Users that use Elastic 8.3.x and contain a currently snoozed rule, will fail to upgrade to 8.4 due to a known issue with saved object migration. This does not apply to indefinite snooze or mute, only to an on-demand snooze i.e. snooze for 1 hour.
Please do not upgrade Kibana from 8.3.x to 8.4 if you have any alerting rules with a snooze notification configured. You can identify snoozed rules in Stack Management / Rules and Connectors. Select to filter the rule list using the View menu option and select Snoozed. Cancel the snooze for all affected rules before upgrading. This must be done for each Space.
To identify snoozed rules in all Spaces using Dev Tools, run the following query:
GET /.kibana/_search
{
"query": {
"exists": {
"field": "alert.isSnoozedUntil"
}
}
}
If you attempt to upgrade Kibana from 8.3 to 8.4 with snoozed rules you will receive the following error message.
FATAL Error: Unable to complete saved object migrations for the [.kibana] index.
You must restore your previous version and cancel any snoozed rules before retrying the upgrade.
A fix (8.4.1) will be released in the upcoming days.