Summary:
With some new use cases onboarding to prefix extractors/seek/filters, one of the risks is existing iterator code, e.g. for maintenance tasks, being unintentionally subject to prefix seek semantics. This is a longstanding known design flaw with prefix seek, and `prefix_same_as_start` and `auto_prefix_mode` were steps in the direction of making that obsolete. However, we can't just immediately set `total_order_seek` to true by default, because that would impact so much code instantly.
Here we add a new DB option, `prefix_seek_opt_in_only` that basically allows users to transition to the future behavior when they are ready. When set to true, all iterators will be treated as if `total_order_seek=true` and then the only ways to get prefix seek semantics are with `prefix_same_as_start` or `auto_prefix_mode`.
Related fixes / changes:
* Make sure that `prefix_same_as_start` and `auto_prefix_mode` are compatible with (or override) `total_order_seek` (depending on your interpretation).
* Fix a bug in which a new iterator after dynamically changing the prefix extractor might mix different prefix semantics between memtable and SSTs. Both should use the latest extractor semantics, which means iterators ignoring memtable prefix filters with an old extractor. And that means passing the latest prefix extractor to new memtable iterators that might use prefix seek. (Without the fix, the test added for this fails in many ways.)
Suggested follow-up:
* Investigate a FIXME where a MergeIteratorBuilder is created in db_impl.cc. No unit test detects a change in value that should impact correctness.
* Make memtable prefix bloom compatible with `auto_prefix_mode`, which might require involving the memtablereps because we don't know at iterator creation time (only seek time) whether an auto_prefix_mode seek will be a prefix seek.
* Add `prefix_same_as_start` testing to db_stress
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13026
Test Plan:
tests updated, added. Add combination of `total_order_seek=true` and `auto_prefix_mode=true` to stress test. Ran `make blackbox_crash_test` for a long while.
Manually ran tests with `prefix_seek_opt_in_only=true` as default, looking for unexpected issues. I inspected most of the results and migrated many tests to be ready for such a change (but not all).
Reviewed By: ltamasi
Differential Revision: D63147378
Pulled By: pdillinger
fbshipit-source-id: 1f4477b730683d43b4be7e933338583702d3c25e
Summary:
* Set write_dbid_to_manifest=true by default
* Add new option write_identity_file (default true) that allows us to opt-in to future behavior without identity file
* Refactor related DB open code to minimize code duplication
_Recommend hiding whitespace changes for review_
Intended follow-up: add support to ldb for reading and even replacing the DB identity in the manifest. Could be a variant of `update_manifest` command or based on it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13019
Test Plan: unit tests and stress test updated for new functionality
Reviewed By: anand1976
Differential Revision: D62898229
Pulled By: pdillinger
fbshipit-source-id: c08b25cf790610b034e51a9de0dc78b921abbcf0
Summary:
We have a request to use the cold tier as primary source of truth for the DB, and to best support such use cases and to complement the existing options controlling SST file temperatures, we add two new DB options:
* `metadata_write_temperature` for DB "small" files that don't contain much user data
* `wal_write_temperature` for WALs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12957
Test Plan: Unit test included, though it's hard to be sure we've covered all the places
Reviewed By: jowlyzhang
Differential Revision: D61664815
Pulled By: pdillinger
fbshipit-source-id: 8e19c9dd8fd2db059bb15f74938d6bc12002e82b
Summary:
POSIX semantics for LinkFile (hard links) allow linking a file
that is still being written two, with both the source and destination
showing any subsequent writes to the source. This may not be practical
semantics for some FileSystem implementations such as remote storage.
They might only link the flushed or sync-ed file contents at time of
LinkFile, or might even have undefined behavior if LinkFile is called on
a file still open for write (not yet "sealed"). This change builds on https://github.com/facebook/rocksdb/issues/12731
to bring more hygiene to our handling of WAL files in Checkpoint.
Specifically, we now Close WAL files as soon as they are either
(a) inactive and fully synced, or (b) inactive and obsolete (so maybe
never fully synced), rather than letting Close() happen in handling
obsolete files (maybe a background thread). This should not be a
performance issue as Close() should be trivial cost relative to other
IO ops, but just in case:
* We don't Close() while holding a mutex, to avoid blocking, and
* The old behavior is available with a new kill switch option
`background_close_inactive_wals`.
