Round robin relayhost

Round robin relayhost

[Jesper Lund]

Hello,

With the tunable, "relayhost", I can set a relayhost. I would like to
be able to specify multiple relayhosts, and round robin between them.
Just put 2 or more adresses in the "relayhost" file.

Is this possible ? Otherwise, this is a feature request :-)

Kind regards,
Jesper Lund

Re: Round robin relayhost

[Charlie Brady]

On Wed, 10 Jan 2007, Jesper Lund wrote:

> With the tunable, "relayhost", I can set a relayhost. I would like to
> be able to specify multiple relayhosts, and round robin between them.
> Just put 2 or more adresses in the "relayhost" file.
>
> Is this possible ? Otherwise, this is a feature request :-)

Is it not possible for you to set up relayhost.your.domain with multiple 
A records in DNS?

Re: Round robin relayhost

[Jesper Lund]

> > With the tunable, "relayhost", I can set a relayhost. I would
> > like to be able to specify multiple relayhosts, and round robin
> > between them. Just put 2 or more adresses in the "relayhost" file.
> >
> > Is this possible ? Otherwise, this is a feature request :-)
> 
> Is it not possible for you to set up relayhost.your.domain with
> multiple A records in DNS?

Been there, done that. But when I do that, it seems that mlmmj uses
the same relayhost to deliver all messages pr. posting, via the same
relayhost. I believe that from posting to posting, it will use
different relayhosts. 

My goal is to share the load between relayhosts, as I might have
about 25k subscribers. With a single relayhost it will take a long
time to deliver mail to all subscribers.

Regards, Jesper

Re: Round robin relayhost

[Charlie Brady]

On Wed, 10 Jan 2007, Jesper Lund wrote:

>>> With the tunable, "relayhost", I can set a relayhost. I would
>>> like to be able to specify multiple relayhosts, and round robin
>>> between them. Just put 2 or more adresses in the "relayhost" file.
>>>
>>> Is this possible ? Otherwise, this is a feature request :-)
>>
>> Is it not possible for you to set up relayhost.your.domain with
>> multiple A records in DNS?
>
> Been there, done that. But when I do that, it seems that mlmmj uses
> the same relayhost to deliver all messages pr. posting, via the same
> relayhost.

Perhaps mlmmj should use a list of addresses if gethostbyname returns more 
than one.

But are you sure that using multiple relayhosts will actually get your 
messages out any quicker?

Re: Round robin relayhost

[Sven 'Darkman' Michels]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Jesper Lund wrote:
 > Been there, done that. But when I do that, it seems that mlmmj uses
> the same relayhost to deliver all messages pr. posting, via the same
> relayhost. I believe that from posting to posting, it will use
> different relayhosts. 

If the host ttl is low enough, this may be right. I guess that it will
use the "first" reply from dns as long as its valid. Then it *may*
switch...


> My goal is to share the load between relayhosts, as I might have
> about 25k subscribers. With a single relayhost it will take a long
> time to deliver mail to all subscribers.

Okay, but, maybe the better way to do this is with ipvs (linux virtual
server) or a tool like balance which enables you to share the load
between multiple servers.
Its imho better because its more robust and the job of tools like
balance is to balance the traffic, while mlmmjs job is beeing a mailing
list manager ;)

HTH,
Darkman
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.2 (GNU/Linux)

iD8DBQFFpUdfQoCguWUBzBwRAmxeAJwMPQP8ljD41OfMDFvVOHTWduss3wCfc9Ig
8TEW5UhjzJW2dkNgkNTSyx4=Hxk4
-----END PGP SIGNATURE-----

Re: Round robin relayhost

[Jesper Lund]

> >>> With the tunable, "relayhost", I can set a relayhost. I would
> >>> like to be able to specify multiple relayhosts, and round robin
> >>> between them. Just put 2 or more adresses in the "relayhost"
> >>> file.
> >>>
> >>> Is this possible ? Otherwise, this is a feature request :-)
> >>
> >> Is it not possible for you to set up relayhost.your.domain with
> >> multiple A records in DNS?
> >
> > Been there, done that. But when I do that, it seems that mlmmj
> > uses the same relayhost to deliver all messages pr. posting, via
> > the same relayhost.
> 
> Perhaps mlmmj should use a list of addresses if gethostbyname
> returns more than one.
> 
> But are you sure that using multiple relayhosts will actually get
> your messages out any quicker?

I think it would be easier for me just to put a list of relayhosts in
the file. But i'm not a programmer. Maybe there is a reason not to do
it.

I can't find a reason why it should not get its messages out faster.
Because of mlmmj being faster than my smtp server(s).

Regards, Jesper

Re: Round robin relayhost

[Jesper Lund]

> >>> With the tunable, "relayhost", I can set a relayhost. I would
> >>> like to be able to specify multiple relayhosts, and round robin
> >>> between them. Just put 2 or more adresses in the "relayhost"
> >>> file.
> >>>
> >>> Is this possible ? Otherwise, this is a feature request :-)
> >>
> >> Is it not possible for you to set up relayhost.your.domain with
> >> multiple A records in DNS?
> >
> > Been there, done that. But when I do that, it seems that mlmmj
> > uses the same relayhost to deliver all messages pr. posting, via
> > the same relayhost.
> 
> Perhaps mlmmj should use a list of addresses if gethostbyname
> returns more than one.
> 
> But are you sure that using multiple relayhosts will actually get
> your messages out any quicker?

