Summary:
The batched version of MultiGet() is not available in RocksDB's C API.
This PR implements rocksdb_batched_multi_get_cf which is a C wrapper function
that invokes the batched version of MultiGet() which takes one single column family.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9952
Test Plan: Added a new test case under "columnfamilies" test case in c_test.cc
Reviewed By: riversand963
Differential Revision: D36302888
Pulled By: ajkr
fbshipit-source-id: fa134c4a1c8e7d72dd4ae8649a74e3797b5cf4e6
Summary:
dont -> don't
refered -> referred
This is a re-run of PR#7785 and acc9679 since these typos keep coming back.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9653
Reviewed By: jay-zhuang
Differential Revision: D34879593
fbshipit-source-id: d7631fb779ea0129beae92abfb838038e60790f8
Summary:
PR 9929 adds a new CompactionFilter::Decision, i.e.
kRemoveWithSingleDelete so that CompactionFilter can indicate to
CompactionIterator that a PUT can only be removed with SD. However, how
CompactionIterator handles such a key is implementation detail which
should not be implied in the public API. In fact,
such a PUT can just be dropped. This is an optimization which we will apply in the near future.
Discussion thread: https://github.com/facebook/rocksdb/pull/9929#discussion_r863198964
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9951
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D36156590
Pulled By: riversand963
fbshipit-source-id: 7b7d01f47bba4cad7d9cca6ca52984f27f88b372
Summary:
If the DB path is specified, the user would expect ldb loads the
options from the path, but it's not:
```
$ ldb list_live_files_metadata --db=`pwd`
```
Default `try_load_options` to true in that case. The user can still
disable that by:
```
$ ldb list_live_files_metadata --db=`pwd` --try_load_options=false
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9937
Test Plan:
`ldb list_live_files_metadata --db=`pwd`` is able to work for
a db generated with different options.num_levels.
Reviewed By: ajkr
Differential Revision: D36106708
Pulled By: jay-zhuang
fbshipit-source-id: 2732fdc027a4d172436b2c9b6a9787b56b10c710
Summary:
It confused users and use that with options.allow_mmap_reads = true, CPU is high with checksum verification. Add a comment to explain it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9936
Reviewed By: anand1976
Differential Revision: D36106529
fbshipit-source-id: 3d723bd686f96a84c694c8b2d91ad28d9ccfd979
Summary:
When compaction filter determines that a key should be removed, it updates the internal key's type
to `Delete`. If this internal key is preserved in current compaction but seen by a later compaction
together with `SingleDelete`, it will cause compaction iterator to return Corruption.
To fix the issue, compaction filter should return more information in addition to the intention of removing
a key. Therefore, we add a new `kRemoveWithSingleDelete` to `CompactionFilter::Decision`. Seeing
`kRemoveWithSingleDelete`, compaction iterator will update the op type of the internal key to `kTypeSingleDelete`.
In addition, I updated db_stress_shared_state.[cc|h] so that `no_overwrite_ids_` becomes `const`. It is easier to
reason about thread-safety if accessed from multiple threads. This information is passed to `PrepareTxnDBOptions()`
when calling from `Open()` so that we can set up the rollback deletion type callback for transactions.
Finally, disable compaction filter for multiops_txn because the key removal logic of `DbStressCompactionFilter` does
not quite work with `MultiOpsTxnsStressTest`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9929
Test Plan:
make check
make crash_test
make crash_test_with_txn
Reviewed By: anand1976
Differential Revision: D36069678
Pulled By: riversand963
fbshipit-source-id: cedd2f1ba958af59ad3916f1ba6f424307955f92
Summary:
`VerifyChecksum()` does not specify `largest_seqno` when creating a `TableReader`. As a result, the `TableReader` uses the `TableReaderOptions` default value (0) for `largest_seqno`. This causes the following error when the file has a nonzero global seqno in its properties:
```
Corruption: An external sst file with version 2 have global seqno property with value , while largest seqno in the file is 0
```
This PR fixes this by specifying `largest_seqno` in `VerifyChecksumInternal` with `largest_seqno` from the file metadata.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9919
Test Plan: `make check`
Reviewed By: ajkr
Differential Revision: D36028824
Pulled By: cbi42
fbshipit-source-id: 428d028a79386f46ef97bb6b6051dc76c83e1f2b
Summary:
When MultiGet() determines that multiple query keys can be
served by examining the same data block in block cache (one Lookup()),
each PinnableSlice referring to data in that data block needs to hold
on to the block in cache so that they can be released at arbitrary
times by the API user. Historically this is accomplished with extra
calls to Ref() on the Handle from Lookup(), with each PinnableSlice
cleanup calling Release() on the Handle, but this creates extra
contention on the block cache for the extra Ref()s and Release()es,
especially because they hit the same cache shard repeatedly.
