Azure Load balancer logs -Diagnostic settings

Racheal 231 Reputation points

Hi ,

We have some issue with load balancer health probes.

LB has been configured to check a html file in server in the interval of 10 sec . In server we can see the requests from LB but sometimes we can see requests with 25 sec or even more time gap . There is a gap from 25sec to 45sec in server for health probe request and VM is consider as unhealthy during this time period and causing the issue in production.

To monitor the Load balancer health probe request and response time in a standard load balancer, diagnostic logs has been enabled to send logs to log analytic workspace . But logs are not logged in Azure diagnostics table. how to fix this ?


Azure Load Balancer
Azure Load Balancer
An Azure service that delivers high availability and network performance to applications.
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  1. Tushar Kumar 3,231 Reputation points MVP

    Well I would say there are a few things that you should check :

    Check diagnostic settings

    • Review the diagnostic settings configured for your Load Balancer and ensure that the Log Analytics Workspace is selected and the appropriate logs are enabled.
    • Confirm that the correct table is specified for storing the logs.

    Validate permissions:

    • Check the permissions for the workspace and verify that the account has the "Contributor" or "Log Analytics Contributor" role assigned.

    Check log ingestion status:

    • Use a query like the following to verify if logs are being received:
        | where TimeGenerated > ago(1d)
        | summarize Count() by bin(TimeGenerated, 1h), SourceSystem

    Validate log retention:

    • If the retention period is too short, it might result in logs being automatically deleted before you can view them

    Please accept as answer if this helps.