Summary:
Previously, the following command:
```USE_CLANG=1 TEST_TMPDIR=/dev/shm/rocksdb OPT=-g make -j$(nproc) analyze```
was raising an error/warning the new_mem could potentially be a `nullptr`. This error appeared due to code changes from https://github.com/facebook/rocksdb/issues/8454, including an if-statement containing "`... && new_mem != nullptr && ...`", which made the analyzer believe that past this `if`-statement, a `new_mem==nullptr` was a possible scenario.
This code patch simply introduces `assert`s and removes this condition in the `if`-statement.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8492
Reviewed By: jay-zhuang
Differential Revision: D29571275
Pulled By: bjlemaire
fbshipit-source-id: 75d72246b70ebbbae7dea11ccb5778686d8bcbea
Summary:
We ended up using a different approach for tracking the amount of
garbage in blob files (see e.g. https://github.com/facebook/rocksdb/pull/8450),
so the ability to apply only a range of table property collectors is
now unnecessary. The patch reverts this part of
https://github.com/facebook/rocksdb/pull/8298 while keeping the cleanup done
in that PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8465
Test Plan: `make check`
Reviewed By: jay-zhuang
Differential Revision: D29399921
Pulled By: ltamasi
fbshipit-source-id: af64816c357d0829b9d7ba8ca1477038138f6f0a
Summary:
Implement an experimental feature called "MemPurge", which consists in purging "garbage" bytes out of a memtable and reuse the memtable struct instead of making it immutable and eventually flushing its content to storage.
The prototype is by default deactivated and is not intended for use. It is intended for correctness and validation testing. At the moment, the "MemPurge" feature can be switched on by using the `options.experimental_allow_mempurge` flag. For this early stage, when the allow_mempurge flag is set to `true`, all the flush operations will be rerouted to perform a MemPurge. This is a temporary design decision that will give us the time to explore meaningful heuristics to use MemPurge at the right time for relevant workloads . Moreover, the current MemPurge operation only supports `Puts`, `Deletes`, `DeleteRange` operations, and handles `Iterators` as well as `CompactionFilter`s that are invoked at flush time .
Three unit tests are added to `db_flush_test.cc` to test if MemPurge works correctly (and checks that the previously mentioned operations are fully supported thoroughly tested).
One noticeable design decision is the timing of the MemPurge operation in the memtable workflow: for this prototype, the mempurge happens when the memtable is switched (and usually made immutable). This is an inefficient process because it implies that the entirety of the MemPurge operation happens while holding the db_mutex. Future commits will make the MemPurge operation a background task (akin to the regular flush operation) and aim at drastically enhancing the performance of this operation. The MemPurge is also not fully "WAL-compatible" yet, but when the WAL is full, or when the regular MemPurge operation fails (or when the purged memtable still needs to be flushed), a regular flush operation takes place. Later commits will also correct these behaviors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8454
Reviewed By: anand1976
Differential Revision: D29433971
Pulled By: bjlemaire
fbshipit-source-id: 6af48213554e35048a7e03816955100a80a26dc5
Summary:
Change the job_id for remote compaction interface, which will include
both internal compaction job_id, also a sub_compaction_job_id. It is not
a backward compatible change. The user needs to update interface during
upgrade. (We will avoid backward incompatible change after the feature is
not experimental.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8364
Reviewed By: ajkr
Differential Revision: D28917301
Pulled By: jay-zhuang
fbshipit-source-id: 6d72a21f652bb517ad6954d0387b496797fc4e11
Summary:
Added BlobMetaData to ColumnFamilyMetaData and LiveBlobMetaData and DB API GetLiveBlobMetaData to retrieve it.
First pass at struct. More tests and maybe fields to come...
