Harald Pehl

Developer notes written down before they get lost.

Polyglot DMR

The dynamic or detyped model representation (DMR) is an API to interact with the management model of a running WildFly instance. There’s an Java API available at https://github.com/jbossas/jboss-dmr which is described in the WildFly Wiki. Though the Java API is very rich and powerful it is somewhat hard to write scripts that perform useful tasks like

  • Periodically read the memory and send an SMS / tweet / email when a threshold is reached
  • Rollout a deployment over all servers in a cluster
  • Monitor the state of an application

To address this challenges we created different client libraries for different languages:


The scala library is hosted at DMR.scala. The DMR.repl library leverages the Scala REPL to execute DMR operations in a very interactive way.


Using DMR.dart you can run DRM operations in Dart. Both executing individual operations, as well as writing whole web applications is possible.


The library for Node.js is called DMR.js.


Bringing the DMR library to different languages opens up many possibilities. We can think of a repository with (parameterized) management scripts, an integration with Gist / Paste.bin to quickly share your operations with your co-workers, … We’d love to heear your feedback and suggestions on this!

Open Issues

One of the main challenges when using the different client libraries is authentication. Right now there’s a workaround to use a CORS enables JBoss AS instance which is however a bit out of date. IMO the solution for this is to bring OAuth support to WildFly. For the time being the usage of the client libraries is somewhat limeted and if any feasible when running on the same host.


The different libraries are very much work in progress, but we’d love to here your feedback!