# ES hangs while indexing(very slow indexing)

**URL:** <https://discuss.elastic.co/t/es-hangs-while-indexing-very-slow-indexing/42317>\
**Category:** Elasticsearch\
**Created:** [February 20, 2016, 10:39pm UTC](https://discuss.elastic.co/t/es-hangs-while-indexing-very-slow-indexing/42317 "2016-02-20T22:39:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Mostafa\_Wattad](https://avatars.discourse-cdn.com/v4/letter/m/e0b2c6/32.png) [@Mostafa\_Wattad](https://discuss.elastic.co/u/Mostafa_Wattad)\
**Post date:** [February 20, 2016, 10:39pm UTC](https://discuss.elastic.co/t/es-hangs-while-indexing-very-slow-indexing/42317/1 "2016-02-20T22:39:58Z")

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Hi  
I have an issue while indexing nested document(60-100MB) using python client.  
I have the last elastic version.  
The indexing is very slow and some times I got readTimeOut.  
After the indexing process the whole index will hangs and searches will be slow as well, I tried to recreate the index but that doesn't help.  
I have 5 machines in the cluster (without replicas), each machine with 32 GB RAM, i configured the memory heap size to be 16 GB and disabled the swapping.  
I tried to use the hot\_thread to see what is going on but I didn't see any thread with high CPU.

Indexing/updating/searching works nice with small documents **before** trying to index the big json (60-100MB) .

Does my mapping impact the indexing process?  
Do I need to configure memory or something ?  
What should I do ?

Thanks

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**Author:** ![jprante](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jprante/32/44941_2.png) [@jprante](https://discuss.elastic.co/u/jprante)\
**Post date:** [February 20, 2016, 11:36pm UTC](https://discuss.elastic.co/t/es-hangs-while-indexing-very-slow-indexing/42317/2 "2016-02-20T23:36:38Z")

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Documents of such excessive size are definitely not working with standard settings, risk of OOM and stalled nodes is high.

Have you tried to increase indices memory buffer?

[https://www.elastic.co/guide/en/elasticsearch/reference/2.2/indexing-buffer.html](https://www.elastic.co/guide/en/elasticsearch/reference/2.2/indexing-buffer.html)

Also, there is a 100mb limit on HTTP receive buffer which might be relevant

[https://www.elastic.co/guide/en/elasticsearch/reference/2.2/modules-http.html](https://www.elastic.co/guide/en/elasticsearch/reference/2.2/modules-http.html)

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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, 11:14pm UTC](https://discuss.elastic.co/t/es-hangs-while-indexing-very-slow-indexing/42317/3 "2017-07-05T23:14:41Z")

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