Anonymous Monk,
Certain types of signals can be trapped and hence ignored. On a *nix platform, signal 9 can not. Depending on how and why your script was killed, there are a handful of options.
Perhaps you could post your code and we could help make it more run-time efficient
Perhaps you could ask the administrator to exempt this particular script if it is an automated cleanup process
Perhaps you could ask the administrator under what circumstances a kill happens and ask for help playing by the rules. Possibly you only run 20 minutes at a time and save your intermittent results to file for persistency.
Cheers - L~R