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8273
Reviewed By: ltamasi
Differential Revision: D29102400
Pulled By: mrambacher
fbshipit-source-id: 8a2383a4446328be6b91dced9841fdd3dfc80b73
Summary:
In PR https://github.com/facebook/rocksdb/issues/7523 , checksum handoff is introduced in RocksDB for WAL, Manifest, and SST files. When user enable checksum handoff for a certain type of file, before the data is written to the lower layer storage system, we calculate the checksum (crc32c) of each piece of data and pass the checksum down with the data, such that data verification can be down by the lower layer storage system if it has the capability. However, it cannot cover the whole lifetime of the data in the memory and also it potentially introduces extra checksum calculation overhead.
In this PR, we introduce a new interface in WritableFileWriter::Append, which allows the caller be able to pass the data and the checksum (crc32c) together. In this way, WritableFileWriter can directly use the pass-in checksum (crc32c) to generate the checksum of data being passed down to the storage system. It saves the calculation overhead and achieves higher protection coverage. When a new checksum is added with the data, we use Crc32cCombine https://github.com/facebook/rocksdb/issues/8305 to combine the existing checksum and the new checksum. To avoid the segmenting of data by rate-limiter before it is stored, rate-limiter is called enough times to accumulate enough credits for a certain write. This design only support Manifest and WAL which use log_writer in the current stage.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8412
Test Plan: make check, add new testing cases.
Reviewed By: anand1976
Differential Revision: D29151545
Pulled By: zhichao-cao
fbshipit-source-id: 75e2278c5126cfd58393c67b1efd18dcc7a30772
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:
`VersionSet::VerifyCompactionFileConsistency` was superseded by the LSM tree
consistency checks introduced in https://github.com/facebook/rocksdb/pull/6901,
which are more comprehensive, more efficient, and are performed unconditionally
even in release builds.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8449
Test Plan: `make check`
Reviewed By: ajkr
Differential Revision: D29337441
Pulled By: ltamasi
fbshipit-source-id: a05324f88e3400e27e6a00406c878a6276e0c9cc
Summary:
Follow-up to https://github.com/facebook/rocksdb/issues/8426 .
The patch adds a new kind of `InternalIterator` that wraps another one and
passes each key-value encountered to `BlobGarbageMeter` as inflow.
This iterator will be used as an input iterator for compactions when the input
SSTs reference blob files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8443
Test Plan: `make check`
Reviewed By: jay-zhuang
Differential Revision: D29311987
Pulled By: ltamasi
fbshipit-source-id: b4493b4c0c0c2e3c2ecc33c8969a5ef02de5d9d8
Summary:
This reverts commit 25be1ed66a.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8438
Test Plan: Run the impacted mysql test 40 times
Reviewed By: ajkr
Differential Revision: D29286247
Pulled By: jay-zhuang
fbshipit-source-id: d3bd056971a19a8b012d5d0295fa045c012b3c04
Summary:
Currently, blob file checksums are incorrectly dumped as raw bytes
in the `ldb manifest_dump` output (i.e. they are not printed as hex).
The patch fixes this and also updates some test cases to reflect that
the checksum value field in `BlobFileAddition` and `SharedBlobFileMetaData`
contains the raw checksum and not a hex string.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8437
Test Plan:
`make check`
Tested using `ldb manifest_dump`
Reviewed By: akankshamahajan15
Differential Revision: D29284170
Pulled By: ltamasi
fbshipit-source-id: d11cfb3435b14cd73c8a3d3eb14fa0f9fa1d2228
Summary:
`DeleteFilesInRange()` marks deleting files to `being_compacted`
before deleting, which may cause ongoing compactions report corruption
exception or ASSERT for debug build.
Adding the missing `ComputeCompactionScore()` when `being_compacted` is set.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8434
Test Plan: Unittest
Reviewed By: ajkr
Differential Revision: D29276127
Pulled By: jay-zhuang
fbshipit-source-id: f5b223e3c1fc6d821e100e3f3442bc70c1d50cf7
Summary:
This is part of an alternative approach to https://github.com/facebook/rocksdb/issues/8316.
Unlike that approach, this one relies on key-values getting processed one by one
during compaction, and does not involve persistence.
