I'm using a large app instance to run a basic java web application (GWT + Spring). There's an expensive operation within my application (report) which takes a long time to execute.
I've tried running it with the cloudbees SDK on my local machine with similar settings as it would be on the cloud and it seems to function just fine. It runs in about 3-4 minutes.
On the cloud, it seems to be taking longer. The problem isn't the fact that it takes long. What happens in that cloudbees terminates the session after 5 minutes and gives me an error in my browser saying 'Unable to connect to server. Please contact your administrator'. A report which doesn't take as long runs just fine. My application has a session timeout of 30 minutes, so that isn't a problem either.
What could possibly be going wrong? Is it something to do with cloudbees?
This may be due to proxy buffering of your request through the routing layer (revproxy) - so it most likely isn't a session timeout - but the http connection getting cut.
You can either set proxyBuffering=false via the bees CLI command (eg when you deploy the app) - this will ensure longer running connections can work.
Ideally, however, you could change the app slightly to return to the browser with some token which you can poll with to get completion status, as even with a connection that lasts that long, over the internet it may provide a bad experience vs locally.
Related
Our app services are experiencing the problem, that they can’t be restarted by the hosting environment (ANCM).
The user is getting the following screen in that case:
Http Error 500.37
Our production subscription consists of up to 8 different app services and the problem can randomly harm one of them ore some of them.
The problem can occur several times a week, or just once a month.
The bootstrapping procedure of our app services is not time consuming.
The last occurrence of the problem has this log entries within the eventlog:
Failed to gracefully shutdown application 'MACHINE/WEBROOT/APPHOST/XXXXXXXXX'.
followed by:
Application '/LM/W3SVC/815681839/ROOT' with physical root 'D:\home\site\wwwroot' failed to load coreclr. Exception message: Managed server didn't initialize after 120000 ms
In most cases the problem can be resolved by manually stopping and starting the app service. In some cases we had to do that twice.
We are not able to reproduce that behavior locally.
The App Service Plan is S2 and we actually use just one instance.
The documentation of the Http error 500.37 recommends:
"You may need to stagger the startup process of multiple apps."
But there is no hint of how to do that.
How can we ensure that our app services are restarted without errors.
HTTP Error 500.37 - ANCM Failed to Start Within Startup Time Limit
You can try following approaches:
Approach 1: If possible, can try to move one app into a new App Service with a separate App Service plan, then check whether it can start as expected.
Please note that creating and using a separate App Service plan would be charged.
Approach 2: Increasing the startupTimeLimit attribute of the aspNetCore element.
For more information about the startupTimeLimit attribute, please check: https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/aspnet-core-module?view=aspnetcore-3.1#attributes-of-the-aspnetcore-element
with a new project we encountered some strange behaviour on our ColdFusion application.
Whenever a single request is initiated from the browser, the code of the cfml-templates is
executed multiple times. Upon viewing the corresponding log-files we found out, that indeed
for some reason the same request fires the evaluation in our application multiple times. One request
generates several entries. This is especially the case for long-running requests, such as database imports.
The ColdFusion application implements a REST-service, but even on manually requesting a resource,
such as a certain cfml page, on the same application - the code gets executed an unknown amount of times(variable initializations, database write-operations etc. take place), and if the request runs too long (cap at around ~4-6 seconds) there is no response to the browser.
About the infrastructure:
The application is Coldfusion18 with Tomcat Standard Edition
The webserver is an Apache (2.4.6).
Everything runs on a Linux machine with Cent OS 7.7
The corresponding Java version is 11.0.4
Our best guess is that there might be some misscommunication between the coldfusion connector with
the apache webserver. We actually searched for some configuration parameters that could cause the
problem, without success. Upon an installation on a windows machine we did not encounter that error.
Anyone got any idea?
we just found our answer in the following post:
Link to Solution
I need to access the internet periodically (every 5 minutes or so) to update a database with a background service. I have tried the following using Android 8 or 9:
Use a boot receiver to start a JobService.
In onStartJob of the class that extends JobService, create a LocationListener and request a single location update.
Have onStartJob schedule the job again to run in 5-10 minutes.
Return true from onStartJob.
