Summary:
In debug mode, we are seeing assertion failure as follows

```
db/compaction/compaction_iterator.cc:980: void rocksdb::CompactionIterator::PrepareOutput(): \
Assertion `ikey_.type != kTypeDeletion && ikey_.type != kTypeSingleDeletion' failed.
```

It is caused by releasing earliest snapshot during compaction between the execution of
`NextFromInput()` and `PrepareOutput()`.

In one case, as demonstrated in unit test `WritePreparedTransaction.ReleaseEarliestSnapshotDuringCompaction_WithSD2`,
incorrect result may be returned by a following range scan if we disable assertion, as in opt compilation
level: the SingleDelete marker's sequence number is zeroed out, but the preceding PUT is also
outputted to the SST file after compaction. Due to the logic of DBIter, the PUT will not be
skipped and will be returned by iterator in range scan. https://github.com/facebook/rocksdb/issues/8661 illustrates what happened.

Fix by taking a more conservative approach: make compaction zero out sequence number only
if key is in the earliest snapshot when the compaction starts.

Another assertion failure is
```
Assertion `current_user_key_snapshot_ == last_snapshot' failed.
```

It's caused by releasing the snapshot between the PUT and SingleDelete during compaction.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8608

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D30145645

Pulled By: riversand963

fbshipit-source-id: 699f58e66faf70732ad53810ccef43935d3bbe81

Summary:
The patch adds statistics support to the integrated BlobDB implementation,
namely the tickers `BLOB_DB_BLOB_FILE_BYTES_READ` and
`BLOB_DB_GC_{NUM_KEYS,BYTES}_RELOCATED`, and the histograms
`BLOB_DB_(DE)COMPRESSION_MICROS`. (Some other statistics, like
`BLOB_DB_BLOB_FILE_BYTES_WRITTEN`, `BLOB_DB_BLOB_FILE_SYNCED`,
`BLOB_DB_BLOB_FILE_{READ,WRITE,SYNC}_MICROS` were already supported.)
Note that the vast majority of the old BlobDB's tickers/histograms are not
really applicable to the new implementation, since they e.g. pertain to calling
dedicated BlobDB APIs (which the integrated BlobDB does not have) or are
tied to the legacy BlobDB's design of writing blob files synchronously when
a write API is called. Such statistics are marked "legacy BlobDB only" in
`statistics.h`.

Fixes https://github.com/facebook/rocksdb/issues/8645 .

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8667

Test Plan: Ran `make check` and tested the new statistics using `db_bench`.

Reviewed By: riversand963

Differential Revision: D30356884

Pulled By: ltamasi

fbshipit-source-id: 5f8a833faee60401c5643c2f0a6c0415488190a4

Summary:
Just like other per_level properties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8668

Test Plan: stress_test

Reviewed By: zhichao-cao

Differential Revision: D30360967

Pulled By: jay-zhuang

fbshipit-source-id: 70da2557b95c55e8081b04ebf1a909a0fe69488f

Summary:
Add a stat for secondary cache hits. The ```Cache::Lookup``` API had an unused ```stats``` parameter. This PR uses that to pass the pointer to a ```Statistics``` object that ```LRUCache``` uses to record the stat.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8666

Test Plan: Update a unit test in lru_cache_test

Reviewed By: zhichao-cao

Differential Revision: D30353816

Pulled By: anand1976

fbshipit-source-id: 2046f78b460428877a26ffdd2bb914ae47dfbe77

Summary:
Use DB session ids in SST table properties to make cache keys
stable across DB re-open and copy / move / restore / etc.

These new cache keys are currently only enabled when FileSystem does not
provide GetUniqueId. For now, they are typically larger, so slightly
less efficient.

Relevant to https://github.com/facebook/rocksdb/issues/7405

This change has a minor regression in PersistentCache functionality:
metaindex blocks are no longer cached in PersistentCache. Table properties
blocks already were not but ideally should be. I didn't spent effort to
fix & test these issues because we don't believe PersistentCache is used much
if at all and expect SecondaryCache to replace it. (Though PRs are welcome.)