In the case of merge operands (possibly more cases?), the problem was
compounded by doing an extra Ref()+eventual Release() for each merge
operand for a key reusing a block (which could be the same key!), rather
than one Ref() per key. (Note: the non-shared case with `biter` was
already one per key.)
This change optimizes MultiGet not to rely on these extra, contentious
Ref()+Release() calls by instead, in the shared block case, wrapping
the cache Release() cleanup in a refcounted object referenced by the
PinnableSlices, such that after the last wrapped reference is released,
the cache entry is Release()ed. Relaxed atomic refcounts should be
much faster than mutex-guarded Ref() and Release(), and much less prone
to a performance cliff when MultiGet() does a lot of block sharing.
Note that I did not use std::shared_ptr, because that would require an
extra indirection object (shared_ptr itself new/delete) in order to
associate a ref increment/decrement with a Cleanable cleanup entry. (If
I assumed it was the size of two pointers, I could do some hackery to
make it work without the extra indirection, but that's too fragile.)
Some details:
* Fixed (removed) extra block cache tracing entries in cases of cache
entry reuse in MultiGet, but it's likely that in some other cases traces
are missing (XXX comment inserted)
* Moved existing implementations for cleanable.h from iterator.cc to
new cleanable.cc
* Improved API comments on Cleanable
* Added a public SharedCleanablePtr class to cleanable.h in case others
could benefit from the same pattern (potentially many Cleanables and/or
smart pointers referencing a shared Cleanable)
* Add a typedef for MultiGetContext::Mask
* Some variable renaming for clarity
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9899
Test Plan:
Added unit tests for SharedCleanablePtr.
Greatly enhanced ability of existing tests to detect cache use-after-free.
* Release PinnableSlices from MultiGet as they are read rather than in
bulk (in db_test_util wrapper).
* In ASAN build, default to using a trivially small LRUCache for block_cache
so that entries are immediately erased when unreferenced. (Updated two
tests that depend on caching.) New ASAN testsuite running time seems
OK to me.
If I introduce a bug into my implementation where we skip the shared
cleanups on block reuse, ASAN detects the bug in
`db_basic_test *MultiGet*`. If I remove either of the above testing
enhancements, the bug is not detected.
Consider for follow-up work: manipulate or randomize ordering of
PinnableSlice use and release from MultiGet db_test_util wrapper. But in
typical cases, natural ordering gives pretty good functional coverage.
Performance test:
In the extreme (but possible) case of MultiGetting the same or adjacent keys
in a batch, throughput can improve by an order of magnitude.
`./db_bench -benchmarks=multireadrandom -db=/dev/shm/testdb -readonly -num=5 -duration=10 -threads=20 -multiread_batched -batch_size=200`
Before ops/sec, num=5: 1,384,394
Before ops/sec, num=500: 6,423,720
After ops/sec, num=500: 10,658,794
After ops/sec, num=5: 16,027,257
Also note that previously, with high parallelism, having query keys
concentrated in a single block was worse than spreading them out a bit. Now
concentrated in a single block is faster than spread out, which is hopefully
consistent with natural expectation.
Random query performance: with num=1000000, over 999 x 10s runs running before & after simultaneously (each -threads=12):
Before: multireadrandom [AVG 999 runs] : 1088699 (± 7344) ops/sec; 120.4 (± 0.8 ) MB/sec
After: multireadrandom [AVG 999 runs] : 1090402 (± 7230) ops/sec; 120.6 (± 0.8 ) MB/sec
Possibly better, possibly in the noise.
