Only one comes to mind: IMNSO, the only OSes I've seen that don't do better with weekly restarts are VMS and MVS (maybe OS/390, I haven't worked with it much.)
Holding a lock for a week at a time and doing a controlled restart should be entirely safe under Windows NT 4.0 or later, any modern Linux, SCO, etc.
Rather than re-inventing the wheel, are there parts of Big Brother or Nagios that could save you some coding time?
Abigail: Thanks for the good idea, I've got a problem similar to Nitrox's in my current project and I like your solution an awful lot better than what I'm doing now. ++.
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Spring: Forces, Coiled Again!
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Nitrox,
As I indicated in my first post. Using a lock file by itself, regardless of type, will not guarantee only a single copy of a script is running in Unix. This is because it is possible to delete a file that is locked. Using the /tmp directory most likely increases the odds of deletion by its nature. The subsequent instance of the script is able to create and lock the new file - and now you have two copies running. You really need to have multiple methods for validation and checking the process table is a good place to start.
Cheers - L~R | [reply] |
This bugs me, why does *nix allow deletion of an open and locked file? On Win32 a file can't be deleted until the ref count == 0, is there a way to explicitly set this in *nix?
-Nitrox
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