What is the version map memory?

Elastic Stack Elasticsearch
1

Hello,

In the cluster or node stats API there is a field version_map_memory.
What is the version map?

Thanks!

2

Welcome to our community! :smiley:

From Cluster stats API | Elasticsearch Guide [8.11] | Elastic;

version_map_memory

(byte units) Total amount of memory used by all version maps across all shards assigned to selected nodes.

3

Thank you Mark!

I read this description in the cluster and node stats API. But what is the version map?

4

It relates to segments, but I am not sure on the details.

Is there a reason for asking?

5

Hi Mark, thanks for your super fast response!

I think indeed it relates to segments because the parent field is "segments".
I understand the other fields but not this one. I'd like to know what it means if the value is always 0.