# Sorting performance trouble **URL:** \ **Category:** Elasticsearch\ **Created:** [August 21, 2015, 12:06am UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809 "2015-08-21T00:06:34Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![liamwhite](https://avatars.discourse-cdn.com/v4/letter/l/ccd318/32.png) [@liamwhite](https://discuss.elastic.co/u/liamwhite)\ **Post date:** [August 21, 2015, 12:06am UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/1 "2015-08-21T00:06:35Z")
Hi, Recently we moved to a new production server and upgraded from ES 1.4.1 to 1.7.1 in the process. Since the upgrade, sorting performance on an entire collection (comments) to return the top 5 newest documents with 4 million documents has decreased a good deal from 75ms average to 175ms average, as well as a 3x slowdown on queries on the images index (~1 million documents) from 50ms to 150ms. To attempt to determine if it was a regression in 1.7.1, I cloned the comments index to a local instance of ES 1.7.1 and attempted to sort using the same query and config file as production; performance was around 70ms for matching/sorting all documents and returning the top 5. Almost the only differences in the config file are naming (ElasticSearch =\> Elasticsearch) and indentation (# commented thing =\> #commented thing); the two seem functionally identical. Any ideas of suggestions on what to poke on production would be very helpful. FWIW, the query is here: ``` { "index": "comments", "type": "comment", "body": { "query": { "filtered": { "query": {"match_all": {}}, "filter": { "term": {"hidden_from_users": "false", "_cache": "true" } } } }, "sort": [{"posted_at": "desc"}], "size": 5, "from": 0 } } ``` ---
**Author:** ![Norberto\_Meijome](https://avatars.discourse-cdn.com/v4/letter/n/ed655f/32.png) [@Norberto\_Meijome](https://discuss.elastic.co/u/Norberto_Meijome)\ **Post date:** [August 21, 2015, 5:14am UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/2 "2015-08-21T05:14:55Z")
Hi Liam, Everything else is the same between your prod env and your local instance? ( io subsystem, CPU, ram, #queries...) ---
**Author:** ![liamwhite](https://avatars.discourse-cdn.com/v4/letter/l/ccd318/32.png) [@liamwhite](https://discuss.elastic.co/u/liamwhite)\ **Post date:** [August 21, 2015, 4:44pm UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/3 "2015-08-21T16:44:12Z")
CPU and RAM are different: Local is an Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz with 24GB of RAM Production is a Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz with 128GB of RAM Both have more than enough memory to fit the entire comments index (645mb, no \_source or \_all) into memory. I didn't measure by number of queries, simply average execution time. While I didn't test that this is the case, it is possible that on production Elastic is busy doing other things when receiving the comments load+sort query. I suppose I can bring a short site downtime to test this, if you think that might be the issue. ---
**Author:** ![liamwhite](https://avatars.discourse-cdn.com/v4/letter/l/ccd318/32.png) [@liamwhite](https://discuss.elastic.co/u/liamwhite)\ **Post date:** [August 22, 2015, 12:09am UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/4 "2015-08-22T00:09:34Z")
I brought the site down temporarily to test whether the issue was concurrent requests; once the site was off, query performance did not change. ---
**Author:** ![Harlin\_ES](https://avatars.discourse-cdn.com/v4/letter/h/977dab/32.png) [@Harlin\_ES](https://discuss.elastic.co/u/Harlin_ES)\ **Post date:** [August 25, 2015, 10:56pm UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/5 "2015-08-25T22:56:42Z")
How much memory are you dedicating to ES? ---
**Author:** ![liamwhite](https://avatars.discourse-cdn.com/v4/letter/l/ccd318/32.png) [@liamwhite](https://discuss.elastic.co/u/liamwhite)\ **Post date:** [August 26, 2015, 12:30am UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/6 "2015-08-26T00:30:59Z")
On production, 31.5 gigabytes. It's only using 18. ---
**Author:** ![ksenji](https://avatars.discourse-cdn.com/v4/letter/k/bb73d2/32.png) [@ksenji](https://discuss.elastic.co/u/ksenji)\ **Post date:** [August 26, 2015, 1:18am UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/7 "2015-08-26T01:18:43Z")
Compare the node stats (/\_nodes/stats?pretty) on both environments to see if something stands out. ---
**Author:** ![liamwhite](https://avatars.discourse-cdn.com/v4/letter/l/ccd318/32.png) [@liamwhite](https://discuss.elastic.co/u/liamwhite)\ **Post date:** [August 26, 2015, 2:05am UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/8 "2015-08-26T02:05:54Z")
Here are the node stats on the old (idle) production server and the new (busy) production server, as well as a diff between them: > ---
**Author:** ![Harlin\_ES](https://avatars.discourse-cdn.com/v4/letter/h/977dab/32.png) [@Harlin\_ES](https://discuss.elastic.co/u/Harlin_ES)\ **Post date:** [August 26, 2015, 4:28pm UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/9 "2015-08-26T16:28:47Z")
Maybe try bringing that down to 30.5GB. I think that is recommended as the maximum in order to avoid 64 bit addresses. ---
**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, 11:53pm UTC](https://discuss.elastic.co/t/sorting-performance-trouble/27809/10 "2017-07-05T23:53:41Z")