ElasticSearch painless, how can I access an array in _source - elasticsearch

Question

I try to execute a search request to the ElasticSearch (6.4.0) API which includes a custom script function. In this function I try to access an array which should part of the response data. But I always get a 'null_pointer_exception':
{
"error": {
"root_cause": [
{
"type": "script_exception",
"reason": "runtime error",
"script_stack": [
"i = 0; i < params['_source']['userStats'].length; i++) { } ",
" ^---- HERE"
],
"script": "double scoreBoost = 1; for (int i = 0; i < params['_source']['userStats'].length; i++) { } return _score * Math.log1p(scoreBoost);",
"lang": "painless"
}
],
"type": "search_phase_execution_exception",
"reason": "all shards failed",
"phase": "query",
"grouped": true,
"failed_shards": [
{
"shard": 0,
"index": "search--project",
"node": "...",
"reason": {
"type": "script_exception",
"reason": "runtime error",
"script_stack": [
"i = 0; i < params['_source']['userStats'].length; i++) { } ",
" ^---- HERE"
],
"script": "double scoreBoost = 1; for (int i = 0; i < params['_source']['userStats'].length; i++) { } return _score * Math.log1p(scoreBoost);",
"lang": "painless",
"caused_by": {
"type": "null_pointer_exception",
"reason": null
}
}
}
]
},
"status": 500
}
Also doc['userStats'] does't work.
Here is the complete request body:
{
"size": 10,
"query": {
"function_score": {
"query": {
"bool": {
"filter": {
"term": {
"_routing": "00000000-0000-0000-0000-000000000000"
}
},
"should": {
"query_string": {
"query": "123*",
"default_operator": "and",
"fuzziness": 1,
"analyze_wildcard": true,
"fields": [
"name^4",
"number^2",
"description",
"projectTypeId",
"projectStatusId",
"tags^1.5",
"company.name^2",
"company.number^2",
"company.industry",
"company.tags^1.5",
"company.companyTypes.name",
"company.companyContactInfos.value",
"company.companyContactInfos.addressLine1^1.25",
"company.companyContactInfos.addressLine2",
"company.companyContactInfos.zipCode^0.5",
"company.companyContactInfos.city",
"company.companyContactInfos.state",
"company.companyContactInfos.country",
"projectType.id",
"projectType.name",
"projectType.description",
"projectStatus.id",
"projectStatus.name",
"members.name",
"members.projectRoleName"
]
}
},
"minimum_should_match": 1
}
},
"functions": [
{
"script_score": {
"script": {
"source": "double scoreBoost = 1; for (int i = 0; i < params['_source']['userStats'].length; i++) { } return _score * Math.log1p(scoreBoost);",
"lang": "painless",
"params": {
"dtNow": 1543589276,
"uId": "00000000-0000-0000-0000-000000000000"
}
}
}
}
],
"score_mode": "multiply"
}
}
}
Without the script_score part the response look like this:
{
"took": 0,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 4,
"hits": [
{
"_index": "search--project",
"_type": "projectentity",
"_id": "00000000-0000-0000-0000-000000000000",
"_score": 4,
"_routing": "00000000-0000-0000-0000-000000000000",
"_source": {
"name": "123",
"description": "123...",
"projectTypeId": "00000000-0000-0000-0000-000000000000",
"projectStatusId": "00000000-0000-0000-0000-000000000000",
"tags": [
"232",
"2331",
"343"
],
"plannedDuration": 0,
"startDate": "2018-07-09T22:00:00Z",
"projectType": {
"id": "00000000-0000-0000-0000-000000000000",
"name": "test 1",
"icon": "poll"
},
"projectStatus": {
"id": "00000000-0000-0000-0000-000000000000",
"name": "In Progress",
"type": "progress"
},
"members": [
{
"userId": "00000000-0000-0000-0000-000000000000",
"name": "dummy",
"projectRoleName": "test",
"hasImage": false
},
{
"userId": "00000000-0000-0000-0000-000000000000",
"name": "dummy ",
"projectRoleName": "Manager",
"hasImage": false
}
],
"id": "00000000-0000-0000-0000-000000000000",
"userStats": [
{
"userId": "00000000-0000-0000-0000-000000000000",
"openCount": 55,
"lastOpened": 1543851773
},
{
"userId": "00000000-0000-0000-0000-000000000000",
"openCount": 9,
"lastOpened": 1542372179
}
],
"indexTime": "2018-12-03T15:42:53.157649Z"
}
}
]
}
}
The mapping look like this:
{
"search--project": {
"aliases": {},
"mappings": {
"projectentity": {
"_routing": {
"required": true
},
"properties": {
"company": {
"properties": {
"companyTypes": {
"properties": {
"icon": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"id": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"indexTime": {
"type": "date"
},
"name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
},
"id": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"indexTime": {
"type": "date"
},
"name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"number": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
},
"id": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"members": {
"properties": {
"hasImage": {
"type": "boolean"
},
"name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"projectRoleName": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"userId": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
},
"name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
...
"plannedDuration": {
"type": "long"
},
"startDate": {
"type": "date"
},
"userStats": {
"properties": {
"lastOpened": {
"type": "long"
},
"openCount": {
"type": "long"
},
"userId": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
}
}
}
},
"settings": {
"index": {
"creation_date": "1539619646426",
"number_of_shards": "5",
"number_of_replicas": "1",
"uuid": "G5ohN1FvQBGkYFh_803Ifw",
"version": {
"created": "6040299"
},
"provided_name": "search--project"
}
}
}
}
Anyone has a suggestion what I'm doing wrong?
Thanks.

Answer 1

In the query you have your params identified as dtdNow and uid. So if you're wanting to use those in your script you would do the params.dtdNow.
If you're wanting to use a property from your _source (i.e. userStats) you should be using ctx._source.userStats.length. There are more examples in the documentation: https://www.elastic.co/guide/en/elasticsearch/painless/current/painless-examples.html.
EDIT
With a function_score query you'll either be using the doc map or params['_source']. The difference being that when you use doc it gets cached in memory and params['_source'] will be loaded up each time (see https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-script-fields.html). The other caveat is that you need to use a non-analyzed field or an analyzed text field if fielddata is enabled. https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-scripting-fields.html#modules-scripting-doc-vals
To achieve what you're trying do, you should be able to just use a non-analyzed field in your userStats object. Something like this doc['userStats.openCount'].length (here I'm assuming that openCount is required on your userStats object).