I think it would be easier for me just to put a list of relayhosts in
the file. But i'm not a programmer. Maybe there is a reason not to do
it.

I can't find a reason why it should not get its messages out faster.
Because of mlmmj being faster than my smtp server(s).

Regards, Jesper

Re: Round robin relayhost

[Charlie Brady]

On Wed, 10 Jan 2007, Jesper Lund wrote:

>> But are you sure that using multiple relayhosts will actually get
>> your messages out any quicker?

...

> I can't find a reason why it should not get its messages out faster.
> Because of mlmmj being faster than my smtp server(s).

There is limited bandwidth between your mlmmj server and your relayhosts. 
You won't necessarily get your messages out more quickly by using multiple 
relay hosts.

Re: Round robin relayhost

[Charlie Brady]

On Wed, 10 Jan 2007, Sven 'Darkman' Michels wrote:

> Jesper Lund wrote:
> > Been there, done that. But when I do that, it seems that mlmmj uses
>> the same relayhost to deliver all messages pr. posting, via the same
>> relayhost. I believe that from posting to posting, it will use
>> different relayhosts.
>
> If the host ttl is low enough, this may be right.

mlmmj shouldn't be looking at ttl.

> I guess that it will
> use the "first" reply from dns as long as its valid. Then it *may*
> switch...

It's best not to guess, but to "use the source, Luke".

mlmmj-send creates only a single socket, and sends all messages over that 
socket. It only calls gethostbyname once, and uses the first address 
returned (which will have been randomly chosen form a list if multiple A 
records exist). There is no reuse, switching or expiry of addresses.

Jesper, it's not just a matter of changing the format or interpretation of 
the relayhost configuration item, you'd need to substantially redesign 
mlmmj-send.

Re: Round robin relayhost

[Jesper Lund]

>  > Been there, done that. But when I do that, it seems that mlmmj
>  > uses
> > the same relayhost to deliver all messages pr. posting, via the
> > same relayhost. I believe that from posting to posting, it will
> > use different relayhosts. 
> 
> If the host ttl is low enough, this may be right. I guess that it
> will use the "first" reply from dns as long as its valid. Then it
> *may* switch...

The server which handles the mailinglist and runs mlmmj, i actually
using the DNS, which i authoritative for the host I am using as
relayhost. Posting by posting, it uses a different relayhost.

> > My goal is to share the load between relayhosts, as I might have
> > about 25k subscribers. With a single relayhost it will take a long
> > time to deliver mail to all subscribers.
> 
> Okay, but, maybe the better way to do this is with ipvs (linux
> virtual server) or a tool like balance which enables you to share
> the load between multiple servers.
> Its imho better because its more robust and the job of tools like
> balance is to balance the traffic, while mlmmjs job is beeing a
> mailing list manager ;)

Hmm..... I get your point :) The servers are all runnning FreeBSD.

Maybe I could do some voodoo with a local postfix, to make it do the
round robin for mlmmj, which just relay to "localhost".

What would you do, if your smtp server was "too slow" to relay the
mails fast enough ?

Regards, Jesper

Re: Round robin relayhost

[Mads Martin Joergensen]

* Jesper Lund <jesper@ballbreaker.dk> [Jan 10. 2007 21:54]:
> Maybe I could do some voodoo with a local postfix, to make it do the
> round robin for mlmmj, which just relay to "localhost".
> 
> What would you do, if your smtp server was "too slow" to relay the
> mails fast enough ?

Even with 25k mails, one single Postfix with VERP should do the job
quickly. But if you cannot use VERP ...

How long does it take to deliver them with the current setup?

-- 
Mads Martin Joergensen, http://mmj.dk
"Why make things difficult, when it is possible to make them cryptic
 and totally illogical, with just a little bit more effort?"
                                 -- A. P. J.

Re: Round robin relayhost

[Jesper Lund]

On Thu, 11 Jan 2007 08:16:51 +0100
Mads Martin Joergensen <mmj@mmj.dk> wrote:

> * Jesper Lund <jesper@ballbreaker.dk> [Jan 10. 2007 21:54]:
> > Maybe I could do some voodoo with a local postfix, to make it do
> > the round robin for mlmmj, which just relay to "localhost".
> > 
> > What would you do, if your smtp server was "too slow" to relay the
> > mails fast enough ?
> 
> Even with 25k mails, one single Postfix with VERP should do the job
> quickly. But if you cannot use VERP ...
> 
> How long does it take to deliver them with the current setup?

Sorry for the answring delay.

With a dedicated host, some postfix tuning og at bit of scripting, It
took about 5 minutes.

I think it is fast enough... I still think, though, that it would be
a nice feature to be able to round robin relayhosts. Just if somebody
had a booring time to waste... :)

Well, thank you all for your answers.

Kind regards, Jesper