Writing a Simple HostDescription Document

A HostDescription document describes a host. This document is used by GFac to create an application service on a specified host and is used by an application service to run its application on a specified host. A simple HostDescription document is given below. For more details refer to the HostDescription schema. This document is usually written by the system administrator and registered with a well known Registry service.

<HostDescription xmlns="http://www.extreme.indiana.edu/namespaces/2004/01/gFac"
    xmlns:lead="http://www.extreme.indiana.edu/lead">

    <hostName>rainier.extreme.indiana.edu</hostName>

    <hostConfiguration>
        <gFacPath>/l/extreme/local/packages/SecureGFac/default</gFacPath>
        <java>
            <name>java1.5</name>
            <version>1.5</version>
            <path>/l/jdk1.5/bin/java</path>
        </java>
        <tmpDir>/tmp</tmpDir>
        <portRange>
            <start>12346</start>
            <end>12446</end>
        </portRange>
        <hostEnv>
            <name>name1</name>
            <value>value1</value>
        </hostEnv>
    </hostConfiguration>
</HostDescription>

The "hostName" specifies the name of the host. If the host has the Generic Service Toolkit installed (needed to create an application service on that host) then the "gFacPath" element has the path to GFac on that host. The path to Java (needed to create an application service instance on that host) is specified by the "java" element. The temporary directory on a host is specified by the "tmpDir" element and is optional. The "portRange" element is also optional and specifies a range of TCP/IP ports that are not blocked by the firewall on that host. When GFac creates an application service on that host, a free port is chosen from the specified port range. Environment variable specific to a host that need to be passed on the the application service or the application must be specified using the "hostEnv" element.

[ << ] [ < ] [ Home ] [ > ] [ >> ]