FIXME: there is more to be fixed for stable cache keys on external SST files

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8659

Test Plan:
new unit test added, which fails when disabling new
functionality

Reviewed By: zhichao-cao

Differential Revision: D30297705

Pulled By: pdillinger

fbshipit-source-id: e8539a5c8802a79340405629870f2e3fb3822d3a

Summary:
This is the `db_test2` parts of https://github.com/facebook/rocksdb/pull/7737 reworked on the latest HEAD.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8640

Reviewed By: akankshamahajan15

Differential Revision: D30303684

Pulled By: mrambacher

fbshipit-source-id: 263e2f82d849bde4048b60aed8b31e7deed4706a

Summary:
- Use dynamic section size when calling IsSectorAligned()
- Support relative path for GetSectorSize().
- Move buffer and sector alignment check to assert for better retail performance.
- Typo fixes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8613

Reviewed By: ajkr

Differential Revision: D30136082

Pulled By: mrambacher

fbshipit-source-id: e8cb849befdcae4fea99de5ed5dd6565e612425f

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8554

Reviewed By: ajkr

Differential Revision: D29756562

Pulled By: mrambacher

fbshipit-source-id: ab2f5ef988c8ac7ea7c633e6a3dacaf16f021529

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8644

Reviewed By: siying, zhichao-cao

Differential Revision: D30236535

Pulled By: jay-zhuang

fbshipit-source-id: 1758d1c46d83a5087560fb63d53a016bf999da81

Summary:
Previously, the `MemPurge` sampling function was assessing whether a random entry from a memtable was garbage or not by simply querying the given memtable (see https://github.com/facebook/rocksdb/issues/8628 for more details).
In this diff, I am updating the sampling function by querying not only the memtable the entry was drawn from, but also all subsequent memtables that have a greater memtable ID.
I also added the size of the value for KV entries in the payload/useful payload estimates (which was also one of the reasons why sampling was not as good as mempurging all the time in terms of L0 SST files reduction).
Once these changes were made, I was able to clean obsolete objects and functions from the `MemtableList` struct, and did a bit of cleanup everywhere.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8656

Reviewed By: pdillinger

Differential Revision: D30288583

Pulled By: bjlemaire

fbshipit-source-id: 7646a545ec56f4715949daa59ab5eee74540feb3

Summary:
- Remove extra `;` in trace_record.h
- Remove some unnecessary `assert` in trace_record_handler.cc
- Initialize `env_` after` exec_handler_` in `ReplayerImpl` to let db be asserted in creating the handler before getting `db->GetEnv()`.
- Update history to include the new `TraceReader::Reset()`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8652

Reviewed By: ajkr

Differential Revision: D30276872

Pulled By: autopear

fbshipit-source-id: 476ee162e0f241490c6209307448343a5b326b37

Summary:
New public interfaces:
`TraceRecord` and `TraceRecord::Handler`, available in "rocksdb/trace_record.h".
`Replayer`, available in `rocksdb/utilities/replayer.h`.

User can use `DB::NewDefaultReplayer()` to create a Replayer to auto/manual replay a trace file.

Unit tests:
- `./db_test2 --gtest_filter="DBTest2.TraceAndReplay"`: Updated with the internal API changes.
- `./db_test2 --gtest_filter="DBTest2.TraceAndManualReplay"`: New for manual replay.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8611

Reviewed By: ajkr

Differential Revision: D30266329

Pulled By: autopear

fbshipit-source-id: 1ecb3cbbedae0f6a67c18f0cc82e002b4d81b6f8

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:
The last few releases overlooked adding to this test. This
change fixes that.

