Is it possible to use NServiceBus in an application without having any input queues?
Reason is, I have an ASP.NET MVC application that sends messages to other applications when something happens (e.g. a new user registers). The web application never recieves any responses or other messages and therefore I would like not to bog the app. with the msmq peeking which throws an exception every second.
That is supported, just remove the msmstranport config section and all should be fine. This works against 2.0.1281.0 (net4) version of NServiceBus with no app.config present
using NServiceBus;
namespace SendOnlyEndpoint.Custom
{
public class Program
{
static void Main(string[] args)
{
var bus = Configure.With()
.DefaultBuilder()
.XmlSerializer()
.MsmqTransport()
.UnicastBus()
.CreateBus()
.Start();
bus.Send("SendOnlyDestination",new TestMessage());
}
}
public class TestMessage : IMessage
{
}
}
More info on send only endpoints here
I would try not configuring an input queue. Bus.Send will use an internal outbound queue to send messages.
Related
I am using Redis Server for message broker in my spring boot application.
Is there any simple way to Junit my publish and receive API?
e.g :
Publisher :
public String publish(Object domainObj) {
template.convertAndSend(topic.getTopic(), domainObj.toString());
return "Event Published";
}
Receiver :
public class Receiver implements MessageListener {
#Override
public void onMessage(Message message, byte[] bytes) {
System.out.println("Consumed Message {}" + message);
}
}
I am using JedisConnectionFactory and RedisMessageListenerContainer and RedisTemplate for my implementation
#Configuration
#EnableRedisRepositories
public class RedisConfig {
#Bean
public JedisConnectionFactory connectionFactory() {
RedisStandaloneConfiguration configuration = new RedisStandaloneConfiguration();
configuration.setHostName("localhost");
configuration.setPort(6379);
return new JedisConnectionFactory(configuration);
}
#Bean
public RedisTemplate<String, Object> template() {
RedisTemplate<String, Object> template = new RedisTemplate<>();
template.setConnectionFactory(connectionFactory());
template.setKeySerializer(new StringRedisSerializer());
template.setHashKeySerializer(new StringRedisSerializer());
template.setHashKeySerializer(new JdkSerializationRedisSerializer());
template.setValueSerializer(new JdkSerializationRedisSerializer());
template.setEnableTransactionSupport(true);
template.afterPropertiesSet();
return template;
}
#Bean
public ChannelTopic topic() {
return new ChannelTopic("common-channel");
}
#Bean
public MessageListenerAdapter messageListenerAdapter() {
return new MessageListenerAdapter(new Receiver());
}
#Bean
public RedisMessageListenerContainer redisMessageListenerContainer() {
RedisMessageListenerContainer container = new RedisMessageListenerContainer();
container.setConnectionFactory(connectionFactory());
container.addMessageListener(messageListenerAdapter(), topic());
return container;
}
Unit Testing Receiver and Publisher implementation is quite straight.
JUnit 5 coupled with Mockito extension should do the job.
For example for testing that :
public String publish(Object domainObj) {
template.convertAndSend(topic.getTopic(), domainObj.toString());
return "Event Published";
}
I expect that topic and template be fields of the current class.
These fields could be set by constructor.
So you could write something that check that convertAndSend() is eventually executed with the correct parameters :
#Mock
RedisTemplate<String, Object> templateMock;
#Test
void publish(){
Topic topicFixture = new Topic(...);
Object domainObjFixture = new FooBar(...);
Publisher publisher = new Publisher(templateMock, topicFixture);
//when
publisher.publish(domainObjFixture);
// then
Mockito.verify(templateMock)
.convertAndSend(topicFixture.getTopic(), domainObjFixture);
}
But I don't think that the unit test of these two classes be enough because it never tests the final things : the JMS processing performed by Redis backend.
Particularly, the RedisConfig part that you set with specific things as serializers that have important side effects on the processing.
