Summary:
This is part of an alternative approach to https://github.com/facebook/rocksdb/issues/8316.
Unlike that approach, this one relies on key-values getting processed one by one
during compaction, and does not involve persistence.
Specifically, the patch adds a class `BlobGarbageMeter` that can track the number
and total size of blobs in a (sub)compaction's input and output on a per-blob file
basis. This information can then be used to compute the amount of additional
garbage generated by the compaction for any given blob file by subtracting the
"outflow" from the "inflow."
Note: this patch only adds `BlobGarbageMeter` and associated unit tests. I plan to
hook up this class to the input and output of `CompactionIterator` in a subsequent PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8426
Test Plan: `make check`
Reviewed By: jay-zhuang
Differential Revision: D29242250
Pulled By: ltamasi
fbshipit-source-id: 597e50ad556540e413a50e804ba15bc044d809bb
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 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
Summary:
The patch makes sure that the functionality required for the new integrated
BlobDB implementation (most importantly, the classes related to reading and
writing blob files) is also built in LITE mode by removing the corresponding
`#ifndef`s.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7272
Test Plan: Ran `make check` in both regular and LITE mode.
Reviewed By: zhichao-cao
Differential Revision: D23173280
Pulled By: ltamasi
fbshipit-source-id: 1596bd1a76409a8a6d83d8f1dbfe08bfdea7ffe6
Summary:
The constant `kNoExpiration` is currently defined in an
internal/implementation header (`blob_log_format.h`); the patch moves it
to the public header `blob_db.h` so it is accessible to users.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7018
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D22191354
Pulled By: ltamasi
fbshipit-source-id: 98c8012a83b999a3f1a30e955ce6bb71ba29dc5c
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 patch refactors and cleans up the logic around creating new blob files
by moving the common code of `SelectBlobFile` and `SelectBlobFileTTL`
to a new helper method `CreateBlobFileAndWriter`, bringing the implementation
of `SelectBlobFile` and `SelectBlobFileTTL` into sync, and increasing encapsulation
by adding new constructors for `BlobFile` and `BlobLogHeader`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6066
Test Plan:
Ran `make check` and used the BlobDB mode of `db_bench` to sanity test both
the TTL and the non-TTL code paths.
Differential Revision: D18646921
Pulled By: ltamasi
fbshipit-source-id: e5705a84807932e31dccab4f49b3e64369cea26d
Summary:
As pointed out in #4059, we miss use string as buffer for file read. Changing to use char array instead.
Closing #4059
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4662
Differential Revision: D13012998
Pulled By: yiwu-arbug
fbshipit-source-id: 41234ba17c0bccea65bd647e362a0e979152bd1e
Summary:
Previously we store sequence number range of each blob files, and use the sequence number range to check if the file can be possibly visible by a snapshot. But it adds complexity to the code, since the sequence number is only available after a write. (The current implementation get sequence number by calling GetLatestSequenceNumber(), which is wrong.) With the patch, we are not storing sequence number range, and check if snapshot_sequence < obsolete_sequence to decide if the file is visible by a snapshot (previously we check if first_sequence <= snapshot_sequence < obsolete_sequence).
Closes https://github.com/facebook/rocksdb/pull/3274
Differential Revision: D6571497
Pulled By: yiwu-arbug
fbshipit-source-id: ca06479dc1fcd8782f6525b62b7762cd47d61909
Summary:
Adding a list of blob db counters.
Also remove WaStats() which doesn't expose the stats and can be substitute by (BLOB_DB_BYTES_WRITTEN / BLOB_DB_BLOB_FILE_BYTES_WRITTEN).
Closes https://github.com/facebook/rocksdb/pull/3193
Differential Revision: D6394216
Pulled By: yiwu-arbug
fbshipit-source-id: 017508c8ff3fcd7ea7403c64d0f9834b24816803
Summary:
Changing blob file format and some code cleanup around the change. The change with blob log format are:
* Remove timestamp field in blob file header, blob file footer and blob records. The field is not being use and often confuse with expiration field.
* Blob file header now come with column family id, which always equal to default column family id. It leaves room for future support of column family.
* Compression field in blob file header now is a standalone byte (instead of compact encode with flags field)
* Blob file footer now come with its own crc.
* Key length now being uint64_t instead of uint32_t
* Blob CRC now checksum both key and value (instead of value only).
* Some reordering of the fields.
The list of cleanups:
* Better inline comments in blob_log_format.h
* rename ttlrange_t and snrange_t to ExpirationRange and SequenceRange respectively.
* simplify blob_db::Reader
* Move crc checking logic to inside blob_log_format.cc
Closes https://github.com/facebook/rocksdb/pull/3081
Differential Revision: D6171304
Pulled By: yiwu-arbug
fbshipit-source-id: e4373e0d39264441b7e2fbd0caba93ddd99ea2af
Summary:
Previously each time we write a blob we write blog_record_header + key + value + blob_record_footer to blob log. The footer only contains a sequence and a crc for the sequence number. The sequence number was used in garbage collection to verify the value is recent. After #2703 we moved to use optimistic transaction and no longer use sequence number from the footer. Remove the footer altogether.
There's another usage of sequence number and we are keeping it: Each blob log file keep track of sequence number range of keys in it, and use it to check if it is reference by a snapshot, before being deleted.
Closes https://github.com/facebook/rocksdb/pull/3005
Differential Revision: D6057585
Pulled By: yiwu-arbug
fbshipit-source-id: d6da53c457a316e9723f359a1b47facfc3ffe090
Summary:
The current blob db implementation use mix of int32_t, uint32_t and uint64_t for TTL and expiration. Update all timestamps to uint64_t for consistency.
Closes https://github.com/facebook/rocksdb/pull/2683
Differential Revision: D5557103
Pulled By: yiwu-arbug
fbshipit-source-id: e4eab2691629a755e614e8cf1eed9c3a681d0c42
Summary:
Introducing blob_db::TTLExtractor to replace extract_ttl_fn. The TTL
extractor can be use to extract TTL from keys insert with Put or
WriteBatch. Change over existing extract_ttl_fn are:
* If value is changed, it will be return via std::string* (rather than Slice*). With Slice* the new value has to be part of the existing value. With std::string* the limitation is removed.
* It can optionally return TTL or expiration.
Other changes in this PR:
* replace `std::chrono::system_clock` with `Env::NowMicros` so that I can mock time in tests.
* add several TTL tests.
* other minor naming change.
Closes https://github.com/facebook/rocksdb/pull/2659
Differential Revision: D5512627
Pulled By: yiwu-arbug
fbshipit-source-id: 0dfcb00d74d060b8534c6130c808e4d5d0a54440
Levi Tamasi