I was developing a sample application to test the timeout management in saga using NserviceBus.
I am tryin to achieve the following
When a saga started set it's timeout to 1 minute
Before the timeout happens if an update came to the nessage updates the timeout to 5 minutes
My code is like below
public class OrderSaga : Saga<OrderSagaData>,
IAmStartedByMessages<SampleMessage>,
IHandleMessages<UpdateMessage>
{
public override void ConfigureHowToFindSaga()
{
ConfigureMapping<UpdateMessage>(s => s.PurchaseOrderNumber, m => m.Update);
}
public void Handle(SampleMessage message)
{
this.Data.PurchaseOrderNumber = message.Name;
RequestTimeout(DateTime.Now.AddMinutes(1), message.Name);
}
private void Complete()
{
MarkAsComplete();
}
public override void Timeout(object state)
{
Complete();
}
#region IMessageHandler<UpdateMessage> Members
public void Handle(UpdateMessage message)
{
this.Data.PurchaseOrderNumber = message.NewValue;
RequestTimeout(DateTime.Now.AddMinutes(5), message.Update);
}
#endregion
}
}
But here the problem is the timeout is not getting updated to 5 minutes.The timeout still works for 1 minute.
Could you please let me know what is doing wrong here?
Thanks in advance,
Ajai
Saga timeouts can't be updated. They will fire no matter what you do. In your case you will receive both timeouts and given that you call Complete in your timeout handler your saga will end after one minute. You need to add some logic in that takes this into account.
Something like this might do it:
if(!updateReceived or state == ThisTimeoutWasRequestedByMyUpdateHandler)
Complete();
Hope this helps!
Related
I have this flow that I am trying to test but nothing works as expected. The flow itself works well but testing seems a bit tricky.
This is my flow:
#Configuration
#RequiredArgsConstructor
public class FileInboundFlow {
private final ThreadPoolTaskExecutor threadPoolTaskExecutor;
private String filePath;
#Bean
public IntegrationFlow fileReaderFlow() {
return IntegrationFlows.from(Files.inboundAdapter(new File(this.filePath))
.filterFunction(...)
.preventDuplicates(false),
endpointConfigurer -> endpointConfigurer.poller(
Pollers.fixedDelay(500)
.taskExecutor(this.threadPoolTaskExecutor)
.maxMessagesPerPoll(15)))
.transform(new UnZipTransformer())
.enrichHeaders(this::headersEnricher)
.transform(Message.class, this::modifyMessagePayload)
.route(Map.class, this::channelsRouter)
.get();
}
private String channelsRouter(Map<String, File> payload) {
boolean isZip = payload.values()
.stream()
.anyMatch(file -> isZipFile(file));
return isZip ? ZIP_CHANNEL : XML_CHANNEL; // ZIP_CHANNEL and XML_CHANNEL are PublishSubscribeChannel
}
#Bean
public SubscribableChannel xmlChannel() {
var channel = new PublishSubscribeChannel(this.threadPoolTaskExecutor);
channel.setBeanName(XML_CHANNEL);
return channel;
}
#Bean
public SubscribableChannel zipChannel() {
var channel = new PublishSubscribeChannel(this.threadPoolTaskExecutor);
channel.setBeanName(ZIP_CHANNEL);
return channel;
}
//There is a #ServiceActivator on each channel
#ServiceActivator(inputChannel = XML_CHANNEL)
public void handleXml(Message<Map<String, File>> message) {
...
}
#ServiceActivator(inputChannel = ZIP_CHANNEL)
public void handleZip(Message<Map<String, File>> message) {
...
}
//Plus an #Transformer on the XML_CHANNEL
#Transformer(inputChannel = XML_CHANNEL, outputChannel = BUS_CHANNEL)
private List<BusData> xmlFileToIngestionMessagePayload(Map<String, File> xmlFilesByName) {
return xmlFilesByName.values()
.stream()
.map(...)
.collect(Collectors.toList());
}
}
I would like to test multiple cases, the first one is checking the message payload published on each channel after the end of fileReaderFlow.
