Summary:
The PR cleans up the logic in `NonBatchedOpsStressTest::VerifyDb` so that
the verification method is picked using a single random number generation.
It also eliminates some repeated key comparisons and makes some small
code hygiene improvements.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10740
Test Plan: Ran a simple blackbox crash test.
Reviewed By: riversand963
Differential Revision: D39828646
Pulled By: ltamasi
fbshipit-source-id: 60ee5a3bb1851278f62c7d83b0c93b902ed9702e
Summary:
This change establishes a distinctive name for the experimental new lock-free clock cache (originally developed by guidotag and revamped in PR https://github.com/facebook/rocksdb/issues/10626). A few reasons:
* We want to make it clear that this is a fundamentally different implementation vs. the old clock cache, to avoid people saying "I already tried clock cache."
* We want to highlight the key feature: it's fast (especially under parallel load)
* Because it requires an estimated charge per entry, it is not drop-in API compatible with old clock cache. This estimate might always be required for highest performance, and giving it a distinct name should reduce confusion about the distinct API requirements.
* We might develop a variant requiring the same estimate parameter but with LRU eviction. In that case, using the name HyperLRUCache should make things more clear. (FastLRUCache is just a prototype that might soon be removed.)
Some API detail:
* To reduce copy-pasting parameter lists, etc. as in LRUCache construction, I have a `MakeSharedCache()` function on `HyperClockCacheOptions` instead of `NewHyperClockCache()`.
* Changes -cache_type=clock_cache to -cache_type=hyper_clock_cache for applicable tools. I think this is more consistent / sustainable for reasons already stated.
For performance tests see https://github.com/facebook/rocksdb/pull/10626
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10684
Test Plan: no interesting functional changes; tests updated
Reviewed By: anand1976
Differential Revision: D39547800
Pulled By: pdillinger
fbshipit-source-id: 5c0fe1b5cf3cb680ab369b928c8569682b9795bf
Summary:
One problem of the previous strategy was `NonBatchedOpsStressTest::TestIngestExternalFile()` could release the lock for `rand_keys[0]` in `rand_column_families[0]`, and then subsequent operations in the same loop iteration (e.g., `TestPut()`) would run without locking. This PR changes the strategy so each `Test*()` function is responsible for acquiring and releasing its own locks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10678
Reviewed By: hx235
Differential Revision: D39516401
Pulled By: ajkr
fbshipit-source-id: bf67f12ebbd293ba8c24fdf8754ff28737bcd758
Summary:
In `db_stress`, DB and expected state files containing changes leading up to a verification failure are often deleted, which makes debugging such failures difficult. On the DB side, flushed WAL files and compacted SST files are marked obsolete and then deleted. Without those files, we cannot pinpoint where a key that failed verification changed unexpectedly. On the expected state side, files for verifying prefix-recoverability in the presence of unsynced data loss are deleted before verification. These include a baseline state file containing the expected state at the time of the last successful verification, and a trace file containing all operations since then. Without those files, we cannot know the sequence of DB operations expected to be recovered.
This PR attempts to address this gap with a new `db_stress` flag: `preserve_unverified_changes`. Setting `preserve_unverified_changes=1` has two effects.
First, prior to startup verification, `db_stress` hardlinks all DB and expected state files in "unverified/" subdirectories of `FLAGS_db` and `FLAGS_expected_values_dir`. The separate directories are needed because the pre-verification opening process deletes files written by the previous `db_stress` run as described above. These "unverified/" subdirectories are cleaned up following startup verification success.
I considered other approaches for preserving DB files through startup verification, like using a read-only DB or preventing deletion of DB files externally, e.g., in the `Env` layer. However, I decided against it since such an approach would not work for expected state files, and I did not want to change the DB management logic. If there were a way to disable DB file deletions before regular DB open, I would have preferred to use that.
Second, `db_stress` attempts to keep all DB and expected state files that were live at some point since the start of the `db_stress` run. This is a bit tricky and involves the following changes.
- Open the DB with `disable_auto_compactions=1` and `avoid_flush_during_recovery=1`
- DisableFileDeletions()
- EnableAutoCompactions()
For this part, too, I would have preferred to use a hypothetical API that disables DB file deletion before regular DB open.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10659
Reviewed By: hx235
Differential Revision: D39407454
Pulled By: ajkr
fbshipit-source-id: 6e981025c7dce147649d2e770728471395a7fa53
Summary:
Same as title
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10632
Test Plan: make crash_test -j32
Reviewed By: anand1976
Differential Revision: D39241479
Pulled By: akankshamahajan15
fbshipit-source-id: 5db5b0c007da786bacc1b30d8926d36d6d029b87
Summary:
Currently, `db_bench` and `db_stress` print the blob cache options even if
a shared block/blob cache is configured, i.e. when they are not actually
in effect. The patch changes this so they are only printed when a separate blob
cache is used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10614
Test Plan: Tested manually using `db_bench` and `db_stress`.
