# Remote reindex of large index using manual slicing **URL:** \ **Category:** Elasticsearch\ **Created:** [June 1, 2017, 6:16am UTC](https://discuss.elastic.co/t/remote-reindex-of-large-index-using-manual-slicing/87848 "2017-06-01T06:16:44Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![nfin](https://avatars.discourse-cdn.com/v4/letter/n/f05b48/32.png) [@nfin](https://discuss.elastic.co/u/nfin)\ **Post date:** [June 1, 2017, 6:16am UTC](https://discuss.elastic.co/t/remote-reindex-of-large-index-using-manual-slicing/87848/1 "2017-06-01T06:16:44Z")
Hello, We are trying to do a remote reindex from a source index on 5.1.1 to a destination index on 5.3.2. The source index has ~6 billion docs, so we want to manually slice to parallelize. I read over the reindex documentation and am a bit confused about the scroll context. It says that manually slicing uses scrolls, but I don't see a way to set the scroll context time setting? I tried adding "scroll=5m" to the URL, but get an exception saying it's unrecognized for the \_reindex endpoint. In the documentation's example, they simply create 2 slices and seem to execute both at once, but we cannot do that. We can only submit a few slice IDs at a time else we get socket timeout exceptions (I have tried increasing this value with no luck). Basically we want to manually slice (by say 100 slices), and then execute 10-20 slice IDs at a time, and continue doing 10-20 till we finish all 100 slices. However, these 10-20 slices will take hours to complete, and I am not sure how to keep the scroll context alive for that long using the reindex API. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [June 29, 2017, 6:28am UTC](https://discuss.elastic.co/t/remote-reindex-of-large-index-using-manual-slicing/87848/2 "2017-06-29T06:28:37Z")
This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.