About system services

A system service runs internal processes for Platform software. System services may have multiple concurrent service instances running on multiple hosts. All system services (except for derbydb) are automatically enabled by default at installation.

By default, management services that are installed with EGO include the following:


System Service

Process

Description

EGO service director

ServiceDirector

A system service that functions as a locating mechanism for other system services.

Platform Management Console

WEBGUI

A system service that runs the Platform Management Console.

EGO web service gateway

WebServiceGateway

A system service that provides a standards-based web services interface for web service clients (applications) to contact EGO.

EGO repository service

RS

A system service that manages package deployment. Allows deployment of a service without reliance on a shared file system.

PERF data purger

purger

A system service used by the reporting feature.

PERF loader controller

plc

A system service used by the reporting feature. Manages the data loaders that gather data from the system and writes the data into the database.

PERF derby database

derbydb

A small-footprint open source database that runs as a system service when first installed. This database is only appropriate for demo clusters. This service is only enabled if an environment variable is set prior to installation (Linux/UNIX) or during the Windows installation.

Session director

SD

The 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.

Session manager

SSM

Primary workload scheduler for an application.There is one session manager per application.


By default, system services are registered to the ManagementServices > EGOManagementServices consumer that uses the ManagementHosts resource group. You do not need to register any non-system services to consumers using the ManagementHosts resource group, although it is recommended that you do so if your service is a scheduler or controlling service instead of a regular application (management hosts are not expected to execute workload units for users, but are configured to run important services instead).

Each started system service requires one slot, assuming the system service is configured for one instance (default setting). By default, EGO allots twelve slots per management host to run system services, although only seven (or eight if derbydb is automatically enabled at installation) are actually used out-of-the-box by the installed management services listed above. For maximum performance in case of failover, you must retain seven or eight of the ten slots on each master candidate for use by the system services; the others can be used by non-system services that you might register that require a management host.

Slots assigned to run system services for consumers the ManagementServices consumer branch do not have to be on the master host (for example, any management host in the cluster can be the web server); the cluster determines where the system service instance runs at startup.

Registered system services do not require a host, only the system service instance that it runs.

Service profile

A service profile is an XML file (configured through the Platform Management Console) that contains the service definition for a service; when you update a system service, you are updating the system service profile containing the system service definition. Every service, whether it is installed by default (a system service) or added by an administrator, has a service profile. The XML file lets you configure properties for the service such as :

  • The maximum and minimum number of service instances required by the service

  • A service instance description, which describes how to start a service instance for this service

  • Any resources required to run the service instances for this service

  • Any dependencies this service has (such as another service being started)

Note:

We do not recommend changing the XML file for any of the system services (those installed by default) unless specifically told to do so. You may need to change ports.

Troubleshooting system services

If a system service has the state error or unknown, check the log files to troubleshoot. The logs for the EGO service controller, the load information manager, and the VEM kernel daemon are good places to start.