Reviewed By: anand1976
Differential Revision: D35907003
Pulled By: pdillinger
fbshipit-source-id: bbd244d703649a8ca12d476f2d03853ed9d1a17e
Summary:
Add stats PREFETCHED_BYTES_DISCARDED and POLL_WAIT_MICROS.
PREFETCHED_BYTES_DISCARDED records number of prefetched bytes discarded by
FilePrefetchBuffer. POLL_WAIT_MICROS records the time taken by underling
file_system Poll API.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9845
Test Plan: Update existing tests
Reviewed By: anand1976
Differential Revision: D35909694
Pulled By: akankshamahajan15
fbshipit-source-id: e009ef940bb9ed72c9446f5529095caabb8a1e36
Summary:
This patch is the first part of adding blob dump support. It only adds blob dump support to the dump command. A follow up patch will add blob dump support to the dump_live_files command.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9881
Reviewed By: ltamasi
Differential Revision: D35796731
Pulled By: jowlyzhang
fbshipit-source-id: 2cc5973b222d505a331ac7b969edcf992b47c5ee
Summary:
This PR does not affect write-committed.
Add a member, `rollback_deletion_type_callback` to TransactionDBOptions
so that a write-prepared transaction, when rolling back, can call this
callback to decide if a `Delete` or `SingleDelete` should be used to
cancel a prior `Put` written to the database during prepare phase.
The purpose of this PR is to prevent mixing `Delete` and `SingleDelete`
for the same key, causing undefined behaviors. Without this PR, the
following can happen:
```
// The application always issues SingleDelete when deleting keys.
txn1->Put('a');
txn1->Prepare(); // writes to memtable and potentially gets flushed/compacted to Lmax
txn1->Rollback(); // inserts DELETE('a')
txn2->Put('a');
txn2->Commit(); // writes to memtable and potentially gets flushed/compacted
```
In the database, we may have
```
L0: [PUT('a', s=100)]
L1: [DELETE('a', s=90)]
Lmax: [PUT('a', s=0)]
```
If a compaction compacts L0 and L1, then we have
```
L1: [PUT('a', s=100)]
Lmax: [PUT('a', s=0)]
```
If a future transaction issues a SingleDelete, we have
```
L0: [SD('a', s=110)]
L1: [PUT('a', s=100)]
Lmax: [PUT('a', s=0)]
```
Then, a compaction including L0, L1 and Lmax leads to
```
Lmax: [PUT('a', s=0)]
```
which is incorrect.
Similar bugs reported and addressed in
https://github.com/cockroachdb/pebble/issues/1255. Based on our team's
current priority, we have decided to take this approach for now. We may
come back and revisit in the future.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9873
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D35762170
Pulled By: riversand963
fbshipit-source-id: b28d56eefc786b53c9844b9ef4a7807acdd82c8d
Summary:
... by filling out remaining testing hole: handling of
db_pathsi+cf_paths. (Note that while GetLiveFilesStorageInfo works
with db_paths / cf_paths, Checkpoint and BackupEngine do not and
are marked appropriately.)
Also improved comments for "live files" APIs, and grouped them
together in db.h.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9868
Test Plan: Adding to existing unit tests
Reviewed By: jay-zhuang
Differential Revision: D35752254
Pulled By: pdillinger
fbshipit-source-id: c70eb67748fad61826e2f554b674638700abefb2
Summary:
This allows to set with true the field `strict_capacity_limit` from C
API and other languages that wrap that.
Signed-off-by: Federico Guerinoni <guerinoni.federico@gmail.com>
Closes: https://github.com/facebook/rocksdb/issues/9707
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9855
Reviewed By: ajkr
Differential Revision: D35724150
Pulled By: jay-zhuang
fbshipit-source-id: d8514797e9d90b1cd88329018f9ac4776722aa0f
Summary:
Add a merge operator that allows users to register specific aggregation function so that they can does aggregation based per key using different aggregation types.
