Hey, sorry, I have to come back to this. I did some testing - created an ILM-Managed index with a 1minute hot -> 3minute delete policy.
I added one or two documents, and let it rest over night. Right now I'm at generation 120, so something has made this index roll over multiple times while it was completely empty. It's a test index I specifically created, so I can be sure that no component (beat, elastic agent, logstash...) ever requested anything about this index nor ingested a document. The behavior seems erratic - right now the indices are >6min old despite a lifetime of at most 4minutes (1min hot + 3 min delete).
I'm wondering if there is a better way to explain or debug this behavior. What prompts ILM to check whether a rollover is necessary? It can't be a strict timer, and it also can't be an incoming document.
GET ilmtest/_ilm/explain
{
"indices" : {
"ilmtest-000122" : {
"index" : "ilmtest-000122",
"managed" : true,
"policy" : "testpolicy",
"lifecycle_date_millis" : 1642101859057,
"age" : "3.96m",
"phase" : "hot",
"phase_time_millis" : 1642101859617,
"action" : "rollover",
"action_time_millis" : 1642101860217,
"step" : "check-rollover-ready",
"step_time_millis" : 1642101860217,
"phase_execution" : {
"policy" : "testpolicy",
"phase_definition" : {
"min_age" : "0ms",
"actions" : {
"set_priority" : {
"priority" : 100
},
"rollover" : {
"max_primary_shard_size" : "50gb",
"max_age" : "1m"
}
}
},
"version" : 1,
"modified_date_in_millis" : 1642028874821
}
},
"ilmtest-000120" : {
"index" : "ilmtest-000120",
"managed" : true,
"policy" : "testpolicy",
"lifecycle_date_millis" : 1642101259707,
"age" : "13.95m",
"phase" : "delete",
"phase_time_millis" : 1642101856411,
"action" : "delete",
"action_time_millis" : 1642101856411,
"step" : "wait-for-shard-history-leases",
"step_time_millis" : 1642101856411,
"phase_execution" : {
"policy" : "testpolicy",
"phase_definition" : {
"min_age" : "3m",
"actions" : {
"delete" : {
"delete_searchable_snapshot" : true
}
}
},
"version" : 1,
"modified_date_in_millis" : 1642028874821
}
},
"ilmtest-000121" : {
"index" : "ilmtest-000121",
"managed" : true,
"policy" : "testpolicy",
"lifecycle_date_millis" : 1642101859017,
"age" : "3.97m",
"phase" : "hot",
"phase_time_millis" : 1642101260308,
"action" : "complete",
"action_time_millis" : 1642101860017,
"step" : "complete",
"step_time_millis" : 1642101860017,
"phase_execution" : {
"policy" : "testpolicy",
"phase_definition" : {
"min_age" : "0ms",
"actions" : {
"set_priority" : {
"priority" : 100
},
"rollover" : {
"max_primary_shard_size" : "50gb",
"max_age" : "1m"
}
}
},
"version" : 1,
"modified_date_in_millis" : 1642028874821
}
}
}
}