I get the error every once in a while then Cron completes successfully, then the error crops up again some hours later, and after about 3-4 tries the system completes cron again without a problem, all of this without my intervention. I don't understand it! I've googled and found several posts about how to fix the error once it happens but nothing that I could find tells me how to prevent this error from happening in the first place and why it happens so randomly. I'm running the latest D7 with cron set to run every hour. Any insight would be highly appreciated!
cron 09/17/2013 - 14:15 Cron run completed. Anonymous (not verified)
cron 09/17/2013 - 14:15 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 14:15 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 14:15 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 13:14 Cron run completed. Anonymous (not verified)
cron 09/17/2013 - 13:12 Cron run completed. Anonymous (not verified)
cron 09/17/2013 - 13:12 Cron run completed. Anonymous (not verified)
cron 09/17/2013 - 13:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 13:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 13:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 13:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 13:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 12:12 Cron run completed. Anonymous (not verified)
cron 09/17/2013 - 12:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 12:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 12:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 12:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 12:12 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 12:11 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 11:59 Attempting to re-run cron while it is already running. Anonymous (not verified)
cron 09/17/2013 - 10:49 Cron run completed. Anonymous (not verified)