Where is this info kept (“this connection is between computer A and server F“)? A TCP connection is recognized by source IP and port and destination IP and port. Your OS, all intermediate session-aware devices and the server’s OS will recognize the connection by this. HTTP works with request-response: client connects to server, performs a … Read more
VOIP app behavior at background (iOS 4.0+): Having a single socket that remains open, flagged as Voip This VOIP socket is maintained by the system, while app suspended at BG You may schedule a keep-alive block, and the OS will wake your app every X time X >= 10min (See [[UIApplication sharedApplication] setKeepAliveTimeout: handler:) this … Read more
Suppose you have a core size of 5, and a maximum size of 15. For some reason your pool gets busy, and uses all 15 available threads. Eventually you run out of work to do – so some of your threads become idle as they finish their final task. So 10 of those threads are … Read more
To modify the number of probes or the probe intervals, you write values to the /proc filesystem like echo 600 > /proc/sys/net/ipv4/tcp_keepalive_time echo 60 > /proc/sys/net/ipv4/tcp_keepalive_intvl echo 20 > /proc/sys/net/ipv4/tcp_keepalive_probes Note that these values are global for all keepalive enabled sockets on the system, You can also override these settings on a per socket basis … Read more
You should use polling, or use a web server which is specially conceived for long requests and COMET, with a good JS backend: function listen() { $.get(“/mylongrequestfile”, {}, function(data) { $(“#mydiv”).html(data); listen(); // then launch again })); }; Remember that COMET is “wait for data, if there’s data return and exit”, so JS backend will … Read more
For Express 3: var express = require(‘express’); var app = express(); var server = app.listen(5001); server.on(‘connection’, function(socket) { console.log(“A new connection was made by a client.”); socket.setTimeout(30 * 1000); // 30 second timeout. Change this as you see fit. });
Global functions like requests.get or requests.post create the requests.Session instance on each call. Connections made with these functions cannot be reused, because you cannot access automatically created session and use it’s connection pool for subsequent requests. It’s fine to use these functions if you have to do just a few requests. Otherwise you’ll want to … Read more
The problems with TCP keepalive are: It is off by default. It operates at two-hour intervals by default, instead of on-demand as the Ping/Pong protocol provides. It operates between proxies rather than end to end. As pointed out by @DavidSchwartz, it operates between TCP stacks, not between the applications so therefore it doesn’t tell us … Read more
You can set the TCP keepalive timers on an already-open socket using setsockopt(). import socket def set_keepalive_linux(sock, after_idle_sec=1, interval_sec=3, max_fails=5): “””Set TCP keepalive on an open socket. It activates after 1 second (after_idle_sec) of idleness, then sends a keepalive ping once every 3 seconds (interval_sec), and closes the connection after 5 failed ping (max_fails), or … Read more
From ioS 7 onwards, there are newer ways for apps to run in background. Apple now recognizes that apps have to constantly download and process data constantly. Here is the new list of all the apps which can run in background. Apps that play audible content to the user while in the background, such as … Read more