We have been playing around with Linux syn cookies to test out the performance and we have came to the following conclusions.

It’s always good to detect SYN floods and then turn on SYN cookies to better use the CPU power – so the SYN flood must be detected and sysctl SYN cookie value set to 1 in the real time. If you have Syn cookies turned on you server CPU and Network stack will be slightly affected, however, no RAM usage will increase in case of SYN flood. The kernel does not allocate the TCP buffers unless there is… Read the rest of this entry »

There are hundreds of blogs that have a lot of daily visitors and require dedicated server custom set-ups to run quickly and without a delay. Many of these blogs quickly outgrow single hardware resources, even if you try to upgrade the server and add more memory, even if you upgrade it to very expensive hardware. It simply doesn’t work and you require more advanced set-up, like front-ends and back-ends that share the load at all levels.

We have seen companies offering one front-end and one back-end MySQL server. Usually, they are run by people who never ran the blogs themselves,… Read the rest of this entry »

We have been processing all COM and NET domain names using our application cluster and based on our tests we have compiled the following:

.NET TLD statistics on September 22, 2007
Registered domains: 10278275
Domains not resolving: 1212471

.COM TLD statistics on September 22, 2007
Registered domains: 73383356
Domains not resolving: 8847418

Here is the chart for your convenience.

If you run a busy DNS server or any other service that uses a lot of UDP traffic, it’s possible that your default Iptable conntrack sessions (connection tracking entries in kernel memory) settings are too low and netfilter is unable to track all your sessions.

The error is usually something like this:

Sep 20 11:53:44 hostname01 kernel: ip_conntrack: table full, dropping packet.

You need to tune sysctl net.ipv4.ip_conntrack_max value, let’s say increase it twice or more times and see if you still get the error messages on the console or syslog.

Depending on your OS, the formula for calculating the… Read the rest of this entry »

Running a small blogs on your multiple domain name account should be no problem as long as it’s not very popular. You can set-up multiple wordpress blogs even if you have allocated one MySQL database – you will need to define the prefix for the tables. The prefix should be different for each of your wordpress blogs, if you are using one mysql database. You can configure this prefix in wp-config.php file

the default:

$table_prefix = ‘wp_’;

if you plan on having two different wordpress blogs in the same MySQL DB, then specify

$table_prefix = ‘wp_’;

for the first blog,… Read the rest of this entry »

We all know that a video basically is the process of electronically capturing and processing it digitally so that it can be viewed later as it is the direct recording of continuous and sequential processes. The logic is simple. It morphs the stills continually on a well-defined basis which gives the form of video telecast.

Streaming of video is nothing but another type of video recording and broadcasting especially found useful in internet and networks. In streaming, what exactly happens is the moving images in a sequential order are sent through the network in a very compressed mode so that… Read the rest of this entry »

It’s no secret that Cpanel servers are load-hungry when you move quite a large site on the server. There are quite a few things to do:

1. server optimization
2. daemon optimization
3. disabling built-in stats processing software
4. updating logfile processing

and much more. I suggest disabling built in automatic stats processing – awstats, analog and webalizer. You can quickly script to logrotate logs and do own stats processing. For folks who prefer awstats there is only ONE OPTION if you have a bandwidth and load hungry site – use -staticlinks option and generate static files with Awstats. This is the… Read the rest of this entry »

Nowadays there are many providers offering unmanaged dedicated servers with 1000′s GBs of data transfer, but not many say what bandwidth measurement system they have in place.

Over 80% providers use 95% industry burstable bandwidth method that usually not work for all web sites. 95% method is where top 5% burst rate bandwidth are cut off from your monthly bandwidth (usually MRTG) bill. This may sound fine at the beginning but if your web site bursts for more than 36 hours then you will pay for the bandwidth you actually didn’t use. However, 95% method is good when you have… Read the rest of this entry »

Lately, I have seen quite a few offers in shared hosting field named seo hosting. I was wondering what is all about and quickly learned the following:

Seo web hosting is a hosting service that is created for search engine optimization hosting (SEO). It is usually a standard shared account with ability to select different C address block IP addresses so that you can do some Grey-hat interlinking between your own sites, for example. It’s been known that if you are linking multiple sites on the same C address block (255 IPs, for example 10.10.10.*) there is not a big… Read the rest of this entry »

What is Streaming media?
A series of moving images that needs to be casted on a web page in the internet which is decompressed (file size is reduced) for accommodating it in the web page. This is known as Streaming media (video). When an internet user opens that particular page he gets to see that streaming video scene after scene.

Streaming flash video
When a streaming video is in form of a flash video it is called Streaming flash. A flash video has always an .flv extension just like the well known .mpeg extension of windows media. These videos are… Read the rest of this entry »