MemoryLeak due to long await in CertificateService issue method of @energyweb/origin-247-certificate package's causing, when trying to issue around 50 certificates

[Ahmed-Suhail]

Description

When using issue method of CertificateService of @energyweb/origin-247-certificate package, we are triggering this method to issue certificates in our system. This warning doesnt comes when we issue 2-5 certificates especially we try to issue more certificates like 50 we get the below warning

Warning in Console

MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 global:completed listeners added to [Queue]. Use emitter.setMaxListeners() to increase limit
at _addListener (events.js:475:17)
at Queue.addListener (events.js:497:10)
at Queue.on (/var/deployment/common/temp/node_modules/.pnpm/bull@3.22.9/node_modules/bull/lib/queue.js:326:14)
at /var/deployment/common/temp/node_modules/.pnpm/bull@3.22.9/node_modules/bull/lib/job.js:504:18
at new Promise ()
at Job.finished (/var/deployment/common/temp/node_modules/.pnpm/bull@3.22.9/node_modules/bull/lib/job.js:480:12)
at runMicrotasks ()
at processTicksAndRejections (internal/process/task_queues.js:95:5)
at async CertificateService.waitForJobResult (/var/deployment/common/temp/node_modules/.pnpm/@energyweb+origin-247-Wecertificate@2.1.2_a1b67e60083a0f64adab87445ef00c80/node_modules/@energyweb/origin-247-certificate/dist/js/src/certificate.service.js:111:20)
at async CertificateService.issue (/var/deployment/common/temp/node_modules/.pnpm/@energyweb+origin-247-certificate@2.1.2_a1b67e60083a0f64adab87445ef00c80/node_modules/@energyweb/origin-247-certificate/dist/js/src/certificate.service.js:48:24)
(node:1) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 global:failed listeners added to [Queue]. Use emitter.setMaxListeners() to increase limit

Alernate Solution

We can have alternate method which doesnt awaits for the job to complete but just puts the job on queue and returns.
Due to long await waitForJobResult we are getting MemoryLeak

This is snippet in issue method of CertificateService of @energyweb/origin-247-certificate
const job = await this.blockchainActionsQueue.add({
payload: command,
type: types_1.BlockchainActionType.Issuance
}, jobOptions);
const result = await this.waitForJobResult(job);

[JonaszJestem]

Have you tried batching the certificates and using batchIssue method?

[Ahmed-Suhail]

I havent tried that but we have different reservations for different devices coming up at different times and they all get queued one after another as of now our system is using issue method.