See comments of function CreateAggMergeOperator() for actual usage.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9780
Test Plan: Add a unit test to coverage various cases.
Reviewed By: ltamasi
Differential Revision: D35267444
fbshipit-source-id: 5b02f31c4f3e17e96dd4025cdc49fca8c2868628
Summary:
This new options allows application to specify that files must be
ingested to bottommost level, otherwise the ingestion will fail instead
of silently ingesting to a non-bottommost level.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9849
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D35680307
Pulled By: riversand963
fbshipit-source-id: 01cf54ef6c76198f7654dc06b5544631dea1be1e
Summary:
This change only add decode blob index support to dump_live_files command, which is part of a task to add blob support to a few commands.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9842
Reviewed By: ltamasi
Differential Revision: D35650167
Pulled By: jowlyzhang
fbshipit-source-id: a78151b98bc38ac6f52c6e01ca6927a3429ddd14
Summary:
Make `DB::GetUpdatesSince` return early if told to scan WALs generated by transactions
with write-prepared or write-unprepared policies (`seq_per_batch` is true), as indicated by
API comment.
Also add checks to `TransactionLogIterator` to clarify some conditions.
No API change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9459
Test Plan:
make check
Closing https://github.com/facebook/rocksdb/issues/1565
Reviewed By: akankshamahajan15
Differential Revision: D33821243
Pulled By: riversand963
fbshipit-source-id: c8b155d020ce0980e2d3b3b1da40b96e65b48d79
Summary:
This gives users the ability to examine the map populated by `GetMapProperty()` with property `kBlockCacheEntryStats`. It also sets us up for a possible future where cache reservations are configured according to `CacheEntryRole`s rather than flags coupled to roles.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9838
Test Plan:
- migrated test DBBlockCacheTest.CacheEntryRoleStats to use this API. That test verifies some of the contents are as expected
- added a DBPropertiesTest to verify the public map keys are present, and nothing else
Reviewed By: hx235
Differential Revision: D35629493
Pulled By: ajkr
fbshipit-source-id: 5c4356b8560e85d1f881fd32c44c15960b02fc68
Summary:
This information has been already available as part of the `rocksdb.blob-stats`
string property. The patch adds a dedicated integer property to make it easier
to surface this information in monitoring systems.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9835
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D35619495
Pulled By: ltamasi
fbshipit-source-id: 03fb0b228aa27d3859a1e3783bcb7eca095607f8
Summary:
Add the ability to cancel remote compaction on the remote side by
setting `OpenAndCompactOptions.canceled` to true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9725
Test Plan: added unittest
Reviewed By: ajkr
Differential Revision: D35018800
Pulled By: jay-zhuang
fbshipit-source-id: be3652f9645e0347df429e42a5614d5a9b3a1ec4
Summary:
Henceforth, the version number in version.h shall reflect the
*next* version number to be tagged (to the best of our knowledge) rather
than the *previous* (unpatched) version.
The primary advantage is being able to distinguish (in source code `#if`s
or human running tools) the development version from the last released
version.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9834
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D35617373
Pulled By: pdillinger
fbshipit-source-id: f3286089d17b82409e6af08e5aa9c1affefe2862
Summary:
So the user is able to set event listener on the compactor
side.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9821
Test Plan: unittest added
Reviewed By: ajkr
Differential Revision: D35485388
Pulled By: jay-zhuang
fbshipit-source-id: 669d8a3aaee012b75b940470306756c03ffa09b2
Summary:
Added a Plugin class to the ObjectRegistry. Enabled compile-time and program-time addition of plugins to the Registry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7949
Reviewed By: mrambacher
Differential Revision: D33517674
Pulled By: pdillinger
fbshipit-source-id: c3e3270aab76a489bfa9e85d78cdfca951912557
Summary:
Update stats in random_access_file_reader for Read and
ReadAsync API to take into account the read latency for async
prefetching.
