Zapcat 1.3 released, adds templates for Java, Hibernate and Tomcat servlet containers

[Kees Jan Koster]

Hi, I just released version 1.2 of Zapcat. My site has a lot of information on how to monitor Java apps, troubleshoot memory issues and thread limits. http://www.kjkoster.org/zapcat/

If you are using an older version of Zapcat, this is a must-upgrade version. It saves you tons of work configuring hosts.

[Kees Jan Koster]

On the Zapcat documentation site, two more tutorials have been added, one for the Oracle IAS/OC4J container and one for Jetty.

http://www.kjkoster.org/zapcat/Jetty_How_To.html for Jetty and
http://www.kjkoster.org/zapcat/Oracl...4J_How_To.html for Oracle IAS/OC4J

[standist]

Can I monitor a jdbcconnectionpool is available or not throug jmx.

Can I monitor a jdbcconnectionpool is available or not throug jmx.
there is some situation like the network connection between tomcat and oracle is broken,so I want to check if the jdbcconnectionpool is available?
If it is possible, how can I do this.

[Kees Jan Koster]

Perhaps. :-)

Dear Standist,

This is something that cannot be statically monitored. I advise you to write a really simple JMX MBean, with a single property named "getAlive()". In that property, perform a trivial SQL query of some kind, like "SELECT 1" or maybe "SELECT COUNT(*) FROM someReallySmallTable".

You can then poll that bean from Zabbix via Zapcat.

Kees Jan

[standist]

thanks

does zapcat document mentioned how to invoke a customer's bean?

[standist]

zabbix_get

I test zapcat with zabbix server it works fine
but I test witch zabbix_get,it repsonse with "ZBX_NOTSUPPORT"

[Kees Jan Koster]

Dear Standist,

There is a tutorial on invoking mbeans in the Zapcat documentation: http://www.kjkoster.org/zapcat/Exploring_JMX.html

Note that zabbix_get does not work, because the Zapcat agent is not a regular Zabbix agent. You can use telnet instead, like so:

$ telnet localhost 10052
Connected to localhost.
Escape character is '^]'.
jmx[java.lang:type=Runtime][VmVersion]
ZBXD
1.5.0_13-119Connection closed by foreign host.
$ _

[standist]

Thanks for sharing

Thanks for sharing

[OneLoveAmaru]

The title of this thread says 1.3 but on your site it's 1.2? That's not my biggest issue though.

The biggest issue is that for all of the zapcat items to monitor tomcat are saying "Not supported by ZABBIX agent". Zabbix agent is 1.4.4 and server is 1.4.5. Ideas? I can get to the zapcat page just fine on the server. I used the tomcat template that was supplied with 1.2. Tomcat version is 5.5, java is 1.5.

I am running debian etch 4.0 on the host system, Ubuntu 8.04 for the zabbix server. In /etc/init.d/tomcat55 I have:

# Look for the right JVM to use
for jdir in $JDK_DIRS; do
if [ -r "$jdir/bin/java -Dcom.sun.management.jmxremote" -a -z "${JAVA_HOME}" ]; then
JAVA_HOME_TMP="$jdir"
# checks for a real JDK like environment, needed to check if
# really the java-gcj-compat-dev package is installed
if [ -r "$jdir/bin/jdb" ]; then
JAVA_HOME="$JAVA_HOME_TMP"
fi
fi
done

Maybe I have it in the wrong spot...? Anyone good with debian and have zapcat and tomcat working great with your zabbix server?? Any help is appreciated. Below this is what my catalina log says. Thanks a lot!

1.5.0.10/jre/lib/i386:/usr/lib/jvm/java-1.5.0-sun-1.5.0.10/jre/../lib/i386
Jul 2, 2008 11:17:20 AM org.apache.coyote.http11.Http11BaseProtocol init
INFO: Initializing Coyote HTTP/1.1 on http-8180
Jul 2, 2008 11:17:20 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 1250 ms
Jul 2, 2008 11:17:21 AM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Jul 2, 2008 11:17:21 AM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/5.5
Jul 2, 2008 11:17:21 AM org.apache.catalina.core.StandardHost start
INFO: XML validation disabled
Jul 2, 2008 11:17:22 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive tomcat.war
Jul 2, 2008 11:17:22 AM org.apache.coyote.http11.Http11BaseProtocol start
INFO: Starting Coyote HTTP/1.1 on http-8180
Jul 2, 2008 11:17:22 AM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Jul 2, 2008 11:17:22 AM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/42 config=null
Jul 2, 2008 11:17:23 AM org.apache.catalina.storeconfig.StoreLoader load
INFO: Find registry server-registry.xml at classpath resource
Jul 2, 2008 11:17:23 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2319 ms

[OneLoveAmaru]

Yeah i'm pretty positive I have that line in the wrong spot in /etc/init.d/tomcat55..... but I can't figure out where it goes... Any help would be awesome!

