Linux Clustering Concept

Jephe Wu -

Objective: understanding basic Linux clustering concept and tools
Environment: CentOS 5, FreeBSD 8

1. What's the clustering
Connecting two or more computers together in such a way that they behave like a single computer.

2. 2 kinds of clustering 
parallel processing, and  load balancing

Parallel processing means the simultaneous use of more than one CPU to execute a program. Ideally, parallel processing makes a program run faster because there are more engines (CPUs) running it. In practice, it is often difficult to divide a program in such a way that separate CPUs can execute different portions without interfering with each other.

Load balancing means distributing processing and communications activity evenly across a computer network so that no single device is overwhelmed. Busy web sites typically employ two or more web servers in a load balancing scheme.

3. some example of web and application load balancing solutions
a. LVS - Linux Virtual Server at
b. Pound -
c. PF carp and pfsync -

d. tomcat connector -