction` but only after the main loop completes.
Setting `valid_` to `false` upon errors enables us to terminate the loop early and fail the
compaction sooner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6170
Test Plan:
Ran `make check` and used `db_bench` in BlobDB mode.
fbshipit-source-id: a2ca88a3ca71115e2605bd34a4c795d8a28bef27
Summary:
The patch adds logic that relocates live blobs from the oldest N non-TTL
blob files as they are encountered during compaction (assuming the BlobDB
configuration option `enable_garbage_collection` is `true`), where N is defined
as the number of immutable non-TTL blob files multiplied by the value of
a new BlobDB configuration option called `garbage_collection_cutoff`.
(The default value of this parameter is 0.25, that is, by default the valid blobs
residing in the oldest 25% of immutable non-TTL blob files are relocated.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6121
Test Plan: Added unit test and tested using the BlobDB mode of `db_bench`.
Differential Revision: D18785357
Pulled By: ltamasi
fbshipit-source-id: 8c21c512a18fba777ec28765c88682bb1a5e694e
Summary:
Compaction iterator has many assert statements that are active only during test runs. Some rare bugs would show up only at runtime could violate the assert condition but go unnoticed since assert statements are not compiled in release mode. Turning the assert statements to runtime check sone pors and cons:
Pros:
- A bug that would result into incorrect data would be detected early before the incorrect data is written to the disk.
Cons:
- Runtime overhead: which should be negligible since compaction cpu is the minority in the overall cpu usage
- The assert statements might already being violated at runtime, and turning them to runtime failure might result into reliability issues.
The patch takes a conservative step in this direction by logging the assert violations at runtime. If we see any violation reported in logs, we investigate. Otherwise, we can go ahead turning them to runtime error.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5935
Differential Revision: D18229697
Pulled By: maysamyabandeh
fbshipit-source-id: f1890eca80ccd7cca29737f1825badb9aa8038a8
Summary:
Some recent commits might not have passed through the formatter. I formatted recent 45 commits. The script hangs for more commits so I stopped there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5827
Test Plan: Run all existing tests.
Differential Revision: D17483727
fbshipit-source-id: af23113ee63015d8a43d89a3bc2c1056189afe8f
Summary:
Manual compaction may bring in very high load because sometime the amount of data involved in a compaction could be large, which may affect online service. So it would be good if the running compaction making the server busy can be stopped immediately. In this implementation, stopping manual compaction condition is only checked in slow process. We let deletion compaction and trivial move go through.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3971
Test Plan: add tests at more spots.
Differential Revision: D17369043
fbshipit-source-id: 575a624fb992ce0bb07d9443eb209e547740043c
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377
Differential Revision: D15551366
Pulled By: siying
fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
Summary:
The recent improvement in https://github.com/facebook/rocksdb/pull/3661 could cause a deadlock: When writing recoverable state, we also commit its sequence number to commit table, which could result into evicting existing commit entry, which could result into advancing max_evicted_seq_, which would need to get snapshots from database, which requires obtaining db mutex. The patch releases db_mutex before calling the callback in WriteRecoverableState to avoid the potential deadlock. It also improves the stress tests to let the issue be manifested in the tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5306
Differential Revision: D15341458
Pulled By: maysamyabandeh
fbshipit-source-id: 05dcbed7e21b789fd1e5fd5ee8eea08077162323
Summary:
Part of compaction cpu goes to processing snapshot list, the larger the list the bigger the overhead. Although the lifetime of most of the snapshots is much shorter than the lifetime of compactions, the compaction conservatively operates on the list of snapshots that it initially obtained. This patch allows the snapshot list to be updated via a callback if the compaction is taking long. This should let the compaction to continue more efficiently with much smaller snapshot list.
For simplicity, to avoid the feature is disabled in two cases: i) When more than one sub-compaction are sharing the same snapshot list, ii) when Range Delete is used in which the range delete aggregator has its own copy of snapshot list.
This fixes the reverted https://github.com/facebook/rocksdb/pull/5099 issue with range deletes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5278
Differential Revision: D15203291
Pulled By: maysamyabandeh
fbshipit-source-id: fa645611e606aa222c7ce53176dc5bb6f259c258
Levi Tamasi
