GT 3.9.3 WS MDS Aggregator : System Administrator's Guide

Introduction

[introduces the guide to sysadmins AND points them to the Installation Guide for comprehensive basic installation/configuration info]

Building and Installing

[information about installing the component - may link to Installation Guide]

Configuring

Information on configuration settings and environment variables can be found in the public interface guide.

There is a command line client globus-servicegroup-register which allows resources to be registered to any MDS resource based on the MDS aggregator (an index resource, a trigger resource, an archiver resource). This client should be run alongside a container to register arbitrary resources into an MDS aggregating resource (index, trigger, archiver). The configuration file syntax is documented in the example configuration files installed in $GLOBUS_LOCATION/etc.

Usage:

globus-servicegroup-register /path/to/reg.xml

The Content block of each registration in the configuration file can contain configuration elements that affect both the aggregator source (i.e. determines how information is collected) and the aggregator sink (i.e. what is done with the information once it has been collected).

Sink-specific configuration information is documented per-service. See the admin guides for the trigger and archiver (the index service does not have sink-specific configuration.)

Each aggregator source has its own set of configuration options. There follows a list of the aggregator sources supplied with GT3.9.3.

QueryAggregatorSource

The QueryAggregatorSource gathers resource property values from the registered resource using one of the three WS-Resource Properties poll operations. The method used depends on the configuration element supplied in the registration content. Note that it is considered a configuration error to specify more than one of these configuration blocks, whether of the same type or different.

  • GetResourcePropertyPollType; requests a single Resource Property from the remote resource. Parameters are a refresh period (in milliseconds) and a single QName specifying the name of the Resource Property to be queried.
  • GetMultipleResourcePropertiesPollType; requests multiple Resource Properties from the remote resource. Parameters are a refresh period (in milliseconds) and a list of QNames specifying the names of the Resource Properties to be queried.
  • QueryResourcePropertiesPollType; requests a query be executed against the Resource Property Set of the remote resource. In the GT3.9.3 implementation of core, the only query language that is supported is XPath. Parameters are a refresh period (specified in milliseconds) and a query to be evaluated against the remote Resource Property Set.

SubscriptionAggregatorSource

The SubscriptionAggregatorSource gathers resource property values from the registered resource using WS-Notification subscriptions.

There is a single configuration type, AggregatorSubscriptionType, which specifies the name of the remote Resource Property (actually Topic) to subscribe to as well as WS-Notification preconditions, selectors, policy and termination time. Details of these can be found in TODO: ref WS-Notif link (TODO: are these all implemented?)

ExecutionAggregatorSource

The ExecutionAggregatorSource gathers arbitrary XML information about a registered resource by executing an external script and passing registration as parameters. See the developers guide for details of this API. (TODO crosslink)

There is a single configuration type, ExecutionPollType, which specifies the period between script executions, and the choice of script. The period parameter is specified in milliseconds. The script parameter is specified as an alphabetic string which names a probe script stored in $GLOBUS_LOCATION/libexec/aggrexec/.

Specific probe scripts can extract additional configuration information from the configuration block.

Deploying

[information about deploying the component into various containers/environments]

Testing

[procedures for how to test the configuration. must include examples of the tests ]

Troubleshooting

[help for common problems sysadmins may experience]