Archive for 'Server'

TechTip: Email Alert on SSH login

To secure your machine, there are hundred different things you can do, but the most important thing is to know what's happening on your Machine. In that getting the alerts as soon as someone login is one of very important and must thing to do.

So, to do the same thing, you can go with two approaches:

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ETAGs vs Expire Headers

When it come to optimization of a site or web-server, ETAGs and Expiry headers are the two main things you should be looking at. ETAGs and Expiry headers will be used to understand by the client whether to fetch the latest file or not, but still there is a difference between these two and are used at different scenarios.

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TechTip: DNS works on TCP or UDP ?

This is one of the very basic questions asked in a lots of interviews: Which protocol DNS works on - UDP or TCP ? And when you don't know the answer then you take a wild guess and says anyone of them :), which in any case is wrong as DNS works on both, TCP as well as UDP.

Two protocols being different from each other, TCP being a connection oriented protocol and UDP being a connection less protocol, but DNS uses both of them, not for the same purpose, but for different purpose.

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GNU Screen – Advanced Tutorial

The Basic working of the screen is already explained in my previous article and if you are not really looking for advanced screen features, you should look at my previous screen article. The link for the same is: Basics of GNU Screen

But there are a lot of advanced features which screen provides which might come handy in a lot of scenarios. I will be explaining them under.

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JBoss Application Server cannot startup

This is one of the very weirdest and very easy problem I have seen while trying to start a JBOSS server.
I checked every single thing, might it be JDK version, permissions on the files and directories and every other thing, but I didn’t find anything. When I tries to start the JBOSS server, the logs looks something like this:…

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