Preparing for a symmetrical cluster

Before you configure a symmetrical cluster, understand the requirements and deployment best practice.

Requirements for a symmetrical cluster are:
  • Each server in the cluster must be at least Domino® 10 and have a Domino® directory design that is based on at least the Domino® 10 pubnames.ntf. Servers in the cluster that don't meet these requirements are ignored.
  • Cluster servers must all have sufficient capacity. The database portion of the repair service enforces folder symmetry across all servers in the cluster. All Domino® servers in the cluster should have roughly equivalent amounts of disk storage and DAOS storage relative to the folders you specify as symmetrical.
  • If you use Domino Attachment and Object Service (DAOS), DAOS must be enabled on all cluster mates with the same minimum object size configuration. In addition, The DAOS catalog must be synchronized across all cluster servers.
  • Each monitored database replica must be in the same folder path on all servers and have the same file name. If you use case-sensitive file names on UNIX® systems, the file name of each monitored database must use the same case. For example, sharyn.nsf in folder mail1 on server A but mail2 in on server B is an unsupported configuration. Use the command Repair list missing to determine if any monitored files have an unsupported configuration.
  • The following types of databases are not supported:
    • Databases with ODS level that is less than ODS 52. Upgrade databases that are monitored in a symmetrical cluster to at least ODS 52.
    • Databases that are locally encrypted with the server key. Note that encrypted DAOS objects referenced by databases are supported, however.
    • Transient or single databases. Exclude these databases from monitored folders. Use the Cluster Database Directory (cldbdir.nsf) as a guide.
    • Databases that do not have cluster replication enabled. All monitored databases should be enabled for cluster replication.
    • Databases that are accessed through directory or database links.
  • The IBM_ID_VAULT subdirectory should be excluded from any symmetrical cluster configuration.
Note: If separate database view indexes are enabled on a server, databases configured with separate view index files can be repaired. However, repairing these databases takes longer than repairing databases that don't use separate view index files because the index (.ndx) files are rebuilt as part of the repair process.
Follow this best practice for enabling a symmetrical cluster:
  1. Verify that you comply with these requirements.
  2. For the Maintain symmetry option, select a few folders.
  3. For the Automatic repair option, select List missing files in the log initially to list the files that are detected as missing in the log file without repairing them. Use the output in the log file and the repair list missing command to identify problems.
  4. When you are satisfied with the configuration, for the Automatic repair option, select Fix missing files.