Exception in a tap will stop the tapped stream from sinking data

Exception in a tap will stop the tapped stream from sinking data.

Background

Running xd-singlenode.
We experienced this when streaming data from a rabbit queue to hdfs. The stream was tapped and we had a groovy processor on the tap stream. Any exceptions in the processor stopped the main stream from writing data to the hdfs sink.

Steps to reproduce.

1: Create a groovy script that throws an exception in modules/processor/scripts/exceptionthrower.groovy. Code below

/**
 * Custom processor to be wired into a tap to throw an exception.
 */
 throw new RuntimeException("Error from processor")

2: Create a sample main stream

xd:>stream create --name ticktock --definition "time | log" --deploy

3: Tail the log to confirm the data is going to the sink. We see 'sink.ticktock' appearing in the log as expected.
4: Add a tap to the stream that will throw an exception.

xd:>stream create --name exTap --definition "tap:stream:ticktock > script --location=exceptionthrower.groovy | log" --deploy

5: Tail the log and we see that there are no more 'sink.ticktock' strings being logged. Looks like the main stream is no longer sending messages to the sink.