As some of you might know, I recently finished my Bachelor of Science in Computer Science and Media. Since it was a very interesting topic, I choose to write a Bachelor thesis covering realtime web applications and the challenges of scaling them.

Abstract

If you're interested: Here is the abstract:

Over the last few years we watched a paradigm shift from static content provided by a few entities to dynamic, user generated content. This content is no longer generated by only a few chosen ones. It is now generated by virtually everybody. Users no longer look at websites every few hours but want to know instantly if there are any news. They also expect, that content they create is visible to their peers instantly.

To fulfill this need for instant updates, more and more websites added dynamic content loading. They changed from websites which provided content to web applications with desktop like features. The next logical step was the transition to “realtime web appli- cations” which allow much faster updates. This generation of web applications will not only enable developers to create realtime collaboration and communication applications but also provide a basis of fast browser based games.

This thesis will discuss the current state of realtime web applications, the need for high performance application servers and design patterns to handle a huge amount of clients with persistent connections to the server.

Long story short: Here is the document.

Es ist kalt, nass und gefroren aber ein tapferer Router in einer Plastikschuessel trotzt den wiedrigen Bedingungen:

Muss ich dazu noch irgendwas sagen?

Im Allgemeinen ist die Berechnung von Subnetzen zwar nicht schwer aber recht zeitaufwaendig. Aber zum Glueck gibt es dafuer ein sehr cooles Tool, dass einem die Arbeit abnimmt. Es nennt sich ipcalc und funtioniert recht schmerzlos:

ipcalc 192.168.13.23/26

Address:   192.168.13.23        11000000.10101000.00001101.00 010111
Netmask:   255.255.255.192 = 26 11111111.11111111.11111111.11 000000
Wildcard:  0.0.0.63             00000000.00000000.00000000.00 111111
=>
Network:   192.168.13.0/26      11000000.10101000.00001101.00 000000
HostMin:   192.168.13.1         11000000.10101000.00001101.00 000001
HostMax:   192.168.13.62        11000000.10101000.00001101.00 111110
Broadcast: 192.168.13.63        11000000.10101000.00001101.00 111111
Hosts/Net: 62                    Class C, Private Internet

[via]