[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: High Availability / Clustering

Using a hardware loadbalancer with multiple slaves, if one of the slaves goes down, and postfix (or any software using the openldap client) is holding open connections to that ldap slave, will the hardware loadbalancer transparently shift that active connection to another slave that is still alive? Im mainly concerned with postfix, which seems to die if the primary ldap server goes down, even if there is a secondary ldap server listed.

L


On Thursday, April 10, 2003, at 06:51 PM, Gary LaVoy wrote:

Not sure what to say about high availability on the masters, but you can front
end your slaves with any hardware/software load balancer and get your fail over
to work. We use Foundry Serverirons and they work just fine.

- gary

From: Lee <lee_hoffman@brown.edu>
Date: Thu, 10 Apr 2003 17:47:17 -0400
Subject: High Availability / Clustering
To: openldap-software@OpenLDAP.org
Comment: openldap-software mailing list <http://www.OpenLDAP.org/lists/>

Ive read through most of the archives concerning high-availability
options for openldap. Right now, we're trying to create make our ldap
infrastructure highly-available, as well as load-balanced between three
servers (more to be added later). From my research it seems like we
have a few options:

1) Experimental Multi-Master: This seems to have a number of atomicity
issues. Plus this doesn't really solve the problem with the ldap
clients not appropriately using the second listed server if the first
goes down.

2) Plain old Master + Multiple Slaves: Same second issue above, plus no
high availability on writes.

3) Master + Slaves, Promotion of Slave if master goes down: Same ldap
client not using second listed server problem as in 1) and 2) above,
plus lots of issues with reclaiming Master status after failure.

4) 1 Master Server Cluster using shared storage: This seems like the
only viable solutions. The problem is we need support for many servers
connecting to one shared storage device, as well some sort of reliable
locking mechanism thats compatible with openldap.

Has anyone successfully implemented 4) ? If so can you recommend any
specific hardware and or software that works nicely with openldap?


Thanks,
L