I have a two-node cluster, and after two years of working without issue, a service under cluster control was started on both nodes, and I want to know how that's possible.
I have a pair of Biztalk 2010 servers that are clustered, and the Host Instances that contain my FTP locations are under cluster control (so they only run on one node at a time) - the rest of the biztalk services aren't under cluster control, and always run on both nodes.
However, after years of working without issue, yesterday I saw that the service under cluster control was started on both nodes - both host instances (there's a 32 and a 64 bit one) were running on both nodes. It was easily resolved - I performed a failover of the cluster application, and the services stopped on the (now) passive node - failing back stopped them on that node and started them on the other, as it should have.
This question isn't really about Biztalk, but really about clustering. I've never seen a case where a service under cluster control could be started on a passive node - when you attempt to start it manually, you get an error message that it can't be started because it's under cluster control. How can a service under cluster control get started on multiple servers? Have others seen this, and is it something I need to be worried about, or a complete fluke?
As a note, I've got quite a bit of experience with windows clustering, and I've never seen this - it's not a misunderstanding about how clusters work, or a mis-configuration. Everything is set up properly, and this is totally unexplained behavior. I tried Googling this, but I get instructions about how clusters work, which I'm already very clear on, and I couldn't find any relevant details about this issue.