Overview
April 10, 2012
by Mohan Cheema
2 Comments
November 30, 2011
by Mohan Cheema
4 Comments
Change / Update SSL certificate for Amazon Elastic Load Balancer
This is in continuation to Amazon ELB SSL Termination HowTo. Earlier we have seen how to setup Elastic Load Balancer with SSL termination on Amazon. Now we will see how do we change the SSL certification once we renew it or revoke it for some reason.
September 30, 2011
by Mohan Cheema
0 comments
Disable Trace/Track in Apache HTTPD
Introduction
Disabling TRACE and TRACK in Apache for PCI-related vulnerabilities like Web Server HTTP Trace/Track Method Support Cross-Site Tracing Vulnerability is surprisingly easy with the Apache web server. The main thing to keep in mind is understanding that if you are running apache and this vulnerability pops up during a scan, you can be reasonably certain that TRACK is not the problem—TRACE is.
September 28, 2011
by Mohan Cheema
0 comments
MySQL MultiMaster Replication
You may know about the MySQL Cluster, which is a complex architecture to achieve high availability and performance. One of the advantages of MySQL Cluster is that each node is a peer to the others, whereas in a normal replicating system you have a master and many slaves, and applications must be careful to write only to the master.
September 22, 2011
by Mohan Cheema
1 Comment
How to test Postfix SMTP using Telnet
1. Telnet to postfix mail server using TCP port 25.
Command is telnet <servername/serverip> 25
response should be as follows
220 ********************************************
August 18, 2011
by Mohan Cheema
0 comments
Linux Screen Shortcuts
Screen is a much under utilised program, which provides the following functionality:
- Remote terminal session management (detaching or sharing terminal sessions)
- unlimited windows (unlike the hard-coded number of Linux virtual consoles)
- Scroll back buffer (not limited to video memory like Linux virtual consoles)
- copy/paste between windows
August 9, 2011
by Mohan Cheema
0 comments
Recover from Failed Amazon EC2 Instances
One of the things that’s not immediately obvious about Amazon EC2 instances is that they could fail, in fact Amazon says:
It’s inevitable that EC2 instances will fail, and you need to plan for it. An instance failure isn’t a problem if your application is designed to handle it.
August 3, 2011
by Mohan Cheema
0 comments
Adding more disk space (EBS volumes) to your instance
Adding more disk space (EBS volumes) to your instance
The AWS Server AMI comes with an attached 30 GB EBS volume. If you need more space, you can create additional volumes and attach them to your EC2 instance.
The steps below explain how to create a new EBS volume and attach it to your EC2 running instance.
Steps:
July 21, 2011
by Mohan Cheema
0 comments
Amazon ELB SSL Termination HowTo
We’ve been using the new Amazon Load Balancers (ELB) for some of our websites, since there’s not much information out there on the subject, I thought a post would be in order.
The load balancers are charged at $0.025 per hour, plus $0.008 per GB of data transferred through them. Personally I think this is very reasonable.
November 1, 2010
by Mohan Cheema
0 comments
Postfix OpenLDAP Courier-imap Amavisd-new SpamAssassin and clamav HowTo
This is a step by step guide on how to configure GNU/Linux system with Postfix, OpenLDAP, Courier-imap, Amavisd-new, SpamAssassin and clamav. Even though this setup was configured on Centos 5, with minor tweaks you should get it working on any GNU/Linux distribution.
Building necessary software