Gordon Brown 1a906897e6 Implement framework for migrating system indices (#78951) ... This PR adds a framework for migrating system indices as necessary prior to Elasticsearch upgrades. This framework uses REST APIs added in another commit: - GET _migration/system_features This API, which gets the status of "features" (plugins which own system indices) with regards to whether they need to be upgraded or not. As of this PR, this API also reports errors encountered while migrating system indices alongside the index that was being processed when this occurred. As an example of this error reporting: ```json { "feature_name": "logstash_management", "minimum_index_version": "8.0.0", "upgrade_status": "ERROR", "indices": [ { "index": ".logstash", "version": "8.0.0", "failure_cause": { "error": { "root_cause": [ { "type": "runtime_exception", "reason": "whoopsie", "stack_trace": "<omitted for brevity>" } ], "type": "runtime_exception", "reason": "whoopsie", "stack_trace": "<omitted for brevity>" } } } ] } ``` - POST _migration/system_features This API starts the migration process. The API for this has no changes, but when called, any system indices which need to be migrated will be migrated, with status information stored in the cluster state for later use by the GET _migration/system_features API.		2021-10-19 18:52:22 -06:00
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deprecation.asciidoc	Filtering setting deprecation info API messages based on a setting (#78725) (#79184)	2021-10-14 16:31:13 -05:00
feature_upgrade.asciidoc	Implement framework for migrating system indices (#78951)	2021-10-19 18:52:22 -06:00