For my part, I try to always write integration or partial integration tests for Redis backend stuffs to ensure a good no regression harness.
The java embedded-redis library is good for that. It allows to start a redis server
on localhost (works on Windows as well as on Linux).
Starting and stopping the redis server is as simple as :
RedisServer redisServer = new RedisServer(6379);
redisServer.start();
// do some work
redisServer.stop();
Move the start() in the #BeforeEach and the stop() in the #AfterEach and the server is ready.
Then it still requires some adjustments to ensure that the redis configuration specified in Spring is well setup during the tests while using your local redis server and not the "real" redis server. Not always simple to set but great when it is done !
The simplest way to unit test this is to use embedded-redis module. What you do is in BeforeAll you can start embedded Redis and stop the embedded Redis in AfterAll method.
You can also PostConstruct PreDestroy annotations to accomplish this.
If you're looking for Junit5 then you can find the code in my repo here
See BootstrapRedis annotation and their usage here
https://github.com/sonus21/rqueue/blob/7ef545c15985ef91ba719f070f7cc80745525047/rqueue-core/src/test/java/com/github/sonus21/rqueue/core/RedisScriptFactoryTest.java#L40
We use Apache Camel in Talend ESB Studio v6.4
In an ESB route, we consume JMS messages, process them then send them to an HTTP server. But that target server is down for maintainance every saturday from 6pm to 10pm.
How can we "pause" message consuming or message processing during that period ? I think quartz only works with file/ftp endpoints.
We could use a Processor component to check in Java if we are in the down period, but what to do after that ?
There are several ways to do this. One camel specific way to do it is through CamelControlBus. It takes in a routeId and performs an action (start/stop/resume etc) on it - Read more here to get an understanding Camel ControlBus
However, there is another approach that you can take. You can create a POJO bean that has 3 methods
shouldRouteStop() : to check the current time and decide if it should stop your route.
startRoute() : Starts a route if it is suspended
stopRoute() : Suspends a route if it is started
A simple implementation can be as follows:
public class ManagementBean {
public boolean shouldRouteStop() {
// Mocking the decision here
return new Random().nextBoolean();
}
public void startRoute(org.apache.camel.CamelContext ctx) throws Exception {
if (ctx.getRouteStatus("GenerateInvoices") == ServiceStatus.Suspended)
// replace the argument with your route Id
ctx.resumeRoute("GenerateInvoices");
}
public void stopRoute(org.apache.camel.CamelContext ctx) throws Exception {
if (ctx.getRouteStatus("GenerateInvoices") == ServiceStatus.Started)
// replace the argument with your route Id
ctx.suspendRoute("GenerateInvoices");
}
}
Make sure that the jms-route that you wish to control has a routeId and add this bean to your base/default CamelContext like this
main.bind("manageRouteBean", new ManagementBean());
Create another timer based route, that checks on each tick, if the route should be stopped or not and then suspends or resumes the route by routeId. This route can be implemented like below:
public class MonitoringRoute extends RouteBuilder {
#Override
public void configure() throws Exception {
onException(Exception.class).log(exceptionMessage().toString());
from("timer:time?period=10000")
.choice()
.when().simple("${bean:manageRouteBean?method=shouldRouteStop}")
.log("Route Should Stop")
.bean(ManagementBean.class, "stopRoute(*)")
.otherwise()
.log("Route Should Start")
.bean(ManagementBean.class, "startRoute(*)")
.end();
}
}
Note that startRoute and stopRoute take the argument as *. This is camel way of automatically binding parameters based on type.
Finally, you can add this route to the main camel context like : main.addRouteBuilder(new MonitoringRoute());
For a complete implementation, have a look at this github repo
I tried to code a 'Hello world' type of exercise to learn Spring Boot support for OAuth2, and the minimum required configuration.
