Summary:
The user may override the detection of whether to use GNU libc (the default) or musl libc by setting the environment variable: `ROCKSDB_MUSL_LIBC=true`.
Builds upon and supersedes: https://github.com/facebook/rocksdb/pull/9977
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10889
Reviewed By: akankshamahajan15
Differential Revision: D40788431
Pulled By: ajkr
fbshipit-source-id: ef594d973fc14cbadf28bfb38434231a18a2107c
Summary:
Resolves see https://github.com/facebook/rocksdb/issues/9006
Fixes 2 related issues with JNI local references in the RocksJava API.
1. Some instances of RocksJava API JNI code appear to have misunderstood the reason for `JNIEnv->EnsureLocalCapacity()` and are carrying out bogus checks which happen to fail with some larger parameter values (many column families in a single call, very long key names or values). Remove these checks and add some regression tests for the previous failures.
2. The helper for Transaction multiGet operations (`multiGet()`, `multiGetForUpdate()`,...) is limited in the number of keys it can `get()` for because it requires a corresponding number of live local references. Refactor the helper slightly, copying out the key contents within a loop so that the references don't have to exist at the same time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10674
Reviewed By: ajkr
Differential Revision: D40515361
Pulled By: jay-zhuang
fbshipit-source-id: f1be0126181a698b3ad27c0945a39c54d950aa25
Summary:
While PR#9749 nominally added support for XXH3 in the Java API, it did not update the `toCppChecksumType` method. As a result, setting the checksum type to XXH3 actually set it to CRC32c instead.
This commit adds the missing entry to portal.h, and also updates the tests so that they verify the options passed to RocksDB, instead of simply checking that the getter returns the value set by the setter.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10862
Reviewed By: pdillinger
Differential Revision: D40665031
Pulled By: ajkr
fbshipit-source-id: 2834419b3361a4bac47db3b858951fb451b5bdc8
Summary:
As of v6.14 (released in 2020), force_consistency_checks is enabled by default. However, the Java documentation does not seem to have been updated to reflect the change at the time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10574
Reviewed By: hx235
Differential Revision: D39006566
Pulled By: ajkr
fbshipit-source-id: c7b029484d62deaa1f260ec55084049fe39eb84a
Summary:
RocksDB's `Cache` abstraction currently supports two priority levels for items: high (used for frequently accessed/highly valuable SST metablocks like index/filter blocks) and low (used for SST data blocks). Blobs are typically lower-value targets for caching than data blocks, since 1) with BlobDB, data blocks containing blob references conceptually form an index structure which has to be consulted before we can read the blob value, and 2) cached blobs represent only a single key-value, while cached data blocks generally contain multiple KVs. Since we would like to make it possible to use the same backing cache for the block cache and the blob cache, it would make sense to add a new, lower-than-low cache priority level (bottom level) for blobs so data blocks are prioritized over them.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10461
Reviewed By: siying
Differential Revision: D38672823
Pulled By: ltamasi
fbshipit-source-id: 90cf7362036563d79891f47be2cc24b827482743
Summary:
Some files miss headers. Also some headers are irregular. Fix them to make an internal checkup tool happy.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10519
Reviewed By: jay-zhuang
Differential Revision: D38603291
fbshipit-source-id: 13b1bbd6d48f5ee15ba20da67544396de48238f1
Summary:
RocksDB's `Cache` abstraction currently supports two priority levels for items: high (used for frequently accessed/highly valuable SST metablocks like index/filter blocks) and low (used for SST data blocks). Blobs are typically lower-value targets for caching than data blocks, since 1) with BlobDB, data blocks containing blob references conceptually form an index structure which has to be consulted before we can read the blob value, and 2) cached blobs represent only a single key-value, while cached data blocks generally contain multiple KVs. Since we would like to make it possible to use the same backing cache for the block cache and the blob cache, it would make sense to add a new, lower-than-low cache priority level (bottom level) for blobs so data blocks are prioritized over them.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10309
Reviewed By: ltamasi
Differential Revision: D38211655
Pulled By: gangliao
fbshipit-source-id: 65ef33337db4d85277cc6f9782d67c421ad71dd5
Summary:
The absence of a public modifier appears to be an omission. prepare() is necessary for the TM to participate as a peer in a distributed transaction.
