I have two application's running independently of one another. At present, ApplicationSend is web-based and ApplicationReceive is desktop-based, but tomorrow it might be the opposite. There are no Multiple UI.
The ApplicationSend keep logging info into the database or Text file. when the ApplicationSend logs info, it needs to display in ApplicationReceive at the same time without any delay.
The ApplicationReceive uses rest API to display the data.
I have two questions:
How this can be achieved in C#. Please note the application's are
completely unaware of each other. Also one application can be
Windows and other can be web.
When the REST API Display 10 logs, next time should it query for all
the logs or only the updated logs?. Ideally it should be only
updated logs. But how would one get the updated logs
Related
Background: I have an ASP.NET Core App and have an API method that takes a file name of a blob that the frontend has uploaded to Azure Blob. It then needs to create a thumbnail version of the blob and return the name of the newly uploaded thumbnail Blob. Sometimes, for exactly the same file size it can take up to 40 seconds to complete. Mostly, it's around 400ms.
Below is the end to end from App Insights, I have a few things I don't understand:
1) The request duration is 37.5 s but yet the other operations add up to nowhere near this time
2) Why are there calls to master db? We are using EF6 with multiple contexts
3) The app is using an Azure App Service and SQL Azure. I don't understand why the response time is so inconsistent.
Any help would be much appreciated!
I've noticed multiple time that the first request after an application is deployed to Azure or after a long period that no requests were made to the application, it takes significantly longer to get a response.
As far as I remember it was related to start-up time of the site (if you're using an App Service on Windows based underlying VM it still uses IIS as a reverse proxy).
I solved the issue by configuring health checks that occasionally perform requests to the app.
Also, in addition to Application Insights (which logs information only after the application has started), you can try the tools listed here to see more information.
Hope it helps!
1.
The way the request timeline is displayed gives you only the time-span for the whole request (37.5s) and the individual time-spans for each dependency.
A dependency being another call that sends its run-time to the application insights.
In your example each call to the database is automatically tracked as a dependency. The code running after each database call is not though.
So e.g. requesting a database entry which takes 200ms and then issuing a Thread.Sleep of 2 seconds and requesting another database entry which takes 300ms would result in a 2 second gap between the two database-call dependencies which will each be listed with 200/300ms respectively.
You can use TelemetryClient.TrackDependency to wrap parts of your own code into its own dependency. This way you will see your own code as an entry on the request timeline.
2.
Depending on your EntityFramework database-initialisier EF will connect to the master db on context creation. (E.g. to create the database if it does not exist).
3.
Try tracking your own code to find out what parts of it are slow. EF has a few performance issues to consider, try to understand the performance caveats of the libs you use. If your calls are inconsistently slow it might be an issue with resources being over-utilized or caches being emptied too early (like for EF warm vs. cold queries).
I'm using Application Insights in multi-component mode, all my telemetry goes to one AI resource. I have two web apps that run an in-browser client each.
In the application map, I correctly get all a rectangle for all the different parts of the system - except for the client business. All client activity shows as "Client: production": ("production" is the name of the AI resource.)
There are actually two such "Client: production" rectangles, each one visible only when selecting the respective server app. That sounds about right, but: If I click on related metrics, I get this filter:
That obviously contains metrics for all clients, not just the selected one. Is there no way to properly separate the two?
There is a current limitation of multi-component application map that neither Availability nor Client telemetry honor multi-component. We're working on fixing it.
I've had Application Insights set up on my ASP.NET project for a couple months with no issues. I use Custom Events for logging certain events.
Recently, I tried to add a Custom Event after a user has authenticated in order to track the login behavior. My custom event DOES log to application insights debug session. I know this because I can see it in the telemetry when paused on a breakpoint just after the event.
However, when I continue running the application, my custom event no longer shows up the telemetry. It just disappears.
I cannot understand what the issue is. Does anyone familiar have any (application) insights? I couldn't help myself ;)
There are some things to check:
are you logging to one resource (iKey) and searching on another? (a lot of people send data to one resource in dev/debug and a different resource in release/prod environments. so make sure you're sending to the place you expect, and searching the place you expect.
is the data actually going out successfully? you may need to use fiddler or some other tool to watch your outbound http for calls to dc.services.visualstudio.com. It could somehow be the case that there's something wrong with the data you're sending, or maybe you're getting capped or throttled by the service. If that's the case, the outbound requests will have responses other than 200, and will generally tell you the reason it didn't accept any items that it rejected.
if the data is getting successfully sent and is going where you expect it to go, there might just be a delay in backend processing. you can always check aka.ms/aistatus to see if there are any current issues with the service.