Stacked on https://github.com/facebook/rocksdb/issues/12731
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12734
Test Plan:
Extended existing unit test, especially adding a hygiene
check to FaultInjectionTestFS to detect LinkFile() on a file still open
for writes. FaultInjectionTestFS already has relevant tracking data, and
tests can opt out of the new check, as in a smoke test I have left for
the old, deprecated functionality `background_close_inactive_wals=true`.
Also ran lengthy blackbox_crash_test to ensure the hygiene check is OK
with the crash test. (The only place I can find we use LinkFile in
production is Checkpoint.)
Reviewed By: cbi42
Differential Revision: D58295284
Pulled By: pdillinger
fbshipit-source-id: 64d90ed8477e2366c19eaf9c4c5ad60b82cac5c6
Summary:
**Context/Summary:** a better API design is decided lately so we decided to revert these two changes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12738
Test Plan: - CI
Reviewed By: ajkr
Differential Revision: D58162165
Pulled By: hx235
fbshipit-source-id: 9bbe4d2fe9fbe39213f4cf137a2d419e6ffb8e16
Summary:
A basic implementation of RocksDB follower mode, which opens a remote database (referred to as leader) on a distributed file system by tailing its MANIFEST. It leverages the secondary instance mode, but is different in some key ways -
1. It has its own directory with links to the leader's database
2. Periodically refreshes itself
3. (Future) Snapshot support
4. (Future) Garbage collection of obsolete links
5. (Long term) Memtable replication
There are two main classes implementing this functionality - `DBImplFollower` and `OnDemandFileSystem`. The former is derived from `DBImplSecondary`. Similar to `DBImplSecondary`, it implements recovery and catch up through MANIFEST tailing using the `ReactiveVersionSet`, but does not consider logs. In a future PR, we will implement memtable replication, which will eliminate the need to catch up using logs. In addition, the recovery and catch-up tries to avoid directory listing as repeated metadata operations are expensive.
The second main piece is the `OnDemandFileSystem`, which plugs in as an `Env` for the follower instance and creates the illusion of the follower directory as a clone of the leader directory. It creates links to SSTs on first reference. When the follower tails the MANIFEST and attempts to create a new `Version`, it calls `VerifyFileMetadata` to verify the size of the file, and optionally the unique ID of the file. During this process, links are created which prevent the underlying files from getting deallocated even if the leader deletes the files.
TODOs: Deletion of obsolete links, snapshots, robust checking against misconfigurations, better observability etc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12540
Reviewed By: jowlyzhang
Differential Revision: D56315718
Pulled By: anand1976
fbshipit-source-id: d19e1aca43a6af4000cb8622a718031b69ebd97b
Summary:
**Context/Summary:**
This is to improve our crash test coverage.
Bonus change:
- Added the missing Options string mapping for `CacheTier::kVolatileCompressedTier`
- Deprecated crash test options `enable_tiered_storage` mainly for setting `last_level_temperature` which is now covered in crash test by itself
- Intensified `verify_checksum_one_in\verify_file_checksums_one_in` as I found out these together with new coverage surface more issues
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12508
Test Plan: CI to look out for trivial failures
Reviewed By: jowlyzhang
Differential Revision: D55768594
Pulled By: hx235
fbshipit-source-id: 9b829da0309a7db3fcdb17992a524dd64498325c
Summary:
As mentioned in https://github.com/facebook/rocksdb/issues/11893, we are going to use the offpeak time information to pre-process TTL-based compactions. To do so, we need to access `daily_offpeak_time_utc` in `VersionStorageInfo::ComputeCompactionScore()` where we pick the files to compact. This PR is to make the offpeak time information available at the time of compaction-scoring. We are not changing any compaction scoring logic just yet. Will follow up in a separate PR.
There were two ways to achieve what we want.
1. Make `MutableDBOptions` available in `ColumnFamilyData` and `ComputeCompactionScore()` take `MutableDBOptions` along with `ImmutableOptions` and `MutableCFOptions`.
