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c#.netazure-functionsazure-blob-trigger

Azure Blob trigger function delays and over crowded locally

I am working with C# and .NET8. Azure Function Version 4 I have a Blob Trigger Azure Function running without issues in Azure cloud. The function is updated using GitHub Actions from my repository. When I want to add new features, I test them locally before deployment. The issue is that now, when I run the function locally, it starts triggering all the blob changes that have occurred since it was run locally. This usually takes a lot of time. When it finally finishes triggering, I run the new changes and it takes them hours to run.

Previously, it was just seconds. How can I reduce that delay in the trigger?

Solution

  • As @Mason A mentioned, if you are connecting to the same storage account which is being used in the deployed environment,

    1. Use Separate Storage:
    • Create a new Storage account or a new Container in the existing storage account.
    • This isolation helps to prevent further issues with the deployed environment.
    1. Use alternate option:

    • Blob Storage trigger with Azure Functions sometimes leads to delay in executions because the trigger polls the blob container for updates.

    • To reduce latency in these cases, trigger the function using an event subscription to the same container.

    • Refer the article.

    I have tested the same in my environment by creating two containers in the same storage account and able to run the function without any delays.

    • Created two containers in the storage account:

    enter image description here

    Local Output:

    Azure Functions Core Tools
Core Tools Version:       4.0.5611 Commit hash: N/A +591b8aec842e333a87ea9e23ba390bb5effe0655 (64-bit)
Function Runtime Version: 4.31.1.22191

[2024-04-05T12:45:41.720Z] Found C:\Users\uname\Source\Repos\FunctionApp.csproj. Using for user secrets file configuration.
[2024-04-05T12:46:14.567Z] Azure Functions .NET Worker (PID: 26804) initialized in debug mode. Waiting for debugger to attach...
[2024-04-05T12:46:14.791Z] Worker process started and initialized.

Functions:

        Function1: blobTrigger

For detailed output, run func with --verbose flag.
[2024-04-05T12:46:19.651Z] Host lock lease acquired by instance ID '000000000000000000000000F72731CC'.
[2024-04-05T12:46:29.201Z] Executing 'Functions.Function1' (Reason='New blob detected(LogsAndContainerScan): samples-workitems/Hello World.txt', Id=881042fd-f65c-4254-841c-ceb6f414003e)
[2024-04-05T12:46:29.208Z] Trigger Details: MessageId: b377cda0-1de5-4524-8e14-ae735f4fa67b, DequeueCount: 1, InsertedOn: 2024-04-05T12:46:28.000+00:00, BlobCreated: 2024-04-05T12:46:24.000+00:00, BlobLastModified: 2024-04-05T12:46:24.000+00:00
[2024-04-05T12:46:31.849Z] C# Blob trigger function Processed blob
 Name: Hello World.txt
 Data: Hello World
[2024-04-05T12:46:31.921Z] Executed 'Functions.Function1' (Succeeded, Id=881042fd-f65c-4254-841c-ceb6f414003e, Duration=3164ms)