Reviewed By: akankshamahajan15
Differential Revision: D39144603
Pulled By: ltamasi
fbshipit-source-id: f714304c5d46186f8514746c27ee6f52aa3e4af8
Summary:
When verification fails for db_stress, print more information about
value read from the db and expected state.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10587
Test Plan:
make check
./db_stress
Reviewed By: akankshamahajan15, hx235
Differential Revision: D39078511
Pulled By: riversand963
fbshipit-source-id: 77ac8ffae01fc3a9b58a02c2e7bbe141e1a18f0b
Summary:
https://github.com/facebook/rocksdb/issues/10538 added `TestIterateAgainstExpected()` in `no_batched_ops_test` to verify iterator correctness against the in memory expected state. It is not compatible when run after some other stress tests, e.g. `TestPut()` in `batched_op_stress`, that either do not set expected state when writing to DB or use keys that cannot be parsed by `GetIntVal()`. The assert [here](d17be55aab/db_stress_tool/db_stress_common.h (L520)) could fail. This PR fixed this issue by setting iterator upperbound to `max_key` when `destroy_db_initially=0` to avoid the key space that `batched_op_stress` touches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10590
Test Plan:
```
# set up DB with batched_op_stress
./db_stress --test_batches_snapshots=1 --verify_iterator_with_expected_state_one_in=1 --max_key_len=3 --max_key=100000000 --skip_verifydb=1 --continuous_verification_interval=0 --writepercent=85 --delpercent=3 --delrangepercent=0 --iterpercent=10 --nooverwritepercent=1 --prefixpercent=0 --readpercent=2 --key_len_percent_dist=1,30,69
# Before this PR, the following test will fail the asserts with error msg like the following
# Assertion failed: (size_key <= key_gen_ctx.weights.size() * sizeof(uint64_t)), function GetIntVal, file db_stress_common.h, line 524.
./db_stress --verify_iterator_with_expected_state_one_in=1 --max_key_len=3 --max_key=100000000 --skip_verifydb=1 --continuous_verification_interval=0 --writepercent=0 --delpercent=3 --delrangepercent=0 --iterpercent=95 --nooverwritepercent=1 --prefixpercent=0 --readpercent=2 --key_len_percent_dist=1,30,69 --destroy_db_initially=0
```
Reviewed By: ajkr
Differential Revision: D39085243
Pulled By: cbi42
fbshipit-source-id: a7dfee2320c330773b623b442d730fd014ec7056
Summary:
As mentioned in https://github.com/facebook/rocksdb/pull/5506#issuecomment-506021913,
`db_stress` does not have much verification for iterator correctness.
It has a `TestIterate()` function, but that is mainly for comparing results
between two iterators, one with `total_order_seek` and the other optionally
sets auto_prefix, upper/lower bounds. Commit 49a0581ad2462e31aa3f768afa769e0d33390f33
added a new `TestIterateAgainstExpected()` function that compares iterator against
expected state. It locks a range of keys, creates an iterator, does
a random sequence of `Next/Prev` and compares against expected state.
This PR is based on that commit, the main changes include some logs
(for easier debugging if a test fails), a forward and backward scan to
cover the entire locked key range, and a flag for optionally turning on
this version of Iterator testing.
Added constraint that the checks against expected state in
`TestIterateAgainstExpected()` and in `TestGet()` are only turned on
when `--skip_verifydb` flag is not set.
Remove the change log introduced in https://github.com/facebook/rocksdb/issues/10553.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10538
Test Plan:
Run `db_stress` with `--verify_iterator_with_expected_state_one_in=1`,
and a large `--iterpercent` and `--num_iterations`. Checked `op_logs`
manually to ensure expected coverage. Tweaked part of the code in
https://github.com/facebook/rocksdb/issues/10449 and stress test was able to catch it.
- internally run various flavor of crash test
Reviewed By: ajkr
Differential Revision: D38847269
Pulled By: cbi42
fbshipit-source-id: 8b4402a9bba9f6cfa08051943cd672579d489599
Summary:
updated `TestGet()` in `no_batched_op_stress` to check the result of `Get()` operations against expected state (`expected_state_manager_`). More specifically, if `Get()` finds a key, expected state should not have `DELETION_SENTINEL` for the same key, and if `Get()` returns NotFound for a key, expected state should not have the key. One intention for this change it to verify correctness of code path change regarding range tombstones.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10553
Test Plan: run db_stress with nonzero readpercent: `./db_stress_branch --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4`. When I initially used wrong column family in `thread->shared->Get`, the test reported inconsistencies.
