NServiceBus Send-Only endpoints not generating heartbeats

Question

I'm using NServiceBus.Core v6.4.3 and NServiceBus.Heartbeat v2.0.0

I have a console application running as a Scheduled Task, it extracts data and send commands to an endpoint for processing.

The console application is configured as a SendOnly endpoint.

My code is as follows:

Main

// Local NServiceBus Configuration
var endpointConfiguration = EndpointConfiguration();
// Global NServiceBus & Ninject configuration
var conventions = new NServiceBusConventions();
conventions.Customize(endpointConfiguration);
// Create and start endpoint
var endpointInstance = await Endpoint.Start(endpointConfiguration).ConfigureAwait(false);

EndpointConfiguration

private static EndpointConfiguration EndpointConfiguration()
{
    var configuration = new EndpointConfiguration("EndpointName");

    // To ensure OctopusDeploy doesn't cause ServicePulse to think multiple services have been deployed
    // http://docs.particular.net/nservicebus/hosting/override-hostid
    configuration.UniquelyIdentifyRunningInstance()
        .UsingNames("EndpointName", Environment.MachineName);

    configuration.SendOnly();

    return configuration;         
}

Conventions

public class NServiceBusConventions
{
    public IKernel Kernel;

    public void Customize(EndpointConfiguration configuration)
    {
        // Custom Logging Factory implementation
        LogManager.UseFactory(new NServiceBusTraceLoggerFactory());

        Kernel = NinjectCommon.Start();

        configuration.UseContainer<NinjectBuilder>(b => b.ExistingKernel(Kernel));
        configuration.UsePersistence<NHibernatePersistence>();
        configuration.UseSerialization<JsonSerializer>();
        configuration.UseTransport<MsmqTransport>();
        var transport = configuration.UseTransport<MsmqTransport>();
        // Enabled by default in MsmqTransport, but to ensure we have it
        transport.Transactions(TransportTransactionMode.TransactionScope);

        configuration.DefineCriticalErrorAction(NServiceBusOnCriticalError.OnCriticalError);    

        configuration.EnableInstallers();
        configuration.Conventions()
            .DefiningCommandsAs(t => t.Namespace != null && t.Namespace.Equals("Contracts.Commands"))
            .DefiningEventsAs(t => t.Namespace != null && t.Namespace.Equals("Contracts.Interfaces.Events"));

        configuration.AuditProcessedMessagesTo(ConfigurationManager.AppSettings["Messaging.NServiceBus.QueueNames.AuditQueue"]);
        configuration.SendFailedMessagesTo(ConfigurationManager.AppSettings["Messaging.NServiceBus.QueueNames.ErrorQueue"]);
        configuration.SendHeartbeatTo(ConfigurationManager.AppSettings["Messaging.NServiceBus.QueueNames.ServiceControlQueue"]);

        var scanner = configuration.AssemblyScanner();

        var excludeRegexs = new List<string>
        {
            @"DevExpress.*\.dll"
        };

        var baseDirectory = AppDomain.CurrentDomain.BaseDirectory;
        foreach (var fileName in Directory.EnumerateFiles(baseDirectory, "*.dll").Select(Path.GetFileName))
        {
            foreach (var pattern in excludeRegexs)
            {
                if (Regex.IsMatch(fileName, pattern, RegexOptions.IgnoreCase))
                {
                    scanner.ExcludeAssemblies(fileName);
                    break;
                }
            }
        }
    }
}

Removing the configuration.SendOnly(); line in EndpointConfiguration makes the endpoint appear in ServicePulse, but it doesn't appear otherwise.

I knew this was an issue in previous versions, but I thought this had been fixed in NServiceBus V5.

I don't have to configure the endpoint as Send-Only, but I was just for completeness.

Any chance you can share your code, so we can try and investigate? — Sean Farmar
I tried to reproduce this using your code, and can't seem to get that to fail, heartbeats work ok... (works on my machine :-) ), so if you can provide a sample to reproduce it that will help — Sean Farmar

Paddy Paddy · Accepted Answer · 2019-07-04T09:40:43

The reason behind the missing heartbeats was:

I have a console application running as a Scheduled Task, it extracts data and send commands to an endpoint for processing.

The process would start fresh each time and the time taken to extract data, process and send the commands was too short for NServiceBus to get the heartbeat messages sent.

Putting an await Task.Delay(10000) at the end of the application was enough to allow NServiceBus to complete its necessary bootstrapping and didn't impact our SLA.

Thanks to Sean Farmar for his help in diagnosing

NServiceBus Send-Only endpoints not generating heartbeats

1 Answers