The goal is to have a failover system with OpenLDAP. The system must switch if
- one of the service stops
- one of the service does not answer (parameters to define)
yum install haproxy
mv /etc/haproxy/haproxy.{cfg,cfg.old}
Use the haproxy.cfg file provided, to copy in /etc/haproxy
Adapt :
- IPs referencing OpenLDAP services,
- listening port of OpenLDAP, both in OpenLDAP and haproxy configuration
Start OpenLDAP and haproxy
Check that everything is ok on the statistics interface of both servers:
http://<IP_SERVEUR>:8080/haproxy?stats
Stopping of OpenLDAP service on one node will trigger trafic redirection on the other node.
The uncommented configuration makes a basic TCP check, which is very efficient, but does not guarantee that the directory has a working database backend. (corruption of data for example, which is quite rare now)
There is an alternative check that sends a binary request, and wait for a correct bind response. The generateBind program is used to generate this bind request by giving it the account (bindDN) and the corresponding password (bindPW).
See the configuration file haproxy.cfg, describing all the useful parameters.