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:
In the original stacked BlobDB implementation, which writes blobs to blob files
immediately and treats blob files as logs, it makes sense to flush the file after
writing each blob to protect against process crashes; however, in the integrated
implementation, which builds blob files in the background jobs, this unnecessarily
reduces performance. This patch fixes this by simply adding a `do_flush` flag to
`BlobLogWriter`, which is set to `true` by the stacked implementation and to `false`
by the new code. Note: the change itself is trivial but the tests needed some work;
since in the new implementation, blobs are now buffered, adding a blob to
`BlobFileBuilder` is no longer guaranteed to result in an actual I/O. Therefore, we can
no longer rely on `FaultInjectionTestEnv` when testing failure cases; instead, we
manipulate the return values of I/O methods directly using `SyncPoint`s.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7892
Test Plan: `make check`
Reviewed By: jay-zhuang
Differential Revision: D26022814
Pulled By: ltamasi
fbshipit-source-id: b3dce419f312137fa70d84cdd9b908fd5d60d8cd
Summary:
The patch adds blob file support to the `Get` API by extending `Version` so that
whenever a blob reference is read from a file, the blob is retrieved from the corresponding
blob file and passed back to the caller. (This is assuming the blob reference is valid
and the blob file is actually part of the given `Version`.) It also introduces a cache
of `BlobFileReader`s called `BlobFileCache` that enables sharing `BlobFileReader`s
between callers. `BlobFileCache` uses the same backing cache as `TableCache`, so
`max_open_files` (if specified) limits the total number of open (table + blob) files.
TODO: proactively open/cache blob files and pin the cache handles of the readers in the
metadata objects similarly to what `VersionBuilder::LoadTableHandlers` does for
table files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7540
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D24260219
Pulled By: ltamasi
fbshipit-source-id: a8a2a4f11d3d04d6082201b52184bc4d7b0857ba
Summary:
The `std::pair(const T1& x, const T2& y);` constructor is `constexpr`
only starting from C++14; relying on this breaks compilation on certain
compilers/platforms we need to support.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7519
Test Plan: `make check`
Reviewed By: ajkr
Differential Revision: D24195747
Pulled By: ltamasi
fbshipit-source-id: 665e8fbc9747675bb49c5d895aad3dcf2714750f
Summary:
The patch adds a class called `BlobFileReader` that can be used to retrieve blobs
using the information available in blob references (e.g. blob file number, offset, and
size). This will come in handy when implementing blob support for `Get`, `MultiGet`,
and iterators, and also for compaction/garbage collection.
When a `BlobFileReader` object is created (using the factory method `Create`),
it first checks whether the specified file is potentially valid by comparing the file
size against the combined size of the blob file header and footer (files smaller than
the threshold are considered malformed). Then, it opens the file, and reads and verifies
the header and footer. The verification involves magic number/CRC checks
as well as checking for unexpected header/footer fields, e.g. incorrect column family ID
or TTL blob files.
Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression
type passed by the caller (because of the presence of the header and footer, the
specified offset cannot be too close to the start/end of the file; also, the compression type
has to match the one in the blob file header), and retrieves and potentially verifies and
uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set,
`BlobFileReader` reads the blob record header as well (as opposed to just the blob itself)
and verifies the key/value size, the key itself, as well as the CRC of the blob record header
and the key/value pair.
In addition, the patch exposes the compression type from `BlobIndex` (both using an
accessor and via `DebugString`), and adds a blob file read latency histogram to
`InternalStats` that can be used with `BlobFileReader`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D23999219
Pulled By: ltamasi
fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
