I have to confess that, for the longest time, I had no idea that an ordinary NoteDatabase.Open() call is not cluster-aware. Clustering in Lotus Notes and Domino, after all, is magic, right? But the ordinary open(server,path) method in LotusScript and Java back-end classes does not fail over if the specified server is not responding There is a special openWithFailover(server,path) method, and that’s what you’re supposed to use if you want failover to occur. I can see the logic in this, as there are many cases where you really do have to carefully control what server you are working with.
So a few weeks ago I started thinking about upgrading some code to use openWithFailover, but this code runs in an unusual configuration (scheduled agent running on a server in domainA accessing databases on servers in domainB), so I decided to do some methodical testing, using a stripped down piece of test code. Before testing this code in the final configuration, however, I figured that I should test it in a simple configuration and prove a few things. After all, it would be nice to know the code doesn’t have bugs before I try it in an environment where I’m not particularly confident that it will work.
First, of course, I had to build a cluster. Nothing could be simpler, really, but it had been a few years since I’ve done it so I took two servers, one on 8.5.1 and one on 8.5.2, and just followed the instructions in the Domino Administrator help file. Half an hour later I had a cluster, with cluster replication doing it’s thing, and failover occurring as expected on a Notes 8.5.2 client when I took either one of the servers down. Then I wrote a few lines of LotusScript and ran it as a client-side agent from the Actions menu. The code instantiated three NotesDatabase objects. It used the open() method on the first object to open a test database on one of the servers in the cluster.
It used the open() method on the second object to open a replica of the same database on the other server. And it used the openWithFailover() method to open the same database again on the first server. In all three cases, the code called the NotesDatabase.isOpen() method to verify success, and when both servers were up the results were exactly as expected — all three databases opened. But when the first server was down, the isOpen() test failed after both the first open() and the openWithFailover() call failed.