弹性 - 在单个请求中更新多个文档

Question

I need to update several thousand items every several minutes in Elastic and unfortunately reindexing is not an option for me . From my research the best way to update an item is using _update_by_query - I have had success updating single documents like so -

{
  "query": {
    "match": {
      "itemId": {
        "query": "1"
      }
    }
  },
  "script": {
    "source": "ctx._source.field = params.updateValue",
    "lang": "painless",
    "params": {
      "updateValue": "test",
    }
  }
}

var response = await Client.UpdateByQueryAsync<dynamic>(q => q
    .Index("masterproducts")
    .Query(q => x.MatchQuery)
    .Script(s => s.Source(x.Script).Lang("painless").Params(x.Params))
    .Conflicts(Elasticsearch.Net.Conflicts.Proceed)
);

Although this works it is extremely inefficient as it generates thousands of requests - is there a way in which I can update multiple documents with a matching ID in a single request? I have already tried Multiple search API which it would seem cannot be used for this purpose. Any help would be appreciated!

Answer 1

If possible, try to generalize your query.

Instead of targeting a single itemId , perhaps try using a terms query :

{
  "query": {
    "terms": {
      "itemId": [
        "1", "2", ...
      ]
    }
  },
  "script": {
    ...
  }
}

From the looks of it, your (seemingly simplified) script sets the same value, irregardless of the document ID / itemId . So that's that.

If the script does indeed set different values based on the doc IDs / itemIds , you could make the params multi-value:

"params": {
 "updateValue1": "test1",
 "updateValue2": "test2",
 ...
}

and then dynamically access them:

...
def value_to_set = params['updateValue' + ctx._source['itemId']];
...

so the target doc is updated with the corresponding value.