HPC Computing Components

Compute Nodes

Compute nodes are the foundation of a computer cluster and do the actual number-crunching. They are servers arranged in a rack, connected by a network, and configured to work together as one unit through cluster management software.

There are three main types of compute nodes:

1. Rack Servers – standard computers built for a wide variety of applications.
2. GPU Servers – rack servers with a GPU (Graphics Processing Unit) card that significantly accelerates the performance of the CPU.
3. High-Density Servers – servers modified to fit more nodes in the same amount of rack space (these can be either Twin or Blade servers).

InfiniBand is currently the best networking technology for HPC clusters, but it is more expensive than Ethernet. Applications which require maximum possible performance – such as oil and gas exploration modeling and financial computation, for example – should build their clusters with InfiniBand networking technology.

Head Node

The head node is the server that manages the cluster. There is nothing exceptionally different about the hardware of the head node compared to the compute nodes. But, the head node does store the operating system (OS) for the entire cluster as well as the cluster middleware, and it also takes care of network and job management for the whole system.

Storage

Storage systems do not have as powerful computational resources (e.g. processors and RAM memory) as compute nodes because they are designed for a different function. Storage servers store the masses of files that compute nodes need to access only on an occasional basis (e.g. a database).

Because of its role in the cluster, storage servers must have high I/O rates so that the compute nodes can quickly read and write data from the hard drives. No matter how fast one's compute nodes are, if there is an I/O bottleneck in the storage servers, the entire cluster may perform poorly.

One of our specialties is finding and offering the best storage configurations on the market that help overcome I/O bottlenecks. There are several technologies that make our cluster storage solutions optimal:

1. 6Gb/s RAID controllers read and write to the drives twice as fast as the older 3Gb/s models that many clusters are still running.
2. CacheCade technology by LSI expands the cache of RAID controllers with solid-state drives (SSDs) by up to 500GB, drastically increasing I/O rates especially for databases.
3. Active-active controllers are available for special storage systems and offer shared storage redundancy between two RAID controllers, maximizing data protection.
4. Lustre File System, developed by Oracle, is the leading storage software for HPC and can be found in both small workgroup clusters as well as in some of the largest supercomputers to date.

To find out more, browse the storage configurations in the sample ICC clusters.