Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Function execution logs are duplicated in App Service log stream

See original GitHub issue

If you access the log stream for your entire function app, you will see duplicated entries for function starting/completion:

When a function executes with file logging enabled, the following entries are written to both the host log and the function log, i.e. to files in:

D:\home\LogFiles\Application\Functions\Host\
D:\home\LogFiles\Application\Functions\Function\function-name\

The entries look like this:

2017-04-18T22:54:20.013 Function started (Id=8c130624-cfb2-47d7-8e1f-05047a10a17d)
2017-04-18T22:54:20.013 Function completed (Success, Id=8c130624-cfb2-47d7-8e1f-05047a10a17d, Duration=0ms)

Because the same entry is written to both locations, it appears in the log stream twice.

Issue Analytics

State:
Created 6 years ago
Reactions:10
Comments:28 (11 by maintainers)

Top GitHub Comments

6reactions

fmannhardtcommented, Jul 12, 2019

This is highly confusing and just cost me a few hours of searching for the reason. It should be fixed or one need to somehow be warned.

4reactions

idusortuscommented, Jun 13, 2022

Five years later and this is still a nuisance. Any solution in sight?

Top Results From Across the Web

Why does azure Function App streaming log viewer ...

It is a bug tracked but not fixed yet. When function code panel is opened, file log(i.e. Application log in Diagnostic logs) is...

Why does azure Function App streaming ... - appsloveworld.com

Log streaming console prints both host logs and function logs, so function related entries appear twice. For example, logs with [Info,Function1] prefix are ......

Enable streaming execution logs in Azure Functions

To view streaming logs in the portal, select the Platform features tab in your function app. Then, under Monitoring, choose Log streaming.

Forwarding Azure Application Logs

Looking to forward Azure platform logs to New Relic? Follow this guide to set up an agentless approach to stream Azure logs to...

Lambda Function Log Collection Troubleshooting Guide

If you don't see logs forwarded from a Datadog forwarder Lambda function in the Log Explorer, follow the troubleshooting steps below.