It also fixes ERROR_HANDLER_AUTORESUME_RETRY_COUNT stat whose value was
incorrect in portal.h
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9810
Test Plan: Update unit test
Reviewed By: anand1976
Differential Revision: D35433081
Pulled By: akankshamahajan15
fbshipit-source-id: aeec3901270e58a003ce6b5214bd25ddcb3a12a9
Summary:
The name of this property "kIsFileDeletionsEnabled" is very, very easy to misunderstand.
I think 0 represents false (i.e. disabled) and non-0 means true (enabled), and this property is just the opposite.
I modified the name of this property, and as few other positions as possible, so that the final meaning remains the same, but the name of this property is more common sense.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9791
Reviewed By: ajkr
Differential Revision: D35362166
Pulled By: jay-zhuang
fbshipit-source-id: 85310d88bdd131893effb64e1adb7d0d7b202f88
Summary:
For write-prepared/write-unprepared transactions,
GetCommitTimeWriteBatch() can be used only if the transaction is started
with `TransactionOptions::use_only_the_last_commit_time_batch_for_recovery` set
to true. Otherwise, it is possible that multiple uncommitted versions of the
same key exist in the database. During bottommost compaction, RocksDB may
set the sequence numbers of both to zero once they become committed, causing
output SST file to have two identical internal keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9794
Test Plan:
make check
pay special attention to the following
```
transaction_test --gtest_filter=MySQLStyleTransactionTest/MySQLStyleTransactionTest.TransactionStressTest/*
```
Reviewed By: lth
Differential Revision: D35327214
Pulled By: riversand963
fbshipit-source-id: 3bae00a28359c10e96e4c6f676d20de5610d8a0f
Summary:
**Context/Todo:**
As requested, allow IOOptions to take in an Env::IOPriority for convenience to pass down rate limiter related hint to file system level and for future interaction between RocksDB internal's rate limiting and custom file system level's rate-limiting.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9806
Test Plan: No actual code changes in RocksDB internals
Reviewed By: ajkr
Differential Revision: D35388966
Pulled By: hx235
fbshipit-source-id: 5891c97c3f9184cd221a9ab8536ce8dfa8526c08
Summary:
much needed
Some other minor tweaks also
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9778
Test Plan: existing tests
Reviewed By: ajkr
Differential Revision: D35258195
Pulled By: pdillinger
fbshipit-source-id: 974ddafc23a540aacceb91da72e81593d818f99c
Summary:
In making `SstFileMetaData` inherit from `FileStorageInfo`, I
overlooked setting some `FileStorageInfo` fields when then default
`SstFileMetaData()` ctor is used. This affected `GetLiveFilesMetaData()`.
Also removed some buggy `static_cast<size_t>`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9769
Test Plan: Updated tests
Reviewed By: jay-zhuang
Differential Revision: D35220383
Pulled By: pdillinger
fbshipit-source-id: 05b4ee468258dbd3699517e1124838bf405fe7f8
Summary:
Fixes https://github.com/facebook/rocksdb/issues/9718
The verify_checksums flag of read_options should be passed to the read options used by the BlockFetcher in a couple of cases where it is not at present. It will now happen (but did not, previously) on iteration and on [multi]get, where a fetcher is created as part of the iterate/get call.
This may result in much better performance in a few workloads where the client chooses to remove verification.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9767
Reviewed By: mrambacher
Differential Revision: D35218986
Pulled By: jay-zhuang
fbshipit-source-id: 329d29764bb70fbc7f2673440bc46c107a813bc8
Summary:
Bloom filters generated by pre-7.0 releases are not read by
7.0.x releases (and vice-versa) due to changes to FilterPolicy::Name()
in https://github.com/facebook/rocksdb/issues/9590. This can severely impact read performance and read I/O on
upgrade or downgrade with existing DB, but not data correctness.