This change also fixes the problem of older branches not understanding
ROCKSDB_NO_FBCODE and referencing compilers no longer supported.
During the test, build_detect_platform is patched to force no FBCODE
compiler usage. (We should not need to update old branches perpetually.)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8651

Test Plan: local run reproduces regression described in https://github.com/facebook/rocksdb/issues/8650

Reviewed By: jay-zhuang, zhichao-cao

Differential Revision: D30261872

Pulled By: pdillinger

fbshipit-source-id: 02b447d224d7e0eb8613c63185437ded146713bc

Summary:
Add comment for `options.allow_fallocate` that btrfs
preallocated space are not freed and a suggestion to disable
preallocation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8646

Test Plan: No code change

Reviewed By: ajkr

Differential Revision: D30240050

Pulled By: jay-zhuang

fbshipit-source-id: 75b7190bc8276ce8d8ac2d0cb9064b386cbf4768

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:
The patch attempts to deflake `DBTestXactLogIterator.TransactionLogIteratorCorruptedLog`
by disabling file deletions while retrieving the list of WAL files and truncating the first WAL file.
This is to prevent the `PurgeObsoleteFiles` call triggered by `GetSortedWalFiles` from
invalidating the result of `GetSortedWalFiles`. The patch also cleans up the test case a bit
and changes it to using `test::TruncateFile` instead of calling the `truncate` syscall directly.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8627

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D30147002

Pulled By: ltamasi

fbshipit-source-id: db11072a4ad8900a2f859cb5294e22b1888c23f6

Summary:
`GenericRateLimiter` slow path handles requests that cannot be satisfied
immediately.  Such requests enter a queue, and their thread stays in `Request()`
until they are granted or the rate limiter is stopped.  These threads are
responsible for unblocking themselves.  The work to do so is split into two main
duties.

(1) Waiting for the next refill time.
(2) Refilling the bytes and granting requests.

Prior to this PR, the slow path logic involved a leader election algorithm to
pick one thread to perform (1) followed by (2).  It elected the thread whose
request was at the front of the highest priority non-empty queue since that
request was most likely to be granted.  This algorithm was efficient in terms of
reducing intermediate wakeups, which is a thread waking up only to resume
waiting after finding its request is not granted.  However, the conceptual
complexity of this algorithm was too high.  It took me a long time to draw a
timeline to understand how it works for just one edge case yet there were so
many.

This PR drops the leader election to reduce conceptual complexity.  Now, the two
duties can be performed by whichever thread acquires the lock first.  The risk
of this change is increasing the number of intermediate wakeups, however, we
took steps to mitigate that.

- `wait_until_refill_pending_` flag ensures only one thread performs (1). This\
prevents the thundering herd problem at the next refill time. The remaining\
threads wait on their condition variable with an unbounded duration -- thus we\
must remember to notify them to ensure forward progress.
- (1) is typically done by a thread at the front of a queue. This is trivial\
when the queues are initially empty as the first choice that arrives must be\
the only entry in its queue. When queues are initially non-empty, we achieve\
this by having (2) notify a thread at the front of a queue (preferring higher\
priority) to perform the next duty.
- We do not require any additional wakeup for (2). Typically it will just be\
done by the thread that finished (1).

Combined, the second and third bullet points above suggest the refill/granting
will typically be done by a request at the front of its queue.  This is
important because one wakeup is saved when a granted request happens to be in an
already running thread.

Note there are a few cases that still lead to intermediate wakeup, however.  The
first two are existing issues that also apply to the old algorithm, however, the
third (including both subpoints) is new.

- No request may be granted (only possible when rate limit dynamically\
decreases).
- Requests from a different queue may be granted.
- (2) may be run by a non-front request thread causing it to not be granted even\
if some requests in that same queue are granted. It can happen for a couple\
(unlikely) reasons.
  - A new request may sneak in and grab the lock at the refill time, before the\
thread finishing (1) can wake up and grab it.
  - A new request may sneak in and grab the lock and execute (1) before (2)'s\
chosen candidate can wake up and grab the lock. Then that non-front request\
thread performing (1) can carry over to perform (2).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8602

