[SLING-6756] Remove setting/advising to set permsize and max heap size

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Assignee: Unassigned
• Reporter: Konrad Windszus
• Created: 30/Mar/17 13:03
• Updated: 12/Sep/19 15:55
• Resolved: 12/Sep/19 15:55

Description

PermSize is no longer an issue with java 8 as Java 8 no longer knows a dedicated permgen space (https://dzone.com/articles/java-8-permgen-metaspace). Still we set -XX:MaxPermSize=256m in https://github.com/apache/sling/blob/trunk/.mvn/jvm.config (SLING-4530) which leads to a warning when building with Java 8.

The related ant check in parent has been removed though in https://issues.apache.org/jira/browse/SLING-5862. Althought the reason why the check has been removed is a bit unclear to me from the comments, I would propose to remove the jvm.config completely and do no longer advise to set permsize or heapsize explicitly.

The heapsize is currently bound to at most 512MB, which is in 90% of the cases just limiting the maximum heapsize of a modern JVM (because it should be 1/4 of the physical memory in most of the JVM, see http://stackoverflow.com/questions/4667483/how-is-the-default-java-heap-size-determined).

Issue Links

• relates to: SLING-1782 Build error: tests take a loooooooooong time
• relates to: SLING-4530 Add .mvn/jvm.config to reactor
• relates to: SLING-5862 Remove maven-antrun-plugin executions related to memory checks