Describe the Apache Storm System and Topology DATA-ENGINEERING-OPTIMIZE Practice Questions (Page 3)

Questions 11–15

1. 11foundation · easy

   What mechanism does Storm use to provide at-least-once processing guarantees?

   • AAcking and failing of tuples
   • BCheckpointing to ZooKeeper
   • CPersistent message queues
   • DExactly-once transactional state
   Reveal Solution Discussion Select an answer first
2. 12expert · hard

   A Storm topology has been running for months. The team needs to increase the parallelism of a CPU-intensive bolt from 4 to 8 to handle increased load. They also need to ensure that the change takes effect without interrupting the data flow. What should they do?

   • AKill the topology, modify the parallelism hint in the code, and resubmit
   • BModify the parallelism hint in the code and use storm activate
   • CUse the storm deactivate command and then modify the parallelism hint in the code
   • DUse the storm rebalance command with the -e option to specify the new parallelism for the bolt
   Reveal Solution Discussion Select an answer first
4. 13application · medium

   A Storm topology has been running in production for several weeks. The team needs to perform a rolling upgrade of the underlying cluster hardware. They want to stop the flow of data temporarily, upgrade the Supervisors one by one, and then resume processing without resubmitting the topology. Which sequence of Storm CLI commands should they use?

   • Astorm kill <topology> ... storm submit <topology>
   • Bstorm deactivate <topology> ... storm activate <topology>
   • Cstorm stop <topology> ... storm start <topology>
   • Dstorm rebalance <topology>
   Reveal Solution Discussion Select an answer first
5. 14application · easy

   A Storm topology has a spout with a parallelism hint of 2 and a bolt with a parallelism hint of 4. The topology is submitted with 2 workers. How many executors will run for the bolt?

   • A8
   • B2
   • C1
   • D4
   Reveal Solution Discussion Select an answer first
6. 15application · medium

   A Storm topology processes financial transactions. The team has enabled acking and uses anchoring. A spout emits a tuple, and a downstream bolt fails to process it, so the spout replays the tuple. What guarantee does this provide?

   • AExactly-once processing
   • BAt-most-once processing
   • CNo processing guarantee
   • DAt-least-once processing
   Reveal Solution Discussion Select an answer first