Misha Dmitriev created OOZIE-3232:
-------------------------------------
Summary: Oozie may waste up to 25% of the heap due to duplicate
strings
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
Attachments: 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!
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)