Specifically, the patch adds a class `BlobGarbageMeter` that can track the number
and total size of blobs in a (sub)compaction's input and output on a per-blob file
basis. This information can then be used to compute the amount of additional
garbage generated by the compaction for any given blob file by subtracting the
"outflow" from the "inflow."
Note: this patch only adds `BlobGarbageMeter` and associated unit tests. I plan to
hook up this class to the input and output of `CompactionIterator` in a subsequent PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8426
Test Plan: `make check`
Reviewed By: jay-zhuang
Differential Revision: D29242250
Pulled By: ltamasi
fbshipit-source-id: 597e50ad556540e413a50e804ba15bc044d809bb
Summary:
Tracing the MultiGet information including timestamp, keys, and CF_IDs to the trace file for analyzing and replay.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8421
Test Plan: make check, add test to trace_analyzer_test
Reviewed By: anand1976
Differential Revision: D29221195
Pulled By: zhichao-cao
fbshipit-source-id: 30c677d6c39ab31ef4bbdf7e0d1fa1fd79f295ff
Summary:
**Summary**:
2 new statistics counters are added to RocksDB: `MEMTABLE_PAYLOAD_BYTES_AT_FLUSH` and `MEMTABLE_GARBAGE_BYTES_AT_FLUSH`. The former tracks how many raw bytes of useful data are present on the memtable at flush time, whereas the latter is tracks how many of these raw bytes are considered garbage, meaning that they ended up not being imported on the SSTables resulting from the flush operations.
**Unit test**: run `make db_flush_test -j$(nproc); ./db_flush_test` to run the unit test.
This executable includes 3 tests, that test support and correct stat calculations for workloads with inserts, deletes, and DeleteRanges. The parameters are set such that the workloads are performed on a single memtable, and a single SSTable is created as a result of the flush operation. The flush operation is manually called in the test file. The tests verify that the values of these 2 statistics counters introduced in this PR can be exactly predicted, showing that we have a full understanding of the underlying operations.
**Performance testing**:
`./db_bench -statistics -benchmarks=fillrandom -num=10000000` repeated 10 times.
Timing done using "date" function in a bash script.
_Results_:
Original Rocksdb fork: mean 66.6 sec, std 1.18 sec.
This feature branch: mean 67.4 sec, std 1.35 sec.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8411
Reviewed By: akankshamahajan15
Differential Revision: D29150629
Pulled By: bjlemaire
fbshipit-source-id: 7b3c2e86d50c6aa34fa50fd134282eacb543a5b1
Summary:
This PR prepopulates warm/hot data blocks which are already in memory
into block cache at the time of flush. On a flush, the data block that is
in memory (in memtables) get flushed to the device. If using Direct IO,
additional IO is incurred to read this data back into memory again, which
is avoided by enabling newly added option.
Right now, this is enabled only for flush for data blocks. We plan to
expand this option to cover compactions in the future and for other types
of blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8242
Test Plan: Add new unit test
Reviewed By: anand1976
Differential Revision: D28521703
Pulled By: akankshamahajan15
fbshipit-source-id: 7219d6958821cedce689a219c3963a6f1a9d5f05
Summary:
RocksDB logs a warning if WAL truncation on DB open fails. Its possible that on some file systems, truncation is not required and they would return ```Status::NotSupported()``` for ```ReopenWritableFile```. Don't log a warning in such cases.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8414
Reviewed By: akankshamahajan15
Differential Revision: D29181738
Pulled By: anand1976
fbshipit-source-id: 6e01e9117e1e4c1d67daa4dcee7fa59d06e057a7
Summary:
This is the next part of the ImmutableOptions cleanup. After changing the use of ImmutableCFOptions to ImmutableOptions, there were places in the code that had did something like "ImmutableOptions* immutable_cf_options", where "cf" referred to the "old" type.
