easyMultiple ChoiceObjective-mapped
PDE Practice Question: A data pipeline ingests streaming data from…
A data pipeline ingests streaming data from Pub/Sub into BigQuery via Dataflow. Recently, the pipeline has been failing with 'deadline exceeded' errors. What is the most likely cause?
⚠ Common exam trap
Google Cloud often tests the distinction between resource quota errors (like BigQuery streaming quota) and Pub/Sub-specific timeout errors, trapping candidates who confuse 'deadline exceeded' with general quota exhaustion.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The Pub/Sub subscription's acknowledgement deadline is too short for the processing time.
'deadline exceeded' errors in a Dataflow pipeline reading from Pub/Sub indicate that the subscriber is taking longer to process messages than the acknowledgement deadline allows. When the deadline expires, Pub/Sub redelivers the message, causing duplicate processing and eventual pipeline failure. This is a common issue when processing time exceeds the default 10-second acknowledgement deadline.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The BigQuery streaming quota is exceeded.
Why it's wrong here
Quota exceeded errors would be 'quota exceeded', not 'deadline exceeded'.
- ✗
Dataflow workers are underutilized due to batch size settings.
Why it's wrong here
Underutilization would not cause deadline exceeded errors; it might cause slow processing.
- ✗
Dataflow autoscaling is disabled.
Why it's wrong here
Autoscaling being disabled might cause performance issues but not specifically deadline exceeded errors.
- ✓
The Pub/Sub subscription's acknowledgement deadline is too short for the processing time.
Why this is correct
A short acknowledgment deadline causes messages to be redelivered, leading to repeated processing attempts and eventual deadline exceeded errors.
Go deeper
Related to this question
About these practice questions
One of 890 original PDE practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PDE practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PDE exam.