2. Make `daily_offpeak_time_utc` and `IsNowOffpeak()` available in `VersionStorageInfo`.
We chose the latter as it involves smaller changes.
This change includes the following
- Introduction of `OffpeakTimeInfo` and `IsNowOffpeak()` has been moved from `MutableDBOptions`
- `OffpeakTimeInfo` added to `VersionSet` and it can be set during construction and by `ChangeOffpeakTimeInfo()`
- During `SetDBOptions()`, if offpeak time info needs to change, it calls `MaybeScheduleFlushOrCompaction()` to re-compute compaction scores and process compactions as needed
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12018
Test Plan:
- `DBOptionsTest::OffpeakTimes` changed to include checks for `MaybeScheduleFlushOrCompaction()` calls and `VersionSet`'s OffpeakTimeInfo value change during `SetDBOptions()`.
- `VersionSetTest::OffpeakTimeInfoTest` added to test `ChangeOffpeakTimeInfo()`. `IsNowOffpeak()` tests moved from `DBOptionsTest::OffpeakTimes`
Reviewed By: pdillinger
Differential Revision: D50723881
Pulled By: jaykorean
fbshipit-source-id: 3cff0291936f3729c0e9c7750834b9378fb435f6
Summary:
Since allowing 24hr peak by setting start_time = end_time is not so intuitive, we are not going to allow it (e.g. `00:00-00:00` doesn't looks like a value that would cover 24hr.). Instead, we are going to compare at minute level (i.e. dropping the seconds to the nearest minute) so that `00:00-23:59` will cover 24hrs. The entire minute from 23:59:00 23:59:59 will be covered with this change.
Minor fixes from previous PR
- release build error
- fixed random seed in test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11911
Test Plan:
`DBOptionsTest::OffPeakTimes`
`make -j64 static_lib` to test release build issue that was fixed
Reviewed By: pdillinger
Differential Revision: D49787795
Pulled By: jaykorean
fbshipit-source-id: e8d045b95f54f61d5dd5f1bb473579f8d55c18b3
Summary:
RocksDB's primary function is to facilitate read and write operations. Compactions, while essential for minimizing read amplifications and optimizing storage, can sometimes compete with these primary tasks. Especially during periods of high read/write traffic, it's vital to ensure that primary operations receive priority, avoiding any potential disruptions or slowdowns. Conversely, during off-peak times when traffic is minimal, it's an opportune moment to tackle low-priority tasks like TTL based compactions, optimizing resource usage.
In this PR, we are incorporating the concept of off-peak time into RocksDB by introducing `daily_offpeak_time_utc` within the DBOptions. This setting is formatted as "HH:mm-HH:mm" where the first one before "-" is the start time and the second one is the end time, inclusive. It will be later used for resource optimization in subsequent PRs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11893
Test Plan:
- New Unit Test Added - `DBOptionsTest::OffPeakTimes`
- Existing Unit Test Updated - `OptionsTest`, `OptionsSettableTest`
Reviewed By: pdillinger
Differential Revision: D49714553
Pulled By: jaykorean
fbshipit-source-id: fef51ea7c0fede6431c715bff116ddbb567c8752
Summary:
... to improve data integrity validation during compaction.
A new option `compaction_verify_record_count` is introduced for this verification and is enabled by default. One exception when the verification is not done is when a compaction filter returns kRemoveAndSkipUntil which can cause CompactionIterator to seek until some key and hence not able to keep track of the number of keys processed.
For expected number of input keys, we sum over the number of total keys - number of range tombstones across compaction input files (`CompactionJob::UpdateCompactionStats()`). Table properties are consulted if `FileMetaData` is not initialized for some input file. Since table properties for all input files were also constructed during `DBImpl::NotifyOnCompactionBegin()`, `Compaction::GetTableProperties()` is introduced to reduce duplicated code.
For actual number of keys processed, each subcompaction will record its number of keys processed to `sub_compact->compaction_job_stats.num_input_records` and aggregated when all subcompactions finish (`CompactionJob::AggregateCompactionStats()`). In the case when some subcompaction encountered kRemoveAndSkipUntil from compaction filter and does not have accurate count, it propagates this information through `sub_compact->compaction_job_stats.has_num_input_records`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11571
Test Plan:
* Add a new unit test `DBCompactionTest.VerifyRecordCount` for the corruption case.