This change simply renames the variables to match the current type. No new functionality is introduced.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8409
Reviewed By: pdillinger
Differential Revision: D29166248
Pulled By: mrambacher
fbshipit-source-id: 96de97f8e743f5c5160f02246e3ed8269556dc6f
Summary:
This reverts commit 9167ece586.
It was found to reliably trip a compaction picking conflict assertion in a MyRocks unit test. We don't understand why yet so reverting in the meantime.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8410
Test Plan: `make check -j48`
Reviewed By: jay-zhuang
Differential Revision: D29150300
Pulled By: ajkr
fbshipit-source-id: 2de8664f355d6da015e84e5fec2e3f90f49741c8
Summary:
- Added CreateFromString method to Env and FilesSystem to replace LoadEnv/Load. This method/signature is a precursor to making these classes extend Customizable.
- Added CreateFromSystem to Env. This method standardizes creating an Env from the environment variables. Previously, some places would check TEST_ENV_URI and others would also check TEST_FS_URI. Now the code is more command/standardized.
- Added CreateFromFlags to Env. These method allows Env to be create from string options (such as GFLAGS options) in a more standard way.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8174
Reviewed By: zhichao-cao
Differential Revision: D28999603
Pulled By: mrambacher
fbshipit-source-id: 88e6911e7e91f908458a7fe10a20e93ecbc275fb
Summary:
(1)Make CompactionService derived from Customizable by defining two extra functions that are needed, as described in customizable.h comment section
(2)Revise the MyTestCompactionService class in compaction_service_test.cc to satisfy the class inheritance requirement
(3)Specify namespace of ToString() in compaction_service_test.cc to avoid function collision with CompactionService's ancestor classes
Test did:
make -j24 compaction_service_test
./compaction_service_test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8395
Reviewed By: jay-zhuang
Differential Revision: D29076068
Pulled By: hx235
fbshipit-source-id: c130100fa466939b3137e917f5fdc4b2ae8e37d4
Summary:
If the block Cache is full with strict_capacity_limit=false,
then our CacheEntryStatsCollector could be immediately evicted on
release, so iterating through column families with shared block cache
could trigger re-scan for each CF. This change fixes that problem by
pinning the CacheEntryStatsCollector from InternalStats so that it's not
evicted.
I had originally thought that this object could participate in LRU like
everything else, but even though a re-load+re-scan only touches memory,
it can be orders of magnitude more expensive than other cache misses.
One service in Facebook has scans that take ~20s over 100GB block cache
that is mostly 4KB entries. (The up-side of this bug and https://github.com/facebook/rocksdb/issues/8369 is that
we had a natural experiment on the effect on some service metrics even
with block cache scans running continuously in the background--a kind
of worst case scenario. Metrics like latency were not affected enough
to trigger warnings.)
Other smaller fixes:
20s is already a sizable portion of 600s stats dump period, or 180s
default max age to force re-scan, so added logic to ensure that (for
each block cache) we don't spend more than 0.2% of our background thread
time scanning it. Nevertheless, "foreground" requests for cache entry
stats (calls to `db->GetMapProperty(DB::Properties::kBlockCacheEntryStats)`)
are permitted to consume more CPU.
Renamed field to cache_entry_stats_ to match code style.
This change is intended for patching in 6.21 release.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8385
Test Plan:
unit test expanded to cover new logic (detect regression),
some manual testing with db_bench
Reviewed By: ajkr
Differential Revision: D29042759
Pulled By: pdillinger
fbshipit-source-id: 236faa902397f50038c618f50fbc8cf3f277308c
Summary:
Recalculate the total size after generate new sst files.
New generated files might have different size as the previous time which
could cause the test failed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8396
Test Plan:
```
gtest-parallel ./db_compaction_test
--gtest_filter=DBCompactionTest.ManualCompactionMax -r 1000 -w 100
```
Reviewed By: akankshamahajan15
Differential Revision: D29083299
Pulled By: jay-zhuang
fbshipit-source-id: 49d4bd619cefc0f9a1f452f8759ff4c2ba1b6fdb
Summary:
The subcompaction boundary picking logic does not currently guarantee
that all user keys that differ only by timestamp get processed by the same
subcompaction. This can cause issues with the `CompactionIterator` state
machine: for instance, one subcompaction that processes a subset of such KVs
might drop a tombstone based on the KVs it sees, while in reality the
tombstone might not have been eligible to be optimized out.
