Linux Makes PalTalk Possible In A Windows World - page 3
Reaching Out and Touching Everyone
As mentioned earlier, the PalTalk system consists of a number of machines clustered together and hosted by AT&T. The audio and video servers are all Java coded, as is the clustering software.
There are about 75 to 80 servers total, including two IBM M80's, a p630, and one p650 maninframe. These are multiprocessor machines that handle the tasks of organizing buddy lists and overall coordination of the instant messaging and audio/video streams.
The balance of the servers are Intel-based 1 and 2U dual processor servers, running Red Hat 7.0, which are used to power the audio and video streams. The machines range from 600-MHz Pentium IIIs to 1.26 GHz Pentium 4s with a standard memory size of 1 GB and SCSI disk of 36 GB capacity. The current ratio is about 60 Dell to 10 IBM machines. The IBMs have a special hardware KVM feature that allow remote management without an external KVM switch being connected between the machines.
To keep an eye on all the PalTalk Linux video and audio machines, the staff uses Ganglia. Ganglia runs on one of the Linux boxes and is a scalable distributed monitoring system for high-performance computing systems such as clusters and grids. It leverages widely used technologies such as XML for data representation, XDR for compact, portable data transport, and RRDtool for data storage and visualization.
Software revisions consist of bug fixes and the addition of new features. The software usually spends a short time in beta, where it is tested out by users and is then moved over to production. Katz doesn't have a very formal process for going from requirements to implementation. The service features are driven by the demand of the users. He also thinks that its a real advantage to be small and quick in business these days. Generally, Katz and his team will decide on a new feature and then they "just go do it." He said that one of his biggest challenges is to avoid losing that small company feeling.
When adding new servers Katz goes through his hardware reseller, Saturn Business Systems. They originally recommended the Dell hardware, but recently moved over to IBM machines. Katz said he was very happy with IBM. "They are clearly the winners at the top of the industry," he said. IBM has also supplied some of the standard system management software for backups and other tasks.