MaxListenersExceededWarning

[netmiller]

I'm getting (occasionally) error/warning message :

08:10:08: (node:187192) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 21 uncaughtException listeners added to [process]. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:390:17)
    at process.addListener (events.js:406:10)
    at Object.xmllint.validateXML (/opt/iris3/server/node_modules/node-xmllint/xmllint.js:12:2315)
    at /opt/iris3/server/node_modules/@authenio/samlify-node-xmllint/index.ts:15:34
    at new Promise (<anonymous>)
    at exports.validate (/opt/iris3/server/node_modules/@authenio/samlify-node-xmllint/index.ts:14:10)
    at Object.<anonymous> (/opt/iris3/server/node_modules/samlify/src/libsaml.ts:636:22)
    at step (/opt/iris3/server/node_modules/samlify/build/src/libsaml.js:38:23)
    at Object.next (/opt/iris3/server/node_modules/samlify/build/src/libsaml.js:19:53)
    at /opt/iris3/server/node_modules/samlify/build/src/libsaml.js:13:71

This is Express-backend serving React client, I think quite normal anyway.
Samlify is updated (yesterday) to [email protected] .
Node app is using typescript, and transpiled with tsc.
Some days ago I tried to increase maxListeners adding : process.setMaxListeners(20) to main.ts. I think default is 10. But this does not help except error message is complaining : 21 uncaughtException....

Any idea what is this and is there anything to change in application.

[tngan]

Hi @netmiller, thanks for your report. Let me check the lint library.

[tngan]

@netmiller There is one ticket in the repo of lint library. Let's continue the discussion in the following ticket.

authenio/samlify-node-xmllint#4

[netmiller]

This memory leak has fixed now by removing schema-validator @authenio/samlify-validate-with-xmllint.
Now skipping validation totally :

samlify.setSchemaValidator({
    validate: (response: string) => {
        return Promise.resolve('skipped');
    }
});

and app seems to behave much better.
This validator (samlify-validate-with-xmllint) has serious bug, and should avoid, imho.