keystonejs/keystone-classic

[0.x] Keystone OOMkilled on large CSV export

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#2592 opened on Apr 8, 2016

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 (1 comment) (0 reactions) (0 assignees)JavaScript (14,656 stars) (2,288 forks)batch import
bughelp wanted

Description

When exporting a keystone list as csv, the entire backing collection is loaded into memory before sending the response. This renders the export feature useless for a large collection; keystone will exhaust the available memory on the machine until it gets OOMkilled.

Instead, the export should be streamed back to the client so that we never load more than a cursor's worth of data in memory.

Contributor guide

Tech stack
javascriptnodejs
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Understanding of Node.js streamsBasic knowledge of CSV generationFamiliarity with Keystone API
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate how the current CSV export is implemented. Look for a file handling CSV export (likely in the keystone admin or export module). Implement streaming using Node.js Readable streams or async generators to send data in chunks instead of loading entire collection. Consider using a cursor for database queries to avoid large memory. Reference the issue comments for any additional context.