(See also https://github.com/facebook/rocksdb/issues/6645, which adjusted the way compaction inputs are picked for the
same reason.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8393
Test Plan: Ran `make check` and the crash test script with timestamps enabled.
Reviewed By: jay-zhuang
Differential Revision: D29071635
Pulled By: ltamasi
fbshipit-source-id: f6c72442122b4e581871e096fabe3876a9e8a5a6
Summary:
DBImpl::DumpStats is supposed to do this:
Dump DB stats to LOG
For each CF, dump CFStatsNoFileHistogram to LOG
For each CF, dump CFFileHistogram to LOG
Instead, due to a longstanding bug from 2017 (https://github.com/facebook/rocksdb/issues/2126), it would dump
CFStats, which includes both CFStatsNoFileHistogram and CFFileHistogram,
in both loops, resulting in near-duplicate output.
This fixes the bug.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8380
Test Plan: Manual inspection of LOG after db_bench
Reviewed By: jay-zhuang
Differential Revision: D29017535
Pulled By: pdillinger
fbshipit-source-id: 3010604c4a629a80347f129cd746ce9b0d0cbda6
Summary:
In the current logic, any IO Error with retryable flag == true will be handled by the special logic and in most cases, StartRecoverFromRetryableBGIOError will be called to do the auto resume. If the NoSpace error with retryable flag is set during WAL write, it is mapped as a hard error, which will trigger the auto recovery. During the recover process, if write continues and append to the WAL, the write process sees that bg_error is set to HardError and it calls WriteStatusCheck(), which calls SetBGError() with Status (not IOStatus). This will redirect to the regular SetBGError interface, in which recovery_error_ will be set to the corresponding error. With the recovery_error_ set, the auto resume thread created in StartRecoverFromRetryableBGIOError will keep failing as long as user keeps trying to write.
To fix this issue. All the NoSpace error (no matter retryable flag is set or not) will be redirect to the regular SetBGError, and RecoverFromNoSpace() will do the recovery job which calls SstFileManager::StartErrorRecovery().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8376
Test Plan: make check and added the new testing case
Reviewed By: anand1976
Differential Revision: D29071828
Pulled By: zhichao-cao
fbshipit-source-id: 7171d7e14cc4620fdab49b7eff7a2fe9a89942c2
Summary:
This PR add support for Merge operation in Integrated BlobDB with base values(i.e DB::Put). Merged values can be retrieved through DB::Get, DB::MultiGet, DB::GetMergeOperands and Iterator operation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8292
Test Plan: Add new unit tests
Reviewed By: ltamasi
Differential Revision: D28415896
Pulled By: akankshamahajan15
fbshipit-source-id: e9b3478bef51d2f214fb88c31ed3c8d2f4a531ff
Summary:
Changed fprintf function to fputc in ApplyVersionEdit, and replaced null characters with whitespaces.
