A client is running our C# gRPC client on a corporate network, behind an HTTP proxy. The http_proxy environment variable is configured, but nevertheless he sees an error message Name resolution failure when attempting to connect to the server on the internet.
DNS resolution from the same machine works fine using nslookup.
Any ideas what I can do to investigate this problem?
You can use the following three lines at application startup to configure the detailed logging that #JanTattermusch suggested:
Environment.SetEnvironmentVariable("GRPC_TRACE", "api");
Environment.SetEnvironmentVariable("GRPC_VERBOSITY", "debug");
Grpc.Core.GrpcEnvironment.SetLogger(new Grpc.Core.Logging.ConsoleLogger());
In order to connect a C# gRPC client on a corporate network, behind an HTTP proxy, add this on the client main method works:
Environment.SetEnvironmentVariable("NO_PROXY", "127.0.0.1");
Related
I have a Python gRPC server running on AWS Fargate (configured very similar to this AWS guide here), and another AWS Fargate task (call it the "client") that attempts to make a connection to my gRPC server (also using Python gRPC). However, the client is unable to make a call to my server, with the following error:
<_InactiveRpcError of RPC that terminated with:
status = StatusCode.UNAVAILABLE
details = "failed to connect to all addresses"
debug_error_string = "{"created":"#1619057124.216955000","description":"Failed to pick subchannel",
"file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":5397,
"referenced_errors":[{"created":"#1619057124.216950000","description":"failed to connect to all addresses",
"file":"src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc",
"file_line":398,"grpc_status":14}]}"
Based on my reading online, it seems like there are myriad situations in which this error is thrown, and I'm having trouble figuring out which one pertains to my case. Here is some additional information:
When running client and server locally, I am able to successfully connect by having the client connect to localhost:[PORT]
I have configured an application load balancer target group following the guide from AWS here that makes health check requests to the / route of my gRPC server, using the gRPC protocol, and expect gRPC response code 12 (UNIMPLEMENTED); these health check requests are coming back as expected, which I believe implies the load balancer is able to successfully communicate with the server (although I could be misunderstanding)
I configured a service discovery system (following this guide here) that should allow me to reach my gRPC server within my VPC via the name service-name.dev.co.local. I can confirm that the corresponding DNS record exists in Route 53, and when I SSH into my VPC, I am indeed able to ping service-name.dev.co.local successfully.
Anyone have any ideas? Would appreciate any and all advice, and I'm happy to answer any further questions.
Thank you for your help!
on your grpc server use 0.0.0.0:[port] and expose this port with TCP on your container.
I have a ASP NET Core web api that uses websockets. I am trying to find out if the server handles internet connection loss (client side) correctly.
However since I have only one machine on which both the server and the client run, i know that localhost does not use the Network Interface, and the desired handler is not triggered when I cut off the internet.
How can I thus have a server that runs a localhost, and a client that also runs on localhost but uses the network interface, so that I can cut the internet off and see how the server behaves for the given client?
I use TCPView to do this sort of testing. You can find the connection in the list, then right-click/close it:
I deployed an Asp.Net Web API project on Amazon Web Services' Elasticbeanstalk (IIS configured machine). Everything works fine except WebSocket. To test the WebSocket easier I use Simple WebSocket Client extension on Chrome.
When I make a request to the API, I get the following (error) message (I observe this message over developer console's network tab):
WebSocket connection to 'ws://my_url' failed: Error during WebSocket handshake: Unexpected response code: 400
I have not found enough information to overcome this problem.
I tried enabling all Inbound/Outbound TCP connections from all ports and all IPs under Security Groups.
I tried creating an empty Asp.Net Web API project that only has a basic sample of WebSockets (just sending a message to the connected user) and deploying it to a brand new environment and application on AWS.
Nothing has worked so far.
I am using Microsoft's WebSockets, .NET Framework 4.5.1.
What are the possible solution ways?
If you are using AWS Elastic Load Balancer in your elastic beanstalk then ELB does not support web sockets and you have to apply a work around. Change your Load Balancer top classic load balancer that supports Websockets.
https://aws.amazon.com/blogs/aws/new-aws-application-load-balancer/
I solved the problem by adding All TCP on Inbound segment of Security Groups and using the IP address of the server instead of AWS created name.
Good afternoon in my timezone.
I am developing a web appp in J2EE.
This web app is called and access inside a sharepoint portal.
When i enter through the sharepoint portal i can access my application, using chrome developes tools i can see all the HTTP traffic, and i see that the browsers sends a request to the following server that is where my app is running serverprd.enterprisename.com.
But when i use the command line in my windows 7 , to ping the machine(server) , for example :
ping serverprd.enterprisename.com it returns me the following message:
"Ping request could not find host serverprd.enterprisename.com"
I am using a proxy.
Can anyone tells me why this happening ? Why through the browser i can access the server and the ping command does not find me the server ?
With the best regards.
Thanks in advance.
Your proxy server id the one who have an access to outside world. All http requests are sent to proxy server and proxy server does DNS lookup. In case of pin, your host have to do DNS lookup and this operation obviously now allowed ( firewall or so).
I am having some issues trying to make an AIR application connect to a RemoteObject when the application is run in a domain that has proxy servers for outbound connection.
The error provided is as below:
[RPC Fault faultString="Send failed" faultCode="Client.Error.MessageSend" faultDetail="Channel.Connect.Failed error NetConnection.Call.Failed: HTTP: Failed: url: 'http://myTestService.org:8080/default/message/amf'"]
Any ideas? I think the proxy server may be preventing the application from accessing the Remote Object. How do I work around this?
Thanks.
Edit:
I saw a quite similar post to this:
Remoting with AIR
And I did declared the endpoint and destination to my RemoteObject.
In application/WEB-INF/flex/services-config.xml give only relative paths, do not use ip address and port number. You can look here for detail moving to production server
And here send failed error
In your case channel url should be
"/default/message/amf"
Drupal RPC Fault looks to be some what same as your problem and has issues with crossdomain.xml
Do check it.