[bug] Exporting logs with OtlpExporter and grpc not working.

[pravinpushkar]

Package

OpenTelemetry

Package Version

Package Name	Version
OpenTelemetry.Api	1.11.1
OpenTelemetry	1.11.1
TBD	TBD

Runtime Version

8

Description

This seems still reproducible with 1.11.1.

Related issue - #6067
#6083

Steps to Reproduce

Here is samle code -

string loggingendpoint = Environment.GetEnvironmentVariable("LOGGING_GRPC_ENDPOINT") ?? "localhost";

if (string.IsNullOrEmpty(loggingendpoint))
{
    Console.WriteLine("No logging endpoint provided.");
}
AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);

Console.WriteLine($"Logging endpoint: {loggingendpoint}");
using var loggerFactory = LoggerFactory.Create(builder =>
{
    builder.AddOpenTelemetry(options =>
    {
        options.IncludeScopes = true;
        options.IncludeFormattedMessage = true;
        options.AddConsoleExporter();
        options.AddOtlpExporter((exOpt, pOpts) =>
        {
            exOpt.Endpoint = new Uri($"http://{loggingendpoint}");
            exOpt.Protocol = OtlpExportProtocol.Grpc;
        });
    });
});

var logger = loggerFactory.CreateLogger("Log");

using (logger.BeginScope(new List<KeyValuePair<string, object>>{
                    new KeyValuePair<string, object>("category", "OTLPLOGExporter"),
                }))
{
    logger.LogInformationWithDetails($"LOGGING_GRPC_ENDPOINT {loggingendpoint}");

    logger.LogInformationWithDetails("All Done!");
    // to flush the in-memory buffer and ensure all logs are exported.

    loggerFactory.Dispose();
}

Expected Result

Logs successfully exported

Actual Result

Logs not able to get exported. No errors.

Additional Context

No response

[Kielek]

To make it your example working I need to change LogInformationWithDetails to LogInformation and I changed localhost to localhost:4317.

Results (same for .NET8 and .NET9):

splunk-collector-1  | 2025-02-19T11:38:16.318Z  info    ResourceLog #0
splunk-collector-1  | Resource SchemaURL:
splunk-collector-1  | Resource attributes:
splunk-collector-1  |      -> telemetry.sdk.name: Str(opentelemetry)
splunk-collector-1  |      -> telemetry.sdk.language: Str(dotnet)
splunk-collector-1  |      -> telemetry.sdk.version: Str(1.11.1)
splunk-collector-1  |      -> service.name: Str(unknown_service:dotnet-6142)
splunk-collector-1  | ScopeLogs #0
splunk-collector-1  | ScopeLogs SchemaURL:
splunk-collector-1  | InstrumentationScope Log
splunk-collector-1  | LogRecord #0
splunk-collector-1  | ObservedTimestamp: 2025-02-19 11:38:16.1039371 +0000 UTC
splunk-collector-1  | Timestamp: 2025-02-19 11:38:16.1039371 +0000 UTC
splunk-collector-1  | SeverityText: Information
splunk-collector-1  | SeverityNumber: Info(9)
splunk-collector-1  | Body: Str(LOGGING_GRPC_ENDPOINT localhost:4317)
splunk-collector-1  | Attributes:
splunk-collector-1  |      -> {OriginalFormat}: Str(LOGGING_GRPC_ENDPOINT localhost:4317)
splunk-collector-1  |      -> category: Str(OTLPLOGExporter)
splunk-collector-1  | Trace ID:
splunk-collector-1  | Span ID:
splunk-collector-1  | Flags: 0
splunk-collector-1  | LogRecord #1
splunk-collector-1  | ObservedTimestamp: 2025-02-19 11:38:16.1244879 +0000 UTC
splunk-collector-1  | Timestamp: 2025-02-19 11:38:16.1244879 +0000 UTC
splunk-collector-1  | SeverityText: Information
splunk-collector-1  | SeverityNumber: Info(9)
splunk-collector-1  | Body: Str(All Done!)
splunk-collector-1  | Attributes:
splunk-collector-1  |      -> {OriginalFormat}: Str(All Done!)
splunk-collector-1  |      -> category: Str(OTLPLOGExporter)
splunk-collector-1  | Trace ID:
splunk-collector-1  | Span ID:
splunk-collector-1  | Flags: 0
splunk-collector-1  |   {"kind": "exporter", "data_type": "logs", "name": "debug/debug"}

Could you please prepare more detailed steps to reproduce? docker compose file could be beneficial to reproduce it.

[pravinpushkar]

@Kielek Thanks a lot for responding quickly.

I need to change LogInformationWithDetails to LogInformation and I changed localhost to localhost:4317.

Sorry, These are my local setup method and need to change it accordingly. The output above shows from console exporter, which work fine for me as well with docker a image. These logs are not actually reaching the grpc receiver.

The same code when I use it with 1.10.0 open telemetry SDK, it works fine and logs are reaching the grpc receiver.

[Kielek]

It is debug log from the collector with grpc receiver

[pravinpushkar]

ok, it it a bit strange that this code works with 1.10.0 but not with 1.11.1.

[Kielek]

As you see, it is working with 1.11.1 for me. Can you share Minimal, Reproducible Example?

[rajkumar-rangaraj]

@pravinpushkar This could be related to #6138. Can you validate this?