Hi,
We’ve been struggling with a recurring Java heap space error in xWiki for some time. Currently, xms and xmx are each set to 4096m. Nevertheless, the error occurs once a week.
The used xwiki version is: XWiki Debian 16.10.6
We’ve now analyzed two Java dumps. Maybe someone here can help with the main problems. Once interest is piqued, I can provide further information via another method if needed.
I’m concerned about the connection to JMX. It’s supposed to help monitor the system, not be the cause of the problem. Could JMX be safely disabled?
Problem 1, Dump 1
95 instances of „org.mariadb.jdbc.client.impl.StandardClient“, loaded by „org.eclipse.jetty.ee8.webapp.WebAppClassLoader @ 0x7356ed600“ occupy 1.275.230.448 (44,28 %) bytes.
Most of these instances are referenced from one instance of „java.util.HashMap$Node[]“, loaded by „<system class loader>“, which occupies 25.840 (0,00 %) bytes. The instance is referenced by „org.infinispan.jmx.CacheManagerJmxRegistration @ 0x700b1bdd0“, loaded by „org.eclipse.jetty.ee8.webapp.WebAppClassLoader @ 0x7356ed600“.
Keywords
org.mariadb.jdbc.client.impl.StandardClient
org.eclipse.jetty.ee8.webapp.WebAppClassLoader
java.util.HashMap$Node[]
org.infinispan.jmx.CacheManagerJmxRegistration
Problem 2, Dump 1
21 instances of „com.xpn.xwiki.XWikiContext“, loaded by „org.eclipse.jetty.ee8.webapp.WebAppClassLoader @ 0x7356ed600“ occupy 601.172.264 (20,88 %) bytes.
Biggest instances:
•com.xpn.xwiki.XWikiContext @ 0x7017ccfe8 - 67.961.632 (2,36 %) bytes.
Most of these instances are referenced from one instance of „java.lang.Thread[]“, loaded by „<system class loader>“, which occupies 1.264 (0,00 %) bytes. The instance is referenced by „org.apache.solr.common.util.SolrNamedThreadFactory @ 0x7009d8f60“, loaded by „org.eclipse.jetty.ee8.webapp.WebAppClassLoader @ 0x7356ed600“.
Keywords
com.xpn.xwiki.XWikiContext
org.eclipse.jetty.ee8.webapp.WebAppClassLoader
java.lang.Thread[]
org.apache.solr.common.util.SolrNamedThreadFactory
Problem 1, dump 2
92 instances of „org.mariadb.jdbc.client.impl.StandardClient“, loaded by „org.eclipse.jetty.ee8.webapp.WebAppClassLoader @ 0x708bcbe60“ occupy 1.426.190.352 (38,39 %) bytes.
Most of these instances are referenced from one instance of „java.util.HashMap$Node[]“, loaded by „<system class loader>“, which occupies 25.120 (0,00 %) bytes. The instance is referenced by „org.apache.solr.metrics.reporters.jmx.JmxMetricsReporter$JmxListener @ 0x700b87880“, loaded by „org.eclipse.jetty.ee8.webapp.WebAppClassLoader @ 0x708bcbe60“.
Keywords
org.mariadb.jdbc.client.impl.StandardClient
org.eclipse.jetty.ee8.webapp.WebAppClassLoader
java.util.HashMap$Node[]
org.apache.solr.metrics.reporters.jmx.JmxMetricsReporter$JmxListener
Problem 2, dump 2
45 instances of „com.xpn.xwiki.doc.XWikiDocument“, loaded by „org.eclipse.jetty.ee8.webapp.WebAppClassLoader @ 0x708bcbe60“ occupy 589.225.600 (15,86 %) bytes.
Keywords
com.xpn.xwiki.doc.XWikiDocument
org.eclipse.jetty.ee8.webapp.WebAppClassLoader
Regards,
Brunt