# Improve ElasticSearch Read Cache **URL:** \ **Category:** Elasticsearch\ **Created:** [September 21, 2015, 9:05am UTC](https://discuss.elastic.co/t/improve-elasticsearch-read-cache/29684 "2015-09-21T09:05:22Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![strfx](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@strfx](https://discuss.elastic.co/u/strfx)\ **Post date:** [September 21, 2015, 9:05am UTC](https://discuss.elastic.co/t/improve-elasticsearch-read-cache/29684/1 "2015-09-21T09:05:22Z")
Hi there I'm doing heavy bulk updating on my elasticsearch cluster on a daily base. While is usually works fine on a fresh index (50k updates/sec), after a few bulks the process slows down terribly (1-5k updates/sec). Investigation shows that Elasticsearch keeps hitting the disk for reads (~1'200 K/s reads per process) - I guess it is checking for the existence of the document to be updated. Is there a way to improve the read cache, so it doesn't has to hit the disk so frequent? Specs: 24 cores, 36 GB RAM (24GB Heap Size, so 12GB are left for the OS disk cache) ---
**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:** [September 21, 2015, 10:05am UTC](https://discuss.elastic.co/t/improve-elasticsearch-read-cache/29684/2 "2015-09-21T10:05:53Z")
Move to SSDs would be one 🙂 ---
**Author:** ![otisg](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/otisg/32/492_2.png) [@otisg](https://discuss.elastic.co/u/otisg)\ **Post date:** [September 21, 2015, 7:33pm UTC](https://discuss.elastic.co/t/improve-elasticsearch-read-cache/29684/3 "2015-09-21T19:33:48Z")
Hi, Maybe you can make your heap a little smaller and give the OS a bit more RAM and see if that makes a difference? ## Otis Monitoring \* Alerting \* Anomaly Detection \* Centralized Log Management Elasticsearch Consulting & Support \* [http://sematext.com/](http://sematext.com/) ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 11:48pm UTC](https://discuss.elastic.co/t/improve-elasticsearch-read-cache/29684/4 "2017-07-05T23:48:57Z")