Re: Multi-Master, referrals, and chaining

Aaron Richton <[email protected]> Thu, 25 Mar 2010 09:51:35 -0400 (EDT)
Newsgroups gmane.network.openldap.general
Message-ID <[email protected]>
On Wed, 24 Mar 2010, Ryan Steele wrote:

> I actually realized that my logic was slightly faulty - since each of the six masters is capable of performing the write
> operation, the referral will never be chased.  Given that, is it impossible to have an N-Way MultiMaster configuration
> in which writes are possible on any node, but the writes at any given time are performed on only one of them to ensure
> consistency?  That is, short of doing what I'm doing now (sending ALL traffic to only one master), which doesn't scale
> very well.

Have you considered mirrormode (possibly combined with some back-ldap on 
the consumers so that you can present as only one always-able-to-write 
IP)?

With N-way multimaster you lose write performance as you add additional 
servers, as the write needs to be committed across an increasing N. More 
commits means more complexity means less performance. mirrormode keeps 
N=1, for good write performance, while still allowing for redundancy.