# Scrolling & Resource usage (lack of close()..) **URL:** \ **Category:** Elasticsearch\ **Created:** [July 20, 2012, 6:24am UTC](https://discuss.elastic.co/t/scrolling-resource-usage-lack-of-close/8474 "2012-07-20T06:24:37Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Paul\_Smith](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/paul_smith/32/1323_2.png) [@Paul\_Smith](https://discuss.elastic.co/u/Paul_Smith)\ **Post date:** [July 20, 2012, 6:24am UTC](https://discuss.elastic.co/t/scrolling-resource-usage-lack-of-close/8474/1 "2012-07-20T06:24:37Z")
Hey all, Scrolling, which keeps resources on the nodes around for a time limit specified in the scroll request, has no ability for the clinte to close(), or 'release' the resources once finished, as I see it from the high level. Subtle reading of the docs and code seem to indicate though that if a Scrolling client iterates over the entire collection of results, that once that loop exits, the resources are automatically closed for the scrol. Is that true? We have a case where an API style request in our application needs to return all results, and we'd like to use ES to perform the search interally, and be able to scroll through all the results to satisfy the API answer, but the lack of clarity of closing/freeing up the resources make this unclear if it's a good idea or not. Anyone have any good info on this? cheers, Paul ---
**Author:** ![Clinton\_Gormley](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@Clinton\_Gormley](https://discuss.elastic.co/u/Clinton_Gormley)\ **Post date:** [July 20, 2012, 8:09am UTC](https://discuss.elastic.co/t/scrolling-resource-usage-lack-of-close/8474/2 "2012-07-20T08:09:45Z")
Hi Paul > Scrolling, which keeps resources on the nodes around for a time limit > specified in the scroll request, has no ability for the clinte to > close(), or 'release' the resources once finished, as I see it from > the high level. Subtle reading of the docs and code seem to indicate > though that if a Scrolling client iterates over the entire collection > of results, that once that loop exits, the resources are automatically > closed for the scrol. > Is that true? That is correct. The "view" on search when you start your scroll request is maintained until either (1) the scroll request finishes or (2) or the scroll times out. Note: on the initial scroll request and on EACH SUBSEQUENT pull of scroll results, you pass a scroll=TIME parameter. This means that the timeout should be sufficient to process the results from a single pull, not all the results in ES. Every time you pull another set of results from the scroll, it extends the timeout to now() + timeout. So lets say that you are sure that you can finish parsing the first X results in 20 seconds, set your scroll timeout to eg '30s'. Every time you pull the next batch of results, you pass scroll=30s which ensures that the scroll stays live for another 30s from now. > We have a case where an API style request in our application needs to > return all results, and we'd like to use ES to perform the search > interally, and be able to scroll through all the results to satisfy > the API answer, but the lack of clarity of closing/freeing up the > resources make this unclear if it's a good idea or not. Scrolling can be very expensive. To return all the results in ES, it is better to combine it with search\_type=scan, which is very efficient. The downside being that you can't sort with scan requests. clint ---
**Author:** ![Paul\_Smith](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/paul_smith/32/1323_2.png) [@Paul\_Smith](https://discuss.elastic.co/u/Paul_Smith)\ **Post date:** [July 20, 2012, 8:27am UTC](https://discuss.elastic.co/t/scrolling-resource-usage-lack-of-close/8474/3 "2012-07-20T08:27:17Z")
Thanks. Yeah I know getting all results is expensive but our API is what it is now. Our old search lframework supported this and it was expensive comparative to a traditional Top X result which Lucene is great at. Is a scroll better or worse than doing subsequent paging of searches including going to the very last page? scroll should be better than that? On Friday, 20 July 2012, Clinton Gormley wrote: > Hi Paul > > > Scrolling, which keeps resources on the nodes around for a time limit > > specified in the scroll request, has no ability for the clinte to > > close(), or 'release' the resources once finished, as I see it from > > the high level. Subtle reading of the docs and code seem to indicate > > though that if a Scrolling client iterates over the entire collection > > of results, that once that loop exits, the resources are automatically > > closed for the scrol. > > > Is that true? > > That is correct. The "view" on search when you start your scroll request > is maintained until either (1) the scroll request finishes or (2) or the > scroll times out. > > Note: on the initial scroll request and on EACH SUBSEQUENT pull of > scroll results, you pass a scroll=TIME parameter. This means that the > timeout should be sufficient to process the results from a single pull, > not all the results in ES. Every time you pull another set of results > from the scroll, it extends the timeout to now() + timeout. > > So lets say that you are sure that you can finish parsing the first X > results in 20 seconds, set your scroll timeout to eg '30s'. Every time > you pull the next batch of results, you pass scroll=30s which ensures > that the scroll stays live for another 30s from now. > > > We have a case where an API style request in our application needs to > > return all results, and we'd like to use ES to perform the search > > interally, and be able to scroll through all the results to satisfy > > the API answer, but the lack of clarity of closing/freeing up the > > resources make this unclear if it's a good idea or not. > > Scrolling can be very expensive. To return all the results in ES, it is > better to combine it with search\_type=scan, which is very efficient. > The downside being that you can't sort with scan requests. > > clint ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 3:19am UTC](https://discuss.elastic.co/t/scrolling-resource-usage-lack-of-close/8474/4 "2017-07-06T03:19:41Z")