Reviewed By: ajkr
Differential Revision: D38927007
Pulled By: cbi42
fbshipit-source-id: f9f61b312ad0b4c21a799329609ba8526169b048
Summary:
To help service owners to manage their memory budget effectively, we have been working towards counting all major memory users inside RocksDB towards a single global memory limit (see e.g. https://github.com/facebook/rocksdb/wiki/Write-Buffer-Manager#cost-memory-used-in-memtable-to-block-cache). The global limit is specified by the capacity of the block-based table's block cache, and is technically implemented by inserting dummy entries ("reservations") into the block cache. The goal of this task is to support charging the memory usage of the new blob cache against this global memory limit when the backing cache of the blob cache and the block cache are different.
This PR is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10321
Reviewed By: ltamasi
Differential Revision: D37913590
Pulled By: gangliao
fbshipit-source-id: eaacf23907f82dc7d18964a3f24d7039a2937a72
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:
This complements https://github.com/facebook/rocksdb/issues/10351. This PR reverts NewClockCache's signature to an older version, expected by the users of the old (buggy) ClockCache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10358
Test Plan: ``make -j24 check`` and re-run the pre-release tests.
Reviewed By: siying
Differential Revision: D37832601
Pulled By: guidotag
fbshipit-source-id: 32a91d3da4119be187935003b7b897272ceb1950
Summary:
Before this PR, we call `now()` to get the wall time before performing point-lookup and range
scans when user-defined timestamp is enabled.
With this PR, we expand the coverage to:
- read with an older timestamp which is larger then the wall time when the process starts but potentially smaller than now()
- add coverage for `ReadOptions::iter_start_ts != nullptr`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10280
Test Plan:
```bash
make check
```
Also,
```bash
TEST_TMPDIR=/dev/shm/rocksdb make crash_test_with_ts
```
So far, we have had four successful runs of the above
In addition,
```bash
TEST_TMPDIR=/dev/shm/rocksdb make crash_test
```
Succeeded twice showing no regression.
Reviewed By: ltamasi
Differential Revision: D37539805
Pulled By: riversand963
fbshipit-source-id: f2d9887ad95245945ce17a014d55bb93f00e1cb5
Summary:
This is the initial step in the development of a lock-free clock cache. This PR includes the base hash table design (which we mostly ported over from FastLRUCache) and the clock eviction algorithm. Importantly, it's still _not_ lock-free---all operations use a shard lock. Besides the locking, there are other features left as future work:
- Remove keys from the handles. Instead, use 128-bit bijective hashes of them for handle comparisons, probing (we need two 32-bit hashes of the key for double hashing) and sharding (we need one 6-bit hash).
- Remove the clock_usage_ field, which is updated on every lookup. Even if it were atomically updated, it could cause memory invalidations across cores.
- Middle insertions into the clock list.
- A test that exercises the clock eviction policy.
- Update the Java API of ClockCache and Java calls to C++.
Along the way, we improved the code and comments quality of FastLRUCache. These changes are relatively minor.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10273
Test Plan: ``make -j24 check``
Reviewed By: pdillinger
Differential Revision: D37522461
Pulled By: guidotag
fbshipit-source-id: 3d70b737dbb70dcf662f00cef8c609750f083943
Summary:
Before this PR, when user-defined timestamp is enabled, db_stress disables compaction filter.
This is no longer necessary after this PR, since the `DbStressCompactionFilter` is now aware of
the presence of timestamps.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10259
Test Plan: TEST_TMPDIR=/dev/shm make crash_test_with_ts
Reviewed By: ajkr
Differential Revision: D37459692
Pulled By: riversand963
fbshipit-source-id: 8fe62e90a63bd9317fe1bb95a2b4984080c9e5ef
Summary:
Need to disable it for now as CI is failing, particularly `MultiOpsTxnsStressTest`. Investigation details in internal task T124324915. This PR disables mempurge more widely than `MultiOpsTxnsStressTest` until we know the issue is contained to that particular test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10252
Reviewed By: riversand963
Differential Revision: D37432948
Pulled By: ajkr
fbshipit-source-id: d0cf5b0e0ec7c3142c382a0347f35a4c34f4607a
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:
In order to facilitate correctness and performance testing, we would like to add the new blob cache to our stress test tool `db_stress` and our continuously running crash test script `db_crashtest.py`, as well as our synthetic benchmarking tool `db_bench` and the BlobDB performance testing script `run_blob_bench.sh`.
As part of this task, we would also like to utilize these benchmarking tools to get some initial performance numbers about the effectiveness of caching blobs.
