Interactive tasks

LSF supports transparent execution of tasks on all server hosts in the cluster. You can run your program on the best available host and interact with it just as if it were running directly on your workstation. Keyboard signals such as CTRL-Z and CTRL-C work as expected.

Interactive tasks communicate with the user in real time. Programs like vi use a text-based terminal interface. Computer Aided Design and desktop publishing applications usually use a graphic user interface (GUI).

This section outlines issues for running interactive tasks with the non-batch utilities lsrun, lsgrun, etc. To run interactive tasks with these utilities, use the -i option.

For more details, see the lsrun(1) and lsgrun(1) man pages.

Interactive tasks on remote hosts

Job controls

When you run an interactive task on a remote host, you can perform most of the job controls as if it were running locally. If your shell supports job control, you can suspend and resume the task and bring the task to background or foreground as if it were a local task.

For a complete description, see the lsrun(1) man page.

Hide remote execution

You can also write one-line shell scripts or csh aliases to hide remote execution. For example:
#Script to remotely execute mytask exec
lsrun -m hostD mytask
alias mytask "lsrun -m hostD mytask"

Interactive processing and scheduling policies

LSF lets you run interactive tasks on any computer on the network, using your own terminal or workstation. Interactive tasks run immediately and normally require some input through a text-based or graphical user interface. All the input and output is transparently sent between the local host and the job execution host.

Shared files and user IDs

When LSF runs a task on a remote host, the task uses standard UNIX system calls to access files and devices. The user must have an account on the remote host. All operations on the remote host are done with the user’s access permissions.

Tasks that read and write files access the files on the remote host. For load sharing to be transparent, your files should be available on all hosts in the cluster using a file sharing mechanism such as NFS or AFS. When your files are available on all hosts in the cluster, you can run your tasks on any host without worrying about how your task will access files.

LSF can operate correctly in cases where these conditions are not met, but the results may not be what you expect. For example, the /tmp directory is usually private on each host. If you copy a file into /tmp on a remote host, you can only read that file on the same remote host.

LSF can also be used when files are not available on all hosts. LSF provides the lsrcp command to copy files across LSF hosts. You can use pipes to redirect the standard input and output of remote commands, or write scripts to copy the data files to the execution host.

Shell mode for remote execution

On UNIX, shell mode support is provided for running interactive applications through RES.

Not supported for Windows.

Shell mode support is required for running interactive shells or applications that redefine the CTRL-C and CTRL-Z keys (for example, jove).

The -S option of lsrun, ch or lsgrun creates the remote task with shell mode support. The default is not to enable shell mode support.

Run windows

Some run windows are only applicable to batch jobs. Interactive jobs scheduled by LIM are controlled by another set of run windows.