mupdate slave & master on the same machine?

[Patrick Radtke]

On Apr 20, 2006, at 5:16 PM, Andrew Morgan wrote:

> On Thu, 20 Apr 2006, Patrick Radtke wrote:
>
>> I'm not sure if its to clear from the documentation (or if its in  
>> there) but you can also configure lmtpproxyd on each frontend to  
>> query the slave mupdate process on the localhost. On a busy system  
>> this can reduce the load on the murder master since lmtpproxyd  
>> won't be connecting to it for every incoming email message.
>
> How do you do this?  I can't find a manpage for lmtpproxyd on my  
> v2.2.12 box.
>
> 	Andy

probably isn't a manpage... I think I just read the lmtpd one and  
assumed they would be similar

in Cyrus.conf we have

    lmtpunix    cmd="lmtpproxyd -C /etc/lmtp.conf" listen="/var/cyrus/ 
socket/lmtp" prefork=15 maxchild=540

/etc/lmtp.conf is identical to our imapd.conf file except that it has  
this line (which tell lmtp to connect locally)
mupdate_server: localhost

we connect locally using plaintext and the 'frontend' user.


Then we run mupdate on the same machine with the relevant portions

admins: cyrus murder frontend
#allowplaintext: no
mupdate_server: notdog



so on each frontend, mupdate talks to the murder master and then  
lmtpproxyd talks to the local mupdate.

We found this had several benefits:
1. Less load on murder master
2. Faster response for lmtpproxyd queries
3. Easier to keep mail being delivered during a murder master outage  
(we had 2-3 hosts dedicated to just lmtpproxyd, so during a murder  
master outage we just run mupdate with the -m on those frontends.  
This effectively makes the machine think its the master, and makes it  
'ready' for connections and allows mail delivery to continue. When  
murder master has been fixed, we remove the '-m' and it becomes a  
salve to the real murder master)


This worked great until our mail volume got to high, so we switched  
most of our mail to be sent directly to the backends using sendmail  
aliases.


anyhow,  hope that helps someone:)

-Patrick