seniorApache Spark
Spark UI: Identifying Bottlenecks in the DAG.
Updated May 5, 2026
Short answer
Senior analysis involves looking for high 'Shuffle Read' time, 'GC Time', and 'Task Deserialization' time.
Deep explanation
If 'Shuffle Read' is high, the network is the bottleneck. If 'GC Time' is >10% of task time, memory is the bottleneck. Long 'Scheduler Delay' indicates a massive number of small tasks.
Unlock with a Pro subscription to view this section.
View pricingReal-world example
No real-world example available yet.
Unlock with a Pro subscription to view this section.
Upgrade to ProCommon mistakes
No common mistakes listed yet.
Unlock with a Pro subscription to view this section.
Upgrade to ProFollow-up questions
No follow-up questions available yet.
Unlock with a Pro subscription to view this section.
Upgrade to Pro