Are following interfaces supported?

[ks881115]

While designing Tajo on REEF, we found we need following interfaces:

1) Sending parameter from client to driver

• When I launch the driver, I want the query request to be sent together. Can we do this? 2) Communication between client-driver
• I want Client to be notified when the driver is ready to receive the query request. Is there any good way to notify the client? 3) Communication between task-driver
• I think the message from the task can be handled by ON_TASK_MESSAGE EventHandler. But, I don't know how I can activate this event. Is there any proper example that we can refer?

1) and 2) are for the same purpose (To send query request to the launched driver). So we will choose one which fits the REEF app model. I think 3) might be supported but we simply don't know how-to.

Thanks in advance :)

[bgchun]

1) You can add parameters when you build DriverConfiguration. The parameters are named parameters in the constructor of Driver.

2) ./reef-examples/src/main/java/org/apache/reef/examples/retained_eval/JobDriver.java private final JobMessageObserver jobMessageObserver; JobMessageObserver sends a JobMessage message from Driver to Client

./reef-examples/src/main/java/org/apache/reef/examples/retained_eval/JobClient.java ClientConfiguration ... .set(ClientConfiguration.ON_JOB_MESSAGE, JobClient.JobMessageHandler.class) ... final class JobMessageHandler implements EventHandler<JobMessage> { ... } JobMessageHandler handles messages received from Driver at Client

3) Refer to the following JIRA issue. https://issues.apache.org/jira/browse/REEF-33

[ks881115]

Thanks for the quick reply professor! We always appreciate you!