Support object fields in star-tree index

[bharath-techie]

Description

We'll support object type fields with this change for star-tree index.
Star-tree index will still block array values for the object fields.

Example :

{
    "settings": {
        "index.number_of_shards": 1,
        "index.composite_index": true
    },
    "mappings": {
        "composite": {
            "startree1": {
                "type": "star_tree",
                "config": {
                    "ordered_dimensions": [
                        {
                            "name": "nested.status"
                        },
                        {
                            "name": "geoip.country_name"
                        }
                    ],
                    "metrics": [
                        {
                            "name": "nested.status"
                        }
                    ]
                }
            }
        },
        "properties": {
            "nested": {
                "properties" : {
                    "status": {
                        "type": "integer"
                    }
                }
            },
            "geoip": {
                "properties": {
                    "country_name": {
                        "type": "keyword"
                    }
                }
            }
        }
    }
}

Related Issues

#16730

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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[github-actions]

✅ Gradle check result for 1ae7561: SUCCESS

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 10 lines in your changes missing coverage. Please review.

Project coverage is 72.12%. Comparing base (b5f651f) to head (4da6d64).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
...va/org/opensearch/index/mapper/StarTreeMapper.java	72.72%	5 Missing and 1 partial ⚠️
...va/org/opensearch/index/mapper/DocumentParser.java	20.00%	1 Missing and 3 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #16728      +/-   ##
============================================
- Coverage     72.21%   72.12%   -0.09%     
+ Complexity    65335    65315      -20     
============================================
  Files          5318     5318              
  Lines        304081   304119      +38     
  Branches      43995    44005      +10     
============================================
- Hits         219578   219360     -218     
- Misses        66541    66765     +224     
- Partials      17962    17994      +32     

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[mgodwan]

Is there a use-case where this method can be used separately from the isFieldPartOfCompositeIndex? Otherwise, can we combine both methods?

[github-actions]

✅ Gradle check result for b1f8fba: SUCCESS

[sachinpkale]

Use imperative mood in the PR title - PR title becomes commit message after merging (I have changed it for this PR Supporting -> Support)

[sachinpkale]

Do we have a test for this new check?

[bharath-techie]

We have tests for the new checks in IT. But I found an edge case where its failing.

{ "index" : { "_index" : "logs-2419985"  } }
{"@timestamp": 1706431663, "clientip": "215.79.163.253", 
"request": "GET /spanish/index.html HTTP/1.0", 
"nested": {"status": [218,219]}, "size": 202, "status": 218}

Say status is part of star-tree mapping but nested.status has array as above example.

arrayFieldName = "status"
context.path().pathAsText(arrayFieldName)) = "nested.status"

so the condition will satisfy for arrayFieldName and doc addition will be blocked.

[sachinpkale]

Changes look good, please add changelog entry.

[github-actions]

❌ Gradle check result for 995f912: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

✅ Gradle check result for 4da6d64: SUCCESS