我有来自node
的工作（股票）脚本var cluster = require('cluster');
var http = require('http');
var numReqs = 0;
if (cluster.isMaster) {
// Fork workers.
for (var i = 0; i < 2; i++) {
var worker = cluster.fork();
worker.on('message', function(msg) {
if (msg.cmd && msg.cmd == 'notifyRequest') {
numReqs++;
}
});
}
setInterval(function() {
console.log("numReqs =", numReqs);
}, 1000);
} else {
// Worker processes have a http server.
http.Server(function(req, res) {
res.writeHead(200);
res.end("hello world\n");
// Send message to master process
process.send({ cmd: 'notifyRequest' });
}).listen(8000);
}
在上面的脚本中，我可以轻松地将数据从worker发送到master进程。但是如何将数据从master发送给worker / workers呢？有了例子，如果可能的话。
答案 0 :(得分：39)
由于cluster.fork是在child_process.fork之上实现的，因此您可以使用worker.send({ msg: 'test' })从主服务器向工作人员发送消息，并通过process.send({ msg: 'test' });从工作人员发送消息到主服务器。您收到如下消息：worker.on('message', callback)（从工人到主人）和process.on('message', callback);（从主人到工人）。
这是我的完整示例，您可以通过浏览http://localhost:8000/来测试它然后工作人员将向主人发送消息，主人将回复：
var cluster = require('cluster');
var http = require('http');
var numReqs = 0;
var worker;
if (cluster.isMaster) {
// Fork workers.
for (var i = 0; i < 2; i++) {
worker = cluster.fork();
worker.on('message', function(msg) {
// we only want to intercept messages that have a chat property
if (msg.chat) {
console.log('Worker to master: ', msg.chat);
worker.send({ chat: 'Ok worker, Master got the message! Over and out!' });
}
});
}
} else {
process.on('message', function(msg) {
// we only want to intercept messages that have a chat property
if (msg.chat) {
console.log('Master to worker: ', msg.chat);
}
});
// Worker processes have a http server.
http.Server(function(req, res) {
res.writeHead(200);
res.end("hello world\n");
// Send message to master process
process.send({ chat: 'Hey master, I got a new request!' });
}).listen(8000);
}
答案 1 :(得分：8)
我在寻找一种向所有子进程发送消息的方法时找到了这个线程，幸好能够通过有关数组的注释找到它。只是想说明使用这种方法向所有子进程发送消息的潜在解决方案。
var cluster = require('cluster');
var http = require('http');
var numReqs = 0;
var workers = [];
if (cluster.isMaster) {
// Broadcast a message to all workers
var broadcast = function() {
for (var i in workers) {
var worker = workers[i];
worker.send({ cmd: 'broadcast', numReqs: numReqs });
}
}
// Fork workers.
for (var i = 0; i < 2; i++) {
var worker = cluster.fork();
worker.on('message', function(msg) {
if (msg.cmd) {
switch (msg.cmd) {
case 'notifyRequest':
numReqs++;
break;
case 'broadcast':
broadcast();
break;
}
});
// Add the worker to an array of known workers
workers.push(worker);
}
setInterval(function() {
console.log("numReqs =", numReqs);
}, 1000);
} else {
// React to messages received from master
process.on('message', function(msg) {
switch(msg.cmd) {
case 'broadcast':
if (msg.numReqs) console.log('Number of requests: ' + msg.numReqs);
break;
}
});
// Worker processes have a http server.
http.Server(function(req, res) {
res.writeHead(200);
res.end("hello world\n");
// Send message to master process
process.send({ cmd: 'notifyRequest' });
process.send({ cmd: 'broadcast' });
}).listen(8000);
}
答案 2 :(得分：3)
以下是我为类似问题实施解决方案的方法。通过挂钩cluster.on('fork')，您可以在分叉时将消息处理程序附加到工作程序（而不是将它们存储在数组中），这样可以处理工作程序死亡或断开连接并且新工作程序分叉的情况
此代码段会从主服务器向所有工作人员发送消息。
if (cluster.isMaster) {
for (var i = 0; i < require('os').cpus.length; i++) {
cluster.fork();
}
cluster.on('disconnect', function(worker) {
cluster.fork();
}
// When a new worker process is forked, attach the handler
// This handles cases where new worker processes are forked
// on disconnect/exit, as above.
cluster.on('fork', function(worker) {
worker.on('message', messageRelay);
}
var messageRelay = function(msg) {
Object.keys(cluster.workers).forEach(function(id) {
cluster.workers[id].send(msg);
});
};
}
else {
process.on('message', messageHandler);
var messageHandler = function messageHandler(msg) {
// Worker received message--do something
};
}
答案 3 :(得分：1)
您应该能够从主服务器向工作人员发送消息，如下所示：
worker.send({message:'hello'})
因为“cluster.fork是在child_process.fork之上实现的”（cluster.fork是在child_process.fork之上实现的）
答案 4 :(得分：1)
我理解您向群集中的所有节点工作进程广播的目的，虽然您不能发送套接字组件，但是有一个解决方案可以提供服务。我将尝试用一个例子来解释：
第1步：当客户端操作需要广播时：
Child.js (Process that has been forked) :
socket.on("BROADCAST_TO_ALL_WORKERS", function (data)
{
process.send({cmd : 'BROADCAST_TO_ALL_WORKERS', message :data.message});
})
第2步：在群集创建方面
Server.js (Place where cluster forking happens):
if (cluster.isMaster) {
for (var i = 0; i < numCPUs; i++) {
var worker = cluster.fork();
worker.on('message', function (data) {
if (data.cmd === "BROADCAST_TO_ALL_WORKERS") {
console.log(server_debug_prefix() + "Server Broadcast To All, Message : " + data.message + " , Reload : " + data.reload + " Player Id : " + data.player_id);
Object.keys(cluster.workers).forEach(function(id) {
cluster.workers[id].send({cmd : "BROADCAST_TO_WORKER", message : data.message});
});
}
});
}
cluster.on('exit', function (worker, code, signal) {
var newWorker = cluster.fork();
newWorker.on('message', function (data) {
console.log(data);
if (data.cmd === "BROADCAST_TO_ALL_WORKERS") {
console.log(data.cmd,data);
Object.keys(cluster.workers).forEach(function(id) {
cluster.workers[id].send({cmd : "BROADCAST_TO_WORKER", message : data.message});
});
}
});
});
}
else {
//Node Js App Entry
require("./Child.js");
}
第3步：在子流程中广播 -
- ＆GT;在Child.js
中将它放在io.on（＆＃34; connection＆＃34;）之前process.on("message", function(data){
if(data.cmd === "BROADCAST_TO_WORKER"){
io.sockets.emit("SERVER_MESSAGE", { message: data.message, reload: data.reload, player_id : data.player_id });
}
});
我希望这会有所帮助。如果需要进一步澄清，请告诉我。
答案 5 :(得分：0)
如果只需要为子进程发送简单的配置数据，则可以使用cluster.fork()发送环境变量。这很有用，并且有利于通过集群和流程send方法发送消息。
const cluster = require('cluster')
if (cluster.isMaster) {
cluster.fork({
MY_DATA: 'something here'
})
} else {
console.log(process.env.MY_DATA) // "something here"
}