* All other unit tests for non-corrupted case.
* Ran crash test for a few hours: `python3 ./tools/db_crashtest.py whitebox --simple`
Reviewed By: ajkr
Differential Revision: D47131965
Pulled By: cbi42
fbshipit-source-id: cc8e94565dd526c4347e9d3843ecf32f6727af92
Summary:
The definition of the Cache class should not be needed by the vast majority of RocksDB users, so I think it is just distracting to include it in cache.h, which is primarily needed for configuring and creating caches. This change moves the class to a new header advanced_cache.h. It is just cut-and-paste except for modifying the class API comment.
In general, operations on shared_ptr<Cache> should continue to work when only a forward declaration of Cache is available, as long as all the Cache instances provided are already shared_ptr. See https://stackoverflow.com/a/17650101/454544
Also, the most common way to customize a Cache is by wrapping an existing implementation, so it makes sense to provide CacheWrapper in the public API. This was a cut-and-paste job except removing the implementation of Name() so that derived classes must provide it.
Intended follow-up: consolidate Release() into one function to reduce customization bugs / confusion
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11192
Test Plan: `make check`
Reviewed By: anand1976
Differential Revision: D43055487
Pulled By: pdillinger
fbshipit-source-id: 7b05492df35e0f30b581b4c24c579bc275b6d110
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.
Most of changes were done through following comments:
unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'`
by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147
Test Plan: See CI
Reviewed By: pdillinger
Differential Revision: D42796341
fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
Summary:
(PR created for informational/testing purposes only.)
- Fixes lost dynamic updates to GenericRateLimiter bandwidth using `SetBytesPerSecond()`
- Benefit over #10374 is eliminating race conditions with Configurable framework.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10378
Reviewed By: pdillinger
Differential Revision: D37914865
fbshipit-source-id: d4f566d60ec9726d26932388c61671adf0ee0f30
Summary:
**Summary**
Make the mempurge option flag a Mutable Column Family option flag. Therefore, the mempurge feature can be dynamically toggled.
**Motivation**
RocksDB users prefer having the ability to switch features on and off without having to close and reopen the DB. This is particularly important if the feature causes issues and needs to be turned off. Dynamically changing a DB option flag does not seem currently possible.
Moreover, with this new change, the MemPurge feature can be toggled on or off independently between column families, which we see as a major improvement.
**Content of this PR**
This PR includes removal of the `experimental_mempurge_threshold` flag as a DB option flag, and its re-introduction as a `MutableCFOption` flag. I updated the code to handle dynamic changes of the flag (in particular inside the `FlushJob` file). Additionally, this PR includes a new test to demonstrate the capacity of the code to toggle the MemPurge feature on and off, as well as the addition in the `db_stress` module of 2 different mempurge threshold values (0.0 and 1.0) that can be randomly changed with the `set_option_one_in` flag. This is useful to stress test the dynamic changes.
**Benchmarking**
I will add numbers to prove that there is no performance impact within the next 12 hours.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10011
Reviewed By: pdillinger
Differential Revision: D36462357
Pulled By: bjlemaire
fbshipit-source-id: 5e3d63bdadf085c0572ecc2349e7dd9729ce1802
Summary:
Start tracking SST unique id in MANIFEST, which is used to verify with
SST properties to make sure the SST file is not overwritten or
misplaced. A DB option `try_verify_sst_unique_id` is introduced to
enable/disable the verification, if enabled, it opens all SST files
during DB-open to read the unique_id from table properties (default is
false), so it's recommended to use it with `max_open_files = -1` to
pre-open the files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9990
Test Plan: unittests, format-compatible test, mini-crash
Reviewed By: anand1976
Differential Revision: D36381863
Pulled By: jay-zhuang
fbshipit-source-id: 89ea2eb6b35ed3e80ead9c724eb096083eaba63f
Summary:
PR https://github.com/facebook/rocksdb/issues/9888 started to enforce the contract of single delete described in https://github.com/facebook/rocksdb/wiki/Single-Delete.
