> How the Teiid decide the loading sequence of vdb? if vdb1 depends on vdb2, will it load the vdb2 first?
Yes the load of vdb1 will wait for vdb2. Teiid relies upon AS service dependencies to resolve the load ordering.
> Also, if a vdb's data source will depends on a JDBC data source in the same Teiid server, how can we make sure the dependent data source published by the same Teiid server is available before loadind it?
A vdb will have a passive service dependency on data sources it uses so that if they are not initially available, when they do become available the load will be re-attempted.
A datasource that provides a local connection to a vdb has a wait_to_load property which allows connections to wait for the vdb to become available. Otherwise an exception will be thrown by the connection attempt.
Thanks Steven. Can you give an example of how to use the wait_to_load property? Does it available in Teiid 8.7?
Yes, it was added for 8.1 - https://issues.jboss.org/browse/TEIID-2059
By default a local connection should wait for up to 10 minutes for the connection to become available, but it needs the vdb version to be specified.
Upon looking at this again, I think I'll make some further refinements.