Computer Cluster

1. What is a Computer Cluster?
• A computer cluster is a group of computers
working together as a single system. Each
node performs the same task, managed by
specialized software. Unlike grid computing,
all nodes in a cluster typically run the same
application.

2. Example: Sun Microsystems Solaris
Cluster
• Sun Microsystems developed clusters using its
Solaris operating system for enterprise-level
parallel processing.

3. Cluster Components and
Connections
• Nodes are connected via high-speed LANs and
run their own OS instances. Each computer
(node) acts as a server in the cluster.

4. Hardware and Software Uniformity
• Clusters typically use identical hardware and
OS. However, systems like OSCAR allow
heterogeneous setups. OSCAR is Linux-based
for managing high-performance clusters.

5. Benefits of Clusters
• • Improved performance
• • Increased availability
• • Cost-effective compared to supercomputers

6. Why Clusters Became Popular
• Driven by:
• • Cheap microprocessors
• • Fast networking
• • Readily available software for distributed
computing

7. Clusters vs. Mainframes
• Clusters are cheaper and easier to scale than
fault-tolerant mainframes, but managing
failures is more complex.

8. Challenges: Administration
• Managing N-node clusters can be as expensive
as managing N independent machines.

9. Challenges: Task Scheduling
• In heterogeneous environments, scheduling
tasks efficiently is difficult. Performance
depends on job and hardware characteristics.

10. Challenges: Task Mapping
• Mapping tasks to CPU cores and GPU devices
is complex and critical for performance.

11. Challenges: Node Failure
• Use fencing to isolate or restrict
malfunctioning nodes. Two types:
• 1. Disable node
• 2. Block access to shared resources.

12. Linux Cluster Software
• • distcc – distributes compilation
• • MPICH – for message passing
• • Linux Virtual Server, Linux-HA – manage
service distribution

13. Kernel-Level Clusters in Linux
• • MOSIX, Kerrighed, OpenSSI – full integration
• • Enable automatic process migration
• • Single-system image for users

14. Windows Cluster Server 2003
• Microsoft’s clustering includes:
• • Job Scheduler
• • MSMPI library
• • Management tools for high performance
computing