In the OnLocationChanged of the LocationListener, write to a local file, and start a thread to make a PHP request to update the database.
Everything works fine while the underlying process is running. When the process dies, the service keeps periodically updating the local file, but the the URLConnection.getResponseCode() now throws an exception - java.net.ConnectionException: failed to connect to ...
Is there a way to get around this using the above approach? If not, how can I have a background service access the internet even after the underlying process dies?
Without getting into much detailed code
I have an 'kiosk' application that is running in about 500-800 different 'kiosk' at about 50 locations. Very simple application that connects to internet via a Verizon MIFI (2-3 MIFI per location). We believe that Verizon has made some changes to the network and now randomly I get
The request failed with HTTP status 417: Expectation failed
I have viewed The request failed with HTTP status 417: Expectation Failed - Using Web Services
and FB Connect: (417) Expectation failed
But you see I already had used
System.Net.ServicePointManager.Expect100Continue = false
in my code.
So one of the issues I have is the application isn't easy to test, and it will fail for 20-30 minutes or several days, then clears itself up.
Changing the config to include
<system.net>
<settings>
<servicePointManager expect100Continue="false" />
</settings>
Would be a large task, I don't know it that would even fix it. Since it is random I'm having troubles because I typically can't get it to fail in my office at my desk more than 1 time.
I happen to use VB and .Net for the application and services that run with the 'kiosk'.
The issue seems to be with the config on the mifi and not the Verizon network itself. We recently switched APNs and when a mifi connects to the Verizon network it is supposed to update automatically. Sometimes the mifi will fail to update the APN setting and that is when we get this error message. There are two ways I have found to fix this issue. The first and easier is to log into the mifi and manually update the setting. If you are dealing with a user who is not tech savvy and walking them through logging into the mifi will not work you can call the Verizon wireless enterprise help desk and have them remove the feature set from the mifi, add the features back, and then pull the battery from the mifi and power cycle it, this will make the mifi request the configuration settings again.
When attempting to connect/communicate with my service i have to wait for almost exactly 20 seconds each time before the exception is fired. Since this all gonna be running on a local network, I would like decrease that timeout period to 5 seconds? I tried decreasing the receiveTimeout on my client, but it didn't work. I looked all over my code for a 20 second timeout variable set, but couldn't find any. What should i be changing?
There are different timeout settings http://msdn.microsoft.com/en-us/library/ms731078.aspx. They can be set for example in a config file (web.config or app.config) see http://msdn.microsoft.com/en-us/library/ms731343.aspx as an example. Under http://msdn.microsoft.com/en-us/library/ms731399.aspx you can choose the binding which you use and set the corresponding setting.
UPDATED: You probably have the timeout set on the TCP level. Try reducing the TcpMaxConnectRetransmissions (Default value 2) or TcpInitialRTT (Default value 3, on NT 4.0 the parameter has the name InitialRTT) parameters in the registry, reboot your computer and try your experiments one more time. About affect of 21 seconds you can read in http://support.microsoft.com/kb/223450, http://support.microsoft.com/kb/175523, http://support.microsoft.com/kb/170359 or http://www.boyce.us/windows/tipcontent.asp?ID=189. You can read a description of the TCP/IP default configuration values at http://support.microsoft.com/kb/314053 (for Windows XP) and http://technet.microsoft.com/en-us/library/cc739819(WS.10).aspx (for Windows Server 2003 with SP2).
What you may actually be seeing is the cold start from your webapp. The Service Not Found exception would fire back pretty quickly unelss you had hit it pretty hard and you started queueing service requests beyond what WCF was configured to do.
However, if you had your website unloaded (appdomain and worker process) it could take 20 seconds to hit to the code that builds the channel to your service. So it may be something masked.
If your website and service are in different application pools then this is maginfied because it has to cold start the website and then coldstart the service, which are done in succession instead of simultaneously.
To somewhat alleviate this you can use a keepalive/ping service. Something that just constantly hits the URL to keep the AppDomain in memory and the worker process alive (if not shared). By default IIS 6 will shutdown the worker process after 20 minutes of inactivity, so when the first request comes in, http.sys starts up a new worker process, which loads the framework, which loads your app, which starts the pipeline, which executes your code, which delivers to your user. :)