Describe the Apache Storm System and Topology DATA-ENGINEERING-OPTIMIZE Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A Storm topology processes order events. A bolt enriches each order with customer details and then emits the enriched order to a downstream bolt that writes to a database. The team has enabled acking on the topology. A tuple is lost because the database write fails. What should the enrichment bolt do to ensure the failed tuple is retried?

   • ACall ack on the input tuple immediately after emitting, regardless of downstream success
   • BAnchor the emitted tuple to the input tuple and call fail on the input tuple if the downstream bolt fails
   • CDo not anchor the emitted tuple, and call ack on the input tuple
   • DCall fail on the emitted tuple
   Reveal Solution Discussion Select an answer first
2. 2expert · hard

   A Storm topology processes user sessions. Each session is identified by a session ID. A bolt performs session-level aggregation and must maintain state per session. The team is considering using a fields grouping on session ID. What is a potential drawback of this approach?

   • AIf a session's tuples are skewed (e.g., one session has many more tuples), the task handling that session may become a bottleneck
   • BIt will not guarantee that all tuples for a session are processed in order
   • CIt will cause duplicate processing because the same session ID is sent to multiple tasks
   • DIt will cause the bolt to lose state if a task fails
   Reveal Solution Discussion Select an answer first
4. 3foundation · easy

   In the Storm topology lifecycle, what does the 'deactivate' operation do?

   • APermanently removes the topology from the cluster
   • BPauses the processing of the topology
   • CRebalances the topology across workers
   • DStarts the topology for the first time
   Reveal Solution Discussion Select an answer first
5. 4foundation · easy

   Which stream grouping ensures that tuples with the same value for a specified field are always sent to the same bolt task?

   • AFields grouping
   • BAll grouping
   • CShuffle grouping
   • DGlobal grouping
   Reveal Solution Discussion Select an answer first
6. 5expert · hard

   A Storm topology processes IoT sensor data. A bolt enriches each reading and emits multiple tuples. The team has enabled acking and uses anchoring. They notice that some tuples are being replayed even though the bolt successfully processed them. What is a likely cause?

   • AThe spout is emitting duplicate tuples by design
   • BThe bolt is not acking all input tuples after processing, causing Storm to time out and replay them
   • CThe bolt is using an all grouping, which duplicates tuples
   • DThe bolt is using a shuffle grouping, which causes tuples to be replayed
   Reveal Solution Discussion Select an answer first