Websockets and uwsgi - detect broken connections client side? -

-

i'm using uwsgi's websockets support , far it's looking great, server detects when client disconnects , client when server goes down. i'm concerned not work in every case/browser.

in other frameworks, namely sockjs, connection monitored sending regular messages work heartbeats/pings. uwsgi sends ping/pong frames (ie. not regular messages/control frames) according websockets spec , client side have no way know when last ping received server. question this:

if connection dropped or blocked proxy browsers reliably (ie. chrome, ie, firefox, opera) detect no ping received server , signal connection down or should implement additional ping/pong system connection detected closed client side?

thanks

you totally right. there no way client side track or send ping/pongs. if connection drops, server able of detecting condition through ping/pong, client let hung... until tries send , underlying tcp mechanism detect other side not acknowledging packets.

therefore, if client application expects "listening" of time, may convenient implement keep alive system works "both ways" stephen explains in link posted. but, keep alive system part of application layer, rather part of transport layer ping/pongs.

for example can have message "{token:'whatever'}" server , client echoes 5 seconds delay. client should have timer 10 seconds timeout stops every time messages received , starts every time message echoed, if timer triggers, connection can consider dropped.


Comments

Post a Comment

Popular posts from this blog

c++ - QTextObjectInterface with Qml TextEdit (QQuickTextEdit) -

-
i registred handler simple qtextobjectinterface , draws 10x10 red rectangle. when used qtextedit in normal qwidget app, worked. when used qquicktextedit (textedit qml component) in qt quick app, doesn't worked (nothing drawed, rectangle in textedit reserved, because when change cursor position, notice there something, empty space, nothing drawed. qtextobjectinterface intrinsicsize method called (that explains why see there empty space 10x10), drawobject method isn't. i did research , found problem here: qquicktextedit.cpp qt 5.3.0 sources (line 1821) qsgnode *qquicktextedit::updatepaintnode(qsgnode *oldnode, updatepaintnodedata *updatepaintnodedata) { . . . if (textframe->firstposition() > textframe->lastposition() && textframe->frameformat().position() != qtextframeformat::inflow) { updatenodetransform(node, d->document->documentlayout()->frameboundingrect(textframe).topleft()); c...
Read more

javascript - angular ng-required radio button not toggling required off in firefox 33, OK in chrome -

-
i trying toggle required attribute on radio button using angular show html5 popup. i cannot following code function correctly in firefox 33. function correctly in chrome. required property being toggled via checkbox value, in firefox, when set false radio button still acts required , shows html5 required popup. see plnkr below example doesn't work me in ff 33. <!doctype html> <html> <head> <script data-require="angular.js@*" data-semver="1.3.1" src="//code.angularjs.org/1.3.1/angular.js"></script> <link href="style.css" rel="stylesheet" /> <script src="script.js"></script> </head> <body ng-app="myapp"> <script> angular.module('myapp',[]) .controller('mycontroller',['$scope',function($scope) { $scope.foorequired=true; $scope.submitform = function() { $scope.submitmessage = ...
Read more

xcode - Swift Playground - Files are not readable -

-
Image
files not readable in swift playground . how make files readable? same code runs on xcode terminal app, fails on swift playground. demo code below. import foundation println("hello, world!") var fname:string = "/users/holyfield/desktop/com.apple.iconcomposer.plist" var fm:nsfilemanager = nsfilemanager.defaultmanager() if(fm.fileexistsatpath(fname)){ println("file exists") if(fm.isreadablefileatpath(fname)){ println("file readable") var fd:nsdata? = nsdata(contentsoffile: fname) println(fd?.length) let pl = nsdictionary(contentsoffile: fname) println(pl?.count) println(pl?.allkeys) }else{ println("file not readable") } } else{ println("file not exists") } sample images: i have thank nate cook first quick response , solid answer. just case share answer post, title misleading. see nate's answer here: https://stackoverf...
Read more