Unable to connect to ElasticSearch server causing main thread to block

[li-zheng-hao]

Does this issue relate to a new feature or an existing bug?

• Bug

What version of Serilog.Sinks.Elasticsearch is affected? Please list the related NuGet package.

What is the target framework and operating system? See target frameworks & net standard matrix.

• NET 6

Please describe the current behavior?

When Serilog connects to a closed ElasticSearch server, the main thread will always be blocked （more than 2 minutes, maybe longer）

Please describe the expected behavior?

I want to throw an exception if I can't connect in about 10 seconds

If the current behavior is a bug, please provide the steps to reproduce the issue and if possible a minimal demo of the problem

here is my init function:

public static Logger InitSeialog(IConfiguration configuration)
    {
        const string OUTPUT_TEMPLATE =
            "[{Level}] {ENV} {Timestamp:yyyy-MM-dd HH:mm:ss.fff} {SourceContext} <{ThreadId}>  {Message:lj}{NewLine}{Exception}";
        var config = new LoggerConfiguration()
#if DEBUG
            .MinimumLevel.Debug()
#else
            .MinimumLevel.Information()
#endif
            .Enrich.WithProperty("ENV", configuration["Env"])
            .Enrich.WithMachineName()
            .Enrich.WithThreadId()
            .Enrich.FromLogContext()
            .Enrich.WithExceptionDetails()
            .WriteTo.Console(outputTemplate: OUTPUT_TEMPLATE)
            .WriteTo.File("logs/applog_.log"
                , rollingInterval: RollingInterval.Day
                , outputTemplate: OUTPUT_TEMPLATE);
        // init elasticsearch
        if (String.IsNullOrWhiteSpace(configuration["ElasticSearchUrl"])==false)
            // block here
            config.WriteTo.Elasticsearch(
                new ElasticsearchSinkOptions(new Uri(configuration["ElasticSearchUrl"])) // for the docker-compose implementation
                    {
                        ConnectionTimeout = TimeSpan.FromSeconds(3),
                        AutoRegisterTemplate = true,
                        OverwriteTemplate = true,
                        DetectElasticsearchVersion = true,
                        AutoRegisterTemplateVersion = AutoRegisterTemplateVersion.ESv7,
                        NumberOfReplicas = 1,
                        NumberOfShards = 2,
                        // BufferBaseFilename = "logs/buffer",
                        // RegisterTemplateFailure = RegisterTemplateRecovery.FailSink,
                        FailureCallback = e => Console.WriteLine("Unable to submit event " + e.MessageTemplate),
                        EmitEventFailure = EmitEventFailureHandling.WriteToSelfLog |
                                           EmitEventFailureHandling.WriteToFailureSink |
                                           EmitEventFailureHandling.RaiseCallback,
                        FailureSink = new FileSink("logs/fail-{Date}.txt", new JsonFormatter(), null, null)
                    });

        var logger = config.CreateLogger();
        Log.Logger = logger;
        return logger;
    }