Symphony management hosts run various processes, depending on their role in the cluster.
The master lim starts vemkd and pem on the master host. There is one master lim per cluster.
There is one vemkd per cluster, and it runs on the master host.
The pem (process execution monitor) monitors vemkd, and notifies the master lim if vemkd fails.
The egosc (EGO service controller) is the first service that runs on top of the EGO kernel. It functions as a bootstrap mechanism for starting the other services in the cluster. It also monitors and recovers the other services. It is somewhat analogous to init on UNIX systems or Service Control Manager on Windows systems. After the kernel boots, it reads a configuration file to retrieve the list of services to be started. There is one egosc per cluster, and it runs on the master host.
The sd (session director) acts as a liaison between the client application and the session manager. There is one session director process per cluster, and it runs on the master or a management host.
The rs (repository service) provides a deployment mechanism for service packages to the compute hosts in the cluster. There is one repository service per cluster, and it runs on the master or a management host.
The lim (load information manager) monitors the load on the management host, and starts pem.
The pem (process execution manager) starts Symphony processes on the host.
The ssm (session manager) is the primary workload scheduler for an application. There is one session manager per application.
The wsm (web interface service) runs the Platform Management Console.
The plc (PERF loader controller) loads data into the reporting database.
The purger (PERF data purger) purges reporting database records.
The lim (load information manager) monitors the load on a compute host, and passes the load information to the master lim on the master host.
The pem (process execution manager) monitors the lim process.
The sim (service instance manager) is started on the compute host when workload is to be submitted to the host if the application is preconfigured. The sim then starts the service instance running. There is one service instance manager per service instance.