This PR is a part of https://github.com/facebook/rocksdb/issues/10156
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10202
Reviewed By: ltamasi
Differential Revision: D37325739
Pulled By: gangliao
fbshipit-source-id: deb65d0d414502270dd4c324d987fd5469869fa8
Summary:
There was a bug in the MultiGet enhancement in https://github.com/facebook/rocksdb/issues/9899 with data
block hash index, which was not caught because data block hash index was
never added to stress tests. This change fixes both issues.
Fixes https://github.com/facebook/rocksdb/issues/10186
I intend to pick this into the 7.4.0 release candidate
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10220
Test Plan:
Failure quickly reproduces in crash test with
kDataBlockBinaryAndHash, and does not seem to with the fix. Reproducing
the failure with a unit test I believe would be too tricky and fragile
to be worthwhile.
Reviewed By: anand1976
Differential Revision: D37315647
Pulled By: pdillinger
fbshipit-source-id: 9f648265bba867275edc752f7a56611a59401cba
Summary:
**Context/Summary:**
https://github.com/facebook/rocksdb/pull/9424 added rate-limiting support for user reads, which does not include batched `MultiGet()`s that call `RandomAccessFileReader::MultiRead()`. The reason is that it's harder (compared with RandomAccessFileReader::Read()) to implement the ideal rate-limiting where we first call `RateLimiter::RequestToken()` for allowed bytes to multi-read and then consume those bytes by satisfying as many requests in `MultiRead()` as possible. For example, it can be tricky to decide whether we want partially fulfilled requests within one `MultiRead()` or not.
However, due to a recent urgent user request, we decide to pursue an elementary (but a conditionally ineffective) solution where we accumulate enough rate limiter requests toward the total bytes needed by one `MultiRead()` before doing that `MultiRead()`. This is not ideal when the total bytes are huge as we will actually consume a huge bandwidth from rate-limiter causing a burst on disk. This is not what we ultimately want with rate limiter. Therefore a follow-up work is noted through TODO comments.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10159
Test Plan:
- Modified existing unit test `DBRateLimiterOnReadTest/DBRateLimiterOnReadTest.NewMultiGet`
- Traced the underlying system calls `io_uring_enter` and verified they are 10 seconds apart from each other correctly under the setting of `strace -ftt -e trace=io_uring_enter ./db_bench -benchmarks=multireadrandom -db=/dev/shm/testdb2 -readonly -num=50 -threads=1 -multiread_batched=1 -batch_size=100 -duration=10 -rate_limiter_bytes_per_sec=200 -rate_limiter_refill_period_us=1000000 -rate_limit_bg_reads=1 -disable_auto_compactions=1 -rate_limit_user_ops=1` where each `MultiRead()` read about 2000 bytes (inspected by debugger) and the rate limiter grants 200 bytes per seconds.
- Stress test:
- Verified `./db_stress (-test_cf_consistency=1/test_batches_snapshots=1) -use_multiget=1 -cache_size=1048576 -rate_limiter_bytes_per_sec=10241024 -rate_limit_bg_reads=1 -rate_limit_user_ops=1` work
Reviewed By: ajkr, anand1976
Differential Revision: D37135172
Pulled By: hx235
fbshipit-source-id: 73b8e8f14761e5d4b77235dfe5d41f4eea968bcd
Summary:
Added an option, `WriteOptions::protection_bytes_per_key`, that controls how many bytes per key we use for integrity protection in `WriteBatch`. It takes effect when `WriteBatch::GetProtectionBytesPerKey() == 0`.
Currently the only supported value is eight. Invoking a user API with it set to any other nonzero value will result in `Status::NotSupported` returned to the user.
There is also a bug fix for integrity protection with `inplace_callback`, where we forgot to take into account the possible change in varint length when calculating KV checksum for the final encoded buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10037
Test Plan:
- Manual
- Set default value of `WriteOptions::protection_bytes_per_key` to eight and ran `make check -j24`
- Enabled in MyShadow for 1+ week
- Automated
- Unit tests have a `WriteMode` that enables the integrity protection via `WriteOptions`
- Crash test - in most cases, use `WriteOptions::protection_bytes_per_key` to enable integrity protection
Reviewed By: cbi42
Differential Revision: D36614569
Pulled By: ajkr
fbshipit-source-id: 8650087ceac9b61b560f1e5fafe5e1baf9c725fb
Summary:
In https://github.com/facebook/rocksdb/issues/9535, release 7.0, we hid the old block-based filter from being created using
the public API, because of its inefficiency. Although we normally maintain read compatibility
on old DBs forever, filters are not required for reading a DB, only for optimizing read
performance. Thus, it should be acceptable to remove this code and the substantial
maintenance burden it carries as useful features are developed and validated (such
as user timestamp).
This change completely removes the code for reading and writing the old block-based
filters, net removing about 1370 lines of code no longer needed. Options removed from
testing / benchmarking tools. The prior existence is only evident in a couple of places:
* `CacheEntryRole::kDeprecatedFilterBlock` - We can update this public API enum in
a major release to minimize source code incompatibilities.
