The Event Management subsystem depends on the following components:
The sections that follow contain more details about each of these components.
The System Performance Monitor Interface (SPMI) library resides at /usr/lib/libSpmi.a. The RMAPI uses the shared memory technology of this library to deliver resource variable values to the Performance Toolbox for AIX product and the Performance Toolbox Parallel Extensions (PTPE) optional feature of PSSP. Thus, a resource monitor supplies data not only for event management, but also for performance monitoring.
Also, the aixos resource monitor uses the SPMI to obtain AIX operating system statistics that are the source of the AIX operating system resource variables that are supplied by the RSCT software.
The Group Services subsystem provides another set of high availability services. The Event Management subsystem primarily uses Group Services to monitor the state of each Event Manager daemon in the domain, as follows. Each Event Manager daemon in the domain joins a Group Services group called ha_em_peers. Group Services informs each Event Manager daemon, in a synchronized fashion, when a daemon has joined or left the group.
Associated with the ha_em_peers group is a group state that contains the version string of the EMCDB. Thus, when an Event Manager daemon joins the ha_em_peers group, it can determine the version of the EMCDB that the rest of the group is using.
The Event Manager daemon also subscribes to the HostMembership, enMembership, and cssMembership system groups. Instances of the IBM.PSSP.Membership.Node.state resource variable are derived from HostMembership group information. Instances of the IBM.PSSP.Membership.LANAdapter.state resource variable are derived from enMembership and cssMembership group information. Instance of the IBM.PSSP.Response.Host.state resource variable are derived from enMembership group information.
The Event Manager daemon uses the SDR primarily as a repository of configuration information. In addition, on the control workstation, the Event Manager daemon polls the SDR for information that it uses to create instances of the IBM.PSSP.Response.Switch.state resource variable. This information is taken from the switch_responds SDR class.