From OpenNMS

There is a nifty trick in OpenNMS where you can replace graph references to nodeId with a combination of the foreign source and foreignId.

For example, suppose there is a node in the database:

nodeid             | 100
foreignsource      | linuxhosts
foreignid          | web.example.com

You could access the reports on this node with:

http://opennms.example.com:8980/opennms/graph/results.htm?reports=all&resourceId=node[100].nodeSnmp[]

However, suppose you want to access those graphs without any knowledge of the somewhat randomly assigned nodeid? If you know the foreignsource and foreignId, you can use:

 
http://opennms.example.com:8980/opennms/graph/results.htm?reports=all&resourceId=nodeSource[linuxhosts:web.example.com].nodeSnmp[]

This works anywhere you would use a resourceId field, such as KSC reports. It is extremely useful in syncing KSC reports across systems with separate databases. If on system A web.example.com is nodeId 100 and on system B it is nodeId 139, as long as the node has the same foreign source on both systems, the nodeSource method will work.