To fix, we go back using the old, unified name in SST metadata but (for
a while anyway) recognize the aliases that could be generated by early
7.0.x releases. This unfortunately requires a public API change to avoid
interfering with all the good changes from https://github.com/facebook/rocksdb/issues/9590, but the API change
only affects users with custom FilterPolicy, which should be very few.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9736
Test Plan:
manual
Generate DBs with
```
./db_bench.7.0 -db=/dev/shm/rocksdb.7.0 -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=fillrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0
```
and similar. Compare with
```
for IMPL in 6.29 7.0 fixed; do for DB in 6.29 7.0 fixed; do echo "Testing $IMPL on $DB:"; ./db_bench.$IMPL -db=/dev/shm/rocksdb.$DB -use_existing_db -readonly -bloom_bits=10 -benchmarks=readrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -duration=10 2>&1 | grep micros/op; done; done
```
Results:
```
Testing 6.29 on 6.29:
readrandom : 34.381 micros/op 29085 ops/sec; 3.2 MB/s (291999 of 291999 found)
Testing 6.29 on 7.0:
readrandom : 190.443 micros/op 5249 ops/sec; 0.6 MB/s (52999 of 52999 found)
Testing 6.29 on fixed:
readrandom : 40.148 micros/op 24907 ops/sec; 2.8 MB/s (249999 of 249999 found)
Testing 7.0 on 6.29:
readrandom : 229.430 micros/op 4357 ops/sec; 0.5 MB/s (43999 of 43999 found)
Testing 7.0 on 7.0:
readrandom : 33.348 micros/op 29986 ops/sec; 3.3 MB/s (299999 of 299999 found)
Testing 7.0 on fixed:
readrandom : 152.734 micros/op 6546 ops/sec; 0.7 MB/s (65999 of 65999 found)
Testing fixed on 6.29:
readrandom : 32.024 micros/op 31224 ops/sec; 3.5 MB/s (312999 of 312999 found)
Testing fixed on 7.0:
readrandom : 33.990 micros/op 29390 ops/sec; 3.3 MB/s (294999 of 294999 found)
Testing fixed on fixed:
readrandom : 28.714 micros/op 34825 ops/sec; 3.9 MB/s (348999 of 348999 found)
```
Just paying attention to order of magnitude of ops/sec (short test
durations, lots of noise), it's clear that with the fix we can read <= 6.29
& >= 7.0 at full speed, where neither 6.29 nor 7.0 can on both. And 6.29
release can properly read fixed DB at full speed.
Reviewed By: siying, ajkr
Differential Revision: D35057844
Pulled By: pdillinger
fbshipit-source-id: a46893a6af4bf084375ebe4728066d00eb08f050
Summary:
The param name force_erase may be misleading, since the handle is erased only if it has last reference even if the param is set true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9728
Reviewed By: pdillinger
Differential Revision: D35038673
Pulled By: gitbw95
fbshipit-source-id: 0d16d1e8fed17b97eba7fb53207119332f659a5f
Summary:
In FilePrefetchBuffer if reads are sequential, after prefetching call ReadAsync API to prefetch data asynchronously so that in next prefetching data will be available. Data prefetched asynchronously will be readahead_size/2. It uses two buffers, one for synchronous prefetching and one for asynchronous. In case, the data is overlapping, the data is copied from both buffers to third buffer to make it continuous.
This feature is under ReadOptions::async_io and is under experimental.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9674
Test Plan:
1. Add new unit tests
2. Run **db_stress** to make sure nothing crashes.
- Normal prefetch without `async_io` ran successfully:
```
export CRASH_TEST_EXT_ARGS=" --async_io=0"
make crash_test -j
```
3. **Run Regressions**.