Added unit test in ldb_test.py - verifies that manifest_dump --verbose output is correct when keys and values containing null characters are inserted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8378
Reviewed By: pdillinger
Differential Revision: D29034584
Pulled By: bjlemaire
fbshipit-source-id: 50833687a8a5f726e247c38457eadc3e6dbab862
Summary:
Currently, we either use the file system inode or a monotonically incrementing runtime ID as the block cache key prefix. However, if we use a monotonically incrementing runtime ID (in the case that the file system does not support inode id generation), in some cases, it cannot ensure uniqueness (e.g., we have secondary cache migrated from host to host). We use DbSessionID (20 bytes) + current file number (at most 10 bytes) as the new cache block key prefix when the secondary cache is enabled. So can accommodate scenarios such as transfer of cache state across hosts.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8360
Test Plan: add the test to lru_cache_test
Reviewed By: pdillinger
Differential Revision: D29006215
Pulled By: zhichao-cao
fbshipit-source-id: 6cff686b38d83904667a2bd39923cd030df16814
Summary:
Logically, subcompactions process a key range [start, end); however, the way
this is currently implemented is that the `CompactionIterator` for any given
subcompaction keeps processing key-values until it actually outputs a key that
is out of range, which is then discarded. Instead of doing this, the patch
introduces a new type of internal iterator called `ClippingIterator` which wraps
another internal iterator and "clips" its range of key-values so that any KVs
returned are strictly in the [start, end) interval. This does eliminate a (minor)
inefficiency by stopping processing in subcompactions exactly at the limit;
however, the main motivation is related to BlobDB: namely, we need this to be
able to measure the amount of garbage generated by a subcompaction
precisely and prevent off-by-one errors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8327
Test Plan: `make check`
Reviewed By: siying
Differential Revision: D28761541
Pulled By: ltamasi
fbshipit-source-id: ee0e7229f04edabbc7bed5adb51771fbdc287f69
Summary:
In final polishing of https://github.com/facebook/rocksdb/issues/8297 (after most manual testing), I
broke my own caching layer by sanitizing an input parameter with
std::min(0, x) instead of std::max(0, x). I resisted unit testing the
timing part of the result caching because historically, these test
are either flaky or difficult to write, and this was not a correctness
issue. This bug is essentially unnoticeable with a small number
of column families but can explode background work with a
large number of column families.
This change fixes the logical error, removes some unnecessary related
optimization, and adds mock time/sleeps to the unit test to ensure we
can cache hit within the age limit.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8369
Test Plan: added time testing logic to existing unit test
Reviewed By: ajkr
Differential Revision: D28950892
Pulled By: pdillinger
fbshipit-source-id: e79cd4ff3eec68fd0119d994f1ed468c38026c3b
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:
This is a duplicate of https://github.com/facebook/rocksdb/issues/4948 by mzhaom to fix tests after rebase.
This change is a follow-up to https://github.com/facebook/rocksdb/issues/4927, which made this possible by allowing tombstone dropping/seqnum zeroing optimizations on the last key in the compaction. Now the `largest_seqno != 0` condition suffices to prevent snapshot release triggered compaction from entering an infinite loop.
The issues caused by the extraneous condition `level_and_file.second->num_deletions > 1` are:
- files could have `largest_seqno > 0` forever making it impossible to tell they cannot contain any covering keys
- it doesn't trigger compaction when there are many overwritten keys. Some MyRocks use case actually doesn't use Delete but instead calls Put with empty value to "delete" keys, so we'd like to be able to trigger compaction in this case too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8357
Test Plan: - make check
Reviewed By: jay-zhuang
Differential Revision: D28855340
Pulled By: ajkr
fbshipit-source-id: a261b51eecafec492499e6d01e8e43112f801798
Summary:
I noticed ```openat``` system call with ```O_WRONLY``` flag and ```sync_file_range``` and ```truncate``` on WAL file when using ```rocksdb::DB::OpenForReadOnly``` by way of ```db_bench --readonly=true --benchmarks=readseq --use_existing_db=1 --num=1 ...```
Noticed in ```strace``` after seeing the last modification time of the WAL file change after each run (with ```--readonly=true```).
I think introduced by 7d7f14480e from https://github.com/facebook/rocksdb/pull/8122
I added a test to catch the WAL file being truncated and the modification time on it changing.
I am not sure if a mock filesystem with mock clock could be used to avoid having to sleep 1.1s.
The test could also check the set of files is the same and that the sizes are also unchanged.
