[FREEMARKER-32] Memory Leak

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Incomplete
• Affects Version/s: 2.3.23
• Component/s: engine
• Labels: freemarker leak memory
• Environment: Linux, JDK 1.8
• Assignee: Unassigned
• Reporter: ashwini kuntamukkala
• Created: 25/Aug/16 19:40
• Updated: 09/Nov/16 21:42
• Resolved: 09/Nov/16 21:42

Description

When processing over 2000 calls to hydrate a freemarker template with supplied pojos, the app server hosting the web app goes out of memory. When I looked at the head dump, the freemarker.template.DefaultObjectWrapper's classInstrospector instance of freemarker.ext.beans.ClassIntrospector seems to holding on to instance of pojos apparently in a hashmap.

freemarker.ext.beans.ClassIntrospector --> java.util.concurrent.ConcurrentHashMap -->
.\java.util.concurrent.ConcurrentHashMap$Segment[16]

I am initializing the set up in this way once when the application boots up

cfg = new Configuration(new Version(2, 3, 23));
cfg.setDefaultEncoding("UTF-8");
cfg.setLocale(Locale.US);
cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
cfg.setClassForTemplateLoading(FreemarkerTransformer.class,
"/templates");

So during a burst of calls, I run out of 512M of PermGenSize on my JVM.

Is there a workaround to solve this problem?

Thank you
Ashwin