Test Plan:
- Use existing tests. The edge cases listed in the comment are all performance\
related; I could not really think of any related to correctness. The logic\
looks the same whether a thread wakes up/finishes its work early/on-time/late,\
or whether the thread is chosen vs. "steals" the work.
- Verified write throughput and CPU overhead are basically the same with and\
  without this change, even in a rate limiter heavy workload:

Test command:
```
$ rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -benchmarks=fillrandom -num_multi_db=64 -num_low_pri_threads=64 -num_high_pri_threads=64 -write_buffer_size=262144 -target_file_size_base=262144 -max_bytes_for_level_base=1048576 -rate_limiter_bytes_per_sec=16777216 -key_size=24 -value_size=1000 -num=10000 -compression_type=none -rate_limiter_refill_period_us=1000
```

Results before this PR:

```
fillrandom   :     108.463 micros/op 9219 ops/sec;    9.0 MB/s
7.40user 8.84system 1:26.20elapsed 18%CPU (0avgtext+0avgdata 256140maxresident)k
```

Results after this PR:

```
fillrandom   :     108.108 micros/op 9250 ops/sec;    9.0 MB/s
7.45user 8.23system 1:26.68elapsed 18%CPU (0avgtext+0avgdata 255688maxresident)k
```

Reviewed By: hx235

Differential Revision: D30048013

Pulled By: ajkr

fbshipit-source-id: 6741bba9d9dfbccab359806d725105817fef818b

Summary: UBSAN revealed a pointer underflow when `LZ4HC_init_internal` is called with a null `start`.

Reviewed By: ajkr

Differential Revision: D30181874

fbshipit-source-id: ca9bbac1a85c58782871d7f153af733b000cc66c

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8631

Reviewed By: siying

Differential Revision: D30200385

Pulled By: jay-zhuang

fbshipit-source-id: 0fa2bb15e74ff81762d767f234078e0fe0106c55

Summary:
Some FIFO users want to keep the data for longer, but the old data is rarely accessed. This feature allows users to configure FIFO compaction so that data older than a threshold is moved to a warm storage tier.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8310

Test Plan: Add several unit tests.

Reviewed By: ajkr

Differential Revision: D28493792

fbshipit-source-id: c14824ea634814dee5278b449ab5c98b6e0b5501

Summary:
FaultInjectionTestFS injects error in Rename operation. Because
of injected error, info.log fails to be created if rename  returns error and info_log is set to nullptr which leads to this assertion

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8632

Test Plan: run the db_stress job locally

Reviewed By: ajkr

Differential Revision: D30167387

Pulled By: akankshamahajan15

fbshipit-source-id: 8d08c4c33e8f0cabd368bbb498d21b9de0660067

Summary:
* `rocksdb_optimistictransactiondb_checkpoint_object_create`
* `rocksdb_optimistictransactiondb_write`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8526

Reviewed By: ajkr

Differential Revision: D30076822

Pulled By: jay-zhuang

fbshipit-source-id: a59956a8d5449e75d39a8087fbb2bad148cf697d

Summary:
This draining mechanism should not be run during `JoinThreads()` because it can detach threads that will be joined. Joining detached threads would throw an exception.

With this PR, we skip draining when `JoinThreads()` has already decided what threads to `join()`, so the threads will exit naturally once the work queue empties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8635

Test Plan: verified it unblocked using `WaitForJobsAndJoinAllThreads()` in https://github.com/facebook/rocksdb/issues/8611.

Reviewed By: riversand963

Differential Revision: D30174587

Pulled By: ajkr

fbshipit-source-id: 144966398a607987e0763c7152a0f653fdbf3c8b

Summary:
`CompareKeyContext::operator()` on the trunk has a bug: when comparing
column family IDs, `lhs` is used for both sides of the comparison. This
results in the `KeyContext`s getting sorted solely based on key, which
in turn means that keys with the same column family do not necessarily
form a single range in the sorted list. This violates an assumption of the
batched `MultiGet` logic, leading to the same column family
showing up multiple times in the list of `MultiGetColumnFamilyData`.
The end result is the code attempting to check out the thread-local
`SuperVersion` for the same CF multiple times, causing an
assertion violation in debug builds and memory corruption/crash in
release builds.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8633