i) Main branch without any change for normal prefetching with async_io disabled:
```
./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -
use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216
```
```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB: version 7.0
Date: Thu Mar 17 13:11:34 2022
CPU: 24 * Intel Core Processor (Broadwell)
CPUCache: 16384 KB
Keys: 32 bytes each (+ 0 bytes user-defined timestamp)
Values: 512 bytes each (256 bytes after compression)
Entries: 5000000
Prefix: 0 bytes
Keys per prefix: 0
RawSize: 2594.0 MB (estimated)
FileSize: 1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_main]
seekrandom : 483618.390 micros/op 2 ops/sec; 338.9 MB/s (249 of 249 found)
```
ii) normal prefetching after changes with async_io disable:
```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_withchange -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB: version 7.0
Date: Thu Mar 17 14:11:31 2022
CPU: 24 * Intel Core Processor (Broadwell)
CPUCache: 16384 KB
Keys: 32 bytes each (+ 0 bytes user-defined timestamp)
Values: 512 bytes each (256 bytes after compression)
Entries: 5000000
Prefix: 0 bytes
Keys per prefix: 0
RawSize: 2594.0 MB (estimated)
FileSize: 1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_withchange]
seekrandom : 471347.227 micros/op 2 ops/sec; 348.1 MB/s (255 of 255 found)
```
Reviewed By: anand1976
Differential Revision: D34731543
Pulled By: akankshamahajan15
fbshipit-source-id: 8e23aa93453d5fe3c672b9231ad582f60207937f
Summary:
The goal of this change is to allow changes to the "current" (in
FileSystem) file temperatures to feed back into DB metadata, so that
they can inform decisions and stats reporting. In part because of
modular code factoring, it doesn't seem easy to do this automagically,
where opening an SST file and observing current Temperature different
from expected would trigger a change in metadata and DB manifest write
(essentially giving the deep read path access to the write path). It is also
difficult to do this while the DB is open because of the limitations of
LogAndApply.
This change allows updating file temperature metadata on a closed DB
using an experimental utility function UpdateManifestForFilesState()
or `ldb update_manifest --update_temperatures`. This should suffice for
"migration" scenarios where outside tooling has placed or re-arranged DB
files into a (different) tiered configuration without going through
RocksDB itself (currently, only compaction can change temperature
metadata).
Some details:
* Refactored and added unit test for `ldb unsafe_remove_sst_file` because
of shared functionality
* Pulled in autovector.h changes from https://github.com/facebook/rocksdb/issues/9546 to fix SuperVersionContext
move constructor (related to an older draft of this change)
Possible follow-up work:
* Support updating manifest with file checksums, such as when a
new checksum function is used and want existing DB metadata updated
for it.
* It's possible that for some repair scenarios, lighter weight than
full repair, we might want to support UpdateManifestForFilesState() to
modify critical file details like size or checksum using same
algorithm. But let's make sure these are differentiated from modifying
file details in ways that don't suspect corruption (or require extreme
trust).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9683
Test Plan: unit tests added
Reviewed By: jay-zhuang
Differential Revision: D34798828
Pulled By: pdillinger
fbshipit-source-id: cfd83e8fb10761d8c9e7f9c020d68c9106a95554
Summary:
The primary goal of this change is to add support for backing up and
restoring (applying on restore) file temperature metadata, without
committing to either the DB manifest or the FS reported "current"
temperatures being exclusive "source of truth".
To achieve this goal, we need to add temperature information to backup
metadata, which requires updated backup meta schema. Fortunately I
prepared for this in https://github.com/facebook/rocksdb/issues/8069, which began forward compatibility in version
6.19.0 for this kind of schema update. (Previously, backup meta schema
was not extensible! Making this schema update public will allow some
other "nice to have" features like taking backups with hard links, and
avoiding crc32c checksum computation when another checksum is already
available.) While schema version 2 is newly public, the default schema
version is still 1. Until we change the default, users will need to set
to 2 to enable features like temperature data backup+restore. New
metadata like temperature information will be ignored with a warning
in versions before this change and since 6.19.0. The metadata is
considered ignorable because a functioning DB can be restored without
it.
Some detail:
* Some renaming because "future schema" is now just public schema 2.
* Initialize some atomics in TestFs (linter reported)
* Add temperature hint support to SstFileDumper (used by BackupEngine)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9660
Test Plan:
related unit test majorly updated for the new functionality,
including some shared testing support for tracking temperatures in a FS.
Some other tests and testing hooks into production code also updated for
making the backup meta schema change public.
Reviewed By: ajkr
Differential Revision: D34686968
Pulled By: pdillinger
fbshipit-source-id: 3ac1fa3e67ee97ca8a5103d79cc87d872c1d862a
Yueh-Hsuan Chiang