node 环境中引入cluster模块，子进程中引入CoAP开启CoAP服务出错?报错

我的本意是在node环境中引入http、mqtt、CoAP三种协议并开启这三种服务，（在else 中开启mqtt服务及http服务毫无问题，但是开启COAP服务则会报错！）仅贴出部分代码，希望有经验的大佬给予指导。代码如下：

const cluster = require('cluster');

const http = require('http');

const numCPUs = require('os').cpus().length;

const mosca = require('mosca');

if (cluster.isMaster) {

console.log(`Master ${process.pid} is running`);

for (let i = 0; i < numCPUs; i++) {

cluster.fork();

console.log(cluster.fork());

}

cluster.on('exit', (worker, code, signal) => {

console.log(`worker ${worker.process.pid} died`);

});

} else {

const coap = require('coap');

const coapServer = coap.createServer();

coapServer.on('request',function(req,res){

res.end('your request is : ' + req.url.split('/')[1] + '\n');

console.log('connect 1')

});

coapServer.listen(8080,function() {

console.log('coapServer is running...')

});

}

将else 中CoAP服务替换为HTTP或者MQTT或者MQTT/HTTP混用皆可，但是一旦开启CoAP就会报错，单独开启COAP也会报错,报错代码如下：

Error: write ENOTSUP
    at _errnoException (util.js:1024:11)
    at ChildProcess.target._send (internal/child_process.js:702:20)
    at ChildProcess.<anonymous> (internal/child_process.js:532:16)
    at emitTwo (events.js:131:20)
    at ChildProcess.emit (events.js:214:7)
    at emit (internal/child_process.js:772:12)
    at _combinedTickCallback (internal/process/next_tick.js:141:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)

尝试将开启CoAP服务的代码从else中摘出来（不使用集群），放在头部或者尾部 但是都会报错，放在头部时CoAP服务可以正常开启，但是运行到else语句时就报错了。