Deprecated legacy settings instead of removing

[penghuo]

Description

1. Address Remove cursor enabling and fetch size setting #75, deprecated opendistro.sql.cursor.enabled and opendistro.sql.cursor.fetch_size
2. Address remove opensearch.sql.engine.new.enabled setting #70, deprecated opendistro.sql.engine.new.enabled
3. Address remove opensearch.sql.query.analysis.* related settings #76, deprecated opensearch.sql.query.analysis.*
4. Address remove opensearch.sql.query.response.format setting #77, deprecated opensearch.sql.query.response.format

Upgrade Test

Before rolling upgrade, put the deprecated setting.

curl -X PUT "localhost:9200/_opendistro/_sql/settings" -H 'Content-Type: application/json' -d'
{
  "persistent" : {
      "opendistro": {
        "sql": {
          "cursor": {
            "enabled" : true,
            "keep_alive": "10m"
          }
        }
      }
  },
  "transient" : {
    "opendistro.sql.query.analysis.enabled" : false
  }
}'

After the rolling upgrade from ODFE 1.13.2 to OpenSearch 1.0, Then update the deprecated setting. The warning will returned.

➜  upgrade-test curl -i -X PUT "localhost:9200/_plugins/_query/settings" -H 'Content-Type: application/json' -d'
{
  "transient" : {
    "opendistro.sql.cursor.enabled" : "false"
  }
}'
HTTP/1.1 200 OK
Warning: 299 OpenSearch-1.0.0-26d579287f50bb33e17c8fe1f05ea208d5c64d1f "[opendistro.sql.cursor.keep_alive] setting was deprecated in OpenSearch and will be removed in a future release! See the breaking changes documentation for the next major version."
Warning: 299 OpenSearch-1.0.0-26d579287f50bb33e17c8fe1f05ea208d5c64d1f "[opendistro.sql.cursor.enabled] setting was deprecated in OpenSearch and will be removed in a future release! See the breaking changes documentation for the next major version."
content-type: application/json; charset=UTF-8
content-length: 103

{"acknowledged":true,"persistent":{},"transient":{"opendistro":{"sql":{"cursor":{"enabled":"false"}}}}}

Issues Resolved

Resolved, #136

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

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[chloe-zh]

LGTM, thanks for the fix!

[dai-chen]

Thanks for the fix!