Service Container Documentation

Description

A Service Container is a container for a service, functionality or application which can act with a variable amount of Resources. The Service Container acts as the bridge between the Service and the Resource Provider, relaying Service needs to the Resource Provider and commands from the Resource Provider to the Service. The Service Container is responsible for tracking the state and the resource needs of the Service.

There is a one to one relationship between a Service Container and a Service. The Service Container handles the life-cycle management of the Service and provides an access point for communications from the Resource Provider. The Service Container is a generic component which provides the communication infrastructure and other common elements to the Service Adapter, the Service-specific component which translates information from project Hedeby into a form usable by the service. In the lifetime of a Service Container, the Service Adapter and associated Service may change according to administrative orders.

The Service Container is capable of starting and stopping the currently running Service and/or Service Adapter. To start a Service Adapter without starting a Service means to connect the Service Adapter to an already running Service. To stop a Service Adapter without stopping the associated Service means to disconnect from the Service but leave it running. Stopping a Service Adapter without stopping the associated Service also means that any resources assigned to that Service are effectively lost to the project Hedeby system. By stopping one Service and starting another, a Service Container can switch Services at runtime.

The Service Container implements a Service Container Interface for use by the Resource Provider. The Service Container Interface is a remote interface that provides access to administrative operations and allows the Resource Provider to register to receive SLO non-compliance events. Additionally, the Service Container may expose the administrative operations through one or more JMX MBeans.

Each Service Container interacts with no more than one Resource Provider. A Service Container can exist without a Resource Provider present. The Service Container resides on a selected master host. Every Service requires at least one host to function. To simplify the deployment model, Services will have one fixed host for the Service and the Service Container. Initially the master host for a service will be selected by the administrator when the Service is started. Starting a Service may include creating the Service. Stopping a Service may include destroying the Service.

Configuration

Following configuration attributes are available for the Service Container Component:

Configuration tag name	Description
Identifier	Specifies the unique name of the OSP component.
Adapter	Configuration sub directory containing the adapter configuration.
ShutdownTimeout	Shutdown timeout

This example shows the configuration values for a Service Container that provides Grid Engine service functionality.

<config name="sc_ge">
    <config name="Identifier">sc_ge</config>
    <config name="Adapter">N1geAdapter</config>
    <config name="ShutdownTimeout">60</config>
</config>