Switching to OpenJ9

OpenJ9 provides the following tools, which might differ in behavior from the HotSpot equivalent.

Note: For information about HotSpot equivalences and differences for items other than tools, see New to OpenJ9?.

Java process status (jps)

Displays information about running Java processes. The main differences from the HotSpot jps tool are as follows:

  • Runs on Windows®, AIX®, and z/OS®
  • Uses the Attach API
  • Shows processes on the current host only
  • There is no -V option

For more information, see Java process status.

Java stack (jstack) tool

Displays information about Java stack traces and thread information for processes. The main differences from the HotSpot jstack tool are as follows:

  • In the interests of security, the OpenJ9 implementation of jstack prints only information about local processes that are owned by the current user.
  • Printing data for core dumps is not supported. Use the Dump viewer instead.
  • There is no -m option. Printing data for native stack frames is not supported.
  • There is no -F option to force a dump, although this might be accomplished using kill -QUIT <pid> on some platforms.

For more information, see jstack.