We inject an Unfollow action before Shrink because the Shrink action
cannot be safely used on a following index, as it may not be fully
caught up with the leader index before the "original" following index is
deleted and replaced with a non-following Shrunken index. The Unfollow
action will verify that 1) the index is marked as "complete", and 2) all
operations up to this point have been replicated from the leader to the
follower before explicitly disconnecting the follower from the leader.
Injecting an Unfollow action before the Rollover action is done mainly
as a convenience: This allow users to use the same lifecycle policy on
both the leader and follower cluster without having to explictly modify
the policy to unfollow the index, while doing what we expect users to
want in most cases.
There are a handful of examples in the ILM documentation that could result in
rolling over indices more quickly than we might normally recommend,
contributing to over-sharding in cases where the examples are copied without
modification. This change makes some numbers bigger to try and avoid this.
Leaving `index.lifecycle.indexing_complete` in place when removing the
lifecycle policy from an index can cause confusion, as if a new policy
is associated with the policy, rollover will be silently skipped.
Removing that setting when removing the policy from an index makes
associating a new policy with the index more involved, but allows ILM to
fail loudly, rather than silently skipping operations which the user may
assume are being performed.
* Adjust order of checks in WaitForRolloverReadyStep
This allows ILM to error out properly for indices that have a valid
alias, but are not the write index, while still handling
`indexing_complete` on old-style aliases and rollover (that is, those
which only point to a single index at a time with no explicit write
index)
Adds a setting that indicates that an index is done indexing, set by ILM
when the Rollover action completes. This indicates that the Rollover
action should be skipped in any future invocations, as long as the index
is no longer the write index for its alias.
This enables 1) an index with a policy that involves the Rollover action
to have the policy removed and switched to another one without use of
the move-to-step API, and 2) integrations with Beats and CCR.
This PR renames the CRUD APIS for ILM
GET _ilm/<policy>, _ilm -> _ilm/policy/<policy>, _ilm/policy
PUT _ilm/<policy> -> _ilm/policy/<policy>
DELETE _ilm/<policy> -> _ilm/policy/<policy>
closes#34929.
Lee Hinman
Gordon Brown
Josh Soref
David Turner
debadair
Tal Levy