Start/notes.ini Parameters/Cluster_Replicators

Cluster_Replicators

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Parameter: Cluster_Replicators
Short description: Number of parallel cluster replicator threads on a server in a Domino cluster.

Profile

Parameter
Cluster_Replicators
Category
Cluster
Component
Server
Available since
R4.5
Supported versions
9.0.1, 10.0, 11.0, 12.0, 14.0, 14.5
GUI equivalent
Server document (Cluster section)
Possible values
Integer, default 1 (2–3 recommended under high load)

Description

Cluster_Replicators controls how many cluster replicator threads (CLREPL) the server runs concurrently. Each thread processes an entry from the cluster replication queue, so that multiple databases can be replicated to other cluster mates in parallel.
For small clusters with few databases, the default of 1 is sufficient; for mail servers with high write load or larger application clusters, 2–3 threads result in significantly lower latency for cluster replication.

Example configuration

Cluster_Replicators=2

Notes & pitfalls

  • Values that are too high create unnecessary CPU and network load – rarely useful >4.
  • Configure the same value on all cluster mates, otherwise backlogs build up on the weaker servers.
  • Takes effect only after restarting the cluster replicator task (restart task clrepl) or a server restart.
  • Monitor via show stat replica.cluster.* and the console command show cluster.
  • For large clusters, prefer adjusting the Cluster_Probe interval rather than increasing the replicators.