title: Elasticsearch 2.1: Result window is too large (index.max_result_window)
body: <p>We retrieve information from Elasticsearch 2.1 and allow the user to page thru the results. When the user requests a high page number we get the following error message:</p>
  
  <blockquote>
    <p>Result window is too large, from + size must be less than or equal
    to: [10000] but was [10020]. See the scroll api for a more efficient
    way to request large data sets. This limit can be set by changing the
    [index.max_result_window] index level parameter</p>
  </blockquote>
  
  <p>The elastic docu says that this is because of high memory consumption and to use the scrolling api:</p>
  
  <blockquote>
    <p>Values higher than can consume significant chunks of heap memory per
    search and per shard executing the search. It’s safest to leave this
    value as it is an use the scroll api for any deep scrolling <a href="https://www.elastic.co/guide/en/elasticsearch/reference/2.x/breaking_21_search_changes.html#_from_size_limits">https://www.elastic.co/guide/en/elasticsearch/reference/2.x/breaking_21_search_changes.html#_from_size_limits</a></p>
  </blockquote>
  
  <p>The thing is that I do not want to retrieve large data sets. I only want to retrieve a slice from the data set which is very high up in the result set. Also  the scrolling docu says:</p>
  
  <blockquote>
    <p>Scrolling is not intended for real time user requests <a href="https://www.elastic.co/guide/en/elasticsearch/reference/2.2/search-request-scroll.html">https://www.elastic.co/guide/en/elasticsearch/reference/2.2/search-request-scroll.html</a></p>
  </blockquote>
  
  <p>This leaves me with some questions: </p>
  
  <p>1) Would the memory consumption really be lower (any if so why) if I use the scrolling api to scroll up to result 10020 (and disregard everything below 10000) instead of doing a "normal" search request for result 10000-10020?</p>
  
  <p>2) It does not seem that the scrolling API is an option for me but that I have to increase "index.max_result_window". Does anyone have any experience with this?</p>
  
  <p>3) Are there any other options to solve my problem?</p>