Below is a simple solution for operating AWstats within a clustered environment in CentOS 5. This solution should work for other operating systems as well. This explanation assumes you’ll be using two application nodes, with front-end directors. I have not tried this solution using three nodes.

• Install AWstats & NFS from yum repository.
• Create profile for your domain within /etc/awstats. (i.e. awstats.www.domain.com.conf)
• Configure NFS mounts on each node. This can be accomplished by modifying your /etc/fstab file as illustrated below.
• Adjust your awstats configuration file to point at both log sources now that the NFS mount has been created.
• On second node, mount /var/lib/awstats
• Configure nightly cron on first application node.
• Configure calling either awstats.pl should display the data processed data stored on node 1, regardless of which node the user is accessing.

Notes / Exceptions

Be sure to backup your Apache log files, and your AWstats data. In this solution the processed information will only be stored on the primary node

Full Setup Process

1. SSH APP1
2. yum install awstats nfs -y
3. nano /etc/exports
4. Add following lines:
/var/log/httpd APP2(rw,sync)
/var/lib/awstats APP2(rw,sync)
/etc/awstats APP2(rw,sync)
5. nano /etc/fstab
6a. Add lines, APP2:/var/log/httpd /var/log/httpd-APP2 nfs rsize=16384,wsize=16384 0 0
6b. mount /var/log/httpd-APP2
7. ln -s /var/log/httpd /var/log/httpd-APP1
8. service nfs start
9. chkconfig nfs on
10. cp /etc/awstats/awstats.model.conf /etc/awstats/awstats.www.domain.com.conf
11. nano /etc/awstats/awstats.www.domain.com.conf
12. Configure normally, exception add
LogFile="/usr/local/awstats/tools/logresolvemerge.pl /var/log/httpd-APP1/domain.com-access_log \
    /var/log/httpd-APP2/domain.com-access_log |"
13. SSH APP2
14. yum install awstats nfs -y
15. nano /etc/exports
16. Add following lines:
/var/log/httpd APP1(rw,sync)
/var/lib/awstats APP1(rw,sync)
/etc/awstats APP1(rw,sync)
17. nano /etc/fstab
18a. Add following lines,
APP1:/var/log/httpd /var/log/httpd-APP1 nfs rsize=16384,wsize=16384 0 0
APP1:/var/lib/awstats /var/lib/awstats nfs rsize=16384,wsize=16384 0 0
18b. mount /var/log/httpd-APP1
18c. mount /var/lib/awstats
19. ln -s /var/log/httpd /var/log/httpd-APP2
20. service nfs start
21. cp /etc/awstats/awstats.model.conf /etc/awstats/awstats.www.domain.com.conf
22. nano /etc/awstats/awstats.www.domain.com.conf
23. Configure normally, exception add
LogFile="/usr/local/awstats/tools/logresolvemerge.pl /var/log/httpd-APP1/domain.com-access_log \
    /var/log/httpd-APP2/domain.com-access_log |"
24. SSH APP1
25. crontab -e add line, perl /usr/local/awstats/tools/awstats_updateall.pl now
26. Configure Apache to expose awstats.pl, refer to awstats setup for additional information.
27. Confirm setup (df -h, perl awstats.pl -update -config=www.domain.com)

This should allow users accessing either node to display the same stats information compiled from both nodes access logs. Be sure to do backups!
Enjoy,
Dustin