I am using spring-cloud-stream 3.2.2 with kafka binder and I am defining a custom retryTemplate to override the default maxAttempts (3) and disable retrying
#StreamRetryTemplate
public RetryTemplate retrier() {
var retry = new RetryTemplate();
retry.setRetryPolicy(new SimpleRetryPolicy(1, new HashMap<>()));
return retry;
}
But when an exception occurs in the consumer still retries 3 times instead of just 1 time
the custom retryTemplate bean doesn't get injected
You must also specify retry-template-name per binding:
https://docs.spring.io/spring-cloud-stream/docs/3.2.2/reference/html/spring-cloud-stream.html#_retry_template
For example:
spring.cloud.stream.bindings.uppercase-in-0.consumer.retry-template-name=retrier
Related
I test a statefull bean with a #QuarkusTest. It keeps a certain state. Obviously, I would like to have a fresh bean for every test. At the moment, each test might modify he current state, which is the effective for a oncoming test. This is highly undersireable and breaks my tests.
Is there a way to force a new bean clean bean getting injected for every test when running a #QuarkusTest?
Eg. A very basic subscription service, which holds the current subscription to avoid double subscriptions:
#ApplicationScoped
public class SubscriptionService {
#Inject
DeviceClient deviceClient;
private final Set<String> subscribedDevices = new HashSet<>();
public void subscribe(String deviceId, Consumer<RadarFrame> consumer){
if(subscriptions.contains(deviceId)){
return;
}
deviceClient.subscribe(deviceId, consumer);
subscriptions.add(deviceId);
}
public void unsubscribe(String deviceId, Consumer<RadarFrame> consumer){
deviceClient.unsubscribe(deviceId);
subscriptions.remove(deviceId);
}
}
I could manually unsubscribe the device after each test, which is a bad small as I use potention untested implemented logic for setup/teardown. It would be nice if a injected bean could be reinitialized before each test on a #QuarkusTest.
Or did I miss another clean option?
#ApplicationScoped beans will be there for the entire life of the container.
The recommended way to do this is to create a reset() method in the bean to later be called in tests. With JUnit 5 this would be something like:
#AfterEach
void tearDown() {
subscriptionService.reset();
}
You can make that method package friendly to limit it's usage.
We are using spring-kafka-2.2.8.RELEASE. I have an specific situation where I need help. I have 4 topics topic, retryTopic, successTopic and errorTopic. If topic fails, should be redirected to retryTopic where the 3 attempts to retry will be made. If those attempts fails, must redirect to errorTopic. In case of sucess on both topic and retryTopic, should be redirected to the sucessTopic. This situation is already implemented based on the question How to retry with spring kafka version 2..2.
But now, I have a new situation where I need to call the retryTopic listener from inside the topic listener based on a business logic error without an Exception been thrown(it already calls the retryTopic when an exception is thrown and it must remain with this behavior). And I also need to know on which retry attempt number the retryTopic is been called as a paramater of the listener bellow.
#KafkaListener(id = "so60172304.2", topics = "retryTopic")
public void listen2(String in) {
RetryTemplate retryTemplate = new RetryTemplate();
retryTemplate.execute(new RetryCallback<Void, RuntimeException>() {
#Override
public Void doWithRetry(RetryContext retryContext) throws RuntimeException {
// Can I get the retry count here? It didn't work
Integer count =RetrySynchronizationManager.getContext().getRetryCount());
return this.doWithRetry(retryContext);
}
});
}
There is no reason you can't call one listener from another (but you won't get retries unless you call it using a RetryTemplate in the first method).
If you use a RetryTemplate configured on the container factory to do the retries (rather than adding a BackOff to the SeektoCurrentErrorHandler in versions 2.3.x and higher), you can obtain the retry count (starting at zero) like this...
#KafkaListener(id = "so60172304.2", topics = "retryTopic")
public void listen2(String in) {
int retryCount = RetrySynchronizationManager.getContext().getRetryCount();
...
}
getContext() will return null if you call this directly from the first method (unless you wrap the call in a RetryTemplate.execute()).
In 2.5.x a delivery attempt header will be available (optionally) even if using the SeektoCurrentErrorHandler with a BackOff instead of using a RetryTemplate in the container factory.
I am moving an asp.net mvc5 application using EF6 to asp.net core MVC 3.0 using EF Core.
In my mvc5 application I have some administrative operation that modify the database and take a long time, so I use a pattern when I create a new DBContext that is not the one that is associated with the request context and then run the task in the background using Task.Run. This has been working fine for years.
In converting to .net core it was unclear how to create a new DBContext in the way that I was doing it in my old codebase. It seems like I should be able to create a Transient DBContext in these cases and all should be fine.
So I created a subclass of MyDbContext called MyTransientDbContex and in my Configure class I added this service:
services.AddDbContext<MyTransientDbContex>(options =>
options.UseSqlServer(
context.Configuration.GetConnectionString("MyContextConnection")),
ServiceLifetime.Transient, ServiceLifetime.Transient);
In my controller I inject the context in the action that needs the transient service and spawn a thread to do something with it:
public ActionResult Update([FromServices] MyTransientContext context) {
Task.Run(() =>
{
try {
// Do some long running operation with context
}
Catch (Exception e) {
// Report Exception
}
finally {
context.Dispose();
}
}
return RedirectToAction("Status");
}
I would not expect my transient context to be disposed until the finally block. But I am getting this exception when attempting to access the context on the background thread:
Cannot access a disposed object. A common cause of this error is disposing a context that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling Dispose() on the context, or wrapping the context in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.
