How to extract jmx statistics from jmx interface only from command line? - command-line

Question

I want to extract this data http://code.google.com/p/memcached-session-manager/wiki/JMXStatistics via jmx but using only command line.
This is because is the only way to enter to the server I got.
Any pointer would help
thanks in advance

Answer 1

I did up this quick-n-dirty solution after banging my head against the JMX protocol's inability to tunnel out over ssh.
(1) found some jmxterm thing, (2) stuff some simple command into it (runs an MBean operation) (after examining what JConsole did when attached to local tomcat..) and (3) format it into something readable.
#!/bin/bash
# wget http://downloads.sourceforge.net/cyclops-group/jmxterm-1.0-alpha-4-uber.jar
JARFILE="jmxterm-1.0-alpha-4-uber.jar"
JMXHOST=127.0.0.1
JMXPORT=9003
function die() { echo $1 ; exit 1 ; }
function checkexe() { [ -x `which $1` ] || die "cant find executable program $1" ; }
PROGS="java grep cat sed tr xsltproc xmllint"
for P in $PROGS ; do checkexe $P ; done
[ -f $JARFILE ] || die "can't see jar file $JARFILE"
## jmxterm commands to get thread stack dump
cat >/tmp/myscript.jmx<<EOF
domain java.lang
bean java.lang:type=Threading
run dumpAllThreads 1 1
quit
EOF
## get the stack traces
java -jar $JARFILE -l $JMXHOST:$JMXPORT -i /tmp/myscript.jmx > /tmp/allthreads.txt
grep "threadId" /tmp/allthreads.txt || die "stack trace get seemed to fail ?!"
## turn them into xml
cat /tmp/allthreads.txt | \
sed \
-e "s|\[ |<array>|g" -e "s| \]|</array>|g" \
-e "s|{|<obj>|g" -e "s|}|</obj>|g" \
-e "s|\([^ <>]*\) = \([^ <>]*\);|<\1>\2</\1>|g" \
-e "s|\([^ ]*\) = \([^;]*\) *;|<\1>\2</\1>|g" | \
tr '\r\n\t' ' ' | tr -s ' ' | \
sed \
-e "s|\([^ =]*\) = \([^;=]*\);|<\1>\2</\1>|g" \
-e "s|\([^ ]*\) = \([^;]*\);|<\1>\2</\1>|g"\
-e "s| *, *||g" > /tmp/allthreads.xml
## xsl to convert xml-ified stack traces to simpler format
cat >/tmp/jmxterm_threads.xslt<<EOF
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xsl:output method="xml" indent="yes"/>
<xsl:template match="/">
<jmx>
<xsl:for-each select="/array/obj">
<xsl:sort select="threadId" data-type="number"/>
<xsl:apply-templates select="." mode="thread"/>
</xsl:for-each>
</jmx>
</xsl:template>
<xsl:template match="obj" mode="thread">
<thread id="{threadId/text()}">
<xsl:copy-of select="threadName"/>
<xsl:copy-of select="threadState"/>
<xsl:copy-of select="suspended"/>
<xsl:copy-of select="inNative"/>
<xsl:copy-of select="waitedCount"/>
<xsl:copy-of select="blockedCount"/>
<xsl:apply-templates select="stackTrace"/>
</thread>
</xsl:template>
<xsl:template match="stackTrace">
<stackTrace>
<xsl:for-each select="./array/obj">
<stackfn class="{className}" method="{methodName}" file="{fileName}" line="{lineNumber}"/>
</xsl:for-each>
</stackTrace>
</xsl:template>
</xsl:stylesheet>
EOF
## simplify xml
xsltproc /tmp/jmxterm_threads.xslt /tmp/allthreads.xml | xmllint --format - > /tmp/allthreads_simple.xml
cat /tmp/allthreads_simple.xml

Answer 2

For CLI access I recommend jmx4perl and the readline based JMX shell j4psh. They require a Jolokia agent on the the server side, though. These agents are available in several flavours (war, osgi, mule, jdk6). Since memcached-session-manager runs within a Tomcat, you probably should use the WAR agent and simply drop it into the webapps/ directory.