loopbackio / loopbackio/loopback-connector-postgresql

PG DataSource Error handler throwing memory leak warning

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bug
Dominant language
JavaScript
Stars
118
Forks
184
Avg merge
1d 22h
Merged PRs (30d)
5

Description

Steps to reproduce

  • Add onError handler in DataSource for Loopback Connector Postgresql.
  • Use DataSource on frequent manner.
  • It should throw warnings like
    (node:80014) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added to [Client]. Use emitter.setMaxListeners() to increase limit

(More details to reproduce the issue are provided in the README.md file in the sandbox repository)

Current Behavior

It doesn't remove the attached error event listeners while releasing the connection back to pool.

Expected Behavior

It should remove attached event listener before releasing connection back to pool.

Link to reproduction sandbox

https://github.com/vinod-hansda/loopback-pg-warning

Additional information

node -e 'console.log(process.platform, process.arch, process.versions.node)' :-
darwin arm64 18.20.6

npm ls --prod --depth 0 | grep loopback :-
npm warn config production Use --omit=dev instead.
loopback-pg@0.0.1 /Users/vinodhansda/Documents/GitHub/loopback-pg-warning
├── @loopback/boot@5.0.10
├── @loopback/core@4.0.10
├── @loopback/repository@5.1.5
├── @loopback/rest-explorer@5.0.10
├── @loopback/rest@12.0.10
├── @loopback/service-proxy@5.0.10
├── loopback-connector-postgresql@7.1.9

Related Issues

See Reporting Issues for more tips on writing good issues

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Use the linked sandbox and its README to reproduce the MaxListenersExceededWarning with a PostgreSQL DataSource and an onError handler. Then inspect the connector's connection-pool release path; done means repeated use no longer accumulates error listeners before a connection is returned to the pool.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, nodejs, postgresql
Domain
database
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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