I have an application setup to stream the same data to two ADH servers using an NI Provider. I am getting some weird failover behaviour and I'm not sure what might be going wrong.
- Start provider application that sends messages to both ADH servers
- Subscribe to Item using a separate application
- Ticks are successfully received.
- Turn off ADH1 which is acting as primary node. Subscriber get's notified and successfully starts receiving the data from the ADH2.
- Restart ADH1. Provider application reconnects and starts sending data there again.
- Stop ADH2 (acting as primary). Subscriber get's notified and pulls an IMAGE from ADH1
- Subscriber receives no further updates. But the publisher is still running.
- Restart ADH2. Provider connects and starts sending data.
- Stop ADH1 again. Subscriber now starts getting updates.
After I have gone through this initial failure cycle. You can successfully flip between both hosts repeatedly. I don't quite know why the first failback to ADH1 fails but after that everything is working.
Also to note, I can create the same behaviour in reverse. So if I start with ADH2 as the primary node then the first failback to ADH2 fails, subsequently you can flip servers without any issues.