Re: [dkim-milter-discuss] A timeout issue with a few possible solutions

[Murray S. K. <ms...@se...>]

SM wrote:
>> The issue: The asynchronous resolver's default timeout (set by the 
>> "-T" command line option) is ten seconds.  However, this is also the 
>> default amount of time the MTA will wait for a reply from the filter.  
>> This means if you actually hit the full ten seconds,
> 
> I have not hit that default timeout.

It's not common.  You'd have to have several unresponsive remote servers and no 
cached data, since retries are every five seconds and the timeout is ten.

In my case it became visible because a packet filter was intercepting DNS 
replies, not a normal use case.

>> (2) Document the problem and explain that the simplest thing to do is 
>> decrease the asynchronous resolver's timeout by running with a value 
>> of "-T" that's less than ten seconds.  Even better, lower the default 
>> value as well.
> 
> I suggest lowering the default value so that the MTA does not win the 
> battle if the default timeout for the resolver is reached.

10 seconds is already pretty short, since the retransmission timer default is 
five.  This allows for only one retransmission and no margin for latency.

> I gather that the above should also apply for dk-milter.

And sid-milter, yes.