Problem: How To Set Up A Loadbalanced High-Availability Apache Cluster

[ndr]

In the tutorial, the setup requires a couple of entries in the ldirectord.conf file that I don't understand. The following:

request="ldirector.html"
receive="Test Page"

I'm not sure why this needs to be specified in a config file in order for the Apache failover to occur. When I tried just creating a random file on both Apache servers and stopped one, it didn't failover to the second Apache server. Does anyone know why this is?

[falko]

Originally Posted by ndr

request="ldirector.html"

The load balancers try to fetch this file from the web servers to see if the web servers are still up.

Originally Posted by ndr

receive="Test Page"

This is the text that should be in that file.

[ndr]

Thanks! I was thinking it was just to run a test, but I see that it is a file used to monitor the web server at all times, even in production.

[ndr]

I have loadb1/loadb2 setup and webserver1/webserver2 setup. Testing as follows:

loadb1 - down
loadb2 - up
webserver1 - up
webserver2 - up
PASS

loadb1 - up
loadb2 - down
webserver1 - up
webserver2 - up
PASS

loadb1 - up
loadb2 - up
webserver1 - down
webserver2 - up
FAIL

loadb1 - up
loadb2 - up
webserver1 - up
webserver2 - down
PASS

So it seems that everything works, with the exception of when webserver1 is not running. The directors are not transferring requests to webserver 2. What information would be helpful to help diagnose the problem here?

Thanks!

[falko]

Did you check the logs in /var/log (especially syslog)?

[ndr]

I've looked at syslog on all 4 servers and cannot figure out why this occurs. I've since rebuilt the entire setup only to find it does the same thing. Therefore, if webserver1 goes down, webserver2 pages aren't served up. Not sure why...

Any suggestions would be greatly appreciated. I followed the tutorial to every detail, which is VERY detailed.