Update modules/ROOT/pages/monitoring/metrics/reference.adoc

Co-authored-by: NataliaIvakina <[email protected]>

Author: RagnarW

modules/ROOT/pages/monitoring/metrics/reference.adoc

@@ -554,7 +554,7 @@ The deprecated Raft core metrics are replaced accordingly by the Raft metrics in
 |<prefix>.cluster.raft.append_index|The append index of the Raft log. Each index represents a write transaction (possibly internal) proposed for commitment. The values mostly increase, but sometimes they can decrease as a consequence of leader changes. The append index should always be bigger than or equal to the commit index. (gauge)
 |<prefix>.cluster.raft.commit_index|The commit index of the Raft log. Represents the commitment of previously appended entries. Its value increases monotonically if you do not unbind the cluster state. The commit index should always be less than or equal to the append index and bigger than or equal to the applied index. (gauge)
 |<prefix>.cluster.raft.applied_index|The applied index of the Raft log. Represents the application of the committed Raft log entries to the database and internal state. The applied index should always be less than or equal to the commit index. The difference between this and the commit index can be used to monitor how up-to-date the follower database is. (gauge)
-|<prefix>.cluster.raft.prune_index |label:new[Introduced in 5.25] The head index of the Raft log. Represents the oldest Raft index that exists in the log. A prune event will increase this value. This can be used to track how much history of Raft logs the member has
+|<prefix>.cluster.raft.prune_index |label:new[Introduced in 5.25] The head index of the Raft log. Represents the oldest Raft index that exists in the log. A prune event will increase this value. This can be used to track how much history of Raft logs the member has. (gauge)
 |<prefix>.cluster.raft.term|The Raft Term of this server. It increases monotonically if you do not unbind the cluster state. (gauge)
 |<prefix>.cluster.raft.tx_retries|Transaction retries. (counter)
 |<prefix>.cluster.raft.is_leader|Is this server the leader? Track this for each rafted primary database in the cluster. It reports `0` if it is not the leader and `1` if it is the leader. The sum of all of these should always be `1`. However, there are transient periods in which the sum can be more than `1` because more than one member thinks it is the leader. Action may be needed if the metric shows `0` for more than 30 seconds. (gauge)