Marc Silver wrote:
> Hi folks,
>
> I apologise for reposting this, but I'm desperate for some insight
> here... any feedback would be very much appreciated...
>
> On Tue, Apr 24, 2007 at 08:13:27AM +0200, Marc Silver wrote:
>> Hey guys,
>>
>> I am currently responsible for the administration of four exim servers
>> (running 4.66) which we utilize as our inbound MX servers. Mail for our
>> domain is then manually routed via the exim machines back to our main
>> offices using the manualroute option over a compressed ssh tunnel. I'm
>> using the randomize option to give me crude load balancing, but it
>> doesn't appear to be working very well. What I'm seeing is that one or
>> two of the servers at our main office seem to be getting much more load
>> than the other two.
>>
>> I am using the following router:
>>
>> forcepath:
>> debug_print = "R: forcepath for $local_part@$domain"
>> driver = manualroute
>> domains = !+local_domains:partial0-lsearch;CONFDIR/forcepath.list
>> route_data = ${lookup{$domain}partial0-lsearch{CONFDIR/forcepath.list}}
>> transport = remote_smtp
>> host_find_failed = defer
>> same_domain_copy_routing = yes
>> self = send
>> no_more
>>
>> And the following transport:
>>
>> remote_smtp:
>> driver = smtp
>>
>> Here are the contents of forcepath.list:
>> domain.co.za: 127.0.0.1::10025:127.0.0.1::10026:127.0.0.1::10027:127.0.0.1::10028 randomize byname
>>
>> Can anyone help me to get these machines to balance more equally? What
>> am I missing?
>
Marc,
I hate to say it, but I experienced the same behavior.
We put a simple Exim mail gateway that only did RBL and anti-virus
checking, then forwarded it on to internal mail servers that did mail
delivery for the users.
We specified two internal mail servers, using the randomize function.
Turned out, it would almost 'prefer' a host for a short while, then use
the next for a brief moment, then switch back to the other one.
It wasn't very random, and the load split was more like 70/30.
Never did figure it out, we eventually settled on a load balancing switch.
But the randomization does need some work, or else its pretty useless.
Regards;
Brent Jones
brent [at] servuhome [dot] net