Also add basic “yes it does work in java” tests.
Resolves https://github.com/facebook/rocksdb/issues/10283
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10412
Reviewed By: ajkr
Differential Revision: D38135513
Pulled By: riversand963
fbshipit-source-id: ff52b96bc7218bc3bf12845dee49f5d8edf0e297
Summary:
Many workloads have temporal locality, where recently written items are read back in a short period of time. When using remote file systems, this is inefficient since it involves network traffic and higher latencies. Because of this, we would like to support prepopulating the blob cache during flush.
This task is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10298
Reviewed By: ltamasi
Differential Revision: D37908743
Pulled By: gangliao
fbshipit-source-id: 9feaed234bc719d38f0c02975c1ad19fa4bb37d1
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:
Currently, if blob files are enabled (i.e. `enable_blob_files` is true), large values are extracted both during flush/recovery (when SST files are written into level 0 of the LSM tree) and during compaction into any LSM tree level. For certain use cases that have a mix of short-lived and long-lived values, it might make sense to support extracting large values only during compactions whose output level is greater than or equal to a specified LSM tree level (e.g. compactions into L1/L2/... or above). This could reduce the space amplification caused by large values that are turned into garbage shortly after being written at the price of some write amplification incurred by long-lived values whose extraction to blob files is delayed.
In order to achieve this, we would like to do the following:
- Add a new configuration option `blob_file_starting_level` (default: 0) to `AdvancedColumnFamilyOptions` (and `MutableCFOptions` and extend the related logic)
- Instantiate `BlobFileBuilder` in `BuildTable` (used during flush and recovery, where the LSM tree level is L0) and `CompactionJob` iff `enable_blob_files` is set and the LSM tree level is `>= blob_file_starting_level`
- Add unit tests for the new functionality, and add the new option to our stress tests (`db_stress` and `db_crashtest.py` )
- Add the new option to our benchmarking tool `db_bench` and the BlobDB benchmark script `run_blob_bench.sh`
- Add the new option to the `ldb` tool (see https://github.com/facebook/rocksdb/wiki/Administration-and-Data-Access-Tool)
- Ideally extend the C and Java bindings with the new option
- Update the BlobDB wiki to document the new option.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10077
Reviewed By: ltamasi
Differential Revision: D36884156
Pulled By: gangliao
fbshipit-source-id: 942bab025f04633edca8564ed64791cb5e31627d
Summary:
In case of non-TransactionDB and avoid_flush_during_recovery = true, RocksDB won't
flush the data from WAL to L0 for all column families if possible. As a
result, not all column families can increase their log_numbers, and
min_log_number_to_keep won't change.
For transaction DB (.allow_2pc), even with the flush, there may be old WAL files that it must not delete because they can contain data of uncommitted transactions and min_log_number_to_keep won't change.
If we persist a new MANIFEST with
advanced log_numbers for some column families, then during a second
crash after persisting the MANIFEST, RocksDB will see some column
families' log_numbers larger than the corrupted wal, and the "column family inconsistency" error will be hit, causing recovery to fail.
As a solution, RocksDB will persist the new MANIFEST after successfully syncing the new WAL.
If a future recovery starts from the new MANIFEST, then it means the new WAL is successfully synced. Due to the sentinel empty write batch at the beginning, kPointInTimeRecovery of WAL is guaranteed to go after this point.
If future recovery starts from the old MANIFEST, it means the writing the new MANIFEST failed. We won't have the "SST ahead of WAL" error.
Currently, RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. This PR buffers the edits in a structure and writes to a new MANIFEST after recovery is successful
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9922
Test Plan:
1. Update unit tests to fail without this change
2. make crast_test -j
Branch with unit test and no fix https://github.com/facebook/rocksdb/pull/9942 to keep track of unit test (without fix)
Reviewed By: riversand963
Differential Revision: D36043701
Pulled By: akankshamahajan15
fbshipit-source-id: 5760970db0a0920fb73d3c054a4155733500acd9
Summary:
For regular db instance and secondary instance, we return error and refuse to open DB if Logger creation fails.
