Local Director Questions

a-kerr · ‎06-07-2002

Our web folks are testing an application that currently does not support server clustering. They want to have all web traffic be directed to one server(server1) and have a second (server2) identical server as a backup.

I was wondering if can bind the real server (server1) to the virtual server and have the second real server (server2) backup the first real server using the backup command? Is there any potential pitfalls that I may need to take into account by doing it this way?

Also they wanted to know if the Local Director would work in the previous scenario if the two servers are physically connected to the same switch but reside in different VLANs?

Any input would be greatly appreciated.

Thanks

mmellet · ‎06-14-2002

As a general rule, two real servers that are bound to a single virtual server cannot be used as backup servers for one another. However, the LocalDirector User Interface list of available backup servers does list these servers as an available option.

cschneid · ‎06-19-2002

This is exactly how you would configure it. There is only one potential pitfall that I can think of in your particular scenario. If server1 fails, server2 starts getting the connections. As soon as server1 comes back into service all the new connections will be sent to server1. This is a good thing in most situations but you need to see if the application can deal with this.

Regarding location of the backup box. When you say the two servers are connected to the same switch but reside in different VLANs do you also mean that the servers are in different subnets? If so, this is a little more complex depending on the topology but can easily be worked out. If the servers are simply located in separate VLANs on the switch but are in the same subnet then this configuration should work without issue.

ddavis · ‎11-25-2003

Although this response is over a year late, it is relevant.

The 'backup' command seems work well, in version 4.2.5, with 2 hosts. However, I have been unable to get the backup command to successfully failover from the backup host to the second backup host. Here's the scenario:

Primary host -----> Backup host ------> Secondary Backup host

Primary host to Backup host works well, especially with a low threshold (1). However, Backup host to secondary Backup host doesn't work. This means that if the original Backup host fails, the entire application fails.

Has anyone realized a workaround for this?

krmenon · ‎11-26-2003

Dean, the problem is that you can not backup a backup with a backup !!! ;)

krmenon · ‎11-27-2003

dean, i wanted to tell that over the phone.... but was not able to get u. Anyway have a nice thanks giving vacation.