Archived cluster settings should not block cluster's upgrade, or we should describe the impact more clear #86022
Description
Description
Background
Per manual,
https://www.elastic.co/guide/en/elasticsearch/reference/8.1/archived-settings.html#archived-cluster-settings
There are 2 kinds of archived settings,
- (A) Archived cluster settings
- (B) Archived index settings
For (B) Archived index settings, it gives a clear description below, that these archived settings can block upgrade:
Before you upgrade, remove any unsupported index settings from index and component templates.
Elasticsearch doesn’t archive unsupported index settings in templates during an upgrade.
Attempts to use a template that contains an unsupported index setting will fail and return an error.
This includes automated operations, such the ILM rollover action.
For (A) Archived cluster settings, there's no such info, and also the manual shows we can simply remove the cluster settings by:
PUT _cluster/settings
{
"persistent": {
"archived.*": null
}
}
What's the problem?
We found that, some archived cluster settings like the following, can block upgrade on ESS.
archived.xpack.monitoring.exporters.found-user-defined.auth.passwordarchived.xpack.monitoring.exporters.monitoring_user_defined.auth.password
We understand the workaround is simply removing the archived settings, as mentioned above.
But it's against the description in the manual, because it's blocking the upgrade, thus the user cannot remove the settings "after upgrading".
We recommend you remove any archived settings after upgrading
Suggested improvements
Logically thinking, depending on whether we want to keep those archived settings on purpose, there could be 2 independent improvements:
[1]
If there's no need to keep those Archived cluster settings, then they should not block the upgrade.
Additionally, whether we should remove those settings automatically during the upgrade, or we put the instructions into i.e. Kibana upgrade assistant and let the user remove them, might be worth discussing later.
[2]
If we want to keep them on purpose, then we should make it more clear, similar to Archived index settings, we should put a banner into the documentation, and also put the instructions into i.e. Kibana upgrade assistant, to let user handle these settings before the upgrading.