For some of existing use cases, it is desirable to have a transition during which compaction will not fail
if the contract is violated. Therefore, we add a temporary option `enforce_single_del_contracts` to allow
application to opt out from this new strict behavior. Once transition completes, the flag can be set to `true` again.
In a future release, the option will be removed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9983
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D36333672
Pulled By: riversand963
fbshipit-source-id: dcb703ea0ed08076a1422f1bfb9914afe3c2caa2
Summary:
Add methods to set the various functions (Parse, Serialize, Equals) to the OptionTypeInfo. These methods simplify the number of constructors required for OptionTypeInfo and make the code a little clearer.
Add functions to the OptionTypeInfo for Prepare and Validate. These methods allow types other than Configurable and Customizable to have Prepare and Validate logic. These methods could be used by an option to guarantee that its settings were in a range or that a value was initialized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9411
Reviewed By: pdillinger
Differential Revision: D36174849
Pulled By: mrambacher
fbshipit-source-id: 72517d8c6bab4723788a4c1a9e16590bff870125
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:
Remove redundant assignment code for member `state` in the constructor of `ImmutableDBOptions`.
There are two identical and redundant statements `stats = statistics.get();` in lines 740 and 748 of the code.
This commit removed the line 740.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9665
Reviewed By: ajkr
Differential Revision: D34686649
Pulled By: riversand963
fbshipit-source-id: 8f246ece382b6845528f4e2c843ce09bb66b2b0f
Summary:
In RocksDB option new_table_reader_for_compaction_inputs has
not effect on Compaction or on the behavior of RocksDB library.
Therefore, we are removing it in the upcoming 7.0 release.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9443
Test Plan: CircleCI
Reviewed By: ajkr
Differential Revision: D33788508
Pulled By: akankshamahajan15
fbshipit-source-id: 324ca6f12bfd019e9bd5e1b0cdac39be5c3cec7d
Summary:
The API is deprecated long time ago. Clean up the codebase by
removing it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9462
Test Plan: CI, fake release: D33835220
Reviewed By: riversand963
Differential Revision: D33835103
Pulled By: jay-zhuang
fbshipit-source-id: 6d2dc12c8e7fdbe2700865a3e61f0e3f78bd8184
Summary:
Add an option to set the WAL compression algorithm - wal_compression.
TODO: WAL compression is not implemented and will only support zstd initially. Will be added in subsequent diffs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9432
Reviewed By: pdillinger
Differential Revision: D33797275
Pulled By: sidroyc
fbshipit-source-id: 8db81d9c9cea5e2e4f1445d3aecad8106137b8e7
Summary:
Currently, if Secondary Cache is provided to the lru cache, it is used by default. We add CacheTier to advanced_options.h to describe the cache tier we used. Add a `lowest_used_cache_tier` option to `DBOptions` (immutable) and pass it to BlockBasedTableReader to decide if secondary cache will be used or not. By default it is `CacheTier::kNonVolatileTier`, which means, we always use both block cache (kVolatileTier) and secondary cache (kNonVolatileTier). By set it to `CacheTier::kVolatileTier`, the DB will not use the secondary cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9050
Test Plan: added new tests
Reviewed By: anand1976
Differential Revision: D31744769
Pulled By: zhichao-cao
fbshipit-source-id: a0575ebd23e1c6dfcfc2b4c8578764e73b15bce6
Summary:
Adds changes to DBOptions (comparable to ColumnFamilyOptions) to allow some option values to be ignored on rehydration from the Options file. This is necessary for some customizable classes that were not registered with the ObjectRegistry but are saved/restored from the Options file.
All tests pass. Will run check_format_compatible.sh shortly.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9045
Reviewed By: zhichao-cao
Differential Revision: D31761664
Pulled By: mrambacher
fbshipit-source-id: 300c2251639cce2b223481c3bb2a63877b1f3766
Summary:
Make the Statistics object into a Customizable object. Statistics can now be stored and created to/from the Options file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8637
Reviewed By: zhichao-cao
Differential Revision: D30530550
Pulled By: mrambacher
fbshipit-source-id: 5fc7d01d8431f37b2c205bbbd8342c9f697023bd
Summary:
Current internal regression tests pass in an old option flag `experimental_allow_mempurge` to a more recently built db.
