XmlCollector

The XmlCollector collects and extracts metrics from XML and JSON documents.

Configuration and use

Class Name

org.opennms.protocols.xml.collector.XmlCollector

Package

core

Supported on Minion

Yes (see limitations)

Configuration Files

$OPENNMS_HOME/etc/xml-datacollection-config.xml
$OPENNMS_HOME/etc/xml-datacollection.d/*.xml

Limitations on Minion

The following handlers are not currently supported on Minion:

  • DefaultJsonCollectionHandler

  • Sftp3gppXmlCollectionHandler

  • Sftp3gppVTDXmlCollectionHandler

Configuration and use

Table 1. Collector-specific parameters for the XmlCollector
Parameter Description Default

Required

collection

The name of the XML Collection to use.

n/a

Optional

handler-class

Class that performs the collection.

org.opennms.protocols.xml.collector.DefaultXmlCollectionHandler

The available handlers include:

  • org.opennms.protocols.xml.collector.DefaultXmlCollectionHandler

  • org.opennms.protocols.xml.collector.Sftp3gppXmlCollectionHandler

  • org.opennms.protocols.xml.vtdxml.DefaultVTDXmlCollectionHandler

  • org.opennms.protocols.xml.vtdxml.Sftp3gppVTDXmlCollectionHandler

  • org.opennms.protocols.json.collector.DefaultJsonCollectionHandler

  • org.opennms.protocols.http.collector.HttpCollectionHandler

XML collection configuration

Understanding resource types helps when editing collector-specific configuration files.

XML Collections are defined in etc/xml-datacollection-config.xml and etc/xml-datacollection/.

This snippet provides a collection definition named xml-opennms-nodes:

<xml-collection name="xml-opennms-nodes">
  <rrd step="300">
    <rra>RRA:AVERAGE:0.5:1:2016</rra>
    <rra>RRA:AVERAGE:0.5:12:1488</rra>
    <rra>RRA:AVERAGE:0.5:288:366</rra>
    <rra>RRA:MAX:0.5:288:366</rra>
    <rra>RRA:MIN:0.5:288:366</rra>
  </rrd>
  <xml-source url="http://admin:admin@{ipaddr}:8980/opennms/rest/nodes">
    <request method="GET">
      <parameter name="use-system-proxy" value="true"/>
    </request>
    <import-groups>xml-datacollection/opennms-nodes.xml</import-groups>
  </xml-source>
</xml-collection>

The request element can have the following optional child elements:

Parameter Description Default

timeout

The connection and socket timeout in milliseconds.

n/a

retries

How often to repeat the request in case of an error.

0

use-system-proxy

Should the system-wide proxy settings be used? Configure the system proxy settings via system properties.

false

The referenced opennms-nodes.xml file contains:

<xml-groups>
    <xml-group name="nodes" resource-type="node" resource-xpath="/nodes">
        <xml-object name="totalCount" type="GAUGE" xpath="@totalCount"/>
    </xml-group>
</xml-groups>

With the configuration in place, you can test it using the collect command available in the Karaf Shell:

opennms:collect -n 1 org.opennms.protocols.xml.collector.XmlCollector 127.0.0.1 collection=xml-opennms-nodes

Caveats

The org.opennms.protocols.json.collector.DefaultJsonCollectionHandler requires the fetched document to be a single element of type object to make xpath query work. If the root element is an array, it will be wrapped in an object, whereas the original array is accessible as /elements.