Jeff Lasman wrote:
> It's taken about a week to figure out a weird problem with apache2.
> 
> The server is a webhosting server run by a control panel, and apache 
> gets restarted from time to time as users make changes to domain setups 
> (beyond our control).
> 
> Whitebox 3.0
> Kernel 2.4.21-15
> 
> But apache is installed from source, not from RPMs.
> 
> Almost once daily it refuses to restart.
> 
> When I try to restart it from the command prompt the restart goes into a 
> loop; I finally found this (from another shell) will stop it:
> 
> # service httpd restart
> 
> The above stops both services so they stop calling each other, and the 
> loop stops.  Then I looked through the output of the looping commands 
> and found that http couldn't listen on port 443 because the kernel 
> process pdflush was holding port 443.
> 
> The process appeared in the output of ps waux as [pdflush].  I thought 
> that meant it was defunct.  True?
> 
> Anyway, I did a kill -9 on the pid, and it disappeared from my ps waux 
> output.  Then apache2 restarted normally.
> 
> Any idea as to how I might stop this from occurring again?
> 
> I've never had this on any of our many servers running apache1, and this 
> is the only apache2 server we run.
> 

Processes surrounded by []'s are kernel threads.

Have you tried doing an apachectl graceful rather than a restart? That 
should be sufficient for most configuration changes and isn't as 
disruptive to the other threads doing work.

What version of apache is this?

-James