* A warning is logged when an old table file is opened that used the old block-based
filter. This is provided as a courtesy, and would be a pain to unit test, so manual testing
should suffice. Unfortunately, sst_dump does not tell you whether a file uses
block-based filter, and the structure of the code makes it very difficult to fix.
* To detect that case, `kObsoleteFilterBlockPrefix` (renamed from `kFilterBlockPrefix`)
for metaindex is maintained (for now).
Other notes:
* In some cases where numbers are associated with filter configurations, we have had to
update the assigned numbers so that they all correspond to something that exists.
* Fixed potential stat counting bug by assuming `filter_checked = false` for cases
like `filter == nullptr` rather than assuming `filter_checked = true`
* Removed obsolete `block_offset` and `prefix_extractor` parameters from several
functions.
* Removed some unnecessary checks `if (!table_prefix_extractor() && !prefix_extractor)`
because the caller guarantees the prefix extractor exists and is compatible
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10184
Test Plan:
tests updated, manually test new warning in LOG using base version to
generate a DB
Reviewed By: riversand963
Differential Revision: D37212647
Pulled By: pdillinger
fbshipit-source-id: 06ee020d8de3b81260ffc36ad0c1202cbf463a80
Summary:
There is `Options::allow_data_in_errors` that controls whether RocksDB
is allowed to log data, e.g. key, value, etc in LOG files. It is false
by default. However, in db_bench and db_stress, it is often ok to log
data because there is no concern about privacy.
This PR allows db_stress and db_bench to set this option on the command
line, while it remains false by default. Furthermore, make
crash/recovery test driven by db_crashtest.py to opt-in.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10171
Test Plan: Stress test and db_bench
Reviewed By: hx235
Differential Revision: D37163787
Pulled By: riversand963
fbshipit-source-id: 0242f24d292ba15b6faf8ff903963b85d3e011f8
Summary:
We make the size of the per-shard hash table fixed. The base level of the hash table is now preallocated with the required capacity. The user must provide an estimate of the size of the values.
Notice that even though the base level becomes fixed, the chains are still dynamic. Overall, the shard capacity mechanisms haven't changed, so we don't need to test this.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10154
Test Plan: `make -j24 check`
Reviewed By: pdillinger
Differential Revision: D37124451
Pulled By: guidotag
fbshipit-source-id: cba6ac76052fe0ec60b8ff4211b3de7650e80d0c
Summary:
Before this PR, there can be a race condition between the thread calling
`StressTest::Open()` and a background compaction thread calling
`MultiOpsTxnsStressTest::VerifyPkSkFast()`.
```
Time thread1 bg_compact_thr
| TransactionDB::Open(..., &txn_db_)
| db_ is still nullptr
| db_->GetSnapshot() // segfault
| db_ = txn_db_
V
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10157
Test Plan: CI
Reviewed By: akankshamahajan15
Differential Revision: D37121653
Pulled By: riversand963
fbshipit-source-id: 6a53117f958e9ee86f77297fdeb843e5160a9331
Summary:
In RocksDB, keys are associated with (internal) sequence numbers which denote when the keys are written
to the database. Sequence numbers in different RocksDB instances are unrelated, thus not comparable.
It is nice if we can associate sequence numbers with their corresponding actual timestamps. One thing we can
do is to support user-defined timestamp, which allows the applications to specify the format of custom timestamps
and encode a timestamp with each key. More details can be found at https://github.com/facebook/rocksdb/wiki/User-defined-Timestamp-%28Experimental%29.
This PR provides a different but complementary approach. We can associate rocksdb snapshots (defined in
https://github.com/facebook/rocksdb/blob/7.2.fb/include/rocksdb/snapshot.h#L20) with **user-specified** timestamps.
Since a snapshot is essentially an object representing a sequence number, this PR establishes a bi-directional mapping between sequence numbers and timestamps.
In the past, snapshots are usually taken by readers. The current super-version is grabbed, and a `rocksdb::Snapshot`
object is created with the last published sequence number of the super-version. You can see that the reader actually
has no good idea of what timestamp to assign to this snapshot, because by the time the `GetSnapshot()` is called,
an arbitrarily long period of time may have already elapsed since the last write, which is when the last published
sequence number is written.
This observation motivates the creation of "timestamped" snapshots on the write path. Currently, this functionality is
exposed only to the layer of `TransactionDB`. Application can tell RocksDB to create a snapshot when a transaction
commits, effectively associating the last sequence number with a timestamp. It is also assumed that application will
ensure any two snapshots with timestamps should satisfy the following:
```
snapshot1.seq < snapshot2.seq iff. snapshot1.ts < snapshot2.ts
```
If the application can guarantee that when a reader takes a timestamped snapshot, there is no active writes going on
in the database, then we also allow the user to use a new API `TransactionDB::CreateTimestampedSnapshot()` to create
a snapshot with associated timestamp.
