Crontab failing, but nothing wrong in logs

I shall suggest you a different way for babysitting a failing service: psmon. It's a small daemon written in Perl, having an Apache stylish config file. It allows you to define all kind of conditions from just making sure a process is alive to restarting it if the process consumes too much RAM/CPU. Restart will happen way sooner than after a potential 10 minute delay you have with your current cron.

It can also send you e-mail/log the events it ran, so you can see how often the process gets restarted if you so want.

Ubuntu uses Upstart to control daemons. See man 5 init. Here is a community HowTo and a Wikipedia entry.

Look at some existing files in /etc/init.d as models for your own liveinstance.conf file. Pay particular attention to the required comment section at the beginning of the files.

As for why your script isn't working as a cron job, Khai is correct that it's usually a difference in environment. You have to make sure that you set $PATH to include any directories that you require that are not in the default $PATH or use fully specified directories to scripts and utilities that you use.

Change line in crontab to look like this (or whatever shell you wrote script in):

*/10 * * * * /bin/bash /var/foo/live/foo25/bin/liveinstance1 start >> /dev/null 2>&1

Also, you need to add your path to crontab, run this script:

#!/bin/bash
#
# Date: August 22, 2013
# Author: Steve Stonebraker
# File: add_current_shell_and_path_to_crontab.sh
# Description: Add current user's shell and path to crontab
# Source: http://brakertech.com/add-current-path-to-crontab
# Github: https://github.com/ssstonebraker/braker-scripts/blob/master/working-scripts/add_current_shell_and_path_to_crontab.sh

# function that is called when the script exits (cleans up our tmp.cron file)
function finish { [ -e "tmp.cron" ] && rm tmp.cron; }

#whenver the script exits call the function "finish"
trap finish EXIT

########################################
# pretty printing functions
function print_status { echo -e "\x1B[01;34m[*]\x1B[0m $1"; }
function print_good { echo -e "\x1B[01;32m[*]\x1B[0m $1"; }
function print_error { echo -e "\x1B[01;31m[*]\x1B[0m $1"; }
function print_notification { echo -e "\x1B[01;33m[*]\x1B[0m $1"; }
function printline { 
  hr=-------------------------------------------------------------------------------------------------------------------------------
  printf '%s\n' "${hr:0:${COLUMNS:-$(tput cols)}}"
}
####################################
# print message and exit program
function die { print_error "$1"; exit 1; }

####################################
# user must have at least one job in their crontab
function require_gt1_user_crontab_job {
        crontab -l &> /dev/null
        [ $? -ne 0 ] && die "Script requires you have at least one user crontab job!"
}


####################################
# Add current shell and path to user's crontab
function add_shell_path_to_crontab {
    #print info about what's being added
    print_notification "Current SHELL: ${SHELL}"
    print_notification "Current PATH: ${PATH}"

    #Add current shell and path to crontab
    print_status "Adding current SHELL and PATH to crontab \nold crontab:"

    printline; crontab -l; printline

    #keep old comments but start new crontab file
    crontab -l | grep "^#" > tmp.cron

    #Add our current shell and path to the new crontab file
    echo -e "SHELL=${SHELL}\nPATH=${PATH}\n" >> tmp.cron 

    #Add old crontab entries but ignore comments or any shell or path statements
    crontab -l | grep -v "^#" | grep -v "SHELL" | grep -v "PATH" >> tmp.cron

    #load up the new crontab we just created
    crontab tmp.cron

    #Display new crontab
    print_good "New crontab:"
    printline; crontab -l; printline
}

require_gt1_user_crontab_job
add_shell_path_to_crontab