title: Reindexing Elastic search via Bulk API, scan and scroll
body: <p>I am trying to re-index my Elastic search setup, currently looking at <a href="http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/scan-scroll.html" rel="nofollow noreferrer">the Elastic search documentation</a> and <a href="https://stackoverflow.com/questions/22921629/elasticsearch-py-scan-and-scroll-to-return-all-documents">an example using the Python API</a></p>
  
  <p>I'm a little bit confused as to how this all works though. I was able to obtain the scroll ID from the Python API:</p>
  
  <pre><code>es = Elasticsearch("myhost")
  
  index = "myindex"
  query = {"query":{"match_all":{}}}
  response = es.search(index= index, doc_type= "my-doc-type", body= query, search_type= "scan", scroll= "10m")
  
  scroll_id = response["_scroll_id"]
  </code></pre>
  
  <p>Now my question is, what use is this to me? What does knowing the scrolling id even give me? The documentation says to use the "Bulk API" but I have no idea how the scoll_id factors into this, it was a little confusing.</p>
  
  <p>Could anyone give a brief example showing my how to re-index from this point, considering that I've got the scroll_id correctly?</p>