Code example
```cpp
// Create a timestamped snapshot when committing transaction.
txn->SetCommitTimestamp(100);
txn->SetSnapshotOnNextOperation();
txn->Commit();
// A wrapper API for convenience
Status Transaction::CommitAndTryCreateSnapshot(
std::shared_ptr<TransactionNotifier> notifier,
TxnTimestamp ts,
std::shared_ptr<const Snapshot>* ret);
// Create a timestamped snapshot if caller guarantees no concurrent writes
std::pair<Status, std::shared_ptr<const Snapshot>> snapshot = txn_db->CreateTimestampedSnapshot(100);
```
The snapshots created in this way will be managed by RocksDB with ref-counting and potentially shared with
other readers. We provide the following APIs for readers to retrieve a snapshot given a timestamp.
```cpp
// Return the timestamped snapshot correponding to given timestamp. If ts is
// kMaxTxnTimestamp, then we return the latest timestamped snapshot if present.
// Othersise, we return the snapshot whose timestamp is equal to `ts`. If no
// such snapshot exists, then we return null.
std::shared_ptr<const Snapshot> TransactionDB::GetTimestampedSnapshot(TxnTimestamp ts) const;
// Return the latest timestamped snapshot if present.
std::shared_ptr<const Snapshot> TransactionDB::GetLatestTimestampedSnapshot() const;
```
We also provide two additional APIs for stats collection and reporting purposes.
```cpp
Status TransactionDB::GetAllTimestampedSnapshots(
std::vector<std::shared_ptr<const Snapshot>>& snapshots) const;
// Return timestamped snapshots whose timestamps fall in [ts_lb, ts_ub) and store them in `snapshots`.
Status TransactionDB::GetTimestampedSnapshots(
TxnTimestamp ts_lb,
TxnTimestamp ts_ub,
std::vector<std::shared_ptr<const Snapshot>>& snapshots) const;
```
To prevent the number of timestamped snapshots from growing infinitely, we provide the following API to release
timestamped snapshots whose timestamps are older than or equal to a given threshold.
```cpp
void TransactionDB::ReleaseTimestampedSnapshotsOlderThan(TxnTimestamp ts);
```
Before shutdown, RocksDB will release all timestamped snapshots.
Comparison with user-defined timestamp and how they can be combined:
User-defined timestamp persists every key with a timestamp, while timestamped snapshots maintain a volatile
mapping between snapshots (sequence numbers) and timestamps.
Different internal keys with the same user key but different timestamps will be treated as different by compaction,
thus a newer version will not hide older versions (with smaller timestamps) unless they are eligible for garbage collection.
In contrast, taking a timestamped snapshot at a certain sequence number and timestamp prevents all the keys visible in
this snapshot from been dropped by compaction. Here, visible means (seq < snapshot and most recent).
The timestamped snapshot supports the semantics of reading at an exact point in time.
Timestamped snapshots can also be used with user-defined timestamp.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9879
Test Plan:
```
make check
TEST_TMPDIR=/dev/shm make crash_test_with_txn
```
Reviewed By: siying
Differential Revision: D35783919
Pulled By: riversand963
fbshipit-source-id: 586ad905e169189e19d3bfc0cb0177a7239d1bd4
Summary:
This PR updates secondary instance testing in stress test by default.
A background thread will be started (disabled by default), running a secondary instance tailing the logs of the primary.
Periodically (every 1 sec), this thread calls `TryCatchUpWithPrimary()` and uses point lookup or range scan
to read some random keys with only very basic verification to make sure no assertion failure is triggered.
Thanks to https://github.com/facebook/rocksdb/issues/10061 , we can enable secondary instance when user-defined timestamp is enabled.
Also removed a less useful test configuration, `secondary_catch_up_one_in`. This is very similar to the periodic
catch-up.