Components:
Authorization server
webapp, which will call the auth server to authenticate the user, and will greet him
Expected flow:
I open the webapp
I get redirected to auth server
I login to auth server
I approve the requested scope
I get redirected back to webapp
I see a greeting (webapp should fetch my username from auth server)
The last point fails with 401:Could not obtain access token.
Last redirect link is http://localhost:9001/ui/login?code=wcXMG4&state=JEEYqC
Am I too naive to assume that the below code&configuration should suffice for my expected flow?
Auth server:
#SpringBootApplication
#EnableAuthorizationServer
#EnableResourceServer
#RestController
public class AuthServer {
public static void main(String[] args) {
SpringApplication.run(AuthServer.class);
}
#GetMapping("/whois")
Principal whois(Principal principal) {
return principal;
}
}
Auth server properties:
server.port=9000
server.contextPath=/sso
security.user.name=joe
security.user.password=password
security.oauth2.client.clientId=SOMEAPP
security.oauth2.client.clientSecret=SECRET
security.oauth2.client.authorized-grant-types=authorization_code,refresh_token,password
security.oauth2.client.scope=read
security.oauth2.resource.userInfoUri=http://localhost:9000/sso/whois
Webapp:
#SpringBootApplication
#EnableOAuth2Sso
#RestController
public class UiServer {
public static void main(String[] args) {
SpringApplication.run(UiServer.class);
}
#GetMapping("/")
String helloWorld(Principal principal) {
return "Yay, auth server provided identity, you are " + principal;
}
}
Webapp properties:
server.port=9001
server.contextPath=/ui
security.oauth2.client.client-id=SOMEAPP
security.oauth2.client.client-secret=SECRET
security.oauth2.client.accessTokenUri=http://localhost:9000/sso/oauth/access_token
security.oauth2.client.userAuthorizationUri=http://localhost:9000/sso/oauth/authorize
security.oauth2.resource.user-info-uri=http://localhost:9000/sso/whois
After spinning up with debug on, it turns out that security.oauth2.client.accessTokenUri is incorrect.
The right endpoint is not .../oauth/access_token, but .../oauth/token.
Probably the tutorial I was looking at used outdated uri.
With that fix, this minimum config does what's expected of it, so I'll close the question.
The real fun begins when you try to customize it, bypassing the defaults; to me it seems that spring oauth still has major bugs, and requires hacky/unexpected approach to work around them in few use cases.
I've read a lot of examples/tutorials (incl. Ayende's Alexandria on MSDN).
But just getting somewhat updated assemblies have proven to be an obstacle in itself. After getting the correct version of Castle.Windsor - it cannot find the correct section in the app.config file. The syntax in both Rhino Service Bus and the CastleBootstrapper has been changed as well - and I'm now totally confused. The 'documentation' on Hibernating Rhinos is really not helping me get started.
Could anyone please help me a working sample with Rhino Service Bus with either Castle Windsor v. 3.0 (beta) or 2.5.3, point me at something already online or just giving me a step-by-step pointers on what I need to get up and running?
after downloading the latest Rhino-ESB bits from github (https://github.com/hibernating-rhinos/rhino-esb) and building it, it's pretty straightforward to get started.
I have a asp.net MVC application which communicates with a backend through Rhino-ESB.
