From the monthly archives: October 2011

Install VPN PPTP Server on CentOS 6

By On 28 October 2011 · 103 Comments

At this moment, my designer encounter problem to access target.com, an online shopping website to see some of the stuff for their design work. Target.com only allowed connections from USA and Canada at this moment due to their website crash issue last couple of weeks. Since this is quite urgent, I need to setup a [...]

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Manage Multiple MySQL Servers using PHPmyAdmin

By On 27 October 2011 · 2 Comments

In my environment, I have 5 different MySQL database servers running separately under different geographical location. Since it run standalone and not in cluster mode, I need to have one platform to manage these database servers altogether.

PHPmyAdmin is able to do this, with some changes on the configuration files. You just need to allow [...]

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Install ModSecurity in Apache2 – The Easiest Way

By On 25 October 2011 · 6 Comments

ModSecurity is a module for Apache to act as a web application firewall, which bring another security layer to your website. Nowadays, it is very important to have this protection so your website will be protected from Internet threats. Based on my experience as system administrator, our intrusion detection system averagely detected 10 – 15 [...]

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Show Real IP in Apache Access Log (Akamai)

By On 21 October 2011 · Leave a Comment

Since our company is using Akamai as the Content Delivery provider (CDN), we need to see the real IP to make sure we can do some log processing accurately.

The Akamai CDN basically working like example below:

Akamai Edge Server will work as the reverse-proxy to cache the website contents [...]

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Create iSCSI Target in OpenFiler

By On 20 October 2011 · 5 Comments

If you have a SAN storage, or a dedicated server to serve as file and storage service to other server, I am suggesting you to use Openfiler. This operating system is specifically built to manage and deliver file-based Network Attached Storage and block-based Storage Area Networking in a single framework.

In this tutorial, I will not [...]

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Installing Java 1.6 in CentOS 6 – The Simplest Way

By On 17 October 2011 · 11 Comments

Default repository in CentOS 6 will give you Java 1.5 JRE and SDK packages. I will show you on how to install version 1.6 using yum.  You just need to enable RPMforge repository and another simple steps required after that.

Variables as follow:

OS: CentOS 6 64bit
Current Java version: 1.5
Upgraded Java [...]

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Eliminate Web Site Bad Traffic

By On 13 October 2011 · Leave a Comment

Nowadays, web hosting has introduced many kind of internet traffic, which we can classified into 3 categories:

Clean/good traffic Bot/crawler traffic Threat/bad traffic

Threat or bad traffic can harm the website and also can bring serious effect to the server, if you not have security in mind. Following example explained how bad traffic can bring [...]

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Bash Script – Delete Comments from a C program

By On 12 October 2011 · Leave a Comment

I wrote a bash script to delete comments from a C program. C language will required /* and */ between the contents of the comment. Example as below:

MQLONG Reason; /* Qualifying reason */ MQOD ObjDesc = {MQOD_DEFAULT}; /* Object descriptor */ MQLONG OpenOptions; /* Options control MQOPEN */ ⋮ /*—————————————– */ /* Initialize the [...]

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NginX: Gateway Time-Out

By On 6 October 2011 · 2 Comments

One of the web server that run on Nginx is having 504 Gateway Time-out error. This can be fixed by increasing the send_timeout directive in nginx.conf.

Steps as below:

1. Open the nginx configuration files via your favourite text editor:

$ vi /usr/local/nginx/nginx.conf

2. Find send_timeout directive and increase the [...]

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Export MySQL Query Result to CSV

By On 4 October 2011 · Leave a Comment

One of my developer team wants me to export some SQL query result and export it to CSV so they can import it to the local MySQL server. Since the database is quite big, around 2 million rows, dumping the whole table can really impact the database performance because he request this during peak hours.

[...]

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Linux: /tmp: Read-only file system Error

By On 3 October 2011 · Leave a Comment

One of the server that I manage has problem as below when I want to edit some files in crontab:

$ crontab -e /tmp/crontab.XXXX1ibTLU: Read-only file system

It shows that the /tmp partition is unwriteable. The read-only has been mounted as read-only because file-system facing some error. To fix this, we need to do file [...]

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