In the last commit, I decided not to enable it now, but just update the tests, since secondary instance does not
work well when the underlying file is renamed by primary, e.g. SstFileManager.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10121
Test Plan:
```
TEST_TMPDIR=/dev/shm/rocksdb make crash_test
TEST_TMPDIR=/dev/shm/rocksdb make crash_test_with_ts
TEST_TMPDIR=/dev/shm/rocksdb make crash_test_with_atomic_flush
```
Reviewed By: ajkr
Differential Revision: D36939458
Pulled By: riversand963
fbshipit-source-id: 1c065b7efc3690fc341569b9d369a5cbd8ef6b3e
Summary:
After https://github.com/facebook/rocksdb/issues/9357 we began seeing the following error attempting to acquire
locks for file ingestion:
```
FATAL: ThreadSanitizer CHECK failed: /home/engshare/third-party2/llvm-fb/12/src/llvm/compiler-rt/lib/sanitizer_common/sanitizer_deadlock_detector.h:67 "((n_all_locks_)) < (((sizeof(all_locks_with_contexts_)/sizeof((all_locks_with_contexts_)[0]))))" (0x40, 0x40)
```
The command was using default values for `ingest_external_file_width`
(1000) and `log2_keys_per_lock` (2). The expected number of locks needed
to update those keys is then (1000 / 2^2) = 250, which is above the 0x40 (64)
limit. This PR reduces the default value of `ingest_external_file_width`
to 100 so the expected number of locks is 25, which is within the limit.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10131
Reviewed By: ltamasi
Differential Revision: D36986307
Pulled By: ajkr
fbshipit-source-id: e918cdb2fcc39517d585f1e5fd2539e185ada7c1
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:
Garbage collection is generally controlled by the BlobDB configuration options `enable_blob_garbage_collection` and `blob_garbage_collection_age_cutoff`. However, there might be use cases where we would want to temporarily override these options while performing a manual compaction. (One use case would be doing a full key-space manual compaction with full=100% garbage collection age cutoff in order to minimize the space occupied by the database.) Our goal here is to make it possible to override the configured GC parameters when using the `CompactRange` API to perform manual compactions. This PR would involve:
- Extending the `CompactRangeOptions` structure so clients can both force-enable and force-disable GC, as well as use a different cutoff than what's currently configured
- Storing whether blob GC should actually be enabled during a certain manual compaction and the cutoff to use in the `Compaction` object (considering the above overrides) and passing it to `CompactionIterator` via `CompactionProxy`
- Updating the BlobDB wiki to document the new options.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10073
Test Plan: Adding unit tests and adding the new options to the stress test tool.
Reviewed By: ltamasi
Differential Revision: D36848700
Pulled By: gangliao
fbshipit-source-id: c878ef101d1c612429999f513453c319f75d78e9
Summary:
Stress tests can run with the experimental FastLRUCache. Crash tests randomly choose between LRUCache and FastLRUCache.
Since only LRUCache supports a secondary cache, we validate the `--secondary_cache_uri` and `--cache_type` flags---when `--secondary_cache_uri` is set, the `--cache_type` is set to `lru_cache`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10081
Test Plan:
- To test that the FastLRUCache is used and the stress test runs successfully, run `make -j24 CRASH_TEST_EXT_ARGS=—duration=960 blackbox_crash_test_with_atomic_flush`. The cache type should sometimes be `fast_lru_cache`.
- To test the flag validation, run `make -j24 CRASH_TEST_EXT_ARGS="--duration=960 --secondary_cache_uri=x" blackbox_crash_test_with_atomic_flush` multiple times. The test will always be aborted (which is okay). Check that the cache type is always `lru_cache`.
Reviewed By: anand1976
Differential Revision: D36839908
Pulled By: guidotag
fbshipit-source-id: ebcdfdcd12ec04c96c09ae5b9c9d1e613bdd1725
Summary:
Thanks to https://github.com/facebook/rocksdb/issues/9919 and https://github.com/facebook/rocksdb/issues/10051 the known bugs in file ingestion (besides mmap read + file checksum) are fixed. Now we can try again to enable file ingestion in crash test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9357
Test Plan: stress file ingestion heavily for an hour: `$ TEST_TMPDIR=/dev/shm python3 tools/db_crashtest.py blackbox --max_key=1000000 --ingest_external_file_one_in=100 --duration=3600 --interval=20 --write_buffer_size=524288 --target_file_size_base=524288 --max_bytes_for_level_base=2097152`
Reviewed By: riversand963
Differential Revision: D33410746
Pulled By: ajkr
fbshipit-source-id: d276431390995a67f68390d61c06a40945fdd280
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:
ROCKSDB_SUPPORT_THREAD_LOCAL definition has been removed.
`__thread`(#define) has been replaced with `thread_local`(C++ keyword) across the code base.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10015
Reviewed By: siying
Differential Revision: D36485491
Pulled By: pdillinger
fbshipit-source-id: 6522d212514ee190b90b4e2750c80c7e34013c78
Summary:
This is similar to https://github.com/facebook/rocksdb/issues/9862, including the following fixes/refactoring:
1. If OPTIONS file is specified via `-options_file`, majority of options will be loaded from the file. We should not
overwrite options that have been loaded from the file. Instead, we configure only fields of options which are
shared objects and not set by the OPTIONS file. We also configure a few fields, e.g. `create_if_missing` necessary
for stress test to run.
