I have tried defining a process like in the image:
My understanding was that boundary error events would triguer if an error ocurs in the task they are binded to. In this case, tascs A and B are scripts that make an HTTP request. When for some reason the service they call is not available, the code throws an exception (either timeout of empty response). If I do not use the boundary error events, the process simply fails and reports an error.
The idea behind this workflow was that if there was an error of this sort, using the boundary error event, I would direct flow of the process to a task assigned to the administrator. Then the administrator could check if the services were running, and once the error is corrected, could proceed with the proces by executing those tasks again.
Unfortunately, when I use the boundary error event, instead of the process failing as before, it just stays in "in progress" status, but no task gets assigned to the administrator.
Am I using the boundary error events wrong? Or are they simply not working in Processmaker 4?
Definitely the boundary error event is catching the error for some reason, because the task is not failin, but it is not directing the flow to the form that I designed and therefore can not continue with the process.
Well, it turns out that boundary error events work. The issue seem to be related with the assignment that the task had. I assigned it to an "Administrators" group and it didn't work. But when I assign it directly to the Admin user, it worked perfectly.
Related
I am serving my service worker from /worker.js and want it to intercept fetches to /localzip/*, but the fetch event is never fired.
I register it like this:
navigator.serviceWorker.register(
"worker.js",
{ scope: "/localzip/" }
);
And I claim all clients when it activates, so that I can start intercepting fetches from the current page immediately. I am sure that the service worker is activating and that clients.claim() is succeeding.
self.addEventListener("activate", (e) => {
// Important! Start processing fetches for all clients immediately.
//
// MDN: "When a service worker is initially registered, pages won't use it
// until they next load. The claim() method causes those pages to be
// controlled immediately."
e.waitUntil(clients.claim());
});
Chrome seems happy with it and the scope appears correct:
My fetch event handler is very simple:
self.addEventListener("fetch", (e) => {
console.log("Trying to make fetch happen!");
});
From my application, after the worker is active, I try to make a request, e.g.,
const response = await fetch("/localzip/lol.jpg");
The fetch does not appear to trigger the above event handler, and the browser instead tries to make a request directly to the server and logs GET http://localhost:3000/localzip/lol.jpg 404 (Not Found).
I have tried:
Making sure the latest version of my worker code is running.
Disabling / clearing caches to make sure the fetch isn't being handled by the browser's cache.
Hosting from an HTTPS server. (Chrome is supposed to support service workers on plaintext localhost for development.)
What more does it want from me?
Live demo: https://rgov.github.io/service-worker-zip-experiment/
Note that the scope is slightly different, and the fetch is performed by creating an <img> tag.
First, let's confirm you are not using hard-reload while testing your code. If you use hard-reload, all requests will not go through the service worker.
See https://web.dev/service-worker-lifecycle/#shift-reload
I also checked chrome://serviceworker-internals/ in Chrome, and your service worker has fetch handler.
Then, let's check the codes in detail.
After trying your demo page, I found a network request is handled by the service worker after clicking "Display image from zip archive" button since I can see this log:
Service Worker: Serving archive/maeby.jpg from zip archive
Then, the error is thrown:
Failed to load ‘https://rgov.github.io/localzip/maeby.jpg’. A ServiceWorker passed a promise to FetchEvent.respondWith() that rejected with ‘TypeError: db is undefined’.
This is caused by db object is not initialized properly. It would be worth confirming whether you see the DB related issue as I see in your demo. If not, my following statement might be incorrect.
I try to explain some service worker mechanism alongside my understanding of your code:
Timing of install handler
Your DB open code happens in the install handler only. This means DB object will be assigned only when the install handler is executed.
Please notice the install handler will be executed only when it's necessary. If a service worker exists already and does not need to update, the install handler won't be called. Hence, the db object in your code might not be always available.
Stop/Start Status
When the service worker does not handle events for a while (how long it would be is by browser's design), the service worker will go to stop/idle state.
When the service worker is stopped/idle (you can check the state in the devtools) and started again, the global db object will be undefined.
In my understanding, this is why I see the error TypeError: db is undefined’.
Whenever the service worker wakes up, the whole worker script will be executed. However, the execution of event handlers will depend on whether the events are coming.
How to prevent stop/idle for debugging?
Open your devtools for the page then the browser will keep it being alive.
Once you close the devtool, the service worker might go to "stop" soon.
Why does the service worker stops?
The service worker is designed for handling requests. If no request/event should be handled by a service worker, the service worker thread is not necessary to run for saving resources.
Please notice both fetch and message events (but not limited to) will awake the service worker.
See Prevent Service Worker from automatically stopping
Solution for the demo page
If the error is from the DB, this means the getFromZip function should open the DB when db is unavailable.
By the way, even without any change, your demo code works well in the following steps:
As a user, I open the demo page at the first time. (This is for ensuring that the install handler is called.)
I open the devtools ASAP once I see the page content. (This is for preventing the service worker goes to "stop" state)
I click "Download zip archive to IndexedDB" button.
I click "Display image from zip archive" button.
Then I can see the image is shown properly.
