Signed-off-by: Zhongnan Su szhongna@amazon.com

Update

After discussion in the thread here opensearch-project/common-utils#155, we decided for now we'll keep the transport interfaces in sql repo, instead of common-utils for the following reasons.

1. