Help needed to understand QuestDB memory usage

Community
1

Hi team,

I’m using QuestDB to store and query financial data, but I keep running into the following error:

could not mmap [size=4120, offset=0, fd=606489918049, memUsed=4389914774, fileLen=4120]

This happens during I am running SAMPLE BY query on a minute level data partitioned hourly, and I have 40G+ available for memory and 10G+ for swap. I’m unsure what’s causing the mmap failure or where to focus my troubleshooting.

Any suggestions or pointers would be greatly appreciated, thank you!

2

hi wxl, we also log OS errno, which usually narrows things down more than error text. That said, have you followed this section of the documentation? Capacity planning | QuestDB