Jake Archibald pointed out that I was confused about the meaning of the service worker's scope, explained here:
We call pages, workers, and shared workers clients. Your service worker can only control clients that are in-scope. Once a client is "controlled", its fetches go through the in-scope service worker.
In other words:
The scope affects which pages (clients) get placed under the service worker's control and not which fetched URLs get intercepted.
We have a delayed_job class that gets unprocessable responses for certain API requests. The responses aren't going to change, so there is no point in re-queuing the job when it fails. However we still want to reqeue other failures, just not this one.
I can avoid the re-queue by capture the exception in perform, but then the failure is not even logged. I would like to have it logged as an error, not as a success.
It seems to me there would be a way to indicate certain exception classes as being exempt from re-queuing - is there?
I thought of using the error hook to simply delete the job, but my guess would be that something would explode if the job disappeared out from under DJ while it was processing it.
Any ideas?
Hey I'm developing an iOS application which communicates with an external web service in order to make various kinds of requests.
I'm aware of Murphy's Law "Anything that can go wrong, will go wrong" and that made me think about timeouts. Currently my application does not handle the situation when a request get completed and times out simultaneously. How should I handle such situations?
Without cooperation from the service provider there's not a lot you can do. If your app sees a timeout it cannot from that deduce whether the request actually completed or not. Could be it worked and something in the infrastructure failed to deliver the response, could be that it failed and hence you saw no timely response.
You have some actions you can take that will help the user. I assume that you have available to you the details of the request you attempted to send, your app should keep that locally. You are now in a position to do some useful things:
Some service authors allow you to safely submit the same request twice. So just resubmit, if it previously worked the service will just say "yep, already done that, here's the details|, if not it will just do the work as normal.
Some service authors allow you to query the status of previous request, so you can determine what has been done and what has not.
In some cases there is no IT system way to deal with the problem, the user will need to contact a help desk or call centre. Here having the details of what was previously attempted can be very useful.
I have a web application which i need to be load tested using LoadRunner. When I record the website using vugen it works good and there is no any application bug. But when I tried to replay the script, script failed after login and while navigating to next page, say, Transaction. At the end of log, I receive error:
Action.c(252): Error -26612: HTTP Status-Code=500 (Internal Server Error)
for "http://rob.com/common/transaction
Please help me to resolve this error.
LoadRunner generates HTTP request just as your browser does, this error is the same error you would get if you would go to that URL using your browser. Error code 500 is a generic server error that is returned when there is no better (more specific error to return).
Most likely the login process requires some form of authentication which is protected against a replay attack by using some form of token. It is up to you to capture this token using Correlations in LoadRunner and replay it as the server expects. The Correlation Studio in VuGen should detect and identify the token for you but since authentication methods vary it is sometimes impossible to do this automatically and you will have to create manual correlation. Please consult the product documentation for more details on how to do it. If your website is publicly available online then post its URL and I will try to record the script on my machine.
Thanks,
Boris.
Most common reasons
You are not checking each request for a valid result being returned and using a 200 HTTP status as an assumed correct step without examining the content of what is being returned. As a result when data being returned is incorrect you are not branching the code to handle the exception. Go one to two steps beyond where your business process has come off the rails with an assumptive success and you will have a 500 status message for an out of context action occurring 100% of the time.
Missed dynamic element. Record three times. Compare the code. Address the changing components.
While I was following the guide http://msdn.microsoft.com/en-us/library/vstudio/jj920163.aspx to add Bugs to the task board I ran into an unexpected issue.
Adding the fields to the WIT was successful but when I started adding the form fields I received a very strange error:
Failed to save the 'Bug' Work Item Type to the server. Please contact
your administrator. There was an error contacting the server.
Technical information (for administrator): HTTP code 200: OK
Now I played around trying to find what field was causing the error... I tried every field seperatly and when added seperately they worked, then I tried adding them in pairs, this worked as well, then I tried adding all of them and even this worked!
BUT: When I try to add all of them in a clean group and column I get the error!
This leads me to believe there is some sort of maximum amount of elements in the layout form of a WIT? For now we have left all the fields added to another category but I wanted to ask if someone else had run into this issue and if there is a solution for this?
Since these are all stored as columns in a SQL Server table, the maximum you can add is 1024 (less the TFS standard, which might be around 33 columns?)
If you think this is the problem, check the Tfs_Warehouse..DimWorkItem table and see if you exceed the maximum.
Any chance you can get more information from the event viewer log on the app server, or provide more information about your bug? That message isn't very useful.
For reference -
http://blogs.msdn.com/b/eugenez/archive/2009/05/07/work-item-customization-tidbits-limits-of-complexity-part-13-of-x.aspx
Today we figured out what was going on by using fiddler and more closely monitoring the exchange between Visual Studio and our TFS server. Apparently the request was hitting the Application Firewall that was installed on the TFS server. This is the reason why you receive the vague error HTTP code 200: OK. The Application Firewall replies with a plain HTML page containing a blocked request ID (so you can pass it to your system admin). Once we passed this ID on to our networking team and they adapted the rules there was no longer an issue.
I hope this helps anyone who unexpectedly runs into an Application Firewall on your TFS server like I did.