Change the semantics of bytes_read in GetBlob/MultiGetBlob for consistency #10248
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
gangliao
commented
Jun 24, 2022
ltamasi
reviewed
Jun 24, 2022
gangliao
changed the title
Summary: This task is to fix assertion failures during the crash test runs. ```bash db_stress: internal_repo_rocksdb/repo/db/blob/blob_source.cc:101: rocksdb::Status rocksdb::BlobSource::GetBlob(const rocksdb::ReadOptions &, const rocksdb::Slice &, uint64_t, uint64_t, uint64_t, uint64_t, rocksdb::CompressionType, rocksdb::FilePrefetchBuffer *, rocksdb::PinnableSlice *, uint64_t *): Assertion `blob_entry.GetValue()->size() == value_size' failed. ``` Tasks: T124246362
gangliao
force-pushed
the
hot_fix_cache_com
branch
from
f289cc3
to
a0bb0f2
Compare
gangliao
commented
Jun 24, 2022
gangliao
commented
Jun 24, 2022
ltamasi
reviewed
Jun 24, 2022
|
@gangliao has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary:
The
bytes_readreturned by the current BlobSource interface is ambiguous. The uncompressed blob size is returned if the cache hits. The size of the blob read from disk, presumably the compressed version, is returned if the cache misses. Two differing semantics might cause ambiguity and consistency issues. For example, this inconsistency causes the assertion failure (T124246362 and its hot fix is #10249).This goal is to require that the value of
byte readalways be an on-disk blob record size.