Our current code allows it, but it is really difficult to debug because
there will be no LOG files. The same for OPTIONS file, which will be explored in another PR.
Furthermore, Arena::AllocateAligned(size_t bytes, size_t huge_page_size, Logger* logger) has an
assertion as the following:
```cpp
#ifdef MAP_HUGETLB
if (huge_page_size > 0 && bytes > 0) {
assert(logger != nullptr);
}
#endif
```
It can be removed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9984
Test Plan: make check
Reviewed By: jay-zhuang
Differential Revision: D36347754
Pulled By: riversand963
fbshipit-source-id: 529798c0511d2eaa2f0fd40cf7e61c4cbc6bc57e
Summary:
Removing unnecessary checks around conversion from int/long to double as it does not lose information (see https://docs.oracle.com/javase/specs/jls/se9/html/jls-5.html#jls-5.1.2).
For example, `value > Double.MAX_VALUE` is always false when value is long or int.
Can you please have a look adamretter? Also fixed some other minor issues (do you prefer a separate PR?)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9194
Reviewed By: ajkr
Differential Revision: D36221694
fbshipit-source-id: bf327c07386560b87ddc0c98039e8d6e8f2f1e82
Summary:
Just fixing a very minor typo in the doc block :) Hope it will help anyway 😊
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9331
Reviewed By: riversand963
Differential Revision: D34339823
fbshipit-source-id: b76104bc3efbc9d1f38cbf5c6dd7648dc909ced3
Summary:
Left HISTORY.md and unit tests.
Added a new unit test to repro the corruption scenario that this PR fixes, and HISTORY.md line for that.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9906
Reviewed By: riversand963
Differential Revision: D35940093
Pulled By: ajkr
fbshipit-source-id: 9816f99e1ce405ba36f316beb4f6378c37c8c86b
Summary:
1) In case of non-TransactionDB and avoid_flush_during_recovery = true, RocksDB won't
flush the data from WAL to L0 for all column families if possible. As a
result, not all column families can increase their log_numbers, and
min_log_number_to_keep won't change.
2) For transaction DB (.allow_2pc), even with the flush, there may be old WAL files that it must not delete because they can contain data of uncommitted transactions and min_log_number_to_keep won't change.
If we persist a new MANIFEST with
advanced log_numbers for some column families, then during a second
crash after persisting the MANIFEST, RocksDB will see some column
families' log_numbers larger than the corrupted wal, and the "column family inconsistency" error will be hit, causing recovery to fail.
As a solution,
1. the corrupted WALs whose numbers are larger than the
corrupted wal and smaller than the new WAL will be moved to archive folder.
2. Currently, RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. This PR buffers the edits in a structure and writes to a new MANIFEST after recovery is successful
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9634
Test Plan:
1. Added new unit tests
2. make crast_test -j
Reviewed By: riversand963
Differential Revision: D34463666
Pulled By: akankshamahajan15
fbshipit-source-id: e233d3af0ed4e2028ca0cf051e5a334a0fdc9d19
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:
Various renaming and fixes to get rid of remaining uses of
"backupable" which is terminology leftover from the original, flawed
design of BackupableDB. Now any DB can be backed up, using BackupEngine.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9792
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D35334386
Pulled By: pdillinger
fbshipit-source-id: 2108a42b4575c8cccdfd791c549aae93ec2f3329
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:
Extend Java RocksDB iterators to support indirect byte buffers, to add to the existing support for direct byte buffers.
Code to distinguish direct/indirect buffers is switched in Java, and a 2nd separate JNI call implemented to support indirect
buffers. Indirect support passes contained buffers using byte[]
There are some Java subclasses of iterator (WBWIIterator, SstFileReaderIterator) which also now have parallel JNI support functions implemented, along with direct/indirect switches in Java methods.