[Kees Jan Koster]

Dear OneLoveAmaru,

1. Use jconsole to test that JMX is enabled and working on your Tomcat server. If jconsole cannot connect locally, neither can Zapcat. Remote JMX is another ballgame altogether. If you cannot run jconsole on the machine locally (perhaps because it is headless) you have to trust it to work instead. :-/
2. You placed the test in the wrong place. This is in an if statement. Note that the line starts with "if". I have no Linux machines, so I cannot help you find the right spot.
3. In your catalina.out I am missing something along the lines of the following.
   INFO: Deploying web application archive zapcat-1.3-beta.war
   
   In your case that should be 1.2, maybe. Are you sure that Zapcat is in your webapps dir?

[OneLoveAmaru]

I actually have auto deploy disable in tomcat. I deployed the war file manually and I can access it's web page, so I know tomcat picked it up or else there wouldn't be a webpage.

Well, since I have that line in the wrong spot, then zapcat can't connect and of course the zabbix server won't be able to read anything.

I guess I'm in uncharted territory, I did some searches and can't find anyone who got zapcat and zabbix working with Debian linux. I guess when I figure it out I'll post back here to help the other Debian peeps who want the same setup.

Unless someone out there can do it but never posted.... I am always down for some help.

[Kees Jan Koster]

Good to hear that the zapcat pages are visible in your Tomcat server. Do you get any error messages when you access the front page, or the mbeans list page?

Also, try telnetting to the zapcat port to see what happens.

Uhm... have you checked your firewalls between the Zapcat and Zabbix machines.

Are you able to connect to the machine using jconsole?

Kees Jan

[OneLoveAmaru]

I played around a whole bunch last night and I got it so that I can get in with JConsole now. I do have the server behind a firewall with NAT and couldn't get in that way but as soon as I jumped on the VPN, then Jconsole would connect. I can see everything about tomcat. For debian / ubuntu users the trick is to add these lines to /etc/default/tomcat5.5 and not /etc/init.d/tomcat5.5.

CATALINA_OPTS="-Djava.awt.headless=true -Xmx512M -server
-Dcom.sun.management.jmxremote \
-Dcom.sun.management.jmxremote.port=8889 \
-Dcom.sun.management.jmxremote.ssl=false \
-Dcom.sun.management.jmxremote.authenticate=false"

The first line there about Xmx512 is something custom the Database admin put there, I added the rest. After I added those I did a /etc/init.d/tomcat5.5 restart. Then I checked to see if it was listening on port 8889 with a "netstat -a" and sure enough, it was listening on 8889.

So now I'm able to connect with jsonsole after all of this as long as I'm local with no firewall/nat between us. I tried just opening port 8889 to that server but jconsole would take 5 minutes and then say error connecting. I think it has to do with jmx opening a 2nd data port that is not open on the firewall.

http://tomcat.apache.org/tomcat-5.5-doc/monitoring.html

That is where I got a lot of good information from. I found that link on some other forum. Unfortunately it doesn't have high page rank so I couldn't find it when searching in google.

OK, so now I have all of that, the next step is to get a zabbix agent running on port 10052. I already have a zabbix agent running on 10050 for the unix template to monitor system services and snmp is also on there, but using default port of 161 for that.



As you can see, I do have something listening on port 10052 but on your page it says I need to get a zabbix agent running on port 10052... so that's where I am stuck now. You put some code there I need to include when compiling the agent but I have never needed to compile the agent. Do I need to download the source of a zabbix agent and then compile it?? I've made it this far so I can be far off from getting it all right.

Oh and I know the screenshot says port 8443, I was messing around with the port #'s and I made the screenshot when it was on port 8443. It's back on port 8889. With your tomcat template I see you have a lot of different lines trying to connect on different ports. Is there a port for jconsole that you specified?? If I run this in port 8889, do I need to change anything in your template to connect on that port? Or is the zabbix agent I compile supposed to connect on those ports locally? Thanks a lot for your help!

[OneLoveAmaru]

Oh and there is no firewall/nat between my zabbix server and the test server I have zapcat on. I did try to add the tomcat template to the host again and i just got all errors saying zabbix agent not supported. So obviously I do need another zabbix agent with that code in there from your page. I'll play some more with that. In the meantime, any advice you have I would love to hear it! Thanks.