Question

I’ve read answers in this question and tried many ways to resolve my issue but could not – hence posting this query from my side.

Basically I have a list of services in an array – which comes to ~ 1500 in numbers running on a different box other that where my NodeJS application is running. As per my code I ssh to the/a box and via expect script, then cd to a specific directory to get each service version / build id which is stored in a specific file at specific individual path for each service. There are chances that for some of the services the same file (having version / build information) may be stored at a different location in the box. So I have algo in app that in case attempt to get the details fails for the first path I will use other script to look for information at different path:

Main Block of code:

exports.getservicedetails = function(box,res) {
        var job = [];
        for (i = 0; i < services.length; i++ )
        {
                var children = new Object();
                children.server = services[i];
                children.box = box;
                children.process = spawn('./scripts/info.sh', [children.server , children.box , getStageURL(children.box)]);
                children.runstate = 1;
                job.push(children);
                createChildEvents(job, i, res);
        }
}

Now I set all events for each spawned tasks:

function createChildEvents(child, id, res){
        (child[id]).process.stderr.on('data', function (data) {
                (child[id]).runstate = 0;
        });
        (child[i]).process.on('exit', function (code) {
                (child[id]).runstate = 0;
                checkstate(child, res); // function to check if all spawned tasks has exited
        });
        (child[id]).process.stdout.on('data', function (data) {
                var result = data.toString().split("\r\n"); // split the stdout outputted lines
                for (var i = 0; i < result.length; i++)
                {
                       console.log('Server : ' +  (child[id]).server + " PID : " + (child[id]).process.pid + ' ' + (child[id]).box);
                        if ((child[id]).box.length > 0 && result[i].match(/No such file or directory/gi) != null) {
                                (child[id]).process = spawn('./scripts/info2.sh ',[(child[id]).server, (child[id]).box, getStageURL((child[id]).box)]);
                                (child[id]).box = '';
                                (child[id]).runstate = 1;
                                createChildEvents(child, id, res);
                                break;
                        }
                        if(result[i].match(/release_version*/) != null || result[i].match(/app.version*/) != null)
                                (child[id]).serversion = (result[i].split('='))[1];
                        if(result[i].match(/release_number*/) != null || result[i].match(/app.id*/) != null)
                                (child[id]).serproduct = (result[i].split('='))[1];
                }
        });
}

The issue is that after getting 11th console logs as mentioned below I see error:

Server : a PID : 27200 myboxname
Server : b PID : 31650 myboxname
Server : d PID : 31644 myboxname
Server : e PID : 31664 myboxname
Server : f PID : 28946 myboxname
Server : g PID : 32507 myboxname
Server : h PID : 29329 myboxname
Server : i PID : 29905 myboxname
Server : j PID : 29883 myboxname
Server : k PID : 481 myboxname
Server : l PID : 777 myboxname
(node) warning: possible EventEmitter memory leak detected. 11 listeners added. Use emitter.setMaxListeners() to increase limit.
Trace
    at EventEmitter.addListener (events.js:168:15)
    at EventEmitter.once (events.js:189:8)
    at Transport.logException (src/node_modules/winston/lib/winston/transports/transport.js:118:8)
    at logAndWait (src/node_modules/winston/lib/winston/logger.js:613:15)
    at async.forEach (src/node_modules/winston/node_modules/async/lib/async.js:86:13)
    at Array.forEach (native)
    at _forEach (src/node_modules/winston/node_modules/async/lib/async.js:26:24)
    at Object.async.forEach (src/node_modules/winston/node_modules/async/lib/async.js:85:9)
    at Logger._uncaughtException (src/node_modules/winston/lib/winston/logger.js:636:9)
    at process.EventEmitter.emit (events.js:115:20)
(node) warning: possible EventEmitter memory leak detected. 11 listeners added. Use emitter.setMaxListeners() to increase limit.
Trace
    at EventEmitter.addListener (events.js:168:15)
    at EventEmitter.once (events.js:189:8)
    at Transport.logException (src/node_modules/winston/lib/winston/transports/transport.js:117:8)
    at logAndWait (src/node_modules/winston/lib/winston/logger.js:613:15)
    at async.forEach (src/node_modules/winston/node_modules/async/lib/async.js:86:13)
    at Array.forEach (native)
    at _forEach (src/node_modules/winston/node_modules/async/lib/async.js:26:24)
    at Object.async.forEach (src/node_modules/winston/node_modules/async/lib/async.js:85:9)
    at Logger._uncaughtException (src/node_modules/winston/lib/winston/logger.js:636:9)
    at process.EventEmitter.emit (events.js:115:20)

I tried adding ‘process.setMaxListeners(0);’ at many points in my code but still I keep seeing this error?

Any idea how can I solve this issue? Thanks in advance.

Answer 1

You have a typo. child[i] instead of child[id]

You are thus setting a listener for the same emitter in each createChildEvents call.