On the asp.net MVC side:
On global.asax.cs:
private IWindsorContainer _container;
protected void Application_Start()
{
_container = new WindsorContainer();
new RhinoServiceBusConfiguration().UseCastleWindsor(_container).Configure();
_container.Install(new YourCustomInstaller());
//Don't forget to start the bus
_container.Resolve<IStartableServiceBus>().Start();
ControllerBuilder.Current.SetControllerFactory(new WindsorControllerFactory(_container));
}
Note that YourCustomInstaller must implement IWindsorInstaller and you register your controllers with the container in the Installmethod:
public void Install(Castle.Windsor.IWindsorContainer container, Castle.MicroKernel.SubSystems.Configuration.IConfigurationStore store)
{
container.Register(Component
.For<HomeController>().LifeStyle.PerWebRequest.ImplementedBy<HomeController>());
Also note that the WindsorControllerFactory internally delegates controller creation to the container:
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType == null)
return null;
return (IController)this.container.Resolve(controllerType);
}
Last but not least, provide the configuration on your web.config
<configSections>
<section name="rhino.esb" type="Rhino.ServiceBus.Config.BusConfigurationSection, Rhino.ServiceBus"/>
</configSections>
<rhino.esb>
<bus threadCount="1"
numberOfRetries="5"
endpoint="rhino.queues://localhost:31316/Client"
queueIsolationLevel="ReadCommitted"
name="Client"/>
<messages>
<add name="YourMessagesNamespace"endpoint="rhino.queues://localhost:31315/Backend"/>
</messages>
</rhino.esb>
This configuration assumes that the backend runs a queue in localhost:31315 and the client runs its queue on localhost:31316.
On the backend side:
assuming we're running it as a console application,
static void Main(string[] args)
{
IWindsorContainer container;
container = new WindsorContainer();
new RhinoServiceBusConfiguration()
.UseCastleWindsor(container)
.Configure();
var host = new RemoteAppDomainHost(typeof(YourBootstrapper));
host.Start();
Console.WriteLine("Starting to process messages");
Console.ReadLine();
Notice that YourBootstrapperclass implements CastleBootstrapper
public class YourBootstrapper: Rhino.ServiceBus.Castle.CastleBootStrapper
{
protected override void ConfigureContainer()
{
Container.Register(Component.For<OneOfYourMessages>());
}
}
in which we're registering a consumer for OneOfYourMessages
I'm trying to build a layer over NServiceBus to make it simpler for other developers to use.
I'm trying to do without the config file and managed to get the publisher to work:
public class NServiceBusPublisher
{
private IBus _Bus { get; set; }
public void NServiceBusPublisher(string argInputQueue, string argErrorQueue)
{
Configure configure = NServiceBus.Configure.With().DefaultBuilder();
var transport = configure.Configurer.ConfigureComponent<MsmqTransport>(ComponentCallModelEnum.Singleton);
transport.ConfigureProperty(t => t.InputQueue, argInputQueue);
transport.ConfigureProperty(t => t.ErrorQueue, argErrorQueue);
transport.ConfigureProperty(t => t.NumberOfWorkerThreads, 1);
transport.ConfigureProperty(t => t.MaxRetries, 5);
_Bus =
configure
.XmlSerializer()
.MsmqTransport()
.IsTransactional(true)
.PurgeOnStartup(false)
.MsmqSubscriptionStorage()
.UnicastBus()
.ImpersonateSender(false)
.CreateBus()
.Start();
}
public void Publish(NServiceBus.IMessage argMessage)
{
_Bus.Publish(argMessage);
}
}
I also want to have an NServiceBus Subscriber and make it possible for developers to subscribe to any number of message types as long as the message inherits from NServiceBus.IMessage:
public class NServiceBusSubscriber
{
private IBus _Bus { get; set; }
public void NServiceBusSubscriber(string argInputQueue, string argOutputQueue, string argErrorQueue, string messagesAssembly)
{
Configure configure = NServiceBus.Configure.With().DefaultBuilder();
var transport = configure.Configurer.ConfigureComponent<MsmqTransport>(ComponentCallModelEnum.Singleton);
transport.ConfigureProperty(t => t.InputQueue, argInputQueue);
transport.ConfigureProperty(t => t.ErrorQueue, argErrorQueue);
transport.ConfigureProperty(t => t.NumberOfWorkerThreads, 1);
transport.ConfigureProperty(t => t.MaxRetries, 5);
var ucb = configure.Configurer.ConfigureComponent<NServiceBus.Unicast.UnicastBus>(ComponentCallModelEnum.Singleton);
ucb.ConfigureProperty(u => u.MessageOwners, new Dictionary<string,string>()
{
{messagesAssembly, argOutputQueue}
});
_Bus =
configure
.XmlSerializer()
.MsmqTransport()
.IsTransactional(true)
.PurgeOnStartup(false)
.MsmqSubscriptionStorage()
.UnicastBus()
.ImpersonateSender(false)
.DoNotAutoSubscribe()
.CreateBus()
.Start();
}
public void Subscribe<T>() where T : NServiceBus.IMessage
{
_Bus.Subscribe<T>();
}
}
The problem is that I couldn't find any way to attach an event handler to a particular message type.
