Summary:
Users can set the priority for file reads associated with their operation by setting `ReadOptions::rate_limiter_priority` to something other than `Env::IO_TOTAL`. Rate limiting `VerifyChecksum()` and `VerifyFileChecksums()` is the motivation for this PR, so it also includes benchmarks and minor bug fixes to get that working.
`RandomAccessFileReader::Read()` already had support for rate limiting compaction reads. I changed that rate limiting to be non-specific to compaction, but rather performed according to the passed in `Env::IOPriority`. Now the compaction read rate limiting is supported by setting `rate_limiter_priority = Env::IO_LOW` on its `ReadOptions`.
There is no default value for the new `Env::IOPriority` parameter to `RandomAccessFileReader::Read()`. That means this PR goes through all callers (in some cases multiple layers up the call stack) to find a `ReadOptions` to provide the priority. There are TODOs for cases I believe it would be good to let user control the priority some day (e.g., file footer reads), and no TODO in cases I believe it doesn't matter (e.g., trace file reads).
The API doc only lists the missing cases where a file read associated with a provided `ReadOptions` cannot be rate limited. For cases like file ingestion checksum calculation, there is no API to provide `ReadOptions` or `Env::IOPriority`, so I didn't count that as missing.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9424
Test Plan:
- new unit tests
- new benchmarks on ~50MB database with 1MB/s read rate limit and 100ms refill interval; verified with strace reads are chunked (at 0.1MB per chunk) and spaced roughly 100ms apart.
- setup command: `./db_bench -benchmarks=fillrandom,compact -db=/tmp/testdb -target_file_size_base=1048576 -disable_auto_compactions=true -file_checksum=true`
- benchmarks command: `strace -ttfe pread64 ./db_bench -benchmarks=verifychecksum,verifyfilechecksums -use_existing_db=true -db=/tmp/testdb -rate_limiter_bytes_per_sec=1048576 -rate_limit_bg_reads=1 -rate_limit_user_ops=true -file_checksum=true`
- crash test using IO_USER priority on non-validation reads with https://github.com/facebook/rocksdb/issues/9567 reverted: `python3 tools/db_crashtest.py blackbox --max_key=1000000 --write_buffer_size=524288 --target_file_size_base=524288 --level_compaction_dynamic_level_bytes=true --duration=3600 --rate_limit_bg_reads=true --rate_limit_user_ops=true --rate_limiter_bytes_per_sec=10485760 --interval=10`
Reviewed By: hx235
Differential Revision: D33747386
Pulled By: ajkr
fbshipit-source-id: a2d985e97912fba8c54763798e04f006ccc56e0c
Summary:
For performance purposes, the lower level routines were changed to use a SystemClock* instead of a std::shared_ptr<SystemClock>. The shared ptr has some performance degradation on certain hardware classes.
For most of the system, there is no risk of the pointer being deleted/invalid because the shared_ptr will be stored elsewhere. For example, the ImmutableDBOptions stores the Env which has a std::shared_ptr<SystemClock> in it. The SystemClock* within the ImmutableDBOptions is essentially a "short cut" to gain access to this constant resource.
There were a few classes (PeriodicWorkScheduler?) where the "short cut" property did not hold. In those cases, the shared pointer was preserved.
Using db_bench readrandom perf_level=3 on my EC2 box, this change performed as well or better than 6.17:
6.17: readrandom : 28.046 micros/op 854902 ops/sec; 61.3 MB/s (355999 of 355999 found)
6.18: readrandom : 32.615 micros/op 735306 ops/sec; 52.7 MB/s (290999 of 290999 found)
PR: readrandom : 27.500 micros/op 871909 ops/sec; 62.5 MB/s (367999 of 367999 found)
(Note that the times for 6.18 are prior to revert of the SystemClock).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8033
Reviewed By: pdillinger
Differential Revision: D27014563
Pulled By: mrambacher
fbshipit-source-id: ad0459eba03182e454391b5926bf5cdd45657b67
Summary:
Removed the uses of the Legacy FileWrapper classes from the source code. The wrappers were creating an additional layer of indirection/wrapping, as the Env already has a FileSystem.
Moved the Custom FileWrapper classes into the CustomEnv, as these classes are really for the private use the the CustomEnv class.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7851
Reviewed By: anand1976
Differential Revision: D26114816
Pulled By: mrambacher
fbshipit-source-id: db32840e58d969d3a0fa6c25aaf13d6dcdc74150
Summary:
Introduces and uses a SystemClock class to RocksDB. This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.
Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead. There are likely more places that can be changed, but this is a start to show what can/should be done. Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.
There are several Env classes that implement these functions. Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR. It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).
Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858
Reviewed By: pdillinger
Differential Revision: D26006406
Pulled By: mrambacher
fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
Summary:
Calculate ```IOOptions::timeout``` using ```ReadOptions::deadline``` and pass it to ```FileSystem::Read/FileSystem::MultiRead```. This allows us to impose a tighter bound on the time taken by Get/MultiGet on FileSystem/Envs that support IO timeouts. Even on those that don't support, check in ```RandomAccessFileReader::Read``` and ```MultiRead``` and return ```Status::TimedOut()``` if the deadline is exceeded.
For now, TableReader creation, which might do file opens and reads, are not covered. It will be implemented in another PR.
Tests:
Update existing unit tests to verify the correct timeout value is being passed
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6751
Reviewed By: riversand963
Differential Revision: D21285631
Pulled By: anand1976
fbshipit-source-id: d89af843e5a91ece866e87aa29438b52a65a8567
Summary:
In direct IO mode, RandomAccessFileReader::Read allocates an internal aligned buffer, and then copies the result into the scratch buffer. If the result is only temporarily used inside a function, there is no need to do the memcpy and just let the result Slice refer to the internally allocated buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6455
Test Plan: make check
Differential Revision: D20106753
Pulled By: cheng-chang
fbshipit-source-id: 44f505843837bba47a56e3fa2c4dd3bd76486b58
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433
Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.
Differential Revision: D19977691
fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
Summary:
The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc.
This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO.
The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before.
This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection.
The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761
Differential Revision: D18868376
Pulled By: anand1976
fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
Summary:
clang-analyzer has uncovered a bunch of places where the code is relying
on pointers being valid and one case (in VectorIterator) where a moved-from
object is being used:
In file included from db/range_tombstone_fragmenter.cc:17:
./util/vector_iterator.h:23:18: warning: Method called on moved-from object 'keys' of type 'std::vector'
current_(keys.size()) {
^~~~~~~~~~~
1 warning generated.
utilities/persistent_cache/block_cache_tier_file.cc:39:14: warning: Called C++ object pointer is null
Status s = env->NewRandomAccessFile(filepath, file, opt);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:47:19: warning: Called C++ object pointer is null
Status status = env_->GetFileSize(Path(), size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:290:14: warning: Called C++ object pointer is null
Status s = env_->FileExists(Path());
^~~~~~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:363:35: warning: Called C++ object pointer is null
CacheWriteBuffer* const buf = alloc_->Allocate();
^~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:399:41: warning: Called C++ object pointer is null
const uint64_t file_off = buf_doff_ * alloc_->BufferSize();
^~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:463:33: warning: Called C++ object pointer is null
size_t start_idx = lba.off_ / alloc_->BufferSize();
^~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:515:5: warning: Called C++ object pointer is null
alloc_->Deallocate(bufs_[i]);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 warnings generated.
ar: creating librocksdb_debug.a
utilities/memory/memory_test.cc:68:25: warning: Called C++ object pointer is null
cache_set->insert(db->GetDBOptions().row_cache.get());
^~~~~~~~~~~~~~~~~~
1 warning generated.
The patch fixes these by adding assertions and explicitly passing in zero
when initializing VectorIterator::current_ (which preserves the existing
behavior).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5821
Test Plan: Ran make check and make analyze to make sure the warnings have disappeared.
Differential Revision: D17455949
Pulled By: ltamasi
fbshipit-source-id: 363619618ea649a0674287f9f3b3393e390571ee
Summary:
Many logging related source files are under util/. It will be more structured if they are together.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387
Differential Revision: D15579036
Pulled By: siying
fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f
Summary:
```
utilities/persistent_cache/block_cache_tier_file.cc
64struct CacheRecordHeader {
2. uninit_member: Non-static class member magic_ is not initialized in this constructor nor in any functions that it calls.
4. uninit_member: Non-static class member crc_ is not initialized in this constructor nor in any functions that it calls.
6. uninit_member: Non-static class member key_size_ is not initialized in this constructor nor in any functions that it calls.
CID 1396161 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
8. uninit_member: Non-static class member val_size_ is not initialized in this constructor nor in any functions that it calls.
65 CacheRecordHeader() {}
66 CacheRecordHeader(const uint32_t magic, const uint32_t key_size,
67 const uint32_t val_size)
68 : magic_(magic), crc_(0), key_size_(key_size), val_size_(val_size) {}
69
1. member_decl: Class member declaration for magic_.
70 uint32_t magic_;
3. member_decl: Class member declaration for crc_.
71 uint32_t crc_;
5. member_decl: Class member declaration for key_size_.
72 uint32_t key_size_;
7. member_decl: Class member declaration for val_size_.
