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Re: Slurpd vs. Syncrepl

--On Monday, October 31, 2005 6:19 PM +0200 Chen Shapira <cshapira@mercury.com> wrote:


I'm using Slurpd for openldap replication in order to have master-slave
high availability in our production environment.

I saw Syncrepl mentioned on this list as another method to have a replica
of the directory. I've read about Syncrepl and how it works, but some
parts of the picture are still missing:

1. Is there any reason to change from Slurpd to Syncrepl? Syncrepl has a
much more complicated protocol, but in what ways is it preferable to

Syncrepl allows a slave to catch up from a given point in time to the master, without the master having to initiate anything. If the slave is too far out of date, it will even completely reload itself. With slurpd, you have to suffer a continually growing replication log while a slave is offline.

2. Are there any good reasons or situations where I should not use

A heavy write environment. The current implementation of syncrepl only does complete entry replacement, rather than doing change delta's to the existing entry. This will hopefully be fixed in 2.3.12 with the introduction of delta-syncrepl.

3. Does Syncrepl overcome any of Slurpd limitations? Can I have two
servers each replicating the other, so I can have a multi-master
environment with much easier failover?

See #1, yes, it does, for your first question. On the second part, I believe some people have been doing things like that.


Quanah Gibson-Mount
Principal Software Developer
ITSS/Shared Services
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html