I am building real time connection server. And want to scale it with Node Clusters
I went through many different websites trying to figure out how to implement Websokets(ws) and Node clustering. So the basic idea which i wanted to try is : I have and array of all users who are connected to the server , like :
{key:ws, key:ws ,key:ws}
So what i want to do is to run Node js Clusters with Websockets , i will get some thing like that
Master : place to store all the connected ws in array : {key:ws, key:ws ,key:ws}
Worker1 : Ws server to connect
Worker2 : Ws server to connect
What i am wondering is for example user which is connected to the Worker2 wants to send message to user which is connected to the Worker2 and worker1.
So i will send message from Worker2 to the Master to get all the users , Master will send {key:ws(worker1), key:ws(worker2) ,key:ws} . And Worker2 will iterate over this array and send message to each user.
Will that implementation work or message will not be send to the user which is connected to another Worker?
Thank you very much for the answer.
There is a package wse-cc that does fully-controlled user balancing between nodes, but the problem - it's not documented very well.
It uses different processes instead of clusters to make it able to work on multiple physical machines. I'm using it for browser MMO games. If you interested - I can make a quick doc on how to set up it. Not required any balancers on top, can work on a single machine or on multiple.
Or you can visit issues page - I'll help with any questions.
Related
I have 2 devices (desktop PCs), each running a browser tab that instantiates an IPFS node using js-ipfs.
//file index.html, served over HTTPS
const node = IpfsCore.create(); //ipfs browser node
Both nodes have peers (calling node.swarm.addrs() returns about 50 peers). They do not list each other as peers.
I want to connect those two nodes to each other, so if I call node.add( ... ) on the first, I can then call node.cat( ... ) on the second, and acquire a file from the first. (Or so that browser 1's pubsub broadcasts always reach browser 2; browser 1 can read browser 2's wantlist etc.)
How do I connect these 2 browser tabs as peers?
The example at https://github.com/ipfs/js-ipfs/blob/master/packages/interface-ipfs-core/src/swarm/connect.js uses this command:
ipfsA.swarm.connect( ipfsBId.addresses[0] )
But in my case, both my browser-tabs have no addresses.
console.log( ( await node.id() ).addresses ); //[] empty array
I don't know how the browser tabs manage connecting to other peers without their own addresses, and I don't know how to make them connect to each other.
There is a 4-year-old question about browser peers here IPFS - pubsub connect to peers from browser, but its fairly unrelated and seems to rely on the the deprecated / out-of-date webrtc-star https://github.com/libp2p/js-libp2p-webrtc-star
I know if I were setting up a WebRTC connection I would use fetch() or XHR or a websocket to a public-facing server (with a DNS record or IP address) to exchange negotiation info while querying a list of iceServers (also with DNS records / IP addresses).
I don't want to rely on a list of servers I own or configure, and I don't want to burden any public example TURN servers or anything. js-libp2p might use multicastDNS? I don't think browser tabs can broadcast signals though (I could be wrong? Maybe fetch() can do that somehow with some sneaky url stuff?)
What do I do? How can these two browser-tab IPFS peers discover each other, specifically?
I suspect this has a very straight-forward answer, but I have been researching for days now and read hundreds of pages, and none of the documentation I have read anywhere is relevant. Wherever the answer is on this vast Internet, I have not been able to find it.
So ive been looking for a way to integrate webRTC into a site im making, but i want to do it on shared hosting. I came across this repo on GitHub by nielsbaloe and it has been a huge help in getting a basic connection.
This is the code i believe is responsible for adding the peer: ( index.html in the repo, line )
function icecandidate(localStream) {
pc = new RTCPeerConnection(configuration);
pc.onicecandidate = function (event) {
if (event.candidate) {
publish('client-candidate', event.candidate);
}
};
try {
pc.addStream(localStream);
}catch(e){
var tracks = localStream.getTracks();
for(var i=0;i<tracks.length;i++){
pc.addTrack(tracks[i], localStream);
}
}
pc.ontrack = function (e) {
document.getElementById('remoteVideo').style.display="block";
document.getElementById('localVideo').style.display="none";
remoteVideo.srcObject = e.streams[0];
};
}
Now the struggle im facing is adding room functionality, and maybe the ability to have more than two concurrent peers present at the same time. I did some experimenting, but in vain. I know that for room functionality id have to tinker around in the php, so at least id like to figure out how to make more than 1 peer possible.
As far as I know, there is no way to re-use the same RTCPeerConnection for multiple peers, so you'll have to do the same thing as 1-on-1 but between every single peer in a group.
As far as signalling, it's pretty simple, goes kind of like this:
Client A -> [Offer] -> Server -> [Offer] -> Client B -> [Answer] -> Server -> [Answer] -> Client A
A nicer explanation at MDN
There isn't necessarily a need for NodeJS or WebSocket. The reason most people go for it it is because the last link in this chain (Server -> Client A) requires server-initiated connection. But that can be substituted with alternative techniques such as (long-)polling. Or, in case of PHP, you might use websocket implementations such as Bloatless or Aerys
To implement the room functionality, you'll have to implement the following:
Variant A (using polling):
An endpoint to throw offers at, e.g. POST /rooms/{id}
An endpoint to regularly check for new offers from, e.g. GET /rooms/{id}
Variant B (with websockets)
Create a broadcast rooms, for example, by dynamically creating HTTP endpoints and websocket server instances. Or by having a single websocket instance but sending whatever room you're intending to join right inside after establishing a connection. From there, it's only a matter of sending correct offers and answers to correct users.
