Changes between Version 19 and Version 20 of cypress/using


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Timestamp:
Apr 27, 2015 3:41:17 PM (7 years ago)
Author:
fuji
Comment:

Add Idev

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  • cypress/using

    v19 v20  
    149149In the script above we request 20 cores on one node of Cypress (which is all the cores available on any node). As SLURM regards tasks as being analogous to MPI processes, it’s better to use the cpus-per-task directive when employing OpenMP parallelism. Additionally, the SLURM export variable $SLURM_JOB_CPUS_PER_NODE stores whatever value we assign to cpus-per-task, and is therefore our candidate for passing to OMP_NUM_THREADS.
    150150
    151 
     151== Submitting an interactive job ==
     152
     153For those who develop their own codes, we provide the app, `idev` to make interactive access to a set of compute nodes, in order to quickly compile, run and validate MPI or other applications multiple times in rapid succession.
     154
     155==== The app `idev`, (Interactive DEVelopment) ====
     156
     157The `idev` application creates an interactive development environment from the user's login window. In the `idev` window the user is connected directly to a compute node from which the user can launch executables directly.
     158The `idev` command submits a batch job that creates a copy of the batch environment and then goes to sleep. After the job begins, `idev` acquires a copy of the batch environment, SSH's to the master node, and then re-creates the batch environment.
     159
     160==== How to use `idev` ====
     161
     162On Cypress login nodes (cypress1 or cypress2),
     163{{{#!bash
     164[user@cypress1 ~]$ idev
     165}}}
     166
     167In default, `idev` submit a job requesting '''one node for one hour'''. It also requests two ''Intel Phi'' (MIC) co-processors.
     168If there is an available node,  your job will become active immediately and `idev` app initiates a ssh session to the computing node. For example:
     169
     170{{{#!bash
     171[fuji@cypress1 ~]$ idev
     172Requesting 1 node(s)  task(s) to normal queue of defq partition
     1731 task(s)/node, 20 cpu(s)/task, 2 MIC device(s)/node
     174Time: 0 (hr) 60 (min).
     175Submitted batch job 8981
     176JOBID=8981 begin on cypress01-100
     177--> Creating interactive terminal session (login) on node cypress01-100.
     178--> You have 0 (hr) 60 (min).
     179Last login: Mon Apr 27 14:45:38 2015 from cypress1.cm.cluster
     180[fuji@cypress01-100 ~]$
     181}}}
     182
     183Note the prompt, "cypress01-100", in the above session. It is your interactive compute-node prompt. You can load modules, compile codes and test codes.
     184`idev` transfers the environmental variables to computing node. Therefore, if you have loaded some module on the login node, you don't have to load the same module again.
     185
     186==== Options ====
     187
     188By default only a single node is requested for 60 minutes. However, you can change the limits with command line options, using syntax similar to the request specifications used in a job script.
     189The syntax is conveniently described in the `idev` help display:
     190
     191{{{#!bash
     192[fuji@cypress1 ~]$ idev --help
     193-c|--cpus-per-task=     : Cpus per Task
     194-N|--nodes=             : Number of Nodes
     195-n|--ntasks-per-node=   : Number of Tasks per Node
     196--gres=                 : Number of MIC per Node
     197-t|--time=              : Wall Time
     198}}}
     199
     200For example, if you want to use 4 nodes for 4 hours,
     201
     202{{{#!bash
     203[fuji@cypress1 ~]$ idev -N 4 -t 4:00:00
     204Requesting 4 node(s)  task(s) to normal queue of defq partition
     2051 task(s)/node, 20 cpu(s)/task, 2 MIC device(s)/node
     206Time: 04 (hr) 00 (min).
     207Submitted batch job 8983
     208JOBID=8983 begin on cypress01-100
     209--> Creating interactive terminal session (login) on node cypress01-100.
     210--> You have 04 (hr) 00 (min).
     211Last login: Mon Apr 27 14:48:45 2015 from cypress1.cm.cluster
     212[fuji@cypress01-100 ~]$
     213}}}
     214
     215==== Questions or Suggestions ====
     216
     217If you have ideas for enhancing `idev` with new features or any questions, please send email to hpcadmin@tulane.edu.