Adding JMX support to your java app

Lets start with the basics -

what is JMX?

JMX is a technology that lets you add management interfaces for Java applications

the jmx interface on your java application will let you monitor and publish graphs for:

• heap memory
• threads and their stack trace
• CPU
• classes
• memory pools

Enabling JMX in Tomcat

wrapper.java.additional.1=-Dcom.sun.management.jmxremote

wrapper.java.additional.2=-Dcom.sun.management.jmxremote.port=<port>

wrapper.java.additional.3=-Dcom.sun.management.jmxremote.ssl=false

wrapper.java.additional.4=-Dcom.sun.management.jmxremote.authenticate=false

wrapper.java.additional.5=-Djava.rmi.server.hostname=<ServerName>

Things to verify before usage:

1. the numbers after the “wrapper.java.additional.” part are in increasing order – make sure to continue from where the last config line showed, and make sure there are no gaps in the counting.
2. change <port> to the port number you wish to expose
3. these settings will enable password-less connection to you JMX server, if you wish to add authentication and SSL you will need to change these settings.
4.  change <ServerName> to your server name – this setting is needed – without it the server will only allow localhost connections and wont allow remote.

  

Technorati Tags: java, jmx, tomcat

Oracle CEO Larry Ellison makes fun of “Cloud Computing”

httpv://www.youtube.com/watch?v=UOEFXaWHppE&feature=share

This is a nice bit from Larry Ellison the CEO of Oracle,
He talks about Cloud Computing term as a new name for the same internet everyone has used for years.

Wiki calls it:

The term “cloud” is used as a metaphor for the Internet, based on the cloud drawing used in the past to represent the telephone network, and later to depict the Internet in computer network diagrams as an abstraction of the underlying infrastructure it represents.

He objects to the absurdity of the term cloud – since it is the same server-based service that was always there and is connected to the internet – the same OS, service, Database etc…

I agree heartily with him – ever since anyone of us joined the first web-based email service or web hosting,
we all have used the cloud.

What do you think?
do we have now a different cloud computing then we had ever since the internet started working?
Please post your thoughts in the comments …

Technorati Tags: Cloud Computing, Internet, interviews, Solaris

Social Networking Map

This Link will lead you to this social-networking-map in full size,
which is a lovely Data Visualization which i love,
you can see in this post here about Management Data Visualization all kind of samples of Management related Data Visualization images.

The issue I want to raise here besides my appreciation for the designing of this concept,
Is the fact I didn’t find ICQ in there.

Now I have a special place in my heart for ICQ,
and since they still have many millions of users, I think they should have ben represented in this image,
But all I could find there are some “receding glaciers of AOL” and “AIM Tundra”.

I think ICQ was the Origin of the internet socializing idea, and some kind of a relic at least should be in it,
although ICQ is still alive and kicking, and in the process of changing ownership – ICQ Sold to the Russians.

So, My question for the day is:

Can you Find ICQ in the picture, Boys and Girls?

Technorati Tags: funny, network, Social Network

Ajax DNS Tool

I’m always searching for better tools to do my work,
and today I have found this nice DNS online testing tool made with Ajax,
It’s quite nice and fast, and its good when you do not have a Linux distro at hand,
or have a problem with whois test from a proxied server.

Read more

Technorati Tags: DNS, Online Tools

NFS mount – When Your Shares Go Wrong

From Wikipedia:

Network File System (NFS) is a network file system protocol originally developed by Sun Microsystems in 1984, allowing a user on a client computer to access files over a network in a manner similar to how local storage is accessed.

So basically its a network share, it allows you to share files between remote computers
in the most easy and seamless way, once it was specifically for UNIX servers,
but today NFS is supported over MS servers as well.

Like everything else in Sysadmin life,
when its working its working well, and nobody hears about it,
but what to do when its not working?
Samba debugging for example is easier from that aspect since it has extensive logs for the sysadmin,
NFS doesn’t keep logs, and NFS issues doesn’t show up in the syslog/messages file as well.

But there are tools that allow you to get extensive information about the running NFS process,
shares, statistics, users connected etc :

Technorati Tags: Command line, NFS, samba, Solaris