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D30169182

Pulled By: ltamasi

fbshipit-source-id: a47710652df7e95b14b40fb710924c11a8478023

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8533

Reviewed By: ajkr

Differential Revision: D29718067

fbshipit-source-id: b4b91c9271362e7a7d47ddbaf28f56fb537cc668

Summary:
Unused since https://github.com/facebook/rocksdb/commit/ab718b415fc9b2a66a2ed642c18803f764839d7b .
Noticed on https://lgtm.com/projects/g/facebook/rocksdb/snapshot/b215f1a83226f111ff52305987af93564272b7d3/files/tools/db_crashtest.py?sort=name&dir=ASC&mode=heatmap#xf254f528ad18f108:1

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8599

Reviewed By: ajkr

Differential Revision: D30057041

Pulled By: zhichao-cao

fbshipit-source-id: e80438cf9717086d2bf67461e19393d426a7676e

Summary:
Fix help message.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8615

Reviewed By: siying

Differential Revision: D30136092

Pulled By: mrambacher

fbshipit-source-id: edf4112570514d709560baaf96a47c5f36f00665

Summary:
Guarantees that if a restore is interrupted, DB::Open will fail. This works by
restoring CURRENT first to CURRENT.tmp then as a final step renaming to CURRENT.

Also makes restore respect BackupEngineOptions::sync (default true). When set,
the restore is guaranteed persisted by the time it returns OK. Also makes the above
atomicity guarantee work in case the interruption is power loss or OS crash (not just
process interruption or crash).

Fixes https://github.com/facebook/rocksdb/issues/8500

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8568

Test Plan:
added to backup mini-stress unit test. Passes with
gtest_repeat=100 (whereas fails 7 times without the CURRENT.tmp)

Reviewed By: akankshamahajan15

Differential Revision: D29812605

Pulled By: pdillinger

fbshipit-source-id: 24e9a993b305b1835ca95558fa7a7152e54cda8e

Summary:
By default, the low priority pool is not the flush pool, so calling `Env#setBackgroundThreads` without providing a priority will not do what the caller expected.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8576

Reviewed By: ajkr

Differential Revision: D29925154

Pulled By: mrambacher

fbshipit-source-id: cd7211fc374e7d9929a9b88ea0a5ba8134b76099

Summary:
- Changed MergeOperator, CompactionFilter, and CompactionFilterFactory into Customizable classes.
 - Added Options/Configurable/Object Registration for TTL and Cassandra variants
 - Changed the StringAppend MergeOperators to accept a string delimiter rather than a simple char.  Made the delimiter into a configurable option
 - Added tests for new functionality

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8481

Reviewed By: zhichao-cao

Differential Revision: D30136050

Pulled By: mrambacher

fbshipit-source-id: 271d1772835935b6773abaf018ee71e42f9491af

Summary:
Dynamically configure BlockBasedTableOptions.prepopulate_block_cache using DB::SetOptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8620

Test Plan: Added new unit test

Reviewed By: anand1976

Differential Revision: D30091319

Pulled By: akankshamahajan15

fbshipit-source-id: fb586d1848a8dd525bba7b2f9eeac34f2fc6d82c

Summary:
We've been seeing occasional crashes on CI while inserting into the
vectors in `ObsoleteFilesTest.DeleteObsoleteOptionsFile`. The crashes
don't reproduce locally (could be either a race or an object lifecycle
issue) but the good news is that the vectors in question are not really
used for anything meaningful by the test. (The assertion about the sizes
of the two vectors being equal is guaranteed to hold, since the two sync
points where they are populated are right after each other.) The patch
simply removes the vectors from the test, alongside the associated
callbacks and sync points.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8624

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D30118485

Pulled By: ltamasi

fbshipit-source-id: 0a4c3d06584e84cd2b1dcc212d274fa1b89cb647

Summary:
Update HISTORY.md for PR https://github.com/facebook/rocksdb/issues/8585 .

