- A
Worker CPU utilization
Why wrong: Worker CPU utilization indicates resource usage but not directly whether the pipeline is falling behind.
- B
System lag
System lag measures the maximum time data is waiting to be processed. High system lag indicates the pipeline is falling behind due to processing bottlenecks.
- C
Element count
Why wrong: Element count is just the number of elements, not a lag metric.
- D
Data freshness
Why wrong: Data freshness indicates the age of the most recently output data, which could be affected by the sink, but it doesn't distinguish between processing and output issues.
Question 171 of 1,000
PDE Maintaining and Automating Data Workloads Practice Question
This PDE practice question tests your understanding of maintaining and automating data workloads. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Your Dataflow streaming pipeline is experiencing increasing system lag over time. You have enabled autoscaling and the pipeline is using the default streaming engine. Which metric should you monitor in Cloud Monitoring to determine if the pipeline is falling behind due to slow processing or due to a bottleneck in the output sink?
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
✓
System lag
In Dataflow streaming pipelines, 'System lag' represents the maximum time that an item has been waiting to be processed. If system lag is high, it indicates that the pipeline cannot keep up with the input rate. However, to pinpoint if the bottleneck is the sink, you should also monitor 'Data freshness' (time since last output) or write to a staging area temporarily. But the question specifically asks for a metric that helps determine if the pipeline is falling behind due to slow processing or a sink bottleneck. The correct answer is 'System lag' as it directly reflects processing delay; if it increases, the pipeline is not processing fast enough regardless of sink.
Key principle: OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Worker CPU utilization
Why it's wrong here
Worker CPU utilization indicates resource usage but not directly whether the pipeline is falling behind.
- ✓
System lag
- ✗
Element count
- ✗
Data freshness
Why it's wrong here
Data freshness indicates the age of the most recently output data, which could be affected by the sink, but it doesn't distinguish between processing and output issues.
Common exam traps
Common exam trap: OSPF can fail even when IP connectivity looks correct
OSPF neighbour formation depends on matching areas, timers, network type, authentication and passive-interface behaviour. Do not choose an answer only because the devices can ping.
Trap categories for this question
Command / output trap
Data freshness indicates the age of the most recently output data, which could be affected by the sink, but it doesn't distinguish between processing and output issues.
Detailed technical explanation
How to think about this question
OSPF questions usually test the details that control adjacency and route selection. Read the neighbour state, area, router ID and interface configuration before deciding what is wrong.
KKey Concepts to Remember
- OSPF neighbours must agree on key parameters.
- Router ID selection can affect neighbour relationships and LSDB output.
- OSPF cost influences the preferred path.
- A route can appear in OSPF information but not become the installed route.
TExam Day Tips
- Check area mismatch first when OSPF adjacency fails.
- Review passive interfaces when a network is advertised but no neighbour forms.
- Use show ip ospf neighbor and show ip route clues carefully.
Key takeaway
OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related PDE OSPF questions on adjacency and route selection.
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FAQ
Questions learners often ask
What does this PDE question test?
Maintaining and Automating Data Workloads — This question tests Maintaining and Automating Data Workloads — OSPF neighbours must agree on key parameters..
What is the correct answer to this question?
The correct answer is: System lag — In Dataflow streaming pipelines, 'System lag' represents the maximum time that an item has been waiting to be processed. If system lag is high, it indicates that the pipeline cannot keep up with the input rate. However, to pinpoint if the bottleneck is the sink, you should also monitor 'Data freshness' (time since last output) or write to a staging area temporarily. But the question specifically asks for a metric that helps determine if the pipeline is falling behind due to slow processing or a sink bottleneck. The correct answer is 'System lag' as it directly reflects processing delay; if it increases, the pipeline is not processing fast enough regardless of sink.
What should I do if I get this PDE question wrong?
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related PDE OSPF questions on adjacency and route selection.
What is the key concept behind this question?
OSPF neighbours must agree on key parameters.
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Last reviewed: Jul 4, 2026
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.
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