Calls to Azure Maps result in server disconnecting the client

Question

Calls to Azure Maps result in server disconnecting the client

Michael Landy 5

We are making a .NET C# 4.8 call to the api: https://atlas.microsoft.com/search/address/json

The call may fail one or more times out of 10 calls. We are NOT calling it multiple times per second. We are passing in an address and waiting for the ___location to be returned. During this time, we get a failure rate in the call of 30-50%, which is crazy. We have it in a loop with an exponential backoff, and it still can fail 5+ times in a row. The exception is the Remote Server has closed the connection to our client. Why would it disconnect us so often? It is very unreliable.

VSawhney 710 Reputation points Microsoft External Staff Moderator

2025-05-16T03:06:38.0433333+00:00
Hello Michael Landy,

Please check for few of the things mentioned:

Network Stability & Firewall Settings – Frequent disconnects could be due to network instability or firewall settings blocking certain requests or it could be VPN connection. You might need to whitelist all blocked URLs identified from your proxy or firewall logs.

API Limitations & Constraints – Azure Maps APIs have specific constraints, such as bounding box limitations for certain requests. If your request parameters exceed these constraints, the API may fail.

Subscription Key & Region Compatibility – Ensure that your Azure Maps subscription key is valid and that the API is being accessed from a supported region.

While you are already using exponential backoff, consider adjusting the retry intervals or implementing jitter to avoid repeated failures in quick succession.

Hope This helps.
Please provide a sample code, full error log and network trace in private chat for further assistance.

Thank you!
VSawhney 710 Reputation points Microsoft External Staff Moderator

2025-05-19T02:38:57.42+00:00

Hello Michael Landy,

Following up to check if the responses provided helped you in solving the issue. Please feel free to reach us for further queries.

Thank you!
Michael Landy 5 Reputation points

2025-05-19T03:03:24.1766667+00:00

I have switched our code to use the Geocode API. I need to test to see if it gets HTTP exceptions.

I wanted to be more clear on our workflow and what is happening. We have a .NET 4.8 winforms application. A user will enter in their address. The system will then call the Search API (changed to geocode api now) with a webview2 browser control on it. The form will take the address and attempt to geocode the address. Based on the number of addresses that come back, it will show a map using the azure maps javascript control inside the webview2 browser control. It will then center the map on one of the addresses.

So, the .net code gets the results from the GeoCode API. It then executes javascript inside the browser control to add markers and center the map. Hitting the search button multiple times would cause the API to start getting HTTP exceptions. I make sure the API has completed its return before allowing a new search call to be made. In some cases, the webview2 control would not render the map and the debug output would indicate the browser control was experiencing HTTP Exceptions as well. In all cases the server was disconnecting the client.

I have switch the API I am calling to the suggested one above and need to test. This form (attached) was the easiest way to get it to throw the exceptions. We have another place where a user enters in an address and it geocodes it with no visuals (no map popup). In this case, with the search API, I was still getting HTTP Exceptions.

I should have the results of my testing tomorrow and will update my findings.
Sampath 3,740 Reputation points Microsoft External Staff Moderator

2025-05-19T05:41:48.5+00:00

Hello Michael Landy, sure, please get back to us. Thank you for the update. Please check private message as well.

3 answers

Your answer

VSawhney 710 Reputation points Microsoft External Staff Moderator

2025-05-16T03:06:38.0433333+00:00

Hello Michael Landy,

Please check for few of the things mentioned:

Network Stability & Firewall Settings – Frequent disconnects could be due to network instability or firewall settings blocking certain requests or it could be VPN connection. You might need to whitelist all blocked URLs identified from your proxy or firewall logs.

API Limitations & Constraints – Azure Maps APIs have specific constraints, such as bounding box limitations for certain requests. If your request parameters exceed these constraints, the API may fail.

Subscription Key & Region Compatibility – Ensure that your Azure Maps subscription key is valid and that the API is being accessed from a supported region.

While you are already using exponential backoff, consider adjusting the retry intervals or implementing jitter to avoid repeated failures in quick succession.

Hope This helps.
Please provide a sample code, full error log and network trace in private chat for further assistance.

Thank you!
VSawhney 710 Reputation points Microsoft External Staff Moderator

2025-05-19T02:38:57.42+00:00

Hello Michael Landy,

Following up to check if the responses provided helped you in solving the issue. Please feel free to reach us for further queries.

Thank you!
Michael Landy 5 Reputation points

2025-05-19T03:03:24.1766667+00:00

I have switched our code to use the Geocode API. I need to test to see if it gets HTTP exceptions.

