# Rollover + Single Index + mapping update =?

**URL:** <https://discuss.elastic.co/t/rollover-single-index-mapping-update/177868>\
**Category:** Elasticsearch\
**Created:** [April 22, 2019, 2:46pm UTC](https://discuss.elastic.co/t/rollover-single-index-mapping-update/177868 "2019-04-22T14:46:26Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![rozling](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rozling/32/16401_2.png) [@rozling](https://discuss.elastic.co/u/rozling)\
**Post date:** [April 22, 2019, 2:46pm UTC](https://discuss.elastic.co/t/rollover-single-index-mapping-update/177868/1 "2019-04-22T14:46:26Z")

</div>

Hi,

We use Elasticsearch for logs, and we're currently:

- adopting the rollover pattern
- transitioning to a single index for all our services (versus the ~30 or so that we have currently)
- implementing ECS

Rollover seems to be straightforward / working well, and the single index seems like it will be do-able (although a lot of work).

My question is: what's the best practise with regard to mapping updates?

I've read that zero-downtime mapping updates are much easier using write aliases, but I'm not sure exactly how to set that up.

I'm presuming that people usually just have a service / cron job that reindexes historical indices; is there anything to be aware of there when also doing rollovers, or is it all just smooth sailing?

I'm _hoping_ that adopting ECS will mean that even if we have a period of time where searches are being carried out across inconsistently-mapped indices, the common schema will reduce the number of 'failed shards' messages when searching...

Any thoughts / advice welcomed!

Thanks :elasticheart:

---

<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:** [May 20, 2019, 2:46pm UTC](https://discuss.elastic.co/t/rollover-single-index-mapping-update/177868/2 "2019-05-20T14:46:34Z")

</div>

Closed on May 20, 2019, 2:46pm UTC

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