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8623

Reviewed By: ltamasi

Differential Revision: D30121910

Pulled By: riversand963

fbshipit-source-id: 525af43fad908a498f22ed4f934ec5cbf60e6d25

Summary:
Previously we attempted to rename "LOG" to "LOG.old.*" without checking
its existence first. "LOG" had no reason to exist in a new DB.

Errors in renaming a non-existent "LOG" were swallowed via
`PermitUncheckedError()` so things worked. However the storage service's
error monitoring was detecting all these benign rename failures. So it
is better to fix it. Also with this PR we can now distinguish rename failure
for other reasons and return them.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8622

Test Plan: new unit test

Reviewed By: akankshamahajan15

Differential Revision: D30115189

Pulled By: ajkr

fbshipit-source-id: e2f337ffb2bd171be0203172abc8e16e7809b170

Summary:
Fixed clang failure because of memory leak

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8621

Test Plan: CircleCI clang job

Reviewed By: pdillinger

Differential Revision: D30114337

Pulled By: akankshamahajan15

fbshipit-source-id: 16572b9bcbaa053c2ab7bc1c344148d0e6f8039c

Summary:
```FaultInjectionTestFS``` injects various types of read errors in ```FileSystem``` APIs. One type of error is corruption errors, where data is intentionally corrupted or truncated. There is corresponding validation in db_stress to verify that an injected error results in a user visible Get/MultiGet error. However, for corruption errors, its hard to know when a corruption is supposed to be detected by the user request, due to prefetching and, in case of direct IO, padding. This results in false positives. So remove that functionality.

Block checksum validation for Get/MultiGet is confined to ```BlockFetcher```, so we don't lose a lot by disabling this since its a small surface area to test.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8616

Reviewed By: zhichao-cao

Differential Revision: D30074422

Pulled By: anand1976

fbshipit-source-id: 6a61fac18f95514c15364b75013799ddf83294df

Summary:
Context:
As need for new feature of resource management using RocksDB's rate limiter like [https://github.com/facebook/rocksdb/issues/8595](https://github.com/facebook/rocksdb/pull/8595) arises, it is about time to re-learn our rate limiter and make this learning process easier for others by improving its readability. The comment/assertion/one extra else-branch are added based on my best understanding toward the rate_limiter.cc and rate_limiter_test.cc up to date after giving it a hard read.
- Add code comments/assertion/one extra else-branch (that is not affecting existing behavior, see PR comment) to describe how leader-election works under multi-thread settings in GenericRateLimiter::Request()
- Add code comments to describe a non-obvious trick during clean-up of rate limiter destructor
- Add code comments to explain more about the starvation being fixed in GenericRateLimiter::Refill() through partial byte-granting
- Add code comments to the rate limiter's setup in a complicated unit test in rate_limiter_test

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8596

Test Plan: - passed existing rate_limiter_test.cc

Reviewed By: ajkr

Differential Revision: D29982590

Pulled By: hx235

fbshipit-source-id: c3592986bb5b0c90d8229fe44f425251ec7e8a0a

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8619

Reviewed By: riversand963

Differential Revision: D30081937

Pulled By: ltamasi

fbshipit-source-id: 57505957ae2c22d4b194aa28cb3fd261b3b39919

Summary:
PR https://github.com/facebook/rocksdb/issues/5908 added `flush_jobs_info_` to `FlushJob` to make sure
`OnFlushCompleted()` is called after committing flush results to
MANIFEST. However, `flush_jobs_info_` is not updated in atomic
flush, causing `NotifyOnFlushCompleted()` to skip `OnFlushCompleted()`.

This PR fixes this, in a similar way to https://github.com/facebook/rocksdb/issues/5908 that handles regular flush.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8585

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D29913720

Pulled By: riversand963

fbshipit-source-id: 4ff023c98372fa2c93188d4a5c8a4e9ffa0f4dda