On Tue, Apr 26, 2011 at 03:59:13PM -0400, John Baker wrote:
> On 04/25/2011 10:59 AM, Victor Duchovni wrote:
>> On Thu, Apr 21, 2011 at 02:59:27PM -0400, John Baker wrote:
>>
>>> There are several ways to make this work right including virtual aliases
>>> but the cleanest way seemed to me to be a per user transport map lookups
>>> for cloud users.
>> I think that per-user transport lookups are unwise.
>
> Hi,
>
> Thanks for the reply, could you tell me why per-user transports are unwise?
The trivial-rewrite service, which is responsible for transport mappings,
is used pervasively in Postfix, including in the queue manager. I prefer
to not add dependencies on potentially unreliable services (LDAP) in
this code path. The handling of temporary LDAP failures is much more
graceful in cleanup(8) (virtual alias rewriting), where lookups can
tempfail. In the queue manager transport lookups canno be set aside,
the lookups retry indefinitely on error... Performance can in some cases
be impacted, but this is less likely, and I think reliability comes first.
Yes, per-user transports are easier to implement, you choose your own
pain thresholds.
--
Viktor.
