child process restarts frequently

[Håvard Futsæter]

Dag-Erling Smørgrav wrote:
> Håvard Futsæter <havard.futseter at met.no> writes:
>> Might this perhaps be an indication that Varnish gets into trouble
>> when it receives a request for a resource while the cached object for
>> this resource is beeing recycled?
> 
> Sounds like it.  Poul-Henning, could you take a closer look at the
> locking in the expiry code?
> 
> DES

Hi. I have some more information regarding the above mentioned problem:

We now think the restart is caused by a conflict between the purging 
routine and the timeout routine.

We have the following scenario:

1. url.purge <regexp>.
2. An object that will be affected by the purge times out and is discarded.
3. AFTER ExpPick, but BEFORE ExpKill, there is a request for the same 
object. The object is consequently banned.
4. Immediately after this ban the child process restarts.

Perhaps the expire-system tries to move the object to deathrow twice? 
Speculation only...

For testing purposes we have temporarily removed the url.purge command, 
and have seen no restart after this was done.


-- 
Mvh,
Håvard Futsæter
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