Currently in WF 10, where a data source is created / removed using the CLI the "reload-status" is set to "requires restart", based how the resource is expected to be managed in WF.
In Teiid, it is common practice to add/remove data sources dynamically and restarting server will affect performance and usability severely.
- Because delete/re-add is in Teiid's workflow to manage a data sources and when we have to restart we loose the whole state of the virtual database. That means we need re-establish runtime status. For example, all the existing sessions will be killed.
- Runtime environment are often shared, that could kill other person's tasks in flight leaving them hanging with errors.
- Every time data source starts we fetch metadata from the source, this is very expensive operation.
- With multi-source feature, it is a feature that user dynamically brings in/out sources as they show up on their dashboard, it would be not possible to support this feature.
- This is a change of behavior from earlier versions of the EAP, our users and customers rely on this feature
As per Teiid project is concerned, we consider this is regression on WF and thus a bug.
Brian Stansberry suggested the WF management practices here in this document https://docs.jboss.org/author/display/WFLY10/Admin+Guide#AdminGuide-ApplyingUpdatestoRuntimeServices
Based on this the conclusion is that Data Sources, is developed under "all-services" paradigm, not under "resource-services" paradigm, where a explicit header from client to whether to restart or not can avoid having to "reload" the server when a new DS is added or removed. We understand the nature of service dependencies in WF, and how this can affect the other dependent services, but we verified that Teiid will not have those side effects as we designed. Since these sources are effectively exclusively defined for Teiid should not interfere with others. Also, since the request is explicit, should not affect current behavior.
Since this highly dependent on configuration based data source creation, we can opt to a deployment based data source creation (-ds.xml), however GSS is quick to dismiss this as this not supported feature.