My code performs the following:
1)Create grpc channel
2)start monitoring completion queue in a different thread
3)Issue shutdown on completion queue
After executing step 3, I expect "(cq.Next(&tag, &ok)" to return false as there are no pending events with above 3 steps. But it is observed that "(cq.Next(&tag, &ok)" never returns false. Please let me know if I am missing something.
Thanks,
Ikshu
In order to get channel state notification, a tag was being added to the queue and that use to always post some events. so the cq->next() never returned false. I fixed this issue by achieving same functionality by using already existing standard API for channel state. So closing the bug.
Related
We have implemented a saga that has a timeout method and worked as expected. Later we wanted to add one more timeout method. So, I have added it to the same saga but the second timeout is not getting called. These two messages will be called at a time. Can we have two IHandlerTimeouts in a single saga?
public class SagaPolicy1 : Saga<SagaPolicyData>,
IAmStartedByMessages<OrderPlacedCommand>,
IHandleTimeouts<TimoutMsg1>,//timespan 20min
IHandleTimeouts<TimoutMsg2>
await RequestTimeout<TimoutMsg1>(context, TimeSpan.FromSeconds(1200));
await RequestTimeout<TimoutMsg2>(context, TimeSpan.FromSeconds(360));
The short answer is yes. The documentation explicitly calls it out. Remember that a timeout can be queued after its saga has been completed (using MarkAsComplete()). Because a timeout is tied to a specific saga instance, it will be ignored once the saga instance is completed.
I have a queue at NiFi that contains the items that will be processed through an API query (invokeHTTP). These items can be processed and return the answer with the data correctly (status 200), they can not be found (status 404) and also a failure (status 500).
However, in the case of status 404 and 500, false negatives can happen, so if I consult the same data that gave an error again, it returns with status 200. But there are cases that there really is a failure and it is not a false negative.
So I created a queue for retry and failure for them to enter involeHTTP again and consult the API. I put an expiration time of 5 minutes so that the data that is really at fault is not forever consulting the API.
However, I wanted to prioritize this Failure and Retry queue, so that by the time a data reaches it, it will be consulted in the API again, in front of the standard processing queue, so as not to lose the data that gave false negatives.
Is it possible to do this treatment with this self relationship or do you need a new flowfile?
Each queue can have a prioritizer configured on the queue's settings. Currently you have two separate queues for InvokeHttp, the failure/retry queue and the incoming queue from the matched relationship of EvaluateJsonPath. You need to put a funnel in front of InvokeHttp and send both of these queues to the funnel, then the funnel to InvokeHttp. This way you can create a single incoming queue to InvokeHttp and configure the prioritizer there.
In order to prioritize it correctly, you may want to use Flow File Attribute prioritizer. You would use UpdateAttribute to add a "priority" attribute to each flow file, the ones for failure/retry get priority "A" and the others get priority "B" (or anything that sorts after A).
Background
We have an app that deals with a considerable amount of requests per second. This app needs to notify an external service, by making a GET call via HTTPS to one of our servers.
Objective
The objective here is to use HTTPoison to make async GET requests. I don't really care about the response of the requests, all I care is to know if they failed or not, so I can write any possible errors into a logger.
If it succeeds I don't want to do anything.
Research
I have checked the official documentation for HTTPoison and I see that they support async requests:
https://hexdocs.pm/httpoison/readme.html#usage
However, I have 2 issues with this approach:
They use flush to show the request was completed. I can't loggin into the app and manually flush to see how the requests are going, that would be insane.
They don't show any notifications mechanism for when we get the responses or errors.
So, I have a simple question:
How do I get asynchronously notified that my request failed or succeeded?
I assume that the default HTTPoison.get is synchronous, as shown in the documentation.
This could be achieved by spawning a new process per-request. Consider something like:
notify = fn response ->
# Any handling logic - write do DB? Send a message to another process?
# Here, I'll just print the result
IO.inspect(response)
end
spawn(fn ->
resp = HTTPoison.get("http://google.com")
notify.(resp)
end) # spawn will not block, so it will attempt to execute next spawn straig away
spawn(fn ->
resp = HTTPoison.get("http://yahoo.com")
notify.(resp)
end) # This will be executed immediately after previoius `spawn`
Please take a look at the documentation of spawn/1 I've pointed out here.
Hope that helps!
I am using rabbitmq to for messaging in my service. Lets suppose there are 2 micro service A and B.
there are more 3 exchange and respective queue is there in between.
A is publisher and B is consumer here. while sending message from A it is successfully updating in queue( able to see in console queue is increases). But here consumer is not able to receive messages. previously it was working.
but for other exchange and queue , consumer is working fine.
I tried purze the queue and restarted application , didnt helped me. there is always 4 unached message in queue and rest is ready to Go. finally I deleted queue and exchange and respective routing key and recreated the same. then all working fine..
Can any one help me here what happened to this. Why it didnt worked?
Sometimes when some failure occur for message processing then if we throw error. it stucks there so go in infinite loop(queue-> processing -> queue > .....) if method keep throwing error.
for other messages who all are in queue, by increasing the batch concurrency we can execute the other. but unack message will be there.that will only go if someone stop consumer..
Now I have one question can i set limit retry for unacked message processing. if some one knows about it then can help here.
In Flex, I'm making a set of asynchronous calls:
service.method1.send().addResponder(responder1);
service.method2.send().addResponder(responder2);
service.method3.send().addResponder(responder3);
I want to execute some code after all of these service calls have returned (either success or failure, I don't care which). How can I do this?
Implement a CallResponder that will monitor the results from each responder & increment a variable in the listener after each result. When the variable hits three, execute some code.