In both cases, you might want to either create multiple offers in advance to pool from the server, or to dynamically create new ones, but, most importantly, make sure you're not connecting the same peers twice, otherwise you will end up with a loop. To prevent it, just provide each user with a randomly generated string to identify themself and send it among offers.
There are turnkey solutions available if you don't want to go this route, but be careful and check whether you can use your own TURN servers with them. A common trend I have noticed is that there are a lot of WebRTC solution providers out there that lure you with their simplicity but then lock you in with their own TURN servers for which you might have to pay a quite hefty bill later on.
How one can communicate with Mettler toledo IND780 device for reading weight through browser application through javascript. I know ActiveXObject will work with only Internet explorer . But is there any documentation or API to do this via javascript.
First, You need to contact the developers of the Mettler toledo IND780 device and confirm with them, whether this product can interact with any Web application or not. As other community member already informed you that this kind of devices can not be accessible from any web app.
I try to visit their site and I find that this product can work like below.
Reference:
IND780 Advanced Weighing Terminal
They can give you the proper idea or any example to interact with this device.
If they deny you that this device cannot work with Web app then try to store the data from that device to any Excel file and then try to import the data from that Excel file to your web app may help you to solve the issue.
You need to use a TelNet client to communicate with the device. Currently i'm using C# to connect and read information. I think you can use a similar library from JavaScript side.
Old thread but maybe this answer can help someone, best way around is to code a back-end application to get the data you need from the Shared Data of the IND780 (Shared Data Reference manual), example in Python3:
import socket
import time
# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Connect the socket to the port where the server is listening
server_address = ('172.16.40.98', 1701)
print('connecting to {} port {}'.format(*server_address))
sock.connect(server_address)
try:
time.sleep(0.1)
data = sock.recv(2048)
print('1 received {!r}'.format(data))
message = b'user admin\n'
print('2 sending {!r}'.format(message))
sock.sendall(message)
data = sock.recv(2048)
print('3 received {!r}'.format(data))
print(len(message))
print('')
message = b'read wt0101\n'
# wt--01 Displayed Gross Weight
print('4 sending {!r}'.format(message))
sock.sendall(message)
data = sock.recv(2048)
print('5 received {!r}'.format(data))
I have setup an account and app in the pusher.com API dashboard and have experimented with both private and public channels and client->client events - I have no trouble doing this.
My project is using CodeIgniter (latest) PHP framework (+ jQuery latest + pusher latest) and I have access to edit everything - nothing is out of bounds in terms of solutions, this is a non commercial project.
My aim is to have client/socket A send an event/message to client/socket B within 'channelX'.
I would like many people/sockets to be possible within 'channelX' - so for example we could have 10 clients connected to this channel, but within it I would like 2 parties to be able to communicate directly with each other (can be via server or just via pusher api).
At the moment, and where my understanding and research leads me: is that any event triggered in my 'channelX' private channel is sent to all clients - now I have used the 'exclude socket' parameter to make sure the event doesn't trigger on 'socketA' (the person doing the initiating of the event) - and this works when there is only 2 clients/sockets connected to a channel - but add more parties and it gets messy.
The question:
Should a channel ONLY have 2 clients/sockets if the events are only to be shared between two?
Ideally what I would like to do:
Have one master channel which holds all users - then each user should be able to send a 'ping' or 'poke' to one of the other users - without all of the other clients receiving this pusher event/trigger.
I do have code but my question is really theory based and so I'm not expecting bundles of code to come from this question - but the docs on the pusher.com website kind of miss this point (or perhaps I did!)
Thanks for any input
There is an old FAQ article on how to implement 1-to-1 chat that may provide a strategy that suits your needs.
I'm trying to use two websockets on one page. This is my code:
var pageViewWs = new WebSocket("ws://localhost:9002/pageView");
var sessionWs = new WebSocket("ws://localhost:9002/session");
pageViewWs.onmessage = function (event) {
alert("PageView");
};
sessionWs.onmessage = function (event) {
alert("Session");
};
Only the PageView alert appears. On the server side no requests are made to /session, only to /pageView.
Now, if I switch var pageViewWs and var sessionWs around then the Session alert is shown instead of the PageView. It is not because they are alerts, I've tried appending to the body and to divs and I've stepped through using Firebug. It seems that only one WebSocket can be created at a time although in Firebug the properties for pageViewWs and sessionWs appear the same with the exception of their url.
I've only tested this in Firefox 15.0.1. Is there some sort of Websocket limitation whereby you can only run one at a time? Or is something wrong with my code?
I faced the same problem to run multiple services through the same port. So, I created a PHP library to do this.
Why ?
Some free plans of hosting providers don't allow you to bind to ports or allow you to bind to one port. In case of OpenShift Cloud Server, you can only bind to port 8080. So, running multiple WebSocket services is not possible. In this case, Francium DiffSocket is useful.
You can run different services on the same port using a PHP library called Francium DiffSocket.
After setting up Francium DiffSocket, you can do this for using different services :
var chatWS = new WebSocket("ws://ws.example.com:8000/?service=chat");
var gameWS = new WebSocket("ws://ws.example.com:8000/?service=game");
An example are these services which are running through a single port :
Finding Value Of Pi
Advanced Live Group Chat With PHP, jQuery & WebSocket
Live Group Chat With PHP, jQuery & WebSocket
I believe you can only create one WebSocket connection from a client to a specific port on the host. Have you tried either running the two services on different ports, or on different servers? This would allow you to determine the limitation...
Apart from the HTTP Request head both the request are the same. They hit the same application server on the same port. It is up to the server side application to treat each connection differently based on the HTTP request that initiated it.
I've done this in node. You could do it manually but packages like
espress-ws
or express-ws-routes
eases the process.