logging strings with line breaks prints multiple messages in cloudwatch

Hi there,

When I print a message with line breaks in it like this

nlogLogger.Info(@"nlog line
breaks
see how it
handles this");

LambdaLogger.Log(@"lambda logger line
break
see how
it handles it");

Console.WriteLine(@"long line
see how console write
handles it");

It looks like this in cloudwatch

I’ve tried using nlog, lambda’s built in logger, and simple console.writes

I’m using a self contained 3.1 .netcoreapp using Amazon.Lambda.AspNetCoreServer 4.1.0 Is this intended behavior or a side-effect or running as a self contained app? Are there any work around like setting line breaks somehow at the logger level?

[RMarinaro]

It would be the same principle, you need to replace all \n with \r

If you are using standard MS logging you will need to write your own logger.

https://stackoverflow.com/questions/44230373/is-there-a-way-to-format-the-output-format-in-net-core-logging

[ashishdhingra]

Hi @RMarinaro,

Good evening.

Thanks for posting the guidance question. Based on my research while going through various blogs/articles, any string after the new line character ‘\n’ (even ‘\n\r’ for DOS based systems) is split to the next entry in CloudWatch Logs. The below string has 4 new line characters:

@"nlog line
breaks
see how it
handles this"

And hence CloudWatch splits this into 4 separate entries. Unfortunately, it appears that this behavior is controlled by CloudWatch. The workaround is to convert new line character ‘\n’ (and/or ‘\n\r’) to carriage return ‘\r’, in which case, the CloudWatch would group the multi-line string into one entry.

Please let me know if this guidance helps and let me know if this issue could be closed.

Thanks, Ashish