Before:
```
[ RUN ] DBBasicTest.ReadOnlyReopenMtimeUnchanged
db/db_basic_test.cc:182: Failure
Expected equality of these values:
file_mtime_after_readonly_reopen
Which is: 1621611136
file_mtime_before_readonly_reopen
Which is: 1621611135
file is: 000010.log
[ FAILED ] DBBasicTest.ReadOnlyReopenMtimeUnchanged (1108 ms)
```
After:
```
[ RUN ] DBBasicTest.ReadOnlyReopenMtimeUnchanged
[ OK ] DBBasicTest.ReadOnlyReopenMtimeUnchanged (1108 ms)
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8313
Reviewed By: pdillinger
Differential Revision: D28656925
Pulled By: jay-zhuang
fbshipit-source-id: ea9e215cb53e7c830e76bc5fc75c45e21f12a1d6
Summary:
https://github.com/facebook/rocksdb/pull/8288 introduces a bug: SequenceIterWrapper should do next for seek key using internal key comparator rather than user comparator. Fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8328
Test Plan: Pass all existing tests
Reviewed By: ltamasi
Differential Revision: D28647263
fbshipit-source-id: 4081d684fd8a86d248c485ef8a1563c7af136447
Summary:
Error:
```
db/db_compaction_test.cc:5211:47: warning: The left operand of '*' is a garbage value
uint64_t total = (l1_avg_size + l2_avg_size * 10) * 10;
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8325
Test Plan: `$ make analyze`
Reviewed By: pdillinger
Differential Revision: D28620916
Pulled By: jay-zhuang
fbshipit-source-id: f6d58ab84eefbcc905cda45afb9522b0c6d230f8
Summary:
With Ribbon filter work and possible variance in actual bits
per key (or prefix; general term "entry") to achieve certain FP rates,
I've received a request to be able to track actual bits per key in
generated filters. This change adds a num_filter_entries table
property, which can be combined with filter_size to get bits per key
(entry).
This can vary from num_entries in at least these ways:
* Different versions of same key are only counted once in filters.
* With prefix filters, several user keys map to the same filter entry.
* A single filter can include both prefixes and user keys.
Note that FilterBlockBuilder::NumAdded() didn't do anything useful
except distinguish empty from non-empty.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8323
Test Plan: basic unit test included, others updated
Reviewed By: jay-zhuang
Differential Revision: D28596210
Pulled By: pdillinger
fbshipit-source-id: 529a111f3c84501e5a470bc84705e436ee68c376
Summary:
Fix a bug that for manual compaction, `max_compaction_bytes` is only
limit the SST files from input level, but not overlapped files on output
level.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8269
Test Plan: `make check`
Reviewed By: ajkr
Differential Revision: D28231044
Pulled By: jay-zhuang
fbshipit-source-id: 9d7d03004f30cc4b1b9819830141436907554b7c
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:
The test want to make sure these's no compaction during `AddFile`
(between `DBImpl::AddFile:MutexLock` and `DBImpl::AddFile:MutexUnlock`)
but the mutex could be unlocked by `EnterUnbatched()`.
Move the lock start point after bumping the ingest file number.
Also fix the dead lock when ASSERT fails.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8307
Reviewed By: ajkr
Differential Revision: D28479849
Pulled By: jay-zhuang
fbshipit-source-id: b3c50f66aa5d5f59c5c27f815bfea189c4cd06cb
Summary:
This change gathers and publishes statistics about the
kinds of items in block cache. This is especially important for
profiling relative usage of cache by index vs. filter vs. data blocks.
It works by iterating over the cache during periodic stats dump
(InternalStats, stats_dump_period_sec) or on demand when
DB::Get(Map)Property(kBlockCacheEntryStats), except that for
efficiency and sharing among column families, saved data from
the last scan is used when the data is not considered too old.
