When IIS Server is the outage, the server is restarted and all applications and web APIs are restarted as well, the problem I'm facing that some Web API depends on BUS. Could we let site/app wait until BUS ready before starting from IIS without touching the application code? In Docker, we can use the WAIT command or other third parties to wait until service is available before starting a container.
The Web API we are built on .Net Core 3.1
Any help is appreciated.
During the startup could you use something like
https://github.com/App-vNext/Polly to enter a period of retry
(https://github.com/App-vNext/Polly#retry). This would allow you to
retry the call to the API until it's hopefully it's available.
Use a windows service to monitor heartbeats of the applications and trigger application pool restarts on applications not working correctly. This should help you get into a running state.
Ultimately I'd try and remove this dependency, if you could give a little more information around the webapi requirements I'd be happy to suggest more ideas.
Related
I am evaluating Hangfire for an upcoming ASP.net Core project that has several scheduled and reoccurring tasks that need to execute independently of users clicking on web pages. I know that HangFire can do this if the web application is started because a request has come in. I need to know whether or not HangFire can execute a scheduled task between being rebooted and the first web request coming in.
Example: Web server is rebooted at 11pm, and no web requests will come in to cause the web server to spin up until 5am the next morning. A scheduled task needs to be performed at 1AM. Will Hangfire execute this task even though the web application hasn't been started by an incoming request?
If it can, is there a certain setup I need to do to allow this?
Details, if needed:
We are going to be using Kestrel hosted in a windows service and sitting behind an NGINX reverse proxy. This setup could be modified if needed to make HangFire meet this requirement.
When running under IIS it would be a real problem, see Making ASP.NET application always running
But it should not be problem for ASP.NET CORE with kestrel, see
It is not necessary for ASP.NET Core, because application is exposed
by a console application that it already always on – there are no
timeouts, no suspends and other optimization techniques yet. All you
need to do is to use supervisor as written in the official docs for
Linux, or use Windows Service with automatic start time, when running
on Windows.
I have a couple of wcf services which will call a registration service at startup (through a custom ServiceHostFactory). All these services (including the registration service) are running in the same app pool. I installed appfabric to auto-start all the services. I won't explain all the detailed settings (because I think it's not necessary yet), but in short, the services use net.tcp bindings and is running in IIS 7.5 on Windows 7.
The problem:
When I set all services to auto-start it will begin with one (random) service, this service tries to connect to the registration service. But somehow this registration service won't start-up. It looks like it wants to start all services sequentially.
The (not wanted) solution 1:
When I put the registration service in it's own app pool everything works fine and alle services come online in a matter of seconds and register themself.
The (not wanted) solution 2:
When I disable the auto-start and try to access one of the services after a iisreset, it all works fine. The service will try to register itself and the registration service in his turn will start.
I'm new to appfabric, so it might be some simple configuration issue. The weird thing though is that it won't work whith auto-start, but seems to work fine with a manual start.
Any idea's?
There is no priority in AppFabric Auto Start feature. You can't assume that one service will always be started before the others. Also, you can't assume they will start all at the same time.
For the specific scenario, it's recommanded to use WCF 4.0 Discovery and Announcement. Announcement feature enables service to announce their availability (by sending Hello and Bye announcements) whereas Discovery feature allow clients to discover service address at runtime.
All your services are on the same server ? could be pertinent to use a namedPipeBinding.
I need to create a Windows Service to watch a folder on our network and action files that are placed within it. The process is quite slow and I need the ability to check the progress from a client application (which will be running in about 10 places on the same network as the machine running the Windows service).
Is hosting some WCF service in the windows service the right way to go about this and if so, are there any resources on how I would do this?
Thanks!
it seems a reasonable approach to me.
you can get details of how to host a WCF service inside a windows service in the MSDN how to
This code project page also has an example.
you might need to debug start up issues with the service, and I find adding a
Debugger.Launch();
to the beginning of the OnStart method is the easiest way of doing that. it enables you to debug through the start up process of your service and see any exceptions that occur.
I'm running AppFabric on IIS7 with Windows 7 for development.
AppFabric works fine for some period of time, but then it will stop updating.
I can send service requests through, and AppFabric doesn't show them in the dashboard when I refresh it.
I think a service is stopping, or there's a permission issue. Does anyone know what services are required to for AppFabric to run properly?
SQL Server and AppFabric Event Collection Service, off the top of my head (for event collection; there are other services, but since you say AppFabric itself runs requests, I presume they're OK). There's also Event Tracing for Windows, but it's not, strictly speaking, a service.
I presume you've also checked the tracking profile is set correctly and have looked in the Application event log?
We have a WCF Service using a wsHttpBinding. When it recieves many requests in a short period of time (25 per second for a few minutes) it stops working and our other asp.net applications and pages to stop responding as well. Some of them timeout and eventually we see the following in the event viewer:
ISAPI 'c:\windows\microsoft.net\framework\v2.0.50727\aspnet_isapi.dll' reported itself as unhealthy for the following reason: 'Deadlock detected'.
Often we get calls about the problem first and restart IIS to solve the problem.
How can we configure our WCF service to handle this many transmissions or at least configure it to not take down our other applications when it can't handle the load. Our classic asp applications run without issues during this time, it's only our .net apps that are effected.
are you running all your asp/wcf sites in the same AppPool? if so, I'd suggest creating a new one and running the WCF service just in that. That in itself might be enough to solve the problem from a practical perspective.
Also can you target a more recent version of the framework with your WCF app? (and leave the other apps the same) It will isolate it much better.