I wanted to be more clear on our workflow and what is happening. We have a .NET 4.8 winforms application. A user will enter in their address. The system will then call the Search API (changed to geocode api now) with a webview2 browser control on it. The form will take the address and attempt to geocode the address. Based on the number of addresses that come back, it will show a map using the azure maps javascript control inside the webview2 browser control. It will then center the map on one of the addresses.

So, the .net code gets the results from the GeoCode API. It then executes javascript inside the browser control to add markers and center the map. Hitting the search button multiple times would cause the API to start getting HTTP exceptions. I make sure the API has completed its return before allowing a new search call to be made. In some cases, the webview2 control would not render the map and the debug output would indicate the browser control was experiencing HTTP Exceptions as well. In all cases the server was disconnecting the client.

I have switch the API I am calling to the suggested one above and need to test. This form (attached) was the easiest way to get it to throw the exceptions. We have another place where a user enters in an address and it geocodes it with no visuals (no map popup). In this case, with the search API, I was still getting HTTP Exceptions.

I should have the results of my testing tomorrow and will update my findings.
Sampath 3,740 Reputation points Microsoft External Staff Moderator

2025-05-19T05:41:48.5+00:00

Hello Michael Landy, sure, please get back to us. Thank you for the update. Please check private message as well.

Answer 1

First time I've come across anyone experiencing this. I'll assume you are calling the REST services directly with HTTPClient or something similar. A couple of things to check:

First, make sure you are escaping your the address you are passing into the query parameter. Special characters can cause issues in URLs. Here is how you do that in C# Uri.EscapeDataString(query)
I'm assuming you aren't making calls from within China or South Korea as is not available in those regions and trying to connect to Azure Maps from within one of those networks would fail.
Likely unrelated, but something to consider doing now while you are working with the code is to use the latest version of the search API. The endpoint you are referencing is v1 and there is a newer, more powerful search geocoding service available. https://learn.microsoft.com/en-us/rest/api/maps/search/get-geocoding?view=rest-maps-2025-01-01&tabs=HTTP
The search services usually respond within 300ms depending on your internet connection. If it is taking a lot longer than that (several seconds) then there is a networking issue such as a firewall that is causing issues.

Beyond the above, we will need more information on how you are calling the services and a couple of example queries (excluding your subscription key of course).

I know you said you weren't making multiple calls a second, but if you have a lot of addresses to geocode as part of a batch like process (e.g. geocoding a file or database of addresses), consider using the batch geocoding service: https://learn.microsoft.com/en-us/rest/api/maps/search/get-geocoding-batch?view=rest-maps-2025-01-01&tabs=HTTP

Answer 2

Michael Landy 5

Using the new URL did not help. I have tried this on 3 different PCs in 2 different places (internet connections) in Chicago and 2 different places in St. Louis. I can rule out a network firewall issues since all of the networks are different. I should also note that is does work 50% of the time but it is not robust even with 5 retries. The address is url encoded as described above, so that is not a problem either.

Here is the error when attempting to geocode an address:

System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host

The webview2 browser control gets an error and the map won't load because the atlas javascript files can't be downloaded so the map can't render. If I refresh that usually resolves the webview2 control. It happens about 50% of the time. The other 50% it will just work.

Failed to load resource: net::ERR_CONNECTION_RESET

atlas.min.js:1

Failed to load resource: net::ERR_CONNECTION_RESET

about:blank:25 Uncaught ReferenceError: atlas is not defined

at initialize (about:blank:25:19)

at onload (about:blank:16:45)

Sampath 3,740 Reputation points Microsoft External Staff Moderator

2025-05-20T03:38:28.87+00:00

Hello @Michael Landy , Could you please send your code in a private message? Thank you.
Sampath 3,740 Reputation points Microsoft External Staff Moderator

2025-05-20T17:03:44.79+00:00

Hello @Michael Landy , We still have not heard back from you. Could you please send your c# code in a private message? Thank you.
Michael Landy 5 Reputation points

2025-05-20T17:11:59.89+00:00

I think I have this solved. I am reviewing my code changes, but I believe the issue was related to the subscription key. I was deleting the default headers first and then adding the subscription key. In addition, I did not set a timeout on the HttpClient. So, I set the timeout, and checked the default header for the subscription key, if it was there, I removed it and added it back. If it was not there, I added it. Finally, on any error I would cancel client connections. This seemed to clear up the issue and I want to make sure I understand why. I will get back to this thread once I finish my analysis.
Sampath 3,740 Reputation points Microsoft External Staff Moderator

2025-05-20T17:15:50.14+00:00

sure please update once conformed let me know that in private chat

Answer 3

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Calls to Azure Maps result in server disconnecting the client

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