Linux Admin Zone

Net::Amazon::S3 is the standard perl module to interact with Amazon S3 service using perl scripts. If you ever tried to install it, you may well aware about its gigantic dependecies on other modules which must be installed correctly. If anything goes wrong, you’ll be in mess because you have check around 66 different modules.

Here is a single command which will install the module and all of its dependecies (known upto the date of this article). I’ve tested this several times in CentOS 5.x boxes but I dont guarantee that it’ll also work seamlessly for you as well:

Recently, after configuring the vsftpd server running in CentOS 5 in several small ec2 instances as per the earlier post , I was not able to connect to vsftpd in one server from my ftp client. It throws the error:

500 OOPS: vsf_sysutil_recv_peek

The solution for this problem is to load capability module:

# modprobe capability

Sometimes we have different servers with different contents, such as one set of servers with all static contents (html, image files) of a website while another set of servers have dynamic contents (cgi, perl, php scripts) This type of config is benefitial in some situations where you want to serve your static data directly from CDN for faster response and dynamic contents from your own servers.

While deploying a load balancer, we need some mechanisam to inform loadbalancer to forward request to different set of servers based on the condition specified. Here I’m using HAProxy load balancer on CentOS 5 box. This is a very small test setup in Amazon EC2 environment having 3 small instances.

This is a quick Howto for setting up MySQL cluster using Amazon EC2 instances. I have used 3 small instances (1 mgmt + 2 data nodes) from RightScale’s CentOS 5 public image to test things. I’ve a working cluster using these steps but there’s no guarantee that these steps works for you as well.

Management server for cluster:
Although we can set up management server for cluster in one of the data node but we should have a third node as if one of the two MySQL cluster nodes fails, and the management server is not running, then the data on the two cluster nodes will become inconsistent and if the same node fails which have management server, then we will not be able to create another node or configure cluster.

For many users, running FTP Sever in Amazon EC2 instance is headache at the first time. You need to experiment before being able to transfer data. The main problems are Ingress firewall in Amazon environment and NAT traversal.

Here I’m using vsftp (vsfptd) Server, which is one of the most popular and easy to configure. The instance is running from base Fedora 4 AMI but the setup should be identical to other Red Hat based distros.

Install vsftpd FTP server, if not installed earlier:

$ yum install vsftpd