when I run following query:

GET /annotations/_search
{
  "query": {
    "match_all": {}
  }
}

I receive following response:

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "annotations",
        "_type" : "_doc",
        "_id" : "I9nlA",
        "_score" : 1.0,
        "_source" : {
          "preferences" : {
            "id" : 1,
            "annotation_id" : "I9nlA",
            "answer_timer" : 24
          }
         // other fields here
        }
      },
      {
        "_index" : "annotations",
        "_type" : "_doc",
        "_id" : "XIP6L",
        "_score" : 1.0,
        "_source" : {
          "id" : "XIP6L",
          "preferences" : {
            "id" : 2,
            "annotation_id" : "XIP6L",
            "answer_timer" : 5
          },
        // other fields here
        }
      }
    ]
  }
}

As you can see, the field Preferences has no null values. My problem is that when I add a scripted field based on the Preferences field, it raises an error. The query:

GET /annotations/_search
{
  "query": {
    "match_all": {}
  },
  "script_fields": {
    "can_answer": {
      "script": {
        "source": """
          if (doc['creator_id'].value == params['user_id']){
            return true;
          }
          else{
            String nowString = params['now'];
            ZonedDateTime now = ZonedDateTime.parse(nowString);
            ZonedDateTime created = doc['created'].value;
            ZonedDateTime createdPlusAnswerTimer = created.plusHours(
              doc['preferences.answer_timer'].value
            );
            Duration d = Duration.between(now, createdPlusAnswerTimer);
            return d.toHours() > 0;
            }
        """,
        "params": {
          "user_id": 1,
          "now": "2022-05-17T16:17:49.366Z"
        }
      }
    }
  }
}

The error:

{
  "error" : {
    "root_cause" : [
      {
        "type" : "script_exception",
        "reason" : "runtime error",
        "script_stack" : [
          "org.elasticsearch.index.fielddata.ScriptDocValues.throwIfEmpty(ScriptDocValues.java:73)",
          "org.elasticsearch.index.fielddata.ScriptDocValues$Longs.get(ScriptDocValues.java:118)",
          "org.elasticsearch.index.fielddata.ScriptDocValues$Longs.getValue(ScriptDocValues.java:113)",
          "createdPlusAnswerTimer = created.plusHours(\n              doc['preferences.answer_timer'].value\n            );\n            Duration ",
          "                                                                                         ^---- HERE"
        ],
        "script" : " ...",
        "lang" : "painless",
        "position" : {
          "offset" : 398,
          "start" : 309,
          "end" : 441
        }
      }
    ],
    "type" : "search_phase_execution_exception",
    "reason" : "all shards failed",
    "phase" : "query",
    "grouped" : true,
    "failed_shards" : [
      {
        "shard" : 0,
        "index" : "annotations",
        "node" : "_ljs4uLdR7eBjL8ioYLqAg",
        "reason" : {
          "type" : "script_exception",
          "reason" : "runtime error",
          "script_stack" : [
            "org.elasticsearch.index.fielddata.ScriptDocValues.throwIfEmpty(ScriptDocValues.java:73)",
            "org.elasticsearch.index.fielddata.ScriptDocValues$Longs.get(ScriptDocValues.java:118)",
            "org.elasticsearch.index.fielddata.ScriptDocValues$Longs.getValue(ScriptDocValues.java:113)",
            "createdPlusAnswerTimer = created.plusHours(\n              doc['preferences.answer_timer'].value\n            );\n            Duration ",
            "                                                                                         ^---- HERE"
          ],
          "script" : " ...",
          "lang" : "painless",
          "position" : {
            "offset" : 398,
            "start" : 309,
            "end" : 441
          },
          "caused_by" : {
            "type" : "illegal_state_exception",
            "reason" : "A document doesn't have a value for a field! Use doc[<field>].size()==0 to check if a document is missing a field!"
          }
        }
      }
    ]
  },
  "status" : 400
}

It said there is some problems with doc['preferences.answer_timer'].value, but I don't know why. This field has value in all documents.

What is the problem and how can I solve it? Thanks.

UPDATE: Mapping added:

 {
  "annotations" : {
    "mappings" : {
      "properties" : {
        
        // other fields
        
        "preferences" : {
          "type" : "nested",
          "properties" : {
            "annotation_id" : {
              "type" : "text",
              "fields" : {
                "keyword" : {
                  "type" : "keyword",
                  "ignore_above" : 256
                }
              }
            },
            "answer_timer" : {
              "type" : "long"
            },
            "id" : {
              "type" : "long"
            }
          }
        }
        
        // other fields
        
      }
    }
  }
}

NOTE when I use params._source.preferences.answer_timer, it works fine. But in the Elasticsearch documentation, it's been said that using _source.field is very slow, so I don't want to use it.

CodePudding user response：

Since the preferences field is nested, we need to call the script in the context of the nested query. The parent document does not have a doc_value field - Thus giving an error. Ref: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-nested-query.html

Solition 1: Change preferences type to object instead of nested.
Solution 2: use query in nested context.