Noel thank you very much,
This is reassuring.
You are right they are fundamentally not that different, except there is
some "scaffolding" and special handling.
Part of the first example is kind of outdated because postfix needs to
be explicitly told the mode to run, and where the configs are so you
can't just copy the folders and the init scripts and hope for the best.
I'm basically using the second/official tutorial now but the scaffolding
didn't create the structure I needed in the queue directory so I just
copied it over.
I guess the main difference in that example is there is a functional
relationship between some of the instances. Obviously in my example the
instances can't have a relationship, I'm careful to ensure that there is
no chained initiation of instances for example. But there is enough
flexibility there.
I will use virtualization for testing on different versions of postfix,
but for general testing I'd rather not.
So far so good. I guess I was unnecessarily hesitant, and didn't take it
all in first time.
Paul
On 27/08/14 15:24, Noel Jones wrote:
On 8/27/2014 3:35 AM, Paul Thomas wrote:
Hello folk, I'm wondering if you can help.
I saw two ways of implementing multiple instance of postfix.
1. http://edoceo.com/howto/postfix-multiple-instances
<http://edoceo.com/howto/postfix-multiple-instances>
This looks like a quick-dirty howto using the "old" hand-built
multi-instance support. It doesn't explain much about how it works.
I haven't looked carefully to see if these instructions are
correct, but the general idea is pretty close. This old method
still works with modern postfix versions, but it's harder to
administer than the new postmulti support.
2. http://www.postfix.org/MULTI_INSTANCE_README.html
<http://www.postfix.org/MULTI_INSTANCE_README.html>
This official document explains in detail the "new" built-in support
for multi-instance management. This is recommended method if your
postfix is version 2.6 or newer.
I tried the first one because it seemed more attractive to me at
first glance, but I think it out of date with how postfix works
these days.
I am running a relay service. The point is inbound emails are
processed than pushed to another protocol. It is not for sending
emails. It works fine. I just want to have other instance like a
test instance. basically identical but processing emails send to
emails using another domain. I want the instances to be completely
separate as to not to disrupt the production service at all.
I'm a little bit unsure of the second solution because I'm not sure
if is valid for my use case, or how independently these instances
are managed. I want them completely separate. I may have to modify
the init script an have two separate ones.
Use the official MULTI_INSTANCE_README as a guideline to set up what
you need. It explains in detail what each parameter does, so it is
a much longer document than most howtos.
The instances will be as separate as anything can be when running
the same binaries -- separate configuration, queues, and IP:port
settings. Messing up the configuration of one won't affect the other.
The postmulti command allows you to control each instance
independently, or all together.
I want to avoid virtualization if I can, just have two or more
instance running independently.
Visualization is recommended if you want to use different postfix
binaries, such as for testing a version upgrade.
I may also want another instance for occasional email sending or
other purpose.
Make as many instances as you need... the per-instance overhead is
fairly small.
-- Noel Jones
