Why does a COPY Activity shows that it took long time in duration, but when we check the sub-tasks it has actually taken less time

TheNerd-0042 50 Reputation points
2024-10-28T11:53:29.73+00:00

Hi Team,

I have a scenario here where a COPY Activity shows that it took long time as per start and end time of the pipeline, but when I check the sub-tasks it has actually taken less time than it is being shown as time taken. Which is true here? If the process takes more time then what could be the problem here? How do I actually fix the problem? Attaching screenshot for reference:

User's image

It would be great, if someone can help me in this?

Thanks

Azure Synapse Analytics
Azure Synapse Analytics
An Azure analytics service that brings together data integration, enterprise data warehousing, and big data analytics. Previously known as Azure SQL Data Warehouse.
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  1. Sina Salam 12,011 Reputation points
    2024-10-28T13:31:23.8066667+00:00

    Hello TheNerd-0042,

    Welcome to the Microsoft Q&A and thank you for posting your questions here.

    I understand that you would like to know reason a COPY Activity shows that it took long time in duration, but when you checked the sub-tasks, it has actually taken less time.

    Regarding your explanation and the image provided, it looks like a discrepancy between the overall duration of a COPY Activity and the time taken by its sub-tasks, makes it confusing, but there are a few primary reasons for this:

    • The total duration of a process includes not only the execution time of sub-tasks but also overhead time, such as setting up the environment and initializing connections.
    • Secondly, when sub-tasks run concurrently, their individual durations might not sum up to the total duration; for instance, two 5-minute tasks running in parallel may still result in a total duration of around 5 minutes.
    • Additionally, tasks may experience queue and wait times for resource availability, which are part of the total duration but not the execution time.
    • Delays in logging and monitoring systems can also cause discrepancies in reported times.

    To resolve this issue:

    1. Check detailed logs to understand where the time is being spent. Look for any significant delays or waiting periods - https://learn.microsoft.com/en-us/azure/azure-monitor/essentials/tutorial-resource-logs
    2. Ensure that sufficient resources are allocated to avoid bottlenecks - https://learn.microsoft.com/en-us/azure/well-architected/performance-efficiency/continuous-performance-optimize
    3. Check if there are any unnecessary steps or configurations that might be adding to the overhead - https://learn.microsoft.com/en-us/azure/well-architected/performance-efficiency/optimize-data-performance

    Use the links for more detailed steps.

    I hope this is helpful! Do not hesitate to let me know if you have any other questions.


    Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful.


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