Re: SMP: process-specific options

2010/2/23 Tsantilas Christos <chtsanti_at_users.sourceforge.net>:
>>
>> Log rotation will probably need special care to avoid rotating the same
>> log many times. It is relatively easy to designate one process to do the
>> rotation (e.g., squid1), but that alone is not enough to synchronize
>> everything. Ideally, I would prefer to avoid locking. Any clever tricks
>> applicable here?
>
> Maybe something like the following:
> - there is a master process
> - master process communicates with one direction pipes with kids, sending
> various commands
>
> For logs rotation:
>  - master process closes the old file and rename it
>  - master process opens a new log file
>  - kids still writing to the old file (because they did not close the
> file descriptor yet)
>  - master process send a command to all kids saying that the log file
> rotated
>  - The kids close the log file and reopen it.
>
> The above will work at least for unix systems (I do not know about
> MS-Windows)
> Master/kids communication using pipes is used by the apache worker server.
> I am also using it in my icap server. I am not seeing any problem.

Why not just having a log writing helper to whom clients write log
lines via some kind of sockets?
That would make the log rotation problem just go away - especially the
part where there may be race conditions among workers writing together
to the same file.

-- 
    /kinkie