了解Elasticsearch中的扫描和滚动

Question

Using ES and AngularJS to make a small search app. I'm trying to understand how to implement the scan and scroll feature in ES to use for pagination.

The docs say to make a search request and then to include a 'search_type: scan' and 'scroll' parameters.

Do I just add those parameters to my current search request or do I need to make another search request and specify request as the scan and scroll search request?

Answer 1

As documentation explain you need to make the first call using

GET /old_index/_search?search_type=scan&scroll=1m 
{
    "query": { "match_all": {}},
    "size":  1000
}

The response to this request doesn't include any hits (means content you search) but scroll id like following

{
    "_scroll_id" : "c2Nhbjs1OzMwNTYzMTkxNjpTSkM2S0cxVFJIeUk1NnZWbGFUV1FnOzMwNTYzMTkxNTpTSkM2S0cxVFJIeUk1NnZWbGFUV1FnOzMwNTYyMjEwNzp4OEkwZE54eVR0cXI4cHAzU2I5UmlBOzMwNTYzNTE0NjpQZEhCSUZXeFJZU3daaDJKZXZCRmh3OzMwNTY0OTg4OTphdEE1OTN2NFFsYVY5ZjJ4SUxuVFpROzE7dG90YWxfaGl0czoyOTIwOw==",
    "took" : 10,
    "timed_out" : false,
    "_shards" : {
        "total" : 5,
        "successful" : 5,
        "failed" : 0
    },
    "hits" : {
        "total" : 2920,
        "max_score" : 0,
        "hits" : []
    }
} 

After this you can use normal call with the scroll_id GET /_search/scroll?scroll=1m&_scroll_idc2Nhbjs1OzMwNTYzMTkxNjpTSkM2S0cxVFJIeUk1NnZWbGFUV1FnOzMwNTYzMTkxNTpTSkM2S0cxVFJIeUk1NnZWbGFUV1FnOzMwNTYyMjEwNzp4OEkwZE54eVR0cXI4cHAzU2I5UmlBOzMwNTYzNTE0NjpQZEhCSUZXeFJZU3daaDJKZXZCRmh3OzMwNTY0OTg4OTphdEE1OTN2NFFsYVY5ZjJ4SUxuVFpROzE7dG90YWxfaGl0czoyOTIwOw==

_scroll_id can be in request or body