DDM server collection hierarchy

DDM probes run on a server and report events to the Domino® Domain Monitor database (DDM.NSF) that is on that server. Rather than visit every Domino Domain Monitor database on every server to review the probe results, create a DDM server collection hierarchy and have the data aggregated to a few servers.

Use the DDM server collection hierarchy document to define how data is collected in a domain. You can designate that one server collect all DDM event data or you can define a custom DDM server collection hierarchy consisting of multiple collecting servers and, optionally, multiple server tiers.

You use the Monitoring Configuration database (EVENTS4.NSF) to create and manage the DDM server collection hierarchy. The first time that you click the DDM server collection hierarchy view in the Monitoring Configuration database, a message indicates that no server collection hierarchies exist. You can create a server collection hierarchy, or you can exit the view. To create a DDM server collection hierarchy, specify one or more collection servers. A collection server collects the probe results that are generated when probes are run against monitored databases and servers. To use a DDM server collection hierarchy, you must specify at least one collection server that collects from other servers.

There are many ways to design a DDM server collection hierarchy. For example, you can set it up to represent an existing Domino server topology, for example, hub and spoke servers. Or, you can set it up to ensure that the administrator receives only information that is pertinent to the servers he or she maintains.

Each Domino server writes its probe results to a local replica of the DDM database. Each collection server's DDM database contains that server's probe results, and the probe results from every server from which it collects data.

The DDM collection hierarchy provides the DDM reporting rollup capability, allowing you to open DDM on a collection server and see all events for that server and its subordinate servers. Without the DDM collection hierarchy, you must open DDM.NSF on each server on which DDM is running to see events for that server.

DDM data roll-up propagates the probe results up the DDM server collection hierarchy. Data roll-up is accomplished using Domino's selective replication to transport the data. The replication formulas are created automatically when you define your DDM server collection hierarchy. Each selective replication formula is specific to each server in the Domino Domain Monitor replica. When fully populated, the selective replication formula references the collection server and all of its monitored servers. The selective replication formula filters out all documents from servers that are not members of the collecting server's hierarchy.

The collected probe results in the DDM database are replicated when one of these occurs:

  • A collection server is notified about the change in an event state -- When a collection server receives notification that one of its monitored servers has an event state change, the collection server replicates the monitored server's DDM database. When a replication triggered by an event state change is complete and the collection server is a monitored by another collection server, it notifies its collection server of the state change. The state change is then replicated up the server collection hierarchy.
  • The collection interval time has been exceeded -- The periodic collection interval is five minutes and is not modifiable. Collection servers monitor replication for each server being monitored. Every five minutes, each collection server uses Pull replication to obtain updates from the DDM database on each of their monitored servers.

You must create a DDM server collection hierarchy to initiate data roll-up.

Note: Review which servers are included in the server collection hierarchy prior to retiring a server from the domain. If you plan to retire a server, remove it from the hierarchy, and then retire the server. Failure to remove the server causes problems with data roll-up after the server is retired.