Document updated descriptions of some Raft metrics

Author: NataliaIvakina

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

@@ -440,7 +440,7 @@ label:deprecated[Deprecated in 5.15]
 |<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 |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.term|The Raft term of this database. It increases monotonically unless you clear the cluster state. (gauge)
 |<prefix>.cluster.raft.tx_retries|label:deprecated[Deprecated in 2025.02] 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)
 |<prefix>.cluster.raft.in_flight_cache.total_bytes|In-flight cache total bytes. (gauge)
@@ -449,18 +449,18 @@ label:deprecated[Deprecated in 5.15]
 |<prefix>.cluster.raft.in_flight_cache.max_elements|In-flight cache maximum elements. (gauge)
 |<prefix>.cluster.raft.in_flight_cache.hits|In-flight cache hits. (counter)
 |<prefix>.cluster.raft.in_flight_cache.misses|In-flight cache misses. (counter)
-|<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.lag|Raft Log Entry Prefetch Lag. (gauge)
-|<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.bytes|Raft Log Entry Prefetch total bytes. (gauge)
-|<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.size|Raft Log Entry Prefetch buffer size. (gauge)
+|<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.lag|Raft log entry prefetch buffer lag. The amount of entries that have been added to the Raft log but not applied to the store. (gauge)
+|<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.bytes|Raft log entry prefetch buffer bytes. The total size of the entries in the prefetch buffer counted in bytes. (gauge)
+|<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.size|Raft log entry prefetch buffer size. The amount of entries that are stored in the prefetch buffer. (gauge)
 |<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.async_put|Raft Log Entry Prefetch buffer async puts. (gauge)
 |<prefix>.cluster.raft.raft_log_entry_prefetch_buffer.sync_put|Raft Log Entry Prefetch buffer sync puts. (gauge)
-|<prefix>.cluster.raft.message_processing_delay|Delay between Raft message receive and process.
+|<prefix>.cluster.raft.message_processing_delay|Delay between receiving a Raft message and starting its processing.
 (gauge)
-|<prefix>.cluster.raft.message_processing_timer|Timer for Raft message processing. (counter, histogram)
+|<prefix>.cluster.raft.message_processing_timer|Metrics Timer for Raft message processing, independent of the message type. The Timer provides different types of statistics, for example, `min`, `max`, `p999`, and `mean_rate`. (counter, histogram)
 |<prefix>.cluster.raft.replication_new|The total number of Raft replication requests. It increases with write transactions (possibly internal) activity. (counter)
 |<prefix>.cluster.raft.replication_attempt|The total number of Raft replication requests attempts. It is bigger or equal to the replication requests. (counter)
 |<prefix>.cluster.raft.replication_fail|The total number of Raft replication attempts that have failed. (counter)
-|<prefix>.cluster.raft.replication_maybe|Raft Replication maybe count. (counter)
+|<prefix>.cluster.raft.replication_maybe|The total number of Raft replication attempts where the result of the replication is not known locally. (counter)
 |<prefix>.cluster.raft.replication_success|The total number of Raft replication requests that have succeeded. (counter)
 |<prefix>.cluster.raft.last_leader_message|The time elapsed since the last message from a leader in milliseconds. Should reset periodically. (gauge)
 |<prefix>.cluster.raft.snapshot_attempt|label:new[Introduced in 2025.01] Total number of attempts to download Raft snapshots triggered. (counter)