The new information can be seen in info LOG, for example:
Block cache LRUCache@0x7fca62229330 capacity: 95.37 MB collections: 8 last_copies: 0 last_secs: 0.00178 secs_since: 0
Block cache entry stats(count,size,portion): DataBlock(7092,28.24 MB,29.6136%) FilterBlock(215,867.90 KB,0.888728%) FilterMetaBlock(2,5.31 KB,0.00544%) IndexBlock(217,180.11 KB,0.184432%) WriteBuffer(1,256.00 KB,0.262144%) Misc(1,0.00 KB,0%)
And also through DB::GetProperty and GetMapProperty (here using
ldb just for demonstration):
$ ./ldb --db=/dev/shm/dbbench/ get_property rocksdb.block-cache-entry-stats
rocksdb.block-cache-entry-stats.bytes.data-block: 0
rocksdb.block-cache-entry-stats.bytes.deprecated-filter-block: 0
rocksdb.block-cache-entry-stats.bytes.filter-block: 0
rocksdb.block-cache-entry-stats.bytes.filter-meta-block: 0
rocksdb.block-cache-entry-stats.bytes.index-block: 178992
rocksdb.block-cache-entry-stats.bytes.misc: 0
rocksdb.block-cache-entry-stats.bytes.other-block: 0
rocksdb.block-cache-entry-stats.bytes.write-buffer: 0
rocksdb.block-cache-entry-stats.capacity: 8388608
rocksdb.block-cache-entry-stats.count.data-block: 0
rocksdb.block-cache-entry-stats.count.deprecated-filter-block: 0
rocksdb.block-cache-entry-stats.count.filter-block: 0
rocksdb.block-cache-entry-stats.count.filter-meta-block: 0
rocksdb.block-cache-entry-stats.count.index-block: 215
rocksdb.block-cache-entry-stats.count.misc: 1
rocksdb.block-cache-entry-stats.count.other-block: 0
rocksdb.block-cache-entry-stats.count.write-buffer: 0
rocksdb.block-cache-entry-stats.id: LRUCache@0x7f3636661290
rocksdb.block-cache-entry-stats.percent.data-block: 0.000000
rocksdb.block-cache-entry-stats.percent.deprecated-filter-block: 0.000000
rocksdb.block-cache-entry-stats.percent.filter-block: 0.000000
rocksdb.block-cache-entry-stats.percent.filter-meta-block: 0.000000
rocksdb.block-cache-entry-stats.percent.index-block: 2.133751
rocksdb.block-cache-entry-stats.percent.misc: 0.000000
rocksdb.block-cache-entry-stats.percent.other-block: 0.000000
rocksdb.block-cache-entry-stats.percent.write-buffer: 0.000000
rocksdb.block-cache-entry-stats.secs_for_last_collection: 0.000052
rocksdb.block-cache-entry-stats.secs_since_last_collection: 0
Solution detail - We need some way to flag what kind of blocks each
entry belongs to, preferably without changing the Cache API.
One of the complications is that Cache is a general interface that could
have other users that don't adhere to whichever convention we decide
on for keys and values. Or we would pay for an extra field in the Handle
that would only be used for this purpose.
This change uses a back-door approach, the deleter, to indicate the
"role" of a Cache entry (in addition to the value type, implicitly).
This has the added benefit of ensuring proper code origin whenever we
recognize a particular role for a cache entry; if the entry came from
some other part of the code, it will use an unrecognized deleter, which
we simply attribute to the "Misc" role.
An internal API makes for simple instantiation and automatic
registration of Cache deleters for a given value type and "role".
Another internal API, CacheEntryStatsCollector, solves the problem of
caching the results of a scan and sharing them, to ensure scans are
neither excessive nor redundant so as not to harm Cache performance.
Because code is added to BlocklikeTraits, it is pulled out of
block_based_table_reader.cc into its own file.
This is a reformulation of https://github.com/facebook/rocksdb/issues/8276, without the type checking option
(could still be added), and with actual stat gathering.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8297
Test Plan: manual testing with db_bench, and a couple of basic unit tests
Reviewed By: ltamasi
Differential Revision: D28488721
Pulled By: pdillinger
fbshipit-source-id: 472f524a9691b5afb107934be2d41d84f2b129fb
Baptiste Lemaire