Object name: 'MyTransientContext'.'
And indeed the _disposed flag is set to true on the context object.
I put a breakpoint on the constructer for MyTransientContext and "Made an Object ID" of the this pointer so that I could track the object. This transient object is being created and is the same one that is inject into my controller action. It's also the same object that I'm trying to reference when the exception is thrown.
I tried setting a data breakpoint on the _disposed member in order to get a callstack on when disposed is being set to true, but the breakpoint won't bind.
I also tried overriding the Dispose method on MyTransientContext, and it isn't called until my explicit dispose in the finally block, which is after the exception is thrown and caught.
I feel like I'm missing something fundamental here. Isn't this what the transient services are for? What would dispose a Transient service?
One last detail - MyTransientContext is derived from MyContext, which is in turn derived from IdentityDbContext (Microsoft.AspNetCore.Identity.EntityFrameworkCore.IdentityDbContex)
Edit: The reason that I went down the path of using a Transient was because of this ef core document page: https://learn.microsoft.com/en-us/ef/core/miscellaneous/configuring-dbcontext. It states that "...any code that explicitly executes multiple threads in parallel should ensure that DbContext instances aren't ever accessed concurrently. Using dependency injection, this can be achieved by either registering the context as scoped and creating scopes (using IServiceScopeFactory) for each thread, or by registering the DbContext as transient (using the overload of AddDbContext which takes a ServiceLifetime parameter)."
As xabikos pointed out, this seems to be overriden by the scoping of the asp.net DI system, where it looks like anything created by that system is scoped to the request context, including Transient objects. Can someone point out where that's documented so that I can better understand how to work with the limitations?
f you want manage the lifetime of service, you can instantiate it manually (or use a factory) :
public ActionResult Update()
{
Task.Run(() =>
{
using(var context = new MyTransientContext(...))
{
try
{
// Do some long running operation with context
}
catch (Exception e)
{
// Report Exception
}
}
}
return RedirectToAction("Status");
}
Or you can use IServiceProvider to get and manage a service :
public class MyController
{
private IServiceProvider _services;
public MyController(IServiceProvider services)
{
_services = services;
}
public ActionResult Update()
{
var context = (MyTransientContext)_services.GetService(typeof(MyTransientContext));
Task.Run(() =>
{
using (context)
{
try
{
// Do some long running operation with context
}
catch (Exception e)
{
// Report Exception
}
}
}
return RedirectToAction("Status");
}
}
You mixed the concepts of transient objects that are created by internal DI container asp.net core provides.
You configure the MyTransientContext to be transient in the internal DI system. This practically means that every time a scope is created then a new instance is returned. For asp.net application this scope matches an HTTP request. When the requests ends then all the objects are disposed if applicable.
Now in your code, that is a synchronous action method you spawn a Task with Task.Run. This is an async operation and you don't await for this. Practically during execution this will be started but not wait to finish, the redirect will happen and the request will end. At this point if you try to use the injected instance you will get the exception.
If you would like to solve this you need change to an async action and await on the Task.Run. And most likely you don't need to spawn a new Task. But you need to understand that this is not probably the best way as it will need for the long operation to finish before the redirect takes place.
An alternative to this would be to use a messaging mechanism, and send a message that triggers this operation. And you have another component, like worker service that listens for those messages and process them.
I have a #SessionScoped bean (CDI) that I would like to access and update from a EJB #Asynchronous method. If I pass a reference to a member variable in the bean via the #Asynchronous method's parameters and work with it, assuming the object being passed in is made thread safe, is there any other issues I should be aware of?
Is there any different to be aware if a #ViewScoped bean is used instead?
The only one I could think of would be if the CDI Session Bean timed out however that shouldn't be an issue because the object would be retained as the #Asynchronous method still has a reference to it.
I'm trying to pass off a long running task so as not to hold up the user clicking on a button but still update the session model with the result of the job so the user can see the outcome in a "job viewer" type interface.
Never access frontend classes from backend classes.
Just pass a callback to the EJB method.
#Asynchronous
public void asyncDoSomething(SomeInput input, Consumer<SomeResult> callback) {
SomeResult result = doSomethingWith(input);
callback.accept(result);
}
public void yourSessionScopedBeanMethod() {
yourEjb.asyncDoSomething(input, this::setResult);
}
public void setResult(SomeResult result) {
this.result = result;
}
I set the concurrency to 10 and I can see 10 different thread id but the thread name is all the same. How can set the listener name? I tried container.setBeanName but no luck. Please help. By the way I am use 1.1.2 version
The thread names are unique; it's just that boot's logging configuration truncates the name by default; we will fix the default thread naming but, in the meantime, you can either change the logging configuration or use named executors. Use setConsumerTaskExecutor(execC()) and setListenerTaskExecutor(execL()) on the container's ContainerProperties ...
#Bean
public AsyncListenableTaskExecutor execC() {
ThreadPoolTaskExecutor tpte = new ThreadPoolTaskExecutor();
tpte.setCorePoolSize(15);
return tpte;
}
#Bean
public AsyncListenableTaskExecutor execL() {
ThreadPoolTaskExecutor tpte = new ThreadPoolTaskExecutor();
tpte.setCorePoolSize(15);
return tpte;
}