Global Rewrite Rules for a Topology are Problematic

Due to the fact that the rewrite rules for a topology are global, matching patterns that are more generic may cause indeterminate URL rewriting. This is more of a problem for proxying UIs than it is for services but since the patterns are up to the discretion of the developer they could certainly also apply to service definitions.

For instance, the JOBHISTORY UI rewrite.xml contains a pattern like "/static/**". This pattern will match an root relative URLs that start with "static". Since other hadoop UIs that may be proxied through the same topology will reference similar resources, the URL rewriting may match the pattern from the wrong application and interject the service/UI name into the URL which will result in 404's.

This has been observed for the HBase UI when the JOBHISTORY UI is also in the same topology.

The workaround for this issue is to deploy separate topologies for UIs that have overlapping matching patterns.