Why use a Cluster?

Overview

Teaching: 15 min
Exercises: 5 min

Questions

• Why would I be interested in High Performance Computing (HPC)?

• What can I expect to learn from this course?

Objectives

• Describe what an HPC system is

• Identify how an HPC system could benefit you.

I’ve Never Used a Server, Have I?

Take a minute and think about which of your daily interactions with a computer may require a remote server or even cluster to provide you with results.

Some Ideas

• Checking email: your computer (possibly in your pocket) contacts a remote machine, authenticates, and downloads a list of new messages; it also uploads changes to message status, such as whether you read, marked as junk, or deleted the message. Since yours is not the only account, the mail server is probably one of many in a data center.
• Searching for a phrase online involves comparing your search term against a massive database of all known sites, looking for matches. This “query” operation can be straightforward, but building that database is a monumental task! Servers are involved at every step.
• Searching for directions on a mapping website involves connecting your (A) starting and (B) end points by traversing a graph in search of the “shortest” path by distance, time, expense, or another metric. Converting a map into the right form is relatively simple, but calculating all the possible routes between A and B is expensive.

Checking email could be serial: your machine connects to one server and exchanges data. Searching by querying the database for your search term (or endpoints) could also be serial, in that one machine receives your query and returns the result. However, assembling and storing the full database is far beyond the capability of any one machine. Therefore, these functions are served in parallel by a large, “hyperscale” collection of servers working together.

Key Points

• High Performance Computing (HPC) typically involves connecting to very large computing systems elsewhere in the world.

• These other systems can be used to do work that would either be impossible or much slower on smaller systems.

• HPC resources are shared by multiple users.

• The standard method of interacting with such systems is via a command line interface.