Red Hat Bugzilla – Bug 107863
Add a command line switch to disable the crond daemon from forking.
Last modified: 2007-04-18 12:58:44 EDT
From Bugzilla Helper: User-Agent: Mozilla/5.0 (compatible; Konqueror/3.1; Linux) Description of problem: This is a request for a command line switch to disable the crond daemon from forking into the background on startup. This feature would be very useful when running crond from init or from DJB's daemontools. I have patched the current version of vixie-cron that is shipped with Redhat 9.0 and added a -n (no fork) option. It is a very simple (9 line) patch. That patch is available here: http://caspian.dotconf.net/menu/Software/Misc/vixie-cron-3.0.1-nofork.patch and I have a modified version of the RH9 vixie-cron source rpm with that patch included here: http://caspian.dotconf.net/menu/Software/Misc/vixie-cron-3.0.1-75.src.rpm Version-Release number of selected component (if applicable): vixie-cron-3.0.1-74 How reproducible: Always Steps to Reproduce: 1. N/A 2. 3. Actual Results: NA Expected Results: NA Additional info: NA
Probably I'm missing something, but what is this patch trying to achieve? Why is forking at startup so bad?
No problem, let me try to explain where I'm coming from. Forking at startup isn't really that bad. In fact most all daemons should and do. However, many daemons also have a command line option to disable forking at startup. Good examples of this are sysklogd, sshd, and ntpd (and many others). This functionality is useful for running the daemon from inittab, or from DJB's daemon tools, or from a bash "while true" loop. Running daemons from any of these sort of "failsafe" configurations usually requires that the daemon not fork at startup, so that if it does die for some reason the loop can immediatly restart the daemon. I manage an enterprise Linux environment for a fortune 50 company, and have decided to deploy DJB's daemon-tools to keep mission critical services running. Every daemon that we needed to run via daemon-tools has a command line switch (or configuration file option) to disable forking at startup, except vixie-cron. In order to keep all our daemons running from daemon-tools I added the -n command line option to it to disable forking. It would be nice if Redhat would incorporate this non-intrusive patch so that I don't have to patch and recompile vixie-cron every time I upgrade our servers :) Brandon Zehm
Ok, cron 4.1 has a -n option to run in the foreground. It may be a little while though before we're ready to upgrade to 4.1.
Now fixed in vixie-cron-4.1-+ (latest version vixie-cron-4.1-7).