I am following the ListFeatures() example in this tutorial: https://github.com/grpc/grpc/blob/v1.31.0/examples/cpp/route_guide/route_guide_client.cc
My server is in Java and my client application is in c++.
I have both the server and the client running locally. What I am observing is that my application crashes when I try to read the stream response via `reader->Read(&feature). I can verify that the server receives the api call and is sending responses back. I am also able to successfully hit the server from bloomRPC.
Any ideas why I can't receive responses in my c++ client application?
Much appreciated!
I had this problem when the context used to create the ClientReader fell out of scope. The context needs to be persistent while the ClientReader is in use.
Related
I have a websocket client in python implemented using tornado.websocket.
WebSocketClientConnection
which connects to a server at remote end and communicate over websocket. Earlier I had implemented the ping/pong like feedback mechanism at application layer to ensure if the remote endpoint is still responsive.
I just recently updated my tornado package and I came across the ping_interval in WebSocketClientConnection. I removed the old ping/pong mechanism at application layer and added this ping_interval in my implementation.
After this updates the websocket is getting closed after the mentioned ping_interval timeout. The server at remote end handles the ping at transport layer and respond accrodingly.
currently I have not implemented the ping method so should I have to implement ping method for WebSocketClientConnection?,
should I have to send any data in ping method?
do I have to implement any method to handle the response send by remote server for the ping request?
No, It's implemented by default.
You may but don't have to.
I assume that by response you've ment pong. If you're using ping_interval you don't have to process pong, but if you're sending pings manually you have to control timeouts by yourself so you have to process pongs by implementing tornado.websocket.WebSocketClientConnection.on_pong method.
I've got server running in background and a program which should display data from server. I want to somehow launch method in my program from server. So server should be a sender, but how to do it ?
There is no reason why a server can't also be a client, just implement the interfaces from both sides and you're good.
The main thing to worry about is deadlocking: if you have a single threaded program which is waiting for the reply of the server, then it will not handle the request that the server sends, so the server is stuck and will not send a reply to the program.
This can be solved by starting the server implementations on different threads and letting them not block on the client thread.
Even better is to avoid having a server send back requests before sending replies, but cascading requests (forward requests to more specialized servers) should be no problem.
I am doing this sample https://msdn.microsoft.com/en-us/library/windows/desktop/ms737889(v=vs.85).aspx that contains a C++ tutorial for client and server with Winsock. To run this the server must be run before the client, obviously, but how to debug these things. I mean when I start the server and put a breakpoint in the main function it executes, but when I do this in the client I want to see the interraction with the server code from its solution. Im confused. Is there an article describing this?
I made a simple program in c++ for connecting to a site and loading a page HTML code or send data using GET/POST requests.
But now I want the program to connect and send/receive data through proxy.
You probably know software like NextVpn and proxifier. when they are running any application which tries to communicate through internet will have to go through these apps.
The problem is that my program connects and communicates directly and my proxy software doesn't interfere.
Communication is done by the socket programming routins (SOCKET class) like this
SOCKET sck=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
connect(sck,(SOCKADDR*)(&SockAddr),sizeof(SockAddr));
send(sck,myRequest,strlen(myRequest),0);
Any solution?
EDIT: The problem was from NextVPN not the Proxifier itself. It seems that NextVPN lacks functionality in hooking into some programs. First NextVPN finds the program which is trying to connect to a remote address then redirects it to its portable version of proxifier with something named "compose.ns" . Unfortunately it was unable or couldn't detect my app connecting to internet. Instead I used Proxifier itself and it successfully detected my app as it was showing in its connection list.
Well...
I am working with an mobile application and a web server.
A characteristic of my web server is that it generates different set of data randomly. In other words, I cannot predict when the server will have ready data to send to the mobile app.
On other hand, the mobile app need to receive all data that the server generates. An approach could be request multiple times to get all these data. Indeed, It isn't a good approach, because I don't know when request the data.
If the mobile app could listen the server, after one start request or keep on the connection, for example, the server could sent any set of data in any time.
The question is: What is protocol suitable to this situation? How could I use that? Examples?
Thank you!
You could create a persistent TCP/IP connection to the server and permanently listen for incoming data (using a custom protocol or propably something websocket based). However such a permanent connection might seriously affect your battery life if it's for a mobile device. You will also lose the connection if the operating system automatically shuts down your application because it's out of memory.
The default approach to this problem are Push notification / Push services, where your server sends a notification about new data to a server of the phone provider (e.g. Microsoft or Apple push server), and this server sends the notification (as well as notificaiton from other online services) to your phone.
Some info for Windows Phone:
http://msdn.microsoft.com/en-us/library/hh221549.aspx
http://msdn.microsoft.com/en-us/library/windowsphone/develop/ff402558%28v=vs.105%29.aspx
Depending on how often you have new data both approaches can make sense.
WebSockets could be the answer: http://en.wikipedia.org/wiki/WebSocket
Specifically, for Windows Phone, there's a solution also: http://msdn.microsoft.com/en-us/library/windowsphone/develop/ff402558(v=vs.105).aspx