Scheduler and Load Balancing
I understood that a way to make an xMII 12 application fully scalable is using the cluster features of Netweaver. In this way we can have multiple dialog instances which are load balanced by a dispatcher so every application server receives a fraction of the global requests to MII.
If this is correct, I have a question about the scheduler.
Is a scheduled transaction executed only in one of the clustered application server or not? I mean, at a given time can I have the same scheduled transaction that runs on multiple servers or does Netweaver assure that the scheduled transactions runs only on one server?
This is an important design issue to consider, to properly avoid potential concurrency problem.
In our solution (not clustered yet) a scheduled transaction reads data from a table in a database. We are assuming that at a given time only one thread can access this table. Is this assumption still correct in a clustered environment?