So I defined this test classe:
#SpringBootTest
#SpringIntegrationTest
#ExtendWith(SpringExtension.class)
class FileInboundFlowTest {
#Autowired
private MockIntegrationContext mockIntegrationContext;
#TempDir
static Path localWorkDir;
#BeforeEach
void setUp() {
copyFileToTheFlowDir(); // here I copy a file to trigger the flow
}
#Test
void checkXmlChannelPayloadTest() throws InterruptedException {
Thread.sleep(1000); //waiting for the flow execution
PublishSubscribeChannel xmlChannel = this.getBean(XML_CHANNEL, PublishSubscribeChannel.class); // I extract the channel to listen to the message sent to it.
xmlChannel.subscribe(message -> {
assertThat(message.getPayload()).isInstanceOf(Map.class); // This is never executed
});
}
}
As expected that test does not work because the assertThat(message.getPayload()).isInstanceOf(Map.class); is never executed.
After reading the documentation I didn't find any hint to help me solved that issue. Any help would be appreciated! Thanks a lot
First of all that channel.setBeanName(XML_CHANNEL); does not effect the target bean. You do this on the bean creation phase and dependency injection container knows nothing about this setting: it just does not consult with it. If you really would like to dictate an XML_CHANNEL for bean name, you'd better look into the #Bean(name) attribute.
The problem in the test that you are missing the fact of async logic of the flow. That Files.inboundAdapter() works if fully different thread and emits messages outside of your test method. So, even if you could subscribe to the channel in time, before any message is emitted to it, that doesn't mean your test will work correctly: the assertThat() will be performed on a different thread. Therefore no real JUnit report for your test method context.
So, what I'd suggest to do is:
Have Files.inboundAdapter() stopped in the beginning of the test before any setup you'd like to do in the test. Or at least don't place files into that filePath, so the channel adapter doesn't emit messages.
Take the channel from the application context and if you wish subscribe or use a ChannelInterceptor.
Have an async barrier, e.g. CountDownLatch to pass to that subscriber.
Start the channel adapter or put file into the dir for scanning.
Wait for the async barrier before verifying some value or state.
I want to schedule a task on Hazelcast that runs at a fixed interval and updates the IMap with some data that I get after hitting a rest endpoint. Below is a sample code:
// Main class
IScheduledExecutorService service = hazelcast.getScheduledExecutorService("default");
service.scheduleAtFixedRate(TaskUtils.named("my-task", myTask), 30, 1);
// Task
#Singleton
public class MyTask implements Runnable, Serializable {
RestClient restClient;
IMap<String, JsonObject> map;
#Inject
MyTask() { // Inject hazelcast and restclient
map = hazelcastInstace.getMap("my-map");
this.restClient = restClient;
}
#Override
public void run() {
Collection<JSONObject> values = map.values(new MyCustomFilter());
for(JSONObject obj : values) {
// query endpoint based on id
map.submitToKey(key, response);
}
}
private static class MyCustomFilter implements Predicate<String, JSONObject> {
public boolean apply(Map.Entry<String, JSONObject> map) {
// logic to filter relevant keys
}
}
}
When I try to execute this on the cluster, I get:
java.io.NotSerializableException: com.hazelcast.map.impl.proxy.MapProxyImpl
Now I need the IMap to selectively query only some keys based on PredicateFilter and this needs to be a background scheduled job so stuck here on how to take this forward. Any help appreciated. TIA
Try making your task also implement HazelcastInstanceAware
When you submit your task, it is serialized, sent to the grid to run, deserialized when it is received, and the run() method is called.
If your task implements HazelcastInstanceAware, then between deserialization and run(), Hazelcast will call the method setHazelcastInstance(HazelcastInstance instance) to pass your code a reference to the particular Hazelcast instance it is running in. From there you can just do instance.getMap("my-map") and store the map reference in a transient field that the run() method can use.
We use LeaderLatch to select leader on my cluster.
we use it like this:
leaderLatch.addListener(new LeaderLatchListener() {
#Override
public void isLeader() {
// create leader tasks runner
}
#Override
public void notLeader() {
// shutdown leader tasks runner
});
leaderLatch.start();
leaderLatch.await();
We also have a graceful shutdown process:
CloseableUtils.closeQuietly(leaderLatch);
now, the problem is when I shutdown a non-leader instance, the await() method throws a EOFException.
