Analyze and optimize crontabs [closed]

Question

Is there a tool to graph, analyze and help optimize crontab execution?

To clarify, I'm thinking of a tool which would generate a graph of when cron jobs are executed, and help the sysadmin reorganize them smartly.

Answer 1

The only thing I've done is move cron jobs into a structured job scheduler in order to graph dependencies and gain visibility into the effects downtime windows.

Answer 2

Some sort of framework to assign a unique ID to each cron job and correlate that in the log file(s), and/or logging to a specific location to record runtime information (as opposed to the normal output log). It's not going to be trivial however you design it, but for small systems it is easy to eyeball this from looking at your crontabs and log files.

I assume you're not talking about small systems, though.

Answer 3

Sounds like this is the functionality you'd like http://www.phpclasses.org/package/6673-PHP-Parse-crontab-schedule-and-generate-Gantt-charts.html

I can't vouch for the above, it is just the results of some web searching.

Answer 4

A script for print all system tasks sorted by time

#!/bin/bash

CRONTAB='/etc/crontab'
CRONDIR='/etc/cron.d'

tab=$(echo -en "\t")

function clean_cron_lines() {
    while read line ; do
        echo "${line}" |
            egrep --invert-match '^($|\s*#|\s*[[:alnum:]_]+=)' |
            sed --regexp-extended "s/\s+/ /g" |
            sed --regexp-extended "s/^ //"
    done;
}

function lookup_run_parts() {
    while read line ; do
        match=$(echo "${line}" | egrep -o 'run-parts (-{1,2}\S+ )*\S+')

        if [[ -z "${match}" ]] ; then
            echo "${line}"
        else
            cron_fields=$(echo "${line}" | cut -f1-6 -d' ')
            cron_job_dir=$(echo  "${match}" | awk '{print $NF}')

            if [[ -d "${cron_job_dir}" ]] ; then
                for cron_job_file in "${cron_job_dir}"/* ; do  # */ <not a comment>
                    [[ -f "${cron_job_file}" ]] && echo "${cron_fields} ${cron_job_file}"
                done
            fi
        fi
    done;
}


temp=$(mktemp) || exit 1


cat "${CRONTAB}" | clean_cron_lines | lookup_run_parts >"${temp}" 


cat "${CRONDIR}"/* | clean_cron_lines >>"${temp}"  # */ <not a comment>

while read user ; do
    crontab -l -u "${user}" 2>/dev/null |
        clean_cron_lines |
        sed --regexp-extended "s/^((\S+ +){5})(.+)$/\1${user} \3/" >>"${temp}"
done < <(cut --fields=1 --delimiter=: /etc/passwd)

cat "${temp}" |
    sed --regexp-extended "s/^(\S+) +(\S+) +(\S+) +(\S+) +(\S+) +(\S+) +(.*)$/\1\t\2\t\3\t\4\t\5\t\6\t\7/" |
    sort --numeric-sort --field-separator="${tab}" --key=2 --key=1 |
    sed "1i\mi\th\td\tm\tw\tuser\tcommand" |
    column -s"${tab}" -t

rm --force "${temp}"