This PR introduces two new fields in to `RepositoryData` (index-N) to track the blob name of `IndexMetaData` blobs and their content via setting generations and uuids. This is used to deduplicate the `IndexMetaData` blobs (`meta-{uuid}.dat` in the indices folders under `/indices` so that new metadata for an index is only written to the repository during a snapshot if that same metadata can't be found in another snapshot.
This saves one write per index in the common case of unchanged metadata thus saving cost and making snapshot finalization drastically faster if many indices are being snapshotted at the same time.
The implementation is mostly analogous to that for shard generations in #46250 and piggy backs on the BwC mechanism introduced in that PR (which means this PR needs adjustments if it doesn't go into `7.6`).
Relates to #45736 as it improves the efficiency of snapshotting unchanged indices
Relates to #49800 as it has the potential of loading the index metadata for multiple snapshots of the same index concurrently much more efficient speeding up future concurrent snapshot delete
* Remove usage of deprecated testCompile configuration
* Replace testCompile usage by testImplementation
* Make testImplementation non transitive by default (as we did for testCompile)
* Update CONTRIBUTING about using testImplementation for test dependencies
* Fail on testCompile configuration usage
We can't use the high level create snapshot request any longer
since we changed some of its default parameters in `8` and those
are not understood by older versions like `7.4`.
Closes#57650
* Refactor Inflexible Snapshot Repository BwC (#52365)
Transport the version to use for a snapshot instead of whether to use shard generations in the snapshots in progress entry. This allows making upcoming repository metadata changes in a flexible manner in an analogous way to how we handle serialization BwC elsewhere.
Also, exposing the version at the repository API level will make it easier to do BwC relevant changes in derived repositories like source only or encrypted.
If some internal `.watcher` or so index gets created during these tests
then the shard counts on snapshot restores and creates won't match up with expectations.
Fixed by only creating the snapshot for the test index
Closes#50819
* Fix MultiVersionRepository BwC Tests
The HLRC doesn't like what its getting back from some older 6.x versions for the restore status
so I moved that request to the low level client.
Closes#50819
Follow up to #50692 that starts writing a `min_version` field to
the `RepositoryData` so that pre-7.6 ES versions can not read it
(and potentially corrupt it if they attempt to modify the repo contents)
after the repository moved to the new metadata format.
* Fix Snapshot Repository Corruption in Downgrade Scenarios (#50692)
This PR introduces test infrastructure for downgrading a cluster while interacting with a given repository.
It fixes the fact that repository metadata in the new format could be written while there's still older snapshots in the repository that require the old-format metadata to be restorable.
Armin Braun
Rene Groeschke
Rene Groeschke
Mark Vieira