Closes https://github.com/facebook/rocksdb/issues/6282
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9222
Reviewed By: ajkr
Differential Revision: D35115283
Pulled By: jay-zhuang
fbshipit-source-id: f8d5d20b975aef700560fbcc99f707bb028dc42e
Summary:
There was a mistake that incorrectly cast SstPartitionerFactory (missed shared pointer). It worked for database (correct cast), but not for family. Trying to set it in family has caused Access violation.
I have also added test and improved it. Older version was passing even without sst partitioner which is weird, because on Level1 we had two SST files with same key "aaaa1". I was not sure if it is a new feature and changed it to overlaping keys "aaaa0" - "aaaa2" overlaps "aaaa1".
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9622
Reviewed By: ajkr
Differential Revision: D34871968
Pulled By: pdillinger
fbshipit-source-id: a08009766da49fc198692a610e8beb19caf737e6
Summary:
For RocksDB v7 major release. Remove previously deprecated Java API methods and associated tests
- where equivalent/alternative functionality exists and is already tested AND
- where the core RocksDB function/feature has also been removed
- OR the functionality exists only in Java so the previous deprecation only affected Java methods
RETAIN deprecated Java which reflects functionality which is deprecated by, but also still supported by, the core of RocksDB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9576
Reviewed By: ajkr
Differential Revision: D34314983
Pulled By: jay-zhuang
fbshipit-source-id: 7cf9c17e3e07be9d289beb99f81b71e8e09ac403
Summary:
For RocksJava 7 we will move from requiring Java 7 to Java 8.
* This simplifies the `Makefile` as we no longer need to deal with Java 7; so we no longer use `javah`.
* Added a java-version target which is invoked by the java target, and which exits if the version of java being used is not 8 or greater.
* Enforces java 8 as a minimum.
* Fixed CMake build.
* Fixed broken java event listener test, as the test was broken and the assertions in the callbacks were not causing assertions in the tests. The callbacks now queue up assertion errors for the main thread of the tests to check.
* Fixed C++ dangling pointers in the test code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9541
Reviewed By: pdillinger
Differential Revision: D34214929
Pulled By: jay-zhuang
fbshipit-source-id: fdff348758d0a23a742e83c87d5f54073ce16ca6
Summary:
Transaction multiGet convert to list-based.
RocksDB Java (non-transactional) has multiGetAsList() methods to expose multiGet(). These return a list of results. These methods replaced multiGet() methods returning an array of results, which were deprecated in Rocks 6 and are being removed in Rocks 7.
The transactional API still presents multiGet() methods returning arrays, so in Rocks 7 we replace these with multiGetAsList()methods and deprecate the multiGet() methods.
This does not require any changes to the supporting JNI/C++ code, only to the wrappers which present the Java API.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9522
Reviewed By: mrambacher
Differential Revision: D34114373
Pulled By: jay-zhuang
fbshipit-source-id: cb22d6095934d951b6aee4aed3e07923d3c18007
Summary:
For RocksDB 7. Remove deprecated dispose() And as a consequence remove finalize(), which is good Modern Java hygiene.
It is extremely non-deterministic when `finalize()` is called on an object, and resource closure/recovery of underlying native/C++ objects and/or non-memory resource cannot be adequately controlled through GC finalization. The RocksDB Java/JNI interface provides and encourages the use of AutoCloseable objects with close() methods, allowing predictable disposal of resources at exit from try-with-resource blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9523
Reviewed By: mrambacher
Differential Revision: D34079843
Pulled By: jay-zhuang
fbshipit-source-id: d1f0463a89a548b5d57bfaa50154379e722d189a
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:
Fixed all RocksJava test failures in Centos and Alpine 32 bit and 64 bit OSes
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9395
Reviewed By: mrambacher
Differential Revision: D33771987
Pulled By: ajkr
fbshipit-source-id: fed91033b8df08f191ad65e1fb745a9264bbfa70
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:
This also removes the obsolete names BackupableDBOptions
and UtilityDB. API users must now use BackupEngineOptions and
DBWithTTL::Open. In C API, `rocksdb_backupable_db_*` is replaced
`rocksdb_backup_engine_*`. Similar renaming in Java API.