73 uint32_t val_size_;
74};
utilities/simulator_cache/sim_cache.cc:
157 miss_times_(0),
CID 1396124 (#1 of 1): Uninitialized pointer field (UNINIT_CTOR)
2. uninit_member: Non-static class member stats_ is not initialized in this constructor nor in any functions that it calls.
158 hit_times_(0) {}
159
```
Closes https://github.com/facebook/rocksdb/pull/3155
Differential Revision: D6427237
Pulled By: sagar0
fbshipit-source-id: 97e493da5fc043c5b9a3e0d33103442cffb75aad
Summary:
This reverts the previous commit 1d7048c598, which broke the build.
Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627
Differential Revision: D5476473
Pulled By: sagar0
fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
Summary:
We've got some DBs where iterators return Status with message "Corruption: block checksum mismatch" all the time. That's not very informative. It would be much easier to investigate if the error message contained the file name - then we would know e.g. how old the corrupted file is, which would be very useful for finding the root cause. This PR adds file name, offset and other stuff to some block corruption-related status messages.
It doesn't improve all the error messages, just a few that were easy to improve. I'm mostly interested in "block checksum mismatch" and "Bad table magic number" since they're the only corruption errors that I've ever seen in the wild.
Closes https://github.com/facebook/rocksdb/pull/2507
Differential Revision: D5345702
Pulled By: al13n321
fbshipit-source-id: fc8023d43f1935ad927cef1b9c55481ab3cb1339
Summary:
introduce new methods into a public threadpool interface,
- allow submission of std::functions as they allow greater flexibility.
- add Joining methods to the implementation to join scheduled and submitted jobs with
an option to cancel jobs that did not start executing.
- Remove ugly `#ifdefs` between pthread and std implementation, make it uniform.
- introduce pimpl for a drop in replacement of the implementation
- Introduce rocksdb::port::Thread typedef which is a replacement for std::thread. On Posix Thread defaults as before std::thread.
- Implement WindowsThread that allocates memory in a more controllable manner than windows std::thread with a replaceable implementation.
- should be no functionality changes.
Closes https://github.com/facebook/rocksdb/pull/1823
Differential Revision: D4492902
Pulled By: siying
fbshipit-source-id: c74cb11
Summary:
Fixes compile error:
In file included from ./util/statistics.h:17:0,
from ./util/stop_watch.h:8,
from ./util/perf_step_timer.h:9,
from ./util/iostats_context_imp.h:8,
from ./util/posix_logger.h:27,
from ./port/util_logger.h:18,
from ./db/auto_roll_logger.h:15,
from db/auto_roll_logger.cc:6:
./util/thread_local.h:65:16: error: 'function' in namespace 'std' does not name a template type
typedef std::function<void(void*, void*)> FoldFunc;
Closes https://github.com/facebook/rocksdb/pull/1656
Differential Revision: D4318702
Pulled By: yiwu-arbug
fbshipit-source-id: 8c5d17a
Summary:
The persistent cache is designed to hop over errors and return key not found. So far, it has shown resilience to write errors, encoding errors, data corruption etc. It is not resilient against disappearing files/directories. This was exposed during testing when multiple instances of persistence cache was started sharing the same directory simulating an unpredictable filesystem environment.
This patch
- makes the write code path more resilient to errors while creating files
- makes the read code path more resilient to handle situation where files are not found
- added a test that does negative write/read testing by removing the directory while writes are in progress
Closes https://github.com/facebook/rocksdb/pull/1472
Differential Revision: D4143413
Pulled By: kradhakrishnan
fbshipit-source-id: fd25e9b
Summary:
The patch is a continuation of part 5. It glues the abstraction for
file layout and metadata, and flush out the implementation of the API. It
adds unit tests for the implementation.
Test Plan: Run unit tests
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57549
Summary:
(1) Integer size correction (mac build break)
(2) snprint usage in Windows (windows build break)
Test Plan: Build in windows and mac
Reviewers: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60927
Summary:
Persistent cache tier is the tier abstraction that can work for any block
device based device mounted on a file system. The design/implementation can
handle any generic block device.
Any generic block support is achieved by generalizing the access patten as
{io-size, q-depth, direct-io/buffered}.
We have specifically tested and adapted the IO path for NVM and SSD.
Persistent cache tier consists of there parts :
1) File layout
Provides the implementation for handling IO path for reading and writing data
(key/value pair).
2) Meta-data
Provides the implementation for handling the index for persistent read cache.
3) Implementation
It binds (1) and (2) and flushed out the PersistentCacheTier interface
This patch provides implementation for (1)(2). Follow up patch will provide (3)
and tests.
Test Plan: Compile and run check
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57117
Andrew Kryczka