# Optimizing segment merge settings for high search throughput

**URL:** <https://discuss.elastic.co/t/optimizing-segment-merge-settings-for-high-search-throughput/35956>\
**Category:** Elasticsearch\
**Created:** [November 30, 2015, 9:45pm UTC](https://discuss.elastic.co/t/optimizing-segment-merge-settings-for-high-search-throughput/35956 "2015-11-30T21:45:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![travisbell](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/travisbell/32/6272_2.png) [@travisbell](https://discuss.elastic.co/u/travisbell)\
**Post date:** [November 30, 2015, 9:45pm UTC](https://discuss.elastic.co/t/optimizing-segment-merge-settings-for-high-search-throughput/35956/1 "2015-11-30T21:45:17Z")

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Hi guys,

I just have a quick question around the best settings for an index that has much higher search qps than indexing qps. My confusion lies around almost every guide and/or document I read deals with getting the highest indexing performance when I am looking for the reverse of that.

We have a 3 node cluster with an index set to use 1 shard and 2 replicas. There's only around 300,000 docs. This index does get written to on a semi-regular basis but very low qps. Maybe 50-80 document updates an hour. Really not very much and this is pretty steady. We handle around 2,000 searches per second across all nodes.

I currently have the merge.policy.max\_merge\_at\_once and segments\_per\_tier set to 3.

It doesn't take that long after an optimize (say 4-6 hours) before our average response times are 2x that of the time after a optimize and they slowly climb throughout the day (we create a new index every day so I only have 24 hours of data to work with). I realize keeping the state of being "right after the optimize" won't be possible but is there anything else I can do to be a little more aggressive about segment merges? I notice that most of my segments only have between 50-100 documents each so I feel like we can afford to be a little more aggressive here.

Thanks in advance!

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**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, 11:34pm UTC](https://discuss.elastic.co/t/optimizing-segment-merge-settings-for-high-search-throughput/35956/2 "2017-07-05T23:34:42Z")

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