IBM App Connect Enterprise (ACE) has provided support for the concept of “shared classes” for many releases, enabling various use cases including providing supporting Java classes for JMS providers and also for caching data in Java static variables to make it available across whole servers (plus other scenarios). Some of these scenarios are less critical in a containerized server, and others might be handled by using shared libraries instead, but for the remaining scenarios there is still a need for the shared classes capability in containers.
What Is the Equivalent of /var/mqsi/shared-classes in Containers?
Adding JARs to shared classes is relatively simple when running ACE in a virtual machine: copying the JAR files into a specific directory such as /var/mqsi/shared-classes allows all flows in all servers to make use of the Java code. There are other locations that apply only to certain integration nodes or servers, but the basic principle is the same, and only needs to be performed once for a given version of supporting JAR as the copy action is persistent across redeploys and reboots.