Re: Replication for high availability?

["shih-chang wang" <purewang@cht.com.tw>]

In my opinion, you can have the following ways to provide high availability:

1. By software:
    -(Master-Slave arichitecture)You can write a simple authentication
program. This program connects to Master
      LDAP server first, when there is no response, connect to the Slave
LDAP server.
    -(Stand-alone)Write a simple check script on LDAP server. This script
will ceck the server status(
     just do connecting, anonymous authentication) every minute(using
crontab), kill the dead slapd daemon and restart
     slapd daemon if there is no response. Because the reponse time is over
several minutes when the slapd
     daemon is crashed(in my experience), the check script must have a lock
mechanism to avoid repeated
     check initiated by crontab.
2. By hardware:
    -You can use the Cluster environment, Slave server will take ove
automatically when the Master server was down.

--------------------------------------------------------
Shih-Chang Wang
Associate Researcher
Internet & Multimedia Application Tech. Lab.
ChungHwa Telecom Laboratories
E-MAIL: purewang@cht.com.tw
TEL: 03-4245340
FAX: 03-4201244
--------------------------------------------------------
-----­ì©l¶l¥ó-----
±H¥óªÌ: David Wright <ichbin@heidegger.rprc.washington.edu>
¦¬¥óªÌ: openLDAP-software@OpenLDAP.org <openLDAP-software@OpenLDAP.org>
¤é´Á: 2001¦~8¤ë9¤é AM 10:53
¥D¦®: Replication for high availability?


>
>(This question is unrelated to my other posts.) My LDAP server went was
>down for ~hour today, which caused chaos at my site, because it does
>login authentication. I would like to avoid such problems in the future
>by setting up a cheap box that replicates its database and could be used
>in its place. The trouble is, how do I configure my client machines to
>use the slave in the event of the master's failure? Can anyone suggest
>some neat trick involving DNS or virtual interfaces or some such magic?
>