Unable to cast object of type 'Serilog.Sinks.Graylog.Batching.PeriodicBatchingGraylogSink' to type 'Serilog.Core.ILogEventSink'

[cubed-it]

Hey there, I have just upgraded to 3.0.1 and was wondering about the following error:

Unhandled exception. System.InvalidCastException: Unable to cast object of type 'Serilog.Sinks.Graylog.Batching.PeriodicBatchingGraylogSink' to type 'Serilog.Core.ILogEventSink'.
   at Serilog.Sinks.Graylog.Batching.LoggerConfigurationGrayLogExtensions.Graylog(LoggerSinkConfiguration loggerSinkConfiguration, BatchingGraylogSinkOptions options)

Thanks!

[da9l]

I've encountered the same problem during runtime.

A strange thing I see in the code is:
https://github.com/whir1/serilog-sinks-graylog/blob/01d4630424120db1ea21de35c33cd2feb47915a6/src/Serilog.Sinks.Graylog.Batching/LoggerConfigurationGrayLogExtensions.cs#L22

The PeriodicBatchingGraylogSink that implements IBatchedLogEventSink is being casted to the unrelated (!?!) ILogEventSink.
My day gig language is not C# so I'm not sure when this is expected to work (if all..)

    public static class LoggerConfigurationGrayLogExtensions
    {
       ///...
        public static LoggerConfiguration Graylog(this LoggerSinkConfiguration loggerSinkConfiguration,
                                                  BatchingGraylogSinkOptions options)
        {
            var sink = (ILogEventSink)new PeriodicBatchingGraylogSink(options);
            return loggerSinkConfiguration.Sink(sink, options.MinimumLogEventLevel);
        }

I'd say the bug is introduced in 3.0.0. The PeriodicBatchingGraylogSink class is not tested so this bug should be possible to expose with a creation test.
Downgrading this nupkg to 1.3.0 seems to be an acceptable workaround.

[danielwertheim]

It seem to be due to this commit whir1@9e99541#diff-ef82283a7d82597f28e186bce8c709b7c6a276a57ff723c3e845b532e26e3b20L14

Before that, it extended the PeriodicBatchingSink in Serilog which implements ILogEventSink: https://github.com/serilog/serilog-sinks-periodicbatching/blob/dev/src/Serilog.Sinks.PeriodicBatching/Sinks/PeriodicBatching/PeriodicBatchingSink.cs#L26

[danielwertheim]

@whir1

Is it supposed to be something in the lines of this?

var sink = new PeriodicBatchingSink(new PeriodicBatchingGraylogSink(options), new PeriodicBatchingSinkOptions
{
    BatchSizeLimit = options.BatchSizeLimit,
    QueueLimit = options.QueueLimit,
    Period = options.Period,
});

return loggerSinkConfiguration.Sink(sink, options.MinimumLogEventLevel);

[danielwertheim]

Also, why has it been locked to UDP? When applying the workaround above in own extension method it didn't use HTTP that I configure it to via config.

Found this: https://github.com/whir1/serilog-sinks-graylog/blob/master/src/Serilog.Sinks.Graylog.Batching/LoggerConfigurationGrayLogExtensions.cs#L85

Hardcoded to UDP.

[danielwertheim]

Also, why has it been locked to UDP? When applying the workaround above in own extension method it didn't use HTTP that I configure it to via config.

Found this: https://github.com/whir1/serilog-sinks-graylog/blob/master/src/Serilog.Sinks.Graylog.Batching/LoggerConfigurationGrayLogExtensions.cs#L85

Hardcoded to UDP.

This seems to have been solved at least. Maybe other issues as well?