topic 499 Client Closed Request in ArcGIS Runtime SDK for iOS Questions

499 Client Closed Request

Selsoe — Wed, 11 Aug 2021 08:01:31 GMT

I have a service monitoring network requests in my iOS app integrating with ArcGIS. It is reporting a high error rate for the URL I'm using for my WMS Service. The HTTP error reported is this:

`499 Client Closed Request`

I suspect this just means that ArcGIS cancels the request because the user moves the map and the requested tile/data is no longer needed. Can you confirm that this is the case or should I be worried about the stability of my service?

Re: 499 Client Closed Request

MarkDostal — Wed, 11 Aug 2021 13:47:22 GMT

@Selsoe Take a look at this Esri Technical Support article and let me know if it matches your situation. If it doesn't, can you give some additional information about your service, the type of authentication it uses, etc?

Mark

Re: 499 Client Closed Request

Selsoe — Thu, 12 Aug 2021 07:21:35 GMT

It is certainly that error code, but I'm not sure it matches my situtation.

The app works and I don't hear complaints from the users about the map service - I only see this very high error rate (> 50%!) in the monitoring tool and wonder where they come from.

I'm not that familiar with WMS-services, so the article doesn't make total sense for me, but as I understand it, if it was an authentication issue, it would fail 100% of the time.

The authentication against the service is a plain username and password.

Here's a screenshot from the monitoring tool:

Re: 499 Client Closed Request

MarkDostal — Thu, 12 Aug 2021 15:44:05 GMT

@Selsoe Thanks for the additional info. I will reach out to my colleagues and see what we can come up with.

Mark

Re: 499 Client Closed Request

MarkDostal — Thu, 12 Aug 2021 19:06:59 GMT

@Selsoe The following is from a colleague who works with WMS Services:

499 errors are expected to happen over connections that suffer from a load interruption. These are just an internal server code that means that the client has closed the connection before processing the request and receiving the reply. I don’t think there is an authentication issue here. The errors might look worrying but I wouldn’t be alarmed especially that the user application is not affected.

So nothing to worry about.

Cheers,

Mark