Azure Application gateway - trouble shooting?

Question

I have deployed my application on Azure kubernetes and I am using Azure Application gateway to expose the services.

I want to trace the incoming requests to understand the complete execution. Eg: how long it takes to process the request by the application gateway.

Is there any way to trace the individual request in azure application gateway?

Answer 1

First of all you have to enable the logs, see the docs

You can use different types of logs in Azure to manage and troubleshoot application gateways. You can access some of these logs through the portal. All logs can be extracted from Azure Blob storage and viewed in different tools, such as Azure Monitor logs, Excel, and Power BI. You can learn more about the different types of logs from the following list:

• Performance log: You can use this log to view how Application Gateway instances are performing. This log captures performance information for each instance, including total requests served, throughput in bytes, total requests served, failed request count, and healthy and unhealthy back-end instance count. A performance log is collected every 60 seconds. The Performance log is available only for the v1 SKU. For the v2 SKU, use Metrics for performance data.
• Access log: You can use this log to view Application Gateway access patterns and analyze important information. This includes the caller's IP, requested URL, response latency, return code, and bytes in and out. An access log is collected every 60 seconds. This log contains one record per instance of Application Gateway. The Application Gateway instance is identified by the instanceId property.

If you enable logs to be written to an Azure Log Analytics Workspace you can then perform queries like:

AzureDiagnostics
| where Category == "ApplicationGatewayAccessLog"  
| project timeStamp_t, requestUri_s, httpMethod_s, httpStatus_d, receivedBytes_d, sentBytes_d, timeTaken_d

and it will show you something like: