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PROFESSIONAL-DATA-ENGINEER · Question #219

You are running a pipeline in Cloud Dataflow that receives messages from a Cloud Pub/Sub topic and writes the results to a BigQuery dataset in the EU. Currently, your pipeline is located in…

The correct answer is A. Increase the number of max workers B. Use a larger instance type for your Cloud Dataflow workers. When all workers are at maximum CPU utilization, the two direct levers are scaling out (A: more workers) and scaling up (B: larger instance type) - both increase total compute capacity without changing the pipeline's architecture or data flow. Why the distractors are wrong: C…

Submitted by ahmad_uae· Mar 30, 2026Building and operationalizing data processing systems

Question

You are running a pipeline in Cloud Dataflow that receives messages from a Cloud Pub/Sub topic and writes the results to a BigQuery dataset in the EU. Currently, your pipeline is located in europe-west4 and has a maximum of 3 workers, instance type n1-standard-1. You notice that during peak periods, your pipeline is struggling to process records in a timely fashion, when all 3 workers are at maximum CPU utilization. Which two actions can you take to increase performance of your pipeline? (Choose two.)

Options

  • AIncrease the number of max workers
  • BUse a larger instance type for your Cloud Dataflow workers
  • CChange the zone of your Cloud Dataflow pipeline to run in us-central1
  • DCreate a temporary table in Cloud Bigtable that will act as a buffer for new data.
  • ECreate a temporary table in Cloud Spanner that will act as a buffer for new data.

How the community answered

(62 responses)
  • A
    84% (52)
  • C
    2% (1)
  • D
    5% (3)
  • E
    10% (6)

Explanation

When all workers are at maximum CPU utilization, the two direct levers are scaling out (A: more workers) and scaling up (B: larger instance type) - both increase total compute capacity without changing the pipeline's architecture or data flow.

Why the distractors are wrong:

  • C is incorrect because moving to us-central1 would move the pipeline outside the EU, potentially violating data residency requirements, and geographic location doesn't fix a CPU bottleneck.
  • D and E are incorrect because adding a buffer in Bigtable or Spanner doesn't process the backlog faster - it just delays the problem. The bottleneck is compute, not ingestion ordering, and introducing an extra hop adds latency and cost without addressing CPU saturation.

Memory tip: Think of it as a factory assembly line that's overwhelmed - you either hire more workers (A) or give each worker better tools/a bigger workstation (B). Moving the factory to another city (C) or adding a waiting room (D/E) doesn't help the workers go faster.

Topics

#Dataflow optimization#Pipeline scaling#Performance tuning#Resource management

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