flock experience

holger krekel pyth at devel.trillke.net
Tue Jan 14 05:50:47 EST 2003

Robin Becker wrote:
> In message <20030114092127.C349 at prim.han.de>, holger krekel
> <pyth at devel.trillke.net> writes
> >Robin Becker wrote:
> .......
> >8 machines?  are you using nfs? then i don't think you should try
> >to do locking.  It's been a problem with smtp+mailprogramms forever
> >and in the end the mailbox format (each message a file) appears to be
> >the simplest working solution.  
> >
> unfortunately I don't know the architecture very well, it's some solaris
> webserver front end, the web people hate putting our (non-java) stuff
> there so they're giving us a standalone document production system.
> >Anyway, couldn't you create a file for each message/process?  another 
> >process could gather it so you wouldn't have to care for locking at all. 
> >you may need an end marker so that the gathering process doesn't
> >assume a message is complete too early. 
> >
> The processes are all cgi-scripts. Currently we have a log file for each
> machine/script. The scripts take about two seconds to complete and the
> (short I hope) log entry is written at termination using
>         f = open(logfile, "a")
>         f.write(text)
>         f.close()

If you have the freedom to choose the logfilename then why
not use a new filename for *each* message?  (that was my
suggestion).  You might want to prepend a timestamp
if you can't reliably access 'mtime' on that machine. 
Reading all the messages in and sorting them is easy.

This is way simpler than any locking scheme. 


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