FAQ: Getting Started on Boulder's HPCS
- What is the architecture of iJet?
- How does Jet perform?
- How do I request an account?
- How do I connect to Jet?
- Can I access Jet without having to type my password?
Q: What is the architecture of iJet?
A: HPCS computing capabilities at the NOAA Boulder Labs currently consists of 3 systems collectively known as “Jet”. The individual machines are ["iJet"], ["eJet"], and ["wJet"]; where the first letter denotes the underlying processor architecture. The Jet systems use a distributed memory high performance computing environment, also known as a cluster. For more information on the general architecture, see the following:
http://en.wikipedia.org/wiki/Computer_cluster
http://en.wikipedia.org/wiki/Beowulf_%28computing%29
http://www.beowulf.org/overview/index.html
The basic building blocks of the clusters are individual computers, known as "nodes". The nodes in each cluster are connected using a high speed, low latency, network that allows distributed memory applications to communicate efficiently. Nodes on the NOAA Boulder HPCS systems generally contain multiple processing units, known as "cores". There are several node types which are specialized for various tasks:
- "Compute" nodes comprise the majority of individual machines, and are used for running both serial and parallel (multi-processor) applications.
- "Serial" nodes are used for running applications that require only a single process thread or multiple process threads which communicate through shared memory.
- "Front End" nodes are used for login, editing, compiling, and submitting jobs to the batch queuing system.
- "Cron" nodes are dedicated for managing periodic tasks through the linux crond process and crontab tool.
- "Visualization" nodes can be used for graphical manipulation and display of scientific data. They generally contain a higher performing external network to facilitate exporting displays back to local workstations
- "Big Mem" nodes each contain more memory than normal compute nodes in order to support applications which have larger memory-resident data sets.
Multiple [filesystems] support the HPCS data requirements. These include a globally visible NFS filesystem for user home directories, multiple NFS file servers for project data, the Rapidscale clustered filesystem for supporting multiple projects, and a Hierarchical Storage Management System ([HSMS]), also known as Mass Storage System (MSS), for backups and archival of data.
TopA: iJet has a theoretical maximum performance of 6.7 Tflops. Its measured speed in Nov. 2002 was 3.337 Tflops made it the 8th fastest computer in the world at the time. Optimizations since then have made the system faster. This performance may or may not relate to your own codes.
HOWEVER, the only good measure of performance is YOUR code, so give it a try.
Q: How do I request an account?
A: All users need to be part of an approved project. Please use the Application Forms.
A: Connecting to wJet requires an approved user account, project, and SafeWord token. We currently only accept remote logins using ssh version 2.
ssh -l {username} ijet.rdhpcs.noaa.gov or ejet.rdhpcs.noaa.gov or wjet.rdhpcs.noaa.gov
Enter your SafeWord token number and pin when prompted.
If you would like to connect directly to a specific wJet Front End, Visualization, or Cron resource, type CTRL-C within 5 seconds after entering a valid password, then follow the instructions and the menu provided
Be sure to read the note about "port tunnels" as you may find it useful in the future for using 'scp' to transfer files between wJet and your workstation.
Messages like the following are normal when creating multiple ssh connections, and simply indicate that a previous connection already initiated ssh port forwarding:
- bind: Address already in use
- channel_setup_fwd_listener: cannot listen to port: 19999
- Could not request local forwarding.
Q: Can I access Jet without having to type my password?
A: No. Remote Access ‘SafeWord’ tokens are a mandatory requirement.
Last Updated 02May08