This is the code from LeaderLatch itself:
public void await() throws InterruptedException, EOFException
{
synchronized(this)
{
while ( (state.get() == State.STARTED) && !hasLeadership.get() )
{
wait();
}
}
if ( state.get() != State.STARTED )
{
throw new EOFException();
}
}
since I have closed it - the state is not STARTED but CLOSED so empty EOFException is thrown.
Is there a better way?
We use curator-recepies-4.2.0
Regards,
Ido
The contract for await() is to not return until it owns the lock. It has no way of indicating that you don't own the lock other than to throw an exception. I suggest you use the version of await that takes a timeout and returns a boolean. You can then close the lock and check the result of await(). Do this in a loop if you want.
I have a scenario where I call an api in one of my handlers and that Api can go down for like 6 hours per month. Therefore, I designed a retry logic with 1sec retry, 1 minute retry and a 6 hour retry. This all works fine but then I found that long delay retries are not a good option.Could you please give me your experience about this?
Thank you!
If I were you, I would use Rebus' ability to defer messages to the future to implement this functionality.
You will need to track the number of failed delivery attempts manually though, by attaching and updating headers on the deferred message.
Something like this should do the trick:
public class YourHandler : IHandleMessages<MakeExternalApiCall>
{
const string DeliveryAttemptHeaderKey = "delivery-attempt";
public YourHandler(IMessageContext context, IBus bus)
{
_context = context;
_bus = bus;
}
public async Task Handle(MakeExternalApiCall message)
{
try
{
await MakeCallToExternalWebApi();
}
catch(Exception exception)
{
var deliveryAttempt = GetDeliveryAttempt();
if (deliveryAttempt > 5)
{
await _bus.Advanced.TransportMessage.Forward("error");
}
else
{
var delay = GetNextDelay(deliveryAttempt);
var headers = new Dictionary<string, string> {
{DeliveryAttemptHeaderKey, (deliveryAttempt+1).ToString()}
};
await bus.Defer(delay.Value, message, headers);
}
}
}
int GetDeliveryAttempt() => _context.Headers.TryGetValue(DeliveryAttemptHeaderKey, out var deliveryAttempt)
? deliveryAttempt
: 0;
TimeSpan GetNextDelay() => ...
}
When running in production, please remember to configure some kind of persistent subscription storage – e.g. SQL Server – otherwise, your deferred messages will be lost in the event of a restart.
You can configure it like this (after having installed the Rebus.SqlServer package):
Configure.With(...)
.(...)
.Timeouts(t => t.StoreInSqlServer(...))
.Start();
I inherited a Silverlight 5 application. On the server side, it has a DomainContext (service) with a method marked as
[Invoke]
public void DoIt
{
do stuff for 10 seconds here
}
On the client side, it has a ViewModel method containing this:
var q = Context.DoIt(0);
var x=1; var y=2;
q.Completed += (a,b) => DoMore(x,y);
My 2 questions are
1) has DoIt already been activated by the time I attach q.Completed, and
2) does the return type (void) enter into the timing at all?
Now, I know there's another way to call DoIt, namely:
var q = Context.DoIt(0,myCallback);
This leads me to think the two ways of making the call are mutually exclusive.
Although DoIt() is executed on a remote computer, it is best to attach Completed event handler immediately. Otherwise, when the process completes, you might miss out on the callback.
You are correct. The two ways of calling DoIt are mutually exclusive.
If you have complicated logic, you may want to consider using the Bcl Async library. See this blog post.
Using async, your code will look like this:
// Note: you will need the OperationExtensions helper
public async void CallDoItAndDosomething()
{
this.BusyIndicator.IsBusy = true;
await context.DoIt(0).AsTask();
this.BusyIndicator.IsBusy = false;
}
public static class OperationExtensions
{
public static Task<T> AsTask<T>(this T operation)
where T : OperationBase
{
TaskCompletionSource<T> tcs =
new TaskCompletionSource<T>(operation.UserState);
operation.Completed += (sender, e) =>
{
if (operation.HasError && !operation.IsErrorHandled)
{
tcs.TrySetException(operation.Error);
operation.MarkErrorAsHandled();
}
else if (operation.IsCanceled)
{
tcs.TrySetCanceled();
}
else
{
tcs.TrySetResult(operation);
}
};
return tcs.Task;
}
}