You are operating a Cloud Dataflow streaming pipeline. The pipeline aggregates events from a Cloud Pub/Sub subscription source, within a window, and sinks the resulting aggregation to a Cloud Storage bucket. The source has consistent throughput. You want to monitor an alert on behavior of the pipeline with Cloud Stackdriver to ensure that it is processing data. Which Stackdriver alerts should you create?
A) An alert based on a decrease of subscription/num_undelivered_messages for the source and a rate of change increase of instance/storage/used_bytes for the destination An alert based on a decrease of subscription/num_undelivered_messages for the source and a rate of change increase of instance/storage/used_bytes for the destination
B) An alert based on an increase of subscription/num_undelivered_messages for the source and a rate of change decrease of instance/storage/used_bytes for the destination An alert based on an increase of for the source and a rate of change decrease of
C) An alert based on a decrease of instance/storage/used_bytes for the source and a rate of change increase of subscription/num_undelivered_messages for the destination subscription/num_undelivered_messages for the destination
D) An alert based on an increase of instance/storage/used_bytes for the source and a rate of change decrease of subscription/num_undelivered_messages for the destination

Question

Quizplus · Accepted Answer

An increase in `subscription/num_undelivered_messages` indicates that messages are not being processed quickly enough, and a decrease in `instance/storage/used_bytes` suggests that data is not being written to the destination, both of which are signs of potential issues in the pipeline.

You Are Operating a Cloud Dataflow Streaming Pipeline