DiagnosticsHandler without reflection ------------------------------------- Key: JGRP-2337 URL: https://issues.jboss.org/browse/JGRP-2337 Project: JGroups Issue Type: Feature Request Reporter: Bela Ban Assignee: Bela Ban Priority: Major Fix For: 4.1.0 Attachments: bla.java Probe.sh sends commands to cluster nodes, and they are handled by each node's DiagnosticsHandler. {{"op"}} and {{"jmx"}} commands are handled via reflection. However, reflection is not allowed by the GraalVM running in native mode, unless all attributes and methods of all protocols would be listed in a JSON file. This is apparently very costly as the native image builder creates a transitive closure over all classes whose methods and/or fields are listed in the JSON file, and thus includes too many classes in the native image. Investigate creating a {{ProbeHandler}} for {{"jmx"}} and {{"op"}} commands, which does not use reflection. 2 alternatives come to mind: * Offline creation and compilation: point to a list of protocols for which code is generated (an alternative ProbeHandler class). This class is then instantiated and set in the channel at runtime by the application * Point to a running stack. The code uses reflection (obviously this needs to run in non-native mode) to generate the native {{ProbeHandler}} from the list of protocols running in the current stack. This code can then be compiled and used in native image generation.