The Symphony daemons running on cluster hosts depend on the role of the host. Symphony consists of two components: SOAM and EGO.
On all hosts in cluster, the following system services will be generally available:
LIM: The LIM (load information manager) monitors the load on a compute host, and passes the loadinformation to the master lim on the master host.
MELIM: The master ELIM (external load information manager) manages all elim executables on the host and reports the external load index values to the LIM
ELIM: The ELIM (external load information manager) is a user-defined executable that collects multiple external load indices
PIM (Linux only): The PIM (process information manager) collects job-level resource usage
PEM: The PEM (process execution manager) monitors the LIM process.
On a master host, the following processes or system services are running:
VEMKD: The enterprise cluster kernel is a process automatically started on one of the hosts within the cluster. It provides a core set of centralized functions that leverage the capabilities of host-level agents. The kernel integrates the resources of all hosts and performs many-to-one virtualization so that mixed physical resources appear to clients as a single virtual computer.
EGOSC: The service controller is always started on the EGO cluster kernel host. It is responsible for starting other system services. Acting as a client to the EGO cluster kernel, it requests resource allocations for running services. It ensures that services are running by detecting failures and restarting service instances based on availability plans.
On management hosts, the following eight system services, can be found per cluster.
WEBGUI: The WEBGUI service (Platform Management Console) is a web-based graphical user interface for administrators and operations staff. The Console is extensible to enable higher-order services to add functionality for managing workload- or application-specific interfaces.
purger: The purger service is used by the reporting feature, and manages the relational database size by deleting old data at regular intervals.
plc: The plc service is used by the reporting feature, and manages the data loader plug-ins.
derbydb: This Apache Derby service runs as a system service when first installed. It is used primarily for demo clusters. The derbydb service is only enabled if an environment variable is set prior to installation (Linux) or during the Windows installation
WebServiceGateway: The web service gateway (WebServiceGateway) service is a runtime component of EGO. The gateway provides a standards-based web services interface for web service clients to access EGO functionality. The web service client sends its request to the gateway via SOAP protocol. The gateway calls the EGO C APIs to perform the required operations on behalf of the web service client and returns the results.
ServiceDirector: Services are dynamically started and can therefore run on any host. This means that clients have to dynamically locate services to access them. Clients can locate services explicitly via API calls to the service controller that starts and tracks those services; alternatively, the service director provides a mechanism, based on standard DNS, for redirecting client requests to the physical instance of that service.
On management hosts, one SOAM daemon per application can be found.