Grid Engine Job Submission Verifier (JSV) using Go

Posted by David Chin

Dan Gruber at Univa wrote a Go API for Univa Grid Engine job submission verifiers (JSV). His testing indicated that it was a fair bit faster than TCL or Perl, the recommended JSV languages for a production environment.

I decided it was a good enough time as any to dabble a little in Go, seeing as I had a simple problem to solve. Users occasionally make mistakes, and submit parallel jobs without requesting a parallel environment with the appropriate number of slots. It could be that they missed the PE line, and a job is assigned only one slot, but ends up actually using 8 (or 16, or whatever). This means the execute host(s) are over-subscribed when other jobs are also scheduled on those same hosts.

I also wanted to take advantage of Univa's new support for cgroups in order to make sure jobs are restricted in terms of their CPU and memory usage. It also helps with process cleanup when the jobs complete (cleanly or not).

This is pretty straightforward to do. Check the job qsub parameters/options, and set binding appropriately. The source is at my github.
 

/*
 * Requires https://github.com/dgruber/jsv
 */

package main

import (
    "github.com/dgruber/jsv"
)

func jsv_on_start_function() {
    //jsv_send_env()
}

func job_verification_function() {

    //
    // Prevent jobs from accidental oversubscription
    //

    var modified_p bool = false
    if !jsv.JSV_is_param("pe_name") {
        jsv.JSV_set_param("binding_strategy", "linear_automatic")
        jsv.JSV_set_param("binding_type", "set")
        jsv.JSV_set_param("binding_amount", "1")
        jsv.JSV_set_param("binding_exp_n", "0")
        modified_p = true
    } else {
        if !jsv.JSV_is_param("binding_strategy") {
            var v string
            v, _ = jsv.JSV_get_param("pe_max")
            jsv.JSV_set_param("binding_strategy", "striding_automatic")
            jsv.JSV_set_param("binding_type", "set")
            jsv.JSV_set_param("binding_amount", v)
            jsv.JSV_set_param("binding_step", "1")
            modified_p = true
        }
    }

    if modified_p {
        jsv.JSV_correct("Job was modified")
    }

    return
}

/* example JSV 'script' */
func main() {
    jsv.Run(true, job_verification_function, jsv_on_start_function)
}