2. Refactor options initialization into three functions, `InitializeOptionsFromFile()`, `InitializeOptionsFromFlags()`
and `InitializeOptionsGeneral()` similar to db_bench. I hope they can be shared in the future. The high-level logic is
as follows:
```cpp
if (!InitializeOptionsFromFile(...)) {
InitializeOptionsFromFlags(...);
}
InitializeOptionsGeneral(...);
```
3. Currently, the setting for `block_cache_compressed` does not seem correct because it by default specifies a
size of `numeric_limits<size_t>::max()` ((size_t)-1). According to code comments, `-1` indicates default value,
which should be referring to `num_shard_bits` argument.
4. Clarify `fail_if_options_file_error`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9943
Test Plan:
1. make check
2. Run stress tests, and manually check generated OPTIONS file and compare them with input OPTIONS files
Reviewed By: jay-zhuang
Differential Revision: D36133769
Pulled By: riversand963
fbshipit-source-id: 35dacdc090a0a72c922907170cd132b9ecaa073e
Summary:
128 bits should suffice almost always and for tracking in manifest.
Note that this changes the output of sst_dump --show_properties to only show 128 bits.
Also introduces InternalUniqueIdToHumanString for presenting internal IDs for debugging purposes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10009
Test Plan: unit tests updated
Reviewed By: jay-zhuang
Differential Revision: D36458189
Pulled By: pdillinger
fbshipit-source-id: 93ebc4a3b6f9c73ee154383a1f8b291a5d6bbef5
Summary:
**Context:**
Previous PR https://github.com/facebook/rocksdb/pull/9748, https://github.com/facebook/rocksdb/pull/9073, https://github.com/facebook/rocksdb/pull/8428 added separate flag for each charged memory area. Such API design is not scalable as we charge more and more memory areas. Also, we foresee an opportunity to consolidate this feature with other cache usage related features such as `cache_index_and_filter_blocks` using `CacheEntryRole`.
Therefore we decided to consolidate all these flags with `CacheUsageOptions cache_usage_options` and this PR serves as the first step by consolidating memory-charging related flags.
**Summary:**
- Replaced old API reference with new ones, including making `kCompressionDictionaryBuildingBuffer` opt-out and added a unit test for that
- Added missing db bench/stress test for some memory charging features
- Renamed related test suite to indicate they are under the same theme of memory charging
- Refactored a commonly used mocked cache component in memory charging related tests to reduce code duplication
- Replaced the phrases "memory tracking" / "cache reservation" (other than CacheReservationManager-related ones) with "memory charging" for standard description of this feature.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9926
Test Plan:
- New unit test for opt-out `kCompressionDictionaryBuildingBuffer` `TEST_F(ChargeCompressionDictionaryBuildingBufferTest, Basic)`
- New unit test for option validation/sanitization `TEST_F(CacheUsageOptionsOverridesTest, SanitizeAndValidateOptions)`
- CI
- db bench (in case querying new options introduces regression) **+0.5% micros/op**: `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_compression_dictionary_building_buffer=1(remove this for comparison) -compression_max_dict_bytes=10000 -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 | egrep 'fillseq'`
#-run | (pre-PR) avg micros/op | std micros/op | (post-PR) micros/op | std micros/op | change (%)
-- | -- | -- | -- | -- | --
10 | 3.9711 | 0.264408 | 3.9914 | 0.254563 | 0.5111933721
20 | 3.83905 | 0.0664488 | 3.8251 | 0.0695456 | **-0.3633711465**
40 | 3.86625 | 0.136669 | 3.8867 | 0.143765 | **0.5289363078**
- db_stress: `python3 tools/db_crashtest.py blackbox -charge_compression_dictionary_building_buffer=1 -charge_filter_construction=1 -charge_table_reader=1 -cache_size=1` killed as normal
Reviewed By: ajkr
Differential Revision: D36054712
Pulled By: hx235
fbshipit-source-id: d406e90f5e0c5ea4dbcb585a484ad9302d4302af
Summary:
This PR
- since we are testing with disable_wal = true and best_efforts_recovery, we should set column family count to 1, due to the requirement of `ExpectedState` tracking and replaying logic.
- during backup and checkpoint restore, disable best-efforts-recovery. This does not matter now because db_crashtest.py always disables wal when testing best-efforts-recovery. In the future, if we enable wal, then not setting `restore_opitions.best_efforts_recovery` will cause backup db not to recover the WALs, and differ from db (that enables WAL).
- during verification of backup and checkpoint restore, print the key where inconsistency exists between expected state and db.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9986
Test Plan: TEST_TMPDIR=/dev/shm/rocksdb make crash_test_with_best_efforts_recovery
Reviewed By: siying
Differential Revision: D36353105
Pulled By: riversand963
fbshipit-source-id: a484da161273e6216a1f7e245bac15a349693917