In reference to https://github.com/facebook/rocksdb/issues/9389
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9438
Test Plan: CI
Reviewed By: mrambacher
Differential Revision: D33780269
Pulled By: pdillinger
fbshipit-source-id: 4a6cfc5c1b4c78bcad790b9d3dd13c5fdf4a1fac
Summary:
**Context/Summary:**
AdvancedColumnFamilyOptions::soft_rate_limit/hard_rate_limit have been marked as deprecated and it's time to actually remove the code.
- Keep `soft_rate_limit`/`hard_rate_limit` in `cf_mutable_options_type_info` to prevent throwing `InvalidArgument` in `GetColumnFamilyOptionsFromMap` when reading an option file still with these options (e.g, old option file generated from RocksDB before the deprecation)
- Keep `soft_rate_limit`/`hard_rate_limit` in under `OptionsOldApiTest.GetOptionsFromMapTest` to test the case mentioned above.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9452
Test Plan: Rely on my eyeball and CI
Reviewed By: ajkr
Differential Revision: D33804938
Pulled By: hx235
fbshipit-source-id: 133d49f7ec5238d7efceeb0a3122a5792a2b9945
Summary:
This PR moves HDFS support from RocksDB repo to a separate repo. The new (temporary?) repo
in this PR serves as an example before we finalize the decision on where and who to host hdfs support. At this point,
people can start from the example repo and fork.
Java/JNI is not included yet, and needs to be done later if necessary.
The goal is to include this commit in RocksDB 7.0 release.
Reference:
https://github.com/ajkr/dedupfs by ajkr
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9170
Test Plan:
Follow the instructions in https://github.com/riversand963/rocksdb-hdfs-env/blob/master/README.md. Build and run db_bench and db_stress.
make check
Reviewed By: ajkr
Differential Revision: D33751662
Pulled By: riversand963
fbshipit-source-id: 22b4db7f31762ed417a20239f5a08dcd1696244f
Summary:
Fixesfacebook/rocksdb#7720
Updated Makefile with flags to define target architecture when compiling/linking,
and added goal `rocksdbjavastaticosxub` to build a OS X Universal Binary native library.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9254
Reviewed By: mrambacher
Differential Revision: D33551160
Pulled By: pdillinger
fbshipit-source-id: 9ce9962e03aacf55014545a6cdf638b5b14b8fa9
Summary:
The LastSequence field in the MANIFEST file is the baseline seqno for a recovered DB. Recovering WAL entries might cause the recovered DB's seqno to advance above this baseline, but the recovered DB will never use a smaller seqno.
Before this PR, we were writing the DB's seqno at the time of LogAndApply() as the LastSequence value. This works in the sense that it is a large enough baseline for the recovered DB that it'll never overwrite any records in existing SST files. At the same time, it's arbitrarily larger than what's needed. This behavior comes from LevelDB, where there was no tracking of largest seqno in an SST file.
Now we know the largest seqno of newly written SST files, so we can write an exact value in LastSequence that actually reflects the largest seqno in any file referred to by the MANIFEST. This is primarily useful for correctness testing with unsynced data loss, where the recovered DB's seqno needs to indicate what records were recovered.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9305
Test Plan:
- https://github.com/facebook/rocksdb/issues/9338 adds crash-recovery correctness testing coverage for WAL disabled use cases
- https://github.com/facebook/rocksdb/issues/9357 will extend that testing to cover file ingestion
- Added assertion at end of LogAndApply() for `VersionSet::descriptor_last_sequence_` consistency with files
- Manually tested upgrade/downgrade compatibility with a custom crash test that randomly picks between a `db_stress` built with and without this PR (for old code it must run with `-disable_wal=0`)
Reviewed By: riversand963
Differential Revision: D33182770
Pulled By: ajkr
fbshipit-source-id: 0bfafaf685f347cc8cb0e1d62e0186340a738f7d
Adam Retter