postfix-users October 2010 archive
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postfix-users: Re: Queue full of double-bounce

Re: Queue full of double-bounce

From: Patric Falinder <patric.falinder_at_nospam>
Date: Mon Oct 11 2010 - 20:42:05 GMT
To: Postfix users <>

  On 10/11/10 8:40 PM, Wietse Venema wrote:
> Small correction in-line.
> Wietse
> Wietse Venema:
>> Wietse Venema:
>>>> How do I fix the system's ZERO-DELAY timer?
>>> I can write a small test program. If it reproduces the problem,
>>> then there are two things that need to be done.
>>> 1) The program needs to be sent to VMware as part of a bug report.
>>> 2) We can try to program around this bug until the vendor fixes
>>> it. Perhaps some system configuration will suffice. For example,
>>> many virtualization systems emulate a number of "hardware" timers
>>> such as ACPI, TSC etc. and some emulations may be less buggy.
>>> But first, you need to get some recent Postfix source code on the
>>> machine so that we can do some quick tests. There is no need to
>>> overwrite the installed Postfix.
>> Attached is a small test program, to be run in the virtual machine.
>> Please save as postfix-x.x-yyyymmdd/src/util/zero_delay.c where
>> postfix-x.x-yyyymmdd is the top-level directory from a recent
>> Postfix release (2.4 or later).
>> Then,
>> cd postfix-x.x-yyyymmdd
>> make
>> (get some coffee)
>> cd src/util
>> make zero_delay | sed 's/$/ libutil/a' | sh
> Grr. That should be:
> make -n zero_delay | sed 's/$/ libutil.a/' | sh
> I pasted the wrong command line.
>> The result is a test program zero_delay, to be run as:
>> ./zero_delay
>> It should run for 10-20 seconds or so then terminate with
>> normal completion after 1000000 iterations
>> If instead it terminates with
>> timer event lost after N iterations
>> then you have found the timer bug that causes Postfix to deliver
>> only one message probe per 300 seconds, and we can start looking
>> for workarounds (such as changing the src/util/events.c module and
>> replacing zero delay requests by 1 millisecond delay requests).
>> Wietse
> [ Attachment, skipping... ]
Cool, I will try that tomorrow when I get to work and feedback the results.
I've been meaning to upgrade to Postfix 2.7 too so might as well do that
when I'm at it.

I should only compile this testprogram and not install it right?