[ https://issues.apache.org/jira/browse/OOZIE-3232?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Andras Piros updated OOZIE-3232: -------------------------------- Summary: Reduce heap waste by reducing duplicate string count (was: Oozie may waste up to 25% of the heap due to duplicate strings) > Reduce heap waste by reducing duplicate string count > ---------------------------------------------------- > > Key: OOZIE-3232 > URL: https://issues.apache.org/jira/browse/OOZIE-3232 > Project: Oozie > Issue Type: Improvement > Components: core > Reporter: Misha Dmitriev > Assignee: Misha Dmitriev > Priority: Major > Attachments: OOZIE-3232-01.patch, jxray-analysis-dup-strings.png > > > I've recently analyzed an Oozie heap dump obtained from a customer's > production job, using jxray (www.jxray.com). In this job, Oozie's heap > consumption is ~6GB, and it turns out that nearly 25% of it is wasted due to > a large number of duplicate strings. The screenshot below, taken from the > jxray report, illustrates the problem. > !jxray-analysis-dup-strings.png|width=638,height=669! > It turns out that a lot of duplicate strings come from the oozie's own code, > i.e. {{org.apache.oozie.*}}. In particular, the top data field wasting memory > is {{org.apache.oozie.StringBlob.string}} (wastes 2.6%, or ~160MB). From the > source code of {{StringBlob}} I see that it would be trivial to intern > (deduplicate) these strings by adding the call to {{String.intern()}} in the > constructor and a few other places. Similarly, various fields of > {{org.apache.oozie.WorkflowJobBean}} and {{WorkflowActionBean}} collectively > waste a lot of memory, and can be fixed in the same way. -- This message was sent by Atlassian JIRA (v7.6.3#76005)