Submitting Interactive Jobs

The submission of interactive jobs instead of batch jobs is useful in situations where a job requires your direct input to influence the job results. Such situations are typical for X Windows applications or for tasks in which your interpretation of immediate results is required to steer further processing.

You can create interactive jobs in three ways:

■ qlogin - An rlogin-like session that is started on a host selected by the Grid Engine software.

Note: Array tasks cannot have interdependencies with other jobs or with other array tasks.

Submitting Interactive Jobs

■ qrsh - The equivalent of the standard UNIX rsh facility. A command is run remotely on a host selected by the Grid Engine system. If no command is specified, a remote rlogin session is started on a remote host.

■ qsh - An xterm that is displayed from the machine that is running the job. The display is set corresponding to your specification or to the setting of the DISPLAY environment variable. If the DISPLAY variable is not set, and if no display

destination is defined, the Grid Engine system directs the xterm to the 0.0 screen of the X server on the host from which the job was submitted.

The default handling of interactive jobs differs from the handling of batch jobs.

Interactive jobs are not queued if the jobs cannot be executed when they are submitted. When a job is not queued immediately, the user is notified that the cluster is currently too busy.

You can change this default behavior with the -now no option to qsh, qlogin, and

qrsh. If you use this option, interactive jobs are queued like batch jobs. When you use the -now yes option, batch jobs that are submitted with qsub can also be handled like interactive jobs. Such batch jobs are either dispatched for running immediately, or they are rejected.

The following sections describe how to use the qlogin and qsh facilities. The qrsh

command is explained in a broader context in Transparent Remote Execution.

2.8.1 How to Submit Interactive Jobs From the Command Line

2.8.1.1 Using qrsh to Submit Interactive Jobs

qrsh supports most of the qsub options. If no options are given, qrsh will open an rlogin-like session.

To submit an interactive job with the qrsh command, type a command like the following:

qrsh -pty y vi

Note: Contact your system administrator to find out if your cluster is prepared for interactive job execution. To function correctly, all the facilities need proper configuration of cluster parameters of the Grid Engine system. The correct xterm execution paths must be defined for qsh. Interactive queues must be available for this type of job.

Note: Interactive jobs can be run only in queues of the type INTERACTIVE. See Oracle Grid Engine Administration Guide for configuring queues details.

Note: The output for an interactive job cannot be redirected with the

-j y|n, -o, and -e options. However, since the output for a prolog and epilog script is sent to the default stdout and stderr

files, you can use the -j y|n, -o, and -e options to redirect this output to different files.

Submitting Interactive Jobs

This command starts a vi editor on any available system in the Grid Engine cluster. The -pty y option starts a job in a pseudo-terminal session. The pseudo-terminal allows full cursor control from within the vi session.

The CTRL-Z behavior of qrsh <jobname> is since version 6.2u7 controllable with the parameter:

qrsh -suspend_remote y[es]| n[o] <your_program>

When your desired behavior is that you want to suspend qrsh and the submitted job, when you press CTRL-Z, then you have to submit the job like the following:

qrsh -suspend_remote yes <your_program>

If you just want to suspend qrsh and let the remote program in running state, then you have to use:

qrsh -suspend_remote no <your_program>

2.8.1.2 Using qsh to Submit Interactive Jobs

qsh is very similar to qsub. qsh supports several of the qsub options, as well as the additional option -display to direct the display of the xterm to be invoked. To submit an interactive job with the qsh command, type a command like the following:

% qsh -l arch=solaris64

This command starts an xterm on any available Sun Solaris 64-bit operating system host.

2.8.1.3 Using qlogin to Submit Interactive Jobs

Use the qlogin command from any terminal window to start an interactive session under the control of the Grid Engine system.

To submit an interactive job with the qlogin command, type a command like the following:

% qlogin -l star-cd=1,h_cpu=6:0:0

This command locates a low-loaded host. The host has a Star-CD license available. The host also has at least one queue that can provide a minimum of six hours hard CPU time limit.

Note: If you have submitted a job in one way but during run time you want to have the opposite behavior than specified, you can press the % key and afterwords the CTRL-Z key.

Note: Depending on the remote login facility that is configured to be used by the Grid Engine system, you might have to provide your user name, your password, or both, at a login prompt.

Submitting Interactive Jobs

2.8.2 How to Submit Interactive Jobs With QMON

1. Click the Job Control button in the QMON Main Control window. The Job Control dialog box appears.