I am confused, however, by what you mean when you say
However, when I continue running the application, my custom event no longer shows up the telemetry. It just disappears.
What do you mean "it just disappears" ? if you see it in the output window, then the SDK saw it, and it will get sent, precluding any of the above 3 items. Where is it "disappearing" from? unless you clear the output window, it's never gone from there. If you're talking about the VS search tools that show data sent by the AI SDK during debug, that tool currently has a cap of the most recent 250 items that have occurred during the debug session.
I need to invoke a long running task from an ASP.NET page, and allow the user to view the tasks progress as it executes.
In my current case I want to import data from a series of data files into a database, but this involves a fair amount of processing. I would like the user to see how far through the files the task is, and any problems encountered along the way.
Due to limited processing resources I would like to queue the requests for this service.
I have recently looked at Windows Workflow and wondered if it might offer a solution?
I am thinking of a solution that might look like:
ASP.NET AJAX page -> WCF Service -> MSMQ -> Workflow Service *or* Windows Service
Does anyone have any ideas, experience or have done this sort of thing before?
I've got a book that covers explicitly how to integrate WF (WorkFlow) and WCF. It's too much to post here, obviously. I think your question deserves a longer answer than can readily be answered fully on this forum, but Microsoft offers some guidance.
And a Google search for "WCF and WF" turns up plenty of results.
I did have an app under development where we used a similar process using MSMQ. The idea was to deliver emergency messages to all of our stores in case of product recalls, or known issues that affect a large number of stores. It was developed and testing OK.
We ended up not using MSMQ because of a business requirement - we needed to know if a message was not received immediately so that we could call the store, rather than just letting the store get it when their PC was able to pick up the message from the queue. However, it did work very well.
The article I linked to above is a good place to start.
Our current design, the one that we went live with, does exactly what you asked about a Windows service.
We have a web page to enter messages and pick distribution lists. - these are saved in a database
we have a separate Windows service (We call it the AlertSender) that polls the database and checks for new messages.
The store level PCs have a Windows service that hosts a WCF client that listens for messages (the AlertListener)
When the AlertSender finds messages that need to go out, it sends them to the AlertListener, which is responsible for displaying the message to the stores and playing an alert sound.
As the messages are sent, the AlertSender updates the status of the message in the database.
As stores receive the message, a co-worker enters their employee # and clicks a button to acknowledge that they've received the message. (Critical business requirement for us because if all stores don't get the message we may need to physically call them to have them remove tainted product from shelves, etc.)
Finally, our administrative piece has a report (ASP.NET) tied to an AlertId that shows all of the pending messages, and their status.
You could have the back-end import process write status records to the database as it completes sections of the task, and the web-app could simply poll the database at arbitrary intervals, and update a progress-bar or otherwise tick off tasks as they're completed, whatever is appropriate in the UI.
I’ve been asked if we can optionally “single-instance” our web portal. See
this post on Hanselman's blog for the same idea in a WinForms app.
Suppose we have 2 shortcuts on the same client machine:
http://MyServer/MyWebPortal/Default.aspx?user=username&document=Foo
http://MyServer/MyWebPortal/Default.aspx?user=username&document=Bar
Clicking on the first shortcut would launch our web portal, log in, and display the document “Foo”. Clicking on the second shortcut should display the document “Bar” in the running instance of the web portal.
My current approach is this: In the Page Load, for the first instance create a per-client Application variable. The second instance looks for the Application variable to see if the portal is running on the client. If it is, the second URL is recorded in another Application variable and the second instance is forcibly exited. I’ve tried creating a ASP.Net AJAX Timer to poll the Application variable for a document to display. This sort of works. In order to respond quickly to the second request I’ve set the Timer interval to 2 seconds. This makes the portal irritating to use because of the frequent postbacks.
Using my approach, is there a way for the second instance to notify the first instance to check the application variable without polling? Is there a better overall approach to this problem?
Thanks in advance
There is no way on the server side to control which browser instance your page opens up on the client. You can't force all requests to open in the same browser window.
Also, an Application scope variable is shared by all users of your application. At least make this a Session-scope variable - otherwise you would only be allowing one user to access your portal at a time!
Honestly this sounds like a silly request from someone who a) probably doesn't understand how these types of things work and b) is trying to do an end-around for users who aren't that bright and actually see a problem with having more than one instance of your portal open.