Multiple host instances

Nov 29, 2012 at 12:51 PM
Edited Nov 29, 2012 at 12:53 PM


I saw a discussion about using this adapter in a failover clustered environment which we also have.

My question is the opposite though :)

Is it ok to use multiple host instances or do I have to failover cluster a host (limiting to one host instance) for use of this adapter? (Like for use of FTP Receive etc)



May 21, 2013 at 8:39 PM
I don't see why not. I believe you can use multiple host instance.
May 21, 2013 at 9:30 PM
You cannot use this adapter on multiple instances of the same Host, just like the FTP adapter. The reason being, a receive location is operational on all running host instances. So the receive location will fire once for every running host instance.
If you have three servers all running instances of the same host with a schedule task receive location running in this host you will get 3 messages published at the same time.

You can use the adapter on instances of different hosts. Here the receive location is tied to a particular host, i.e. receivelocation1 on host1 and receivelocation2 on host2

The only way to overcome this behaviour is for a receive location to synchronise itself with all running instances. Given that the instances will be running on different servers they cannot communicate directly with each other. The easiest way would be for the receive locations to communicate via a database table. And only the first instance hitting this table would fire - not sure of the exact mechanism, maybe a trigger that errors if the scheduled time is the same.