This flag was retired and removed in a recent PR (https://github.com/facebook/rocksdb/issues/8628), and therefore, the following error comes up : `Failed: Invalid argument: Could not find option: : experimental_allow_mempurge`.
In this PR, I reintroduce the two flags retired in https://github.com/facebook/rocksdb/issues/8628, `experimental_allow_mempurge` and `experimental_mempurge_policy` in `db_options.cc` and mark them both as `kDeprecated`.
This is a temporary fix to save us time to find a long term solution, which hopefully will consist in ignoring options prefixed with `experimental_` that are no longer recognized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8650
Reviewed By: pdillinger
Differential Revision: D30257307
Pulled By: bjlemaire
fbshipit-source-id: 35303655fd2dd9789fd9e3c450e9d8009f3c1f54
Summary:
Changes the API of the MemPurge process: the `bool experimental_allow_mempurge` and `experimental_mempurge_policy` flags have been replaced by a `double experimental_mempurge_threshold` option.
This change of API reflects another major change introduced in this PR: the MemPurgeDecider() function now works by sampling the memtables being flushed to estimate the overall amount of useful payload (payload minus the garbage), and then compare this useful payload estimate with the `double experimental_mempurge_threshold` value.
Therefore, when the value of this flag is `0.0` (default value), mempurge is simply deactivated. On the other hand, a value of `DBL_MAX` would be equivalent to always going through a mempurge regardless of the garbage ratio estimate.
At the moment, a `double experimental_mempurge_threshold` value else than 0.0 or `DBL_MAX` is opnly supported`with the `SkipList` memtable representation.
Regarding the sampling, this PR includes the introduction of a `MemTable::UniqueRandomSample` function that collects (approximately) random entries from the memtable by using the new `SkipList::Iterator::RandomSeek()` under the hood, or by iterating through each memtable entry, depending on the target sample size and the total number of entries.
The unit tests have been readapted to support this new API.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8628
Reviewed By: pdillinger
Differential Revision: D30149315
Pulled By: bjlemaire
fbshipit-source-id: 1feef5390c95db6f4480ab4434716533d3947f27
Summary:
Prior to this change, the "wal_dir" DBOption would always be set (defaults to dbname) when the DBOptions were sanitized. Because of this setitng in the options file, it was not possible to rename/relocate a database directory after it had been created and use the existing options file.
After this change, the "wal_dir" option is only set under specific circumstances. Methods were added to the ImmutableDBOptions class to see if it is set and if it is set to something other than the dbname. Additionally, a method was added to retrieve the effective value of the WAL dir (either the option or the dbname/path).
Tests were added to the core and ldb to test that a database could be created and renamed without issue. Additional tests for various permutations of wal_dir were also added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8582
Reviewed By: pdillinger, autopear
Differential Revision: D29881122
Pulled By: mrambacher
fbshipit-source-id: 67d3d033dc8813d59917b0a3fba2550c0efd6dfb
Summary:
- Added Type/CreateFromString
- Added ability to load EventListeners to DBOptions
- Since EventListeners did not previously have a Name(), defaulted to "". If there is no name, the listener cannot be loaded from the ObjectRegistry.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8473
Reviewed By: zhichao-cao
Differential Revision: D29901488
Pulled By: mrambacher
fbshipit-source-id: 2d3a4aa6db1562ac03e7ad41b360e3521d486254
Summary:
Add `experimental_mempurge_policy` option flag and introduce two new `MemPurge` (Memtable Garbage Collection) policies: 'ALWAYS' and 'ALTERNATE'. Default value: ALTERNATE.
`ALWAYS`: every flush will first go through a `MemPurge` process. If the output is too big to fit into a single memtable, then the mempurge is aborted and a regular flush process carries on. `ALWAYS` is designed for user that need to reduce the number of L0 SST file created to a strict minimum, and can afford a small dent in performance (possibly hits to CPU usage, read efficiency, and maximum burst write throughput).
`ALTERNATE`: a flush is transformed into a `MemPurge` except if one of the memtables being flushed is the product of a previous `MemPurge`. `ALTERNATE` is a good tradeoff between reduction in number of L0 SST files created and performance. `ALTERNATE` perform particularly well for completely random garbage ratios, or garbage ratios anywhere in (0%,50%], and even higher when there is a wild variability in garbage ratios.
