Today when creating a follower index via the put follow API, or via an
auto-follow pattern, it is not possible to specify settings overrides
for the follower index. Instead, we copy all of the leader index
settings to the follower. Yet, there are cases where a user would want
some different settings on the follower index such as the number of
replicas, or allocation settings. This commit addresses this by allowing
the user to specify settings overrides when creating follower index via
manual put follower calls, or via auto-follow patterns. Note that not
all settings can be overrode (e.g., index.number_of_shards) so we also
have detection that prevents attempting to override settings that must
be equal between the leader and follow index. Note that we do not even
allow specifying such settings in the overrides, even if they are
specified to be equal between the leader and the follower
index. Instead, the must be implicitly copied from the leader index, not
explicitly set by the user.
This commit adds functionality so that aliases that are manipulated on
leader indices are replicated by the shard follow tasks to the follower
indices. Note that we ignore write indices. This is due to the fact that
follower indices do not receive direct writes so the concept is not
useful.
Relates #41815
This commit introduces the forget follower API. This API is needed in cases that
unfollowing a following index fails to remove the shard history retention leases
on the leader index. This can happen explicitly through user action, or
implicitly through an index managed by ILM. When this occurs, history will be
retained longer than necessary. While the retention lease will eventually
expire, it can be expensive to allow history to persist for that long, and also
prevent ILM from performing actions like shrink on the leader index. As such, we
introduce an API to allow for manual removal of the shard history retention
leases in this case.
This commit modifies the put follow index action to use a
CcrRepository when creating a follower index. It routes
the logic through the snapshot/restore process. A
wait_for_active_shards parameter can be used to configure
how long to wait before returning the response.
* Add ccr follow info api
This api returns all follower indices and per follower index
the provided parameters at put follow / resume follow time and
whether index following is paused or active.
Closes#37127
* iter
* [DOCS] Edits the get follower info API
* [DOCS] Fixes link to remote cluster
* [DOCS] Clarifies descriptions for configured parameters
This commit uses the index settings version so that a follower can
replicate index settings changes as needed from the leader.
Co-authored-by: Martijn van Groningen <martijn.v.groningen@gmail.com>
* Changed the auto follow stats to also include follow stats.
* Renamed the auto follow stats api to stats api and changed its url path
from `/_ccr/auto_follow/stats` `/_ccr/stats`.
* Removed `/_ccr/stats` url path for the follow stats api, which makes
the index parameter a required parameter.
* Fixed docs.
This commit is our first introduction to cross-cluster replication
docs. In this commit, we introduce the cross-cluster replication API
docs. We also add skelton docs for additional content that will be added
in a series of follow-up commits.
Jason Tedor
CJ Cenizal
Lisa Cawley
James Rodewig
Tim Brooks
Martijn van Groningen
Josh Soref