HDDS-1138, the OM client will not talk to SCM directly to fetch the pipeline info. Instead the pipeline info is returned as part of the keyLocation cached by OM.
In case SCM pipeline is changed such as closed, the client may get invalid pipeline exception. In this case, the client need to getKeyLocation with OmKeyArgs#refreshPipeline = true to force OM update its pipeline cache for this key.
An optimization could be queue a background task to update all the keyLocations that is affected when OM does a refreshPipeline. (This part can be done in 0.5)