This PR also includes support for `experimental_mempurge_policy` in `db_bench`.
Testing was done locally by replacing all the `MemPurge` policies of the unit tests with `ALTERNATE`, as well as local testing with `db_crashtest.py` `whitebox` and `blackbox`. Overall, if an `ALWAYS` mempurge policy passes the tests, there is no reasons why an `ALTERNATE` policy would fail, and therefore the mempurge policy was set to `ALWAYS` for all mempurge unit tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8583
Reviewed By: pdillinger
Differential Revision: D29888050
Pulled By: bjlemaire
fbshipit-source-id: e2cf26646d66679f6f5fb29842624615610759c1
Summary:
Try avoid expensive updating options operation if
`SetDBOptions()` does not change any option value.
Skip updating is not guaranteed, for example, changing `bytes_per_sync`
to `0` may still trigger updating, as the value could be sanitized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8518
Test Plan: added unittest
Reviewed By: riversand963
Differential Revision: D29672639
Pulled By: jay-zhuang
fbshipit-source-id: b7931de62ceea6f1bdff0d1209adf1197d3ed1f4
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:
- 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:
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:
Added ParseType, SerializeType, and TypesAreEqual methods to OptionTypeInfo. These methods can be used for serialization and deserialization of basic types.
Change the MutableCF/DB Options to use this format.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8249
Reviewed By: jay-zhuang
Differential Revision: D28351190
Pulled By: mrambacher
fbshipit-source-id: 72a78643b804f2f0bf59c32ffefa63346672ad16
Summary:
The ImmutableCFOptions contained a bunch of fields that belonged to the ImmutableDBOptions. This change cleans that up by introducing an ImmutableOptions struct. Following the pattern of Options struct, this class inherits from the DB and CFOption structs (of the Immutable form).
Only one structural change (the ImmutableCFOptions::fs was changed to a shared_ptr from a raw one) is in this PR. All of the other changes involve moving the member variables from the ImmutableCFOptions into the ImmutableOptions and changing member variables or function parameters as required for compilation purposes.
Follow-on PRs may do a further clean-up of the code, such as renaming variables (such as "ImmutableOptions cf_options") and potentially eliminating un-needed function parameters (there is no longer a need to pass both an ImmutableDBOptions and an ImmutableOptions to a function).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8262
Reviewed By: pdillinger
Differential Revision: D28226540
Pulled By: mrambacher
fbshipit-source-id: 18ae71eadc879dedbe38b1eb8e6f9ff5c7147dbf
Summary:
Renaming ImmutableCFOptions::info_log and statistics to logger and stats. This is stage 2 in creating an ImmutableOptions class. It is necessary because the names match those in ImmutableOptions and have different types.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8227
Reviewed By: jay-zhuang
Differential Revision: D28000967
Pulled By: mrambacher
fbshipit-source-id: 3bf2aa04e8f1e8724d825b7deacf41080c14420b
Summary:
As previously coded, a Configurable extension would need access to code not in the public API. This change moves RegisterOptions into the Configurable class and therefore available to public extensions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8223
Reviewed By: anand1976
Differential Revision: D27960188
Pulled By: mrambacher
fbshipit-source-id: ac88b19397183df633902def5b5701b9b65fbf40
Summary:
This PR is a first step at attempting to clean up some of the Mutable/Immutable Options code. With this change, a DBOption and a ColumnFamilyOption can be reconstructed from their Mutable and Immutable equivalents, respectively.
readrandom tests do not show any performance degradation versus master (though both are slightly slower than the current 6.19 release).
There are still fields in the ImmutableCFOptions that are not CF options but DB options. Eventually, I would like to move those into an ImmutableOptions (= ImmutableDBOptions+ImmutableCFOptions). But that will be part of a future PR to minimize changes and disruptions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8176
Reviewed By: pdillinger
Differential Revision: D27954339
Pulled By: mrambacher
fbshipit-source-id: ec6b805ba9afe6e094bffdbd76246c2d99aa9fad
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
