IBM Support

When is cluster.ncf created by a Notes client or a Domino server?

Technote (FAQ)


When is cluster.ncf created by a Notes® client or a Domino® server? What is the cluster.ncf file used for?


The cluster.ncf file is created on a Notes client or a Domino server when it connects to a Domino server that is a member of a cluster, even if the requester and the cluster are not in the same domain or Notes Named Network (NNN)."
The cluster.ncf file is first created or updated in a memory cache. Even on the initial setup or activation of clustering, the cluster.ncf is not created at the OS level until the Domino server is brought down again. It is updated on disk in the Notes Data directory when stopping the server or the workstation.

For example, if you need to create a new cluster.ncf file (in order to troubleshoot a clustering issue), and bring down the Domino server, rename the existing cluster.ncf, and then bring the Domino server back up, you will not see a new cluster.ncf created. You must restart the server again to see the new NCF file.

When connecting to a server which is a member of a cluster, an entry is added to this file with details about the cluster (cluster name, member servers, etc.).

Please be aware that you may failover to a clustermate without previously having accessed a clustered server. The cluster information will be stored in memory or cluster.ncf. For example, if the cluster.ncf has been deleted on a client and the client has been shut down, the server information will be restored in memory after connecting to a single server (which includes all clustered servers this server has connected to). This information is then written to cluster.ncf upon the subsequent shut down. Reference SPR #PAZR6GPRWU.

NOTE: The update of the cluster.ncf to the disk has been found to be inconsistent. This issue has been reported to Quality Engineering.

Cluster.ncf is central to several functions of clustering for both the client and the server. Each time this file is used to determine the connection path for a cluster, the date/time stamp for each member is updated. Cluster.ncf is used on the client to help increase performance to cluster members. On a server, cluster.ncf is used to determine routing points for mail failover. An incorrect cluster.ncf can lead to failover problems.

Historical Number


Document information

More support for: IBM Domino

Software version: 8.0, 8.5, 9.0

Operating system(s): Platform Independent

Reference #: 1087756

Modified date: 27 July 2006