Picking the server(s) to run the Dircat task

The Dircat task (Directory Cataloger) is the server task that initially aggregates information from source Domino® Directories into a directory catalog, and then continues to run at scheduled intervals to update the directory catalog to reflect changes to the source Domino® Directories, or to the directory catalog configuration. The Dircat task aggregates both condensed Directory Catalogs and Extended Directory Catalogs.

About this task

A server that runs the Dircat task (a Dircat server) should:

  • Have enough disk space to store local replicas of the source Domino® Directories that are aggregated, if you choose to store the directories locally on the server, rather than have the server access them over the network.
  • Have enough disk space to store the resulting aggregated directory catalog(s) and full-text indexes. Only condensed Directory Catalogs have full-text indexes by default.
  • Be able to replicate the directory catalog(s) it aggregates to any servers and clients that will use them.

Typically it is best to run the Dircat task to build and maintain a directory catalog on a server in one domain, and then replicate the directory catalog to servers throughout an organization that need to use the directory catalog. Using this approach, rather than having each domain build an maintain its own version of the directory catalog, is beneficial because only one server then does the CPU-intensive Dircat processing of the directory catalog. Aggregate the primary Domino® Directory of the domain in which you build the directory catalog so that servers in other domains can use the directory catalog to look up information from the directory.

The Dircat task on one server can process more than one directory catalog. The Dircat task is single-threaded so it processes directory catalogs sequentially rather than simultaneously. Because Dircat is a CPU-intensive task, it's often beneficial to dedicate one server solely to Dircat processing.

Allowing only one server to aggregate a directory catalog

You can run the Dircat task on more than one server, with each server aggregating separate directory catalogs. Dircat tasks running on separate servers should never aggregate the same directory catalog, however, because doing so causes replication conflicts in the directory catalog. When you configure a directory catalog, choose the option Restrict aggregation to serverin the configuration document for the directory catalog to specify the name of the one server that can aggregate that directory catalog. If you complete this field, when someone tries to run the Dircat task against a replica of the directory catalog on a server not specified in the configuration document, the server aborts the Dircat task and returns the message Aggregation of this catalog can only be done by servername.