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possible EventEmitter memory leak detected with mpromise

See original GitHub issue

var def = Model.find({}).exec()

// if we have more then 11 "then waiters"
def.then(function(){
...
})

if we have more then 11 “then waiters” we have an error in console:

(node) warning: possible EventEmitter memory leak detected. 11 listeners added. Use emitter.setMaxListeners() to in
crease limit.
Trace
    at Promise.EventEmitter.addListener (events.js:160:15)
    at Promise.on (...\node_modules\mongoose\node_modules\mprom
ise\lib\promise.js:61:31)
    at Promise.onReject (...\node_modules\mongoose\node_modules
\mpromise\lib\promise.js:154:15)
    at Promise.then (...\node_modules\mongoose\node_modules\mpr
omise\lib\promise.js:216:10)
    at Object.<anonymous> (...\app\models\muller-word.js:227:21
)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)

Not sure if this is expected, but I often use promises in such a way that there may be a lot of listeners for deferred result.

Issue Analytics

State:
Created 9 years ago
Comments:13

Top GitHub Comments

3reactions

mattcaseycommented, Jun 9, 2015

FYI if you have the connection object, you can setMaxListeners() on it…

var connection = mongoose.createConnection(config.MONGO_URI, config.MONGO_OPTIONS);
connection.setMaxListeners(0); // allow infinite listeners

0reactions

vkarpov15commented, Oct 12, 2015

Just use mongoose.Promise = global.Promise; (if you’re using node 4 and mongoose 4.1) and this issue should go away as specified in https://github.com/Automattic/mongoose/issues/1992#issuecomment-134257407

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