I was looking at how to implement a load balancing/load sharing system for a data centre.  The data centre hosts websites and other servers on a domain name www.mydomain.com (for example). Servers within the data centre are load balanced by Cisco Content Switches. The company wants 3 data centres. The traffic coming to www.mydomain.com should be shared among the data centres providing redundancy and scalability. These 3 data centres are in different physical locations, and will be served by different ISPs (ideally).

 

The solution to this is to implement a DNS based load balancing system. In this solution the primary name server for www.mydomain.com will be replaced with an "intelligent" DNS server.

Instead of replying to DNS request with just one IP address, this smart DNS server will give out the IP addresses based on the load at each of the data centres. The client resolving an IP address for www.mydomain.com will get the IP address of the data centre with the least load.

The DNS server can also stop clients from going to a data centre that is not functioning.

This solution is explained in more detail at http://ntrg.cs.tcd.ie/undergrad/4ba2.01/group8/DNS.html

 

These are some of the solutions available in the market.

 

http://www.sysmaster.com/s_net_dns.htm

 

Cisco GSS Global Server Load-Balancing

 

Microsoft, AMD and Sun begin their partnership.

Will we see Sun servers using AMD processors running Windows 2003 ?

http://www.theregister.co.uk/2005/03/11/ms_gets_sunkit/

http://blogs.msdn.com/eec/archive/2005/03/03/384874.aspx

In my limited experience with presentations and from what I've learned here are some few pointers.

1. Keep each slide brief , but cover the main points. Do not cram a lot of text on the slide.
2. Keep the presentation notes simple. Do not have a huge pile of notes. Your notes should be brief and expand upon the text in the slide.
3. Keep eye contact with the audience. Look at everyone. This has two affects. First, is that you can see how the audience is responding and secondly, it builds the confidence levels since it feels like you are talking to someone and not just an empty room.
4. Know the power of pauses and silences. Pausing during a presentation gives the impression that you are confident. It also allows to recover from nervousness. Use frequents pauses to make the presentation enjoyable, and not seem like reading something
5. It is normal to be nervous. If someone says that they are not nervous during a presentation, then something is wrong with them. It is natural. You have to know that you are nervous and not let it overwhelm you.
6. Always look at the audience, and not at the screen or the computer.
7. Do not talk down to the audience. You are the expert in what you are presenting, but do not treat the audience like dummies.
8. You must be able to explain anything you put on the slide, no matter how insignificant it is. If you put something up there and someone asks you a question about it, it will look very very bad if you can't explain it. So if you don't know what it is, do not put it on the slide
9. Relax, and smile.
10. Practice, Practice and practice. No matter how many you have done, do this. It builds confidence
11. Never try to read from your notes. Remember, you are presenting not reading
12. Create your own presentation, and make your own notes. If you are using someone else's slides, atleast make your own notes

Credit goes out to my tutors who have hammered these points into me :)

This is now hosted at www.webfusion.co.uk.
dasBlog is the only engine I found so far, that is built using .Net and does not need a database.
However, I had to do some code changes so that it will work on my shared hosting account.

1. Use of XmlNamespaceUpgradeReader
I changed all occurances of

XmlSerializer ser = new XmlSerializer(typeof(DayExtra),Data.NamespaceURI);
using (StreamReader reader = new StreamReader(fileStream))
{
XmlNamespaceUpgradeReader upg = new XmlNamespaceUpgradeReader( reader, "", Data.NamespaceURI );
DayExtra e = (DayExtra)ser.Deserialize(upg);
}

to

XmlSerializer ser = new XmlSerializer(typeof(DayExtra),Data.NamespaceURI);
using (StreamReader reader = new StreamReader(fileStream))
{

DayExtra e = (DayExtra)ser.Deserialize(reader);
}

The XmlNamespaceUpgradeReader class causes a Security exception, due to a policy implemented by the host.

2. The startup code reads the registry. This is also not allowed. The code accessed the registry to read the time zones available on the server. This code too is disabled. It is now hard coded to the UTC time zone.

Good thing  I had the source code. More power to Open Source. :)

Finished debugging the code, had to do some changes to the dasBlog code so that it would work on a shared hosting account.

I will migrate all the old posts later ....

testing