# What is the version map memory?

**URL:** <https://discuss.elastic.co/t/what-is-the-version-map-memory/280332>\
**Category:** Elasticsearch\
**Created:** [August 3, 2021, 2:46pm UTC](https://discuss.elastic.co/t/what-is-the-version-map-memory/280332 "2021-08-03T14:46:56Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![eyecan](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@eyecan](https://discuss.elastic.co/u/eyecan)\
**Post date:** [August 3, 2021, 2:46pm UTC](https://discuss.elastic.co/t/what-is-the-version-map-memory/280332/1 "2021-08-03T14:46:56Z")

</div>

Hello,

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

Thanks!

---

<div class="post-metadata">

**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [August 3, 2021, 10:49pm UTC](https://discuss.elastic.co/t/what-is-the-version-map-memory/280332/2 "2021-08-03T22:49:36Z")

</div>

Welcome to our community! 😃

From [Cluster stats API | Elasticsearch Guide [8.11] | Elastic](https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-stats.html);

> `version_map_memory`
> 
> ([byte units](https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#byte-units)) Total amount of memory used by all version maps across all shards assigned to selected nodes.

---

<div class="post-metadata">

**Author:** ![eyecan](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@eyecan](https://discuss.elastic.co/u/eyecan)\
**Post date:** [August 4, 2021, 8:06am UTC](https://discuss.elastic.co/t/what-is-the-version-map-memory/280332/3 "2021-08-04T08:06:14Z")

</div>

Thank you Mark!

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

---

<div class="post-metadata">

**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [August 4, 2021, 8:27am UTC](https://discuss.elastic.co/t/what-is-the-version-map-memory/280332/4 "2021-08-04T08:27:37Z")

</div>

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

Is there a reason for asking?

---

<div class="post-metadata">

**Author:** ![eyecan](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@eyecan](https://discuss.elastic.co/u/eyecan)\
**Post date:** [August 4, 2021, 8:46am UTC](https://discuss.elastic.co/t/what-is-the-version-map-memory/280332/5 "2021-08-04T08:46:36Z")

</div>

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.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [September 1, 2021, 8:47am UTC](https://discuss.elastic.co/t/what-is-the-version-map-memory/280332/6 "2021-09-01T08:47:11Z")

</div>

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.