Exporter omits log formatter

[jose-mf]

Hi there, I don't know if I miss something in the configuration but when I try to use a log formatter always it's omitted and the output format is a simple string.

This is the example code using a ConsoleExporter:

var serviceName = "Samples.ConsoleExporter";
ActivitySource source;

using var tracerProvider = Sdk.CreateTracerProviderBuilder()
.AddSource(serviceName)
.AddConsoleExporter()
.Build();

if (Activity.Current == null)
{
source = new ActivitySource(serviceName);
}
else
{
source = Activity.Current.Source;
}

using var loggerFactory = LoggerFactory.Create(builder =>
{
builder.ClearProviders();
builder.AddJsonConsole();
builder.AddOpenTelemetry(opt =>
{
opt.AddConsoleExporter();
opt.IncludeFormattedMessage = true;
});
});

using var rootSpan = source.StartActivity("Samples.ConsoleExporter.Handler", ActivityKind.Server);

var logger = loggerFactory.CreateLogger();

logger.LogInformation("Traces are being created and exported");

And the output is:

LogRecord.Timestamp: 2022-12-16T09:20:58.2482340Z
LogRecord.TraceId: 69e3c44e83459b5cbc6d71adb837afea
LogRecord.SpanId: 057c72070fc3bdc1
LogRecord.TraceFlags: Recorded
LogRecord.CategoryName: Program
LogRecord.LogLevel: Information
LogRecord.FormattedMessage: Traces are being created and exported
LogRecord.State (Key:Value):
OriginalFormat (a.k.a Body): Traces are being created and exported

Resource associated with LogRecord:
service.name: unknown_service:dotnet

Activity.TraceId: 69e3c44e83459b5cbc6d71adb837afea
Activity.SpanId: 057c72070fc3bdc1
Activity.TraceFlags: Recorded
Activity.ActivitySourceName: Samples.ConsoleExporter

The expected log format should be:
{"EventId":0,"LogLevel":"Information","Category":"Program","Message":"Traces are being created and exported","State":{"Message":"Traces are being created and exported","{OriginalFormat}":"Traces are being created and exported"}}

[cijothomas]

I try to use a log formatter always it's omitted and the output format is a simple string.

Could you elaborate? I am not sure if I follow the issue. LogRecord.FormattedMessage contains the formatted message as expected. What is missing?

[jose-mf]

You can see in the output that the LogRecord.FormattedMessage and the OriginalFormat contain the same data. It seems the option "includeFormattedMessage" is ignored somehow.
If you execute the code I pasted in the original message you can reproduce the behavior I'm describing.

The expected content in the LogRecord.FormattedMessage should be:

{"EventId":0,"LogLevel":"Information","Category":"Program","Message":"Traces are being created and exported","State":{"Message":"Traces are being created and exported","{OriginalFormat}":"Traces are being created and exported"}}

[cijothomas]

The example uses unstructured logging (in this case a simple string), so the original format and formatted message is same - just the string.

For the logging statement which can be one way of doing structured logging, "logger.LogInformation("Hello from {name} {price}.", "tomato", 2.99)",, the Body will be "Hello from {name} {price}" by default. If IncludeFormattedMessage is true, then the body will be "Hello from tomato 2.99". In both cases, name, price will be printed as key-value pairs too.

Under the hoods, the IncludeFormattedMessage decides if body will be populated from "template" vs the "formattedMessage" which is the result of calling the "formatter" from the Log call. (https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.logging.ilogger.log?view=dotnet-plat-ext-7.0)

Let me know if this clarifies.

[jose-mf]

I didn't understand well the behavior of IncludeFormattedMessage. I thought it was related if the output log message was a simple string or a structured JSON message. Then, Let me rephrase the question:
If I have a logging provider like AddJsonConsole and the output format is in a JSON format, I should see the JSON value in the OriginalFormat property. Or Why is the reason I only see the content of the logger.LogInformation("Hello World"), for example.

I hope it clarifies more my question/problem.

[cijothomas]

IncludeFormattedMessage only determines if we invoke the formatter, which is the last parameter to ILogger.Log call.
It is unrelated to the AddJsonConsoles formatting, which is mostly about how the output is formatted while displaying on console.

See also : #2042 (comment)