Update to Murder docs (D69) and question on style.

[Bron Gondwana]

On Fri, Aug 21, 2015, at 17:58, Michael Menge wrote:
> Hi,
> 
> 
> Quoting Nic Bernstein <nic at onlight.com>:
> 
> > On 08/20/2015 09:07 PM, Bron Gondwana wrote:
> >> On Fri, Aug 21, 2015, at 11:42, Nicola Nye wrote:
> >>> On Fri, Aug 21, 2015, at 11:35 AM, Bron Gondwana wrote:
> >>>> Murder plus replication is a giant ball of suck right now.  They  
> >>>> don't know about each other, and they interact badly :(
> >>> So is that a case for documenting "Here be dragons, enter at your  
> >>> own risk" for the moment?
> >>> Does it mean that admins should look at other backup mechanisms to  
> >>> handle failover and redundancy in a murder environment, because  
> >>> Cyrus's replication doesn't play nicely with murder?
> >>> Or... ?
> >> Or we need to fix murder and replication to work together nicely,  
> >> but that's hard work[tm].
> >>
> >
> > Ahem, some of us run Murderous Replicas all day long and it works  
> > well enough...  Doesn't it? ;-)
> >
> > I can write this up, I just wasn't sure if it was still needed.  I  
> > put a big ol' Note: in the replication page saying:
> >
> >    Important
> >
> >    Within a Cyrus /Murder/
> >     
> > <https://docs.cyrus.foundation/imap/developer/architecture.html#architecture-murder>
> >    environment, replicas must *not* be configured to invoke
> >    ctl_mboxlist(8)
> >    <http://docs.cyrus.foundation/imap/admin/commands/ctl_mboxlist.html>
> >    on startup (pushing the local mailbox list to the *Mupdate Master*).
> >    This may only be done on the Master instance.
> >
> > That's the only real gotcha I know of, but, having said that, I did  
> > write up a brief set of instructions about this very topic not that  
> > long ago (IIRC) for user mailing list.  I figured I could start with  
> > that.
> >
> 
> 
> For the initial configuration I second this. But there are IHMO things
> to consider on failover.
> 
> 
> 1. ctl_mboxlist must be used with -m and -a Option on failover
> 2. on big installations updating all entries in mailbox.db on the
>     mupdate server can take some time, on our setup we switch the IP address
>     of master and replic on failover

At which time you'll absolutely want them to both have the same servername!

Bron.

-- 
  Bron Gondwana
  brong at fastmail.fm