We have a service hook created for one of our projects in ADO. It was going fine until last weekend. Suddenly few webhooks started queued and I am not sure how to force it to get processed. Can someone help me if there is a way to force those items to get processed.
Thanks,
Venu
I am afraid that you cannot get that you want during process.
Under the process, the queued service hooks will not be picked again and will not be processed again.
When the main thread, such as a work item, is running, you cannot forcefully intervene or exit the content that is already queued.
And there is a similar issue also discussing about this situation.
And waiting service hooks are actually coupled, which also depends on your memory, because they actually run in memory. If there are occasional memory loss and other problems during execution, this cannot ensure that all service hooks can be executed as expected.
Or you should interrupt the current process and reduce the service hooks for it. But it is not a good solution.
So it is the best way to add a function that can handle the queued service hooks in the process. But currently there is no such function. Therefore we recommend you submit the suggestion ticket to the Team to suggest them add that feature.
Related
I am making an application which will need to use NestJS' CQRS module, as the requirements naturally lend themselves to that pattern.
Updates to the application logic are expected to be frequent and to happen during busy hours (that's just how my management works...), so the application needs to be able to restart gracefully. However, this means that events started just before the shutdown may not finish, or even if they do, some sagas may not trigger due to some events having happened before the restart... I'd like to ensure that doesn't happen.
I'm aware of NestJS' OnApplicationShutdown and OnApplicationBootstrap hooks, which is exactly for this purpose, but what I'm not sure is what I should do there. How can I capture all events that have unfinished handlers and sagas? Then after a restart, how can I make the event bus aware of the events monitored by sagas, without executing the already executed handlers?
I guess the second part could be worked around with a random ID per event/handler combo, that will be looked up in a log, and if present, the handler will be skipped, and if not, it will be executed and added to the log... But even with such a workaround, I don't see how I could do the first part. There will be a lot of events, and sagas (by definition) execute commands, meaning they have side effects... Even if all commands can become idempotent, the sheer quantity of events and frequent restarts means restarting from the very first command is a no go.
I've seen this package but I'm not sure if it solves this particular use case, or if it's really just logging the events, and pretty much nothing more.
I have read that "Protractor can automatically execute the next step in your test the moment the webpage finishes pending tasks, so you don’t have to worry about waiting"
But, I had to implement waiting(s) or sleeps in my test script to make them all PASS.
Can anyone help to understand this waiting.
Read At :http://www.protractortest.org/#/
Automatic Waiting:
You no longer need to add waits and sleeps to your test. Protractor can automatically execute the next step in your test the moment the webpage finishes pending tasks, so you don’t have to worry about waiting for your test and webpage to sync.
Right, I find this description as confusing as you. I think it describes the ideal world with no network delays and timeouts, no animations and layout issues.
The description originates from the following:
Protractor runs an extra command before performing any action on the
browser to ensure that the application being tested has stabilized.
This extra command is an async script which asks Angular to respond when the application is done with all timeouts and asynchronous requests, and ready for the test to resume.
Now, what does that "application is ready" statement mean? It basically means that, there are no pending requests, promises and "macro tasks" inside the Angular running application (source for angular testability).
From what I understand, this helps to cover most of the timing and waiting issues, but, if there is a pending JS code executed outside of Angular, or if there are any pending animations or other UI-related changes - this may potentially have an effect on your test stability - for instance, an element might not be yet visible or clickable, an input may not yet get enabled etc.
And, this does not actually contribute to the feedback from the end-to-end tests being stable and helpful - for example, in our project we often find ourselves adding browser.wait()s here and there to tackle occasionally failing tests. Also, here is a set of things that helped us to tackle this flakiness:
Protractor flakiness
I have implemented a Notify/Listen mechanism, so when a special request is sent to the web server, using notify I can notify the workers (in Python) that there's a pending request waiting to be processed.
The implementation works fine, but the problem is that if the workers server is restarting, the notification gets lost, since at that particular time there's no listener.
I can implement a service like MQRabbit or similar, but my needs are so simple that implement such a monster is too much.
Is there any way, a configuration variable perhaps, that can give some persistence to the notification mechanism?
Thanks in advance
I don't think there is a way to persist notification channels, but you can simply store the pending requests to a table, and have the worker check for any missed work on startup.
Either a timestamp or a pending/completed flag would work, depending on what kind of work it's doing.
For consistency, you can have the NOTIFY fire from an INSERT trigger on the queue table, and have the worker always check for any remaining work (not just a specific request) when notified.
I have a WCF Windows Workflow (4.5) Workflow Service hosted under IIS and using AppFabric 1.1. The workflow instances are long-running (up to about a week), but much of the time is spent in Delay activities.
This seemed to work fine at first, but when running multiple instances of the workflow at the same time (2+ instances causes this), some of them just never wake up once they've unloaded from memory during the Delay step. When I look at the logs, the errors I find all look like this:
System.OperationCanceledException: The execution of InstancePersistenceCommands has been canceled because the InstanceHandle was freed.
at System.Runtime.AsyncResult.End[TAsyncResult](IAsyncResult result)
at System.ServiceModel.Activities.Dispatcher.DurableInstanceManager.WaitAndHandleStoreEventsCallback(IAsyncResult result)
Unfortunately, I'm not finding any useful information on that error message.
