Armin Braun 004eb8bd7e
Fix Bug With RepositoryData Caching (#57785) (#57800)
* Fix Bug With RepositoryData Caching

This fixes a really subtle bug with caching `RepositoryData`
that can corrupt a repository.
We were caching `RepositoryData` serialized in the newest
metadata format. This lead to a confusing situation where
numeric shard generations would be cached in `ShardGenerations`
that were not written to the repository because the repository
or cluster did not yet support `ShardGenerations`.
In the case where shard generations are not actually supported yet,
these cached numeric generations are not safe and there's multiple
scenarios where they would be incorrect, leading to the repository
trying to read shard level metadata from index-N that don't exist.
This commit makes it so that cached metadata is always in the same
format as the metadata in the repository.

Relates #57798
2020-06-08 13:16:45 +02:00
..