OOM when downloading csv on harvest.data.gov

[FuhuXia]

Download CSV gives OOM error

[ERROR] Worker (pid:207) was sent SIGKILL! Perhaps out of memory?

How to reproduce

https://harvest.data.gov/harvest_job/7df8043f-f0df-4bc4-bdd0-3342845501c3

Sketch

It is fine for small csv
https://harvest.data.gov/harvest_job/5322fb7b-16f8-47c6-85ce-2a043e4b2198

Find out why csv generation cause this error for big csv

current RAM and Disk for the instance are 1G and 4G.

[FuhuXia]

Increased RAM to 2GB, issue is resolved, but still need to look at the code to see if this can be resolved by optimizing code.