The SuspensionExceptionName and SuspensionReason fields in the AppFabric Persisted Instances Table show System.NullReferenceException: Object reference not set to an instance of an object. But this doesn't happen inside my workflow, only outside.
Additional Info:
I'm running the activity as a Fire & Forget (receive activity, no send)
My workflow calls into other WCF services to fetch data.
I am running this on Server 2012 R2, IIS 8 (not azure)
Workflow Persistence is working. I can reset IIS, reboot... its just when I run 2 instances that it has problems.
I'm definitely not hitting any kind of throttling limits. While the workflow deals with a few MB of data, this issue happens at 2+ instances.
Any idea what might be happening here?
Edit:
I realized I found more information on how the issue operates and never added it to the question. When the delay issue happens, it operates a lot like a static variable getting written by 2 threads.
Here's a visualization:
WF1 Start ---->Do Stuff--->Sleep------------*1----->Cancelled Exception at some point
------WF 2 Start---->Do Stuff------->Sleep->Wake up---------*2------>More Stuff---->End Successfully
*1 - When WF Instance 1 Should Wake up (Same time as WF 2 wakes)
*2 - When WF Instance 2 Should have woken up (Seems to be ignored)
Before anyone asks... I got rid of every static variable, method, class in my code. Nothing is static anymore.
I've been struggling with similar issues for quite a while. I use WFW4 and I find similar errors when a workflow instance is in a long delay.
I don't know what the cause of the problem is, but I have a work around that you might find helpful.
In my case, the errors I get are from Workflow Management Service and say:
Failed to invoke service management endpoint at 'net.pipe://.svc' to activate service '/Alerts/Workflows/.xamlx'. Exception: 'Access is denied.'
These errors start happening sometime between 6 and 30 hours after the instance goes into a long delay.
I have found that if I create a new instance of the workflow when the first instance is in delay and the errors are happening, then Workflow Management Service is able to resume interacting with the first sleeping instance.
So, I made a new workflow whose sole purpose is to periodically launch and then kill instances of the workflow that contains the long delay.
It actually gets a bit more complicated to make this work. I wanted this new workflow to also go to sleep between times when it creates and kills a new instance of the first workflow. But this going to sleep causes the instance of the new workflow to suffer the same problem as the first workflow. So, I modified the new workflow so it does the following:
-- delay for some rather short period, such as 30 minutes
-- create an instance of the first workflow
-- wait a minute
-- kill the just-created instance of the first workflow
-- create a new instance of this new error-preventing workflow
-- terminate
Since having done this, I no longer get the Access is Denied error from Workflow Management Service!
Hope this helps
Turns out my first answer was not correct, but I believe this answer is right, and solves the issue ChrisG is having.
My workaround did not actually work. Took a while for the problem to resurface. 29 hours to be precise - the default time it takes for an app pool to recycle.
So for me, the solution was to make my app pool not recycle. When an app pool recycles while a workflow instance is in a delay activity, the workflowManagementService is not able to wake up the instance and throws Access is Denied errors. If you create a new instance of the workflow after the app pool has recycled, the first instance will pick up where it left off, but sometimes still has problems, which is what I believe is happening to ChrisG.
ChrisG, looking at your visualization, is it possible that an appPool is recycling during the time wf1 is sleeping? I believe that is the cause the exception. If you then launch a new wf instance after *2 has passed (and if an app pool recycle happened prior to *1), that will wake up both wf1 and wf2, but wf1 won't work properly (at least in my experience)
Also, this happens after iisresets and server reboots. To handle those, you need to use IIS7 which allows the web application (as well as the web site) which is hosting the xamlx files to autostart after an iisreset or server reboot. This option is not available in IIS6. See http://www.postseek.com/meta/991815402b369e71ce925cde47ac907d for details
Hope this helps!
I'm looking for a lightweight system that will let me queue up a one-off (non-recurring) task and have it execute at a specific time in the future.
This is for the backend of a game where the user does tasks that are time-based. I need the server to check the status of the user's "job" at the completion time and perform the necessary housekeeping on their game state.
I'm somewhat familiar with Redis, Celery, Beanstalkd, ZeroMQ, et al., but I haven't found any info on scheduling a single unit of work to be executed in the future. (or pop off the queue at a set time) Celerybeat has a scheduler for cron-type recurring tasks, but I didn't see anything for one-off.
I've also seen the "at" command in *nix, but I'm not aware of any frontend for it that can help me manage the jobs.
I realize there are some easy solutions such as ordering keys in Redis and doing a blocking pop, but I'd like to not have to continuously poll a queue to see if the next job is ready.
The closest I've found is the deferred library on GAE, but I was hoping for something that runs on my own Linux box along with my other components.
I'd appreciate any suggestions!
Celery allows you to specify a countdown or an ETA at the call of a task to be executed.
The documentation says it best:
http://docs.celeryproject.org/en/latest/userguide/calling.html#eta-and-countdown