The email below came to the users list a little while back. Can anyone shed any light (by responding to the original post on the users list) on why the broker would be using such a large amount of non-heap memory? In particular, I thought it was odd that there were so many large and similar-but-not-identical sized blocks of memory allocated. Do either KahaDB or LevelDB do anything exotic like memory-mapped files?
Tim ---------- Forwarded message ---------- From: "Abhinav2510" <[email protected]> Date: Sep 4, 2017 2:01 PM Subject: activemq memory usage 4 times greater than Maximum heap allocated To: <[email protected]> Cc: Hi All, > > I have below configuration for my java actvemq process where Xmx is 15360M > but when I see the process usage of memory using glance I see RSS 41.8gb > and VSS 51.6gb . pmap <process_id>|grep total gives me total 54059348K. I > am not sure what is happening in activemq that is causing this much amount > of memory being utilized. While heap usage is pretty low till 60%. > > In the output of pmap I see lot of anon blocks. Please find attached PMAP > output > > > /XXXXX 111922 1 22 14:30 pts/0 00:04:26 > /u/users/user/jdk1.7.0_71/bin/java -Xms1024M -Xmx15360M -Xss512K > -XX:+UseG1GC -XX:NewRatio=4 -XX:InitiatingHeapOccupancyPercent=45 > -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Xloggc:/x/logs/AMQGC.log > -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=20M > -Djava.util.logging.config.file=logging.properties > -Djava.security.auth.login.config=/u/users/user/ > POSInterfaces/apache-activemq-5.13.2//conf/login.config > -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote > -Djava.awt.headless=true > -Djava.io.tmpdir=/u/users/user/POSInterfaces/apache-activemq-5.13.2//tmp > -Dactivemq.classpath=/u/users/user/POSInterfaces/apache- > activemq-5.13.2//conf:/u/users/user/POSInterfaces/ > apache-activemq-5.13.2//../lib/: > -Dactivemq.home=/u/users/user/POSInterfaces/apache-activemq-5.13.2/ > -Dactivemq.base=/u/users/user/POSInterfaces/apache-activemq-5.13.2/ > -Dactivemq.conf=/u/users/user/POSInterfaces/apache-activemq-5.13.2//conf > -Dactivemq.data=/u/users/user/POSInterfaces/apache-activemq-5.13.2//data > -jar /u/users/user/POSInterfaces/apache-activemq-5.13.2//bin/activemq.jar > start/ > pmap.txt <http://activemq.2283324.n4.nabble.com/file/t378515/pmap.txt> > > > > -- > Sent from: http://activemq.2283324.n4.nabble.com/ActiveMQ-User- > f2341805.html >