Could you please help me figure this out?
Its been a while since the question has been asked, so I am not sure if the problem has been solved, but here's one way you can do it using Bus.Subscribe (although as has been said by other respondents this is not the prescribed way of doing it NServiceBus)
Subscribe the to the message type using the subscribe overload
void Subscribe(Type messageType, Predicate<IMessage> condition);
Then you can handle the message in the delegate
private bool Handle(NServiceBus.IMessage nsbMsg)
{
//you get the message instance that you can handle
//return true
}
So, your code would then be
class MySubscriber
{
public IBus Bus {get; set;}
public void Subscribe()
{
Bus.Subscribe(typeof(MyMessage), Handle);
}
public void Handle(NServiceBus.IMessage nsbMsg)
{
var msg = nsbMsg as MyMessage;
//your code
return true;
}
}
However please note that by doing this you have to manage the lifetime of the handler yourself, which otherwise would have been managed for you by NServiceBus using the IOC framework of your choice.
You will also have to pass the reference to IBus explicitly which would be injected for you automatically if you were just implementing the IHandleMessage interface.
An architectural point here is that NSB is a full fledged 'ESB', its not just a messaging layer. Adding another layer over your ESB is IMHO an abstraction too many.
I think you are missing the concept behind NServiceBus.
Based on the code you show I get the impression that you envision services that publish messages and others that process those messages. In my experience most processes do both: they subscribe to events or process incoming commands and in result publish new events and send new commands.
In your setup you would need to have publisher and subscriber instances for each of these message types.
NServiceBus is built for the situation I describe. You configure and start 1 bus instance and that orchestrates the complete application.
If you want to make it easier for developers to use NServiceBus I would concentrate on the configuration part only. In our company I have created a ServicebusConfigurator class that configures NServiceBus according our company standards and extracted that in a framework and a simple extension method for the .NET Core generic host. The only code our developers need to write to create a Windows Service that hosts an NServiceBus endpoint is something like this:
internal static class Program
{
private static int Main(string[] args)
{
return (int)Host.CreateDefaultBuilder(args) //.NET Core generic host
.WithNServiceBus() //configure NServiceBus according to our standards and start it.
.UseTopshelf<Worker>() // use Worker as the actual service doing the work.
.EnableNsbInstallersDuringInstall() // Execute any NServiceBus transport specific installation code during install of the service.
.Run(); // Run the thing.
}
}
Since you are not auto-subscribing the first thing you will need to do is subscribe to the message type via Bus.Subscribe(). Others could do this at the IWantToRunAtStartUp extension point(implement the interface in a class somewhere). From there, each subscriber will implement the IHandleMessages<T> interface. Implementing this interface wires you to a message where "T" is the message type.
When NSB starts up it will scan the local bin dir and find all your interface implementations and wire them up on your behalf internally. From there it will dispatch to the correct handler when a message of that type arrives.
NServiceBus automatically handles the subscription of messages. When you invoke Configure.With()....Start(); NServiceBus will scan to determine which assemblies implement IHandleMessages(SomeMessage) and it will send a subscription request to the publisher.
When you add "DoNotAutoSubscribe", you've got to manually get all messages being handled and do a Bus.Subscribe() for each of them.
Beyond that, NServiceBus will automatically handle the routing of an incoming message to the appropriate handler. In your subscriber code above, are you receiving an error message or are the messages disappearing from the queue?