we are trying to use a load balancing appliance to do failover not noticeable to users.
We have a virtual IP in the appliance pointing to the IP’s of the cluster members, and we are resolving the names of servers to this virtual IP.
It’s working fine for web access, but we have no success accessing by Notes client.
When Notes access a DB using the cluster name or the name of a member server (say server1), it do that without problems, but if a failover happens, traffic is redirected to the other server IP (say server2) by the appliance but Notes client thinks the failover has not happened and it’s still accessing server1 while the server answers as server2. So, Notes client stops accessing DB with a message or network problem.
Are there any way to to avoid this behavior like no verifying the name of server being accessed?
You should be able to configure your “load balancing appliance” to work only on connections over port 80 (http). Thus, it will redirect web clients in the event of a failure of one of the cluster server members.
Regarding a notes client to domino server failover (port 1352): the notes client handles this. Thus your “load balancing appliance” does not have to, and should not, redirect the traffic.
as I’ve said in my post, our solution is working well for http traffic.
But Notes client doesn’t handle failover without users intervention in all situations (like refreshing the inbox). We want the users have no notice of a server crash and notes client doesn’t handle this properly.
Following is a quote from an IBM redbook on the issue of clustering domino servers:
"Conditions that do not cause failover
Failover does not occur:
• If a server becomes unavailable while a user has a database open
• If a server becomes unavailable while a user is editing a document. In this situation a user cannot save the document but could copy it to the clipboard, open the database again (which would trigger failover to occur) and then paste it into a replica on a clustered server.
• If you select a database icon and choose any of the following options:
File → Database → Properties
File → Database → Access Control
File → Database → Open
File → Database → New Copy
• If you click a database icon and select View → Go To from the menu.
• When replicating with a server that is restricted by the administrator or has reached the maximum number of users or the maximum usage level set by the administrator. Also, when replicating with a database marked “Out of Service”. Replication occurs regardless of such restrictions, so there is no need for failover to occur.
• When the Mail Router on a Domino R4 mail server attempts to deliver mail while MailClusterFailover is set to 0 or when cluster failover has been disabled for the Domino R5 mail server.
• When running agents, other than the mail pre-delivery agent.
• When you want to use a server as a template server when creating a new database (File → Database → New)."
The file is sg245141.pdf.
Thus, the user has to exit the notes database and try to re-enter via double-clicking the workspace icon. At this point, the notes client will automatically open the db on the cluster server.
I know this conditions (is also in the admin online help). Is for that we want to use an external appliance to load balance the Notes traffic an make invisible to users the crash of a server.
We don’t want the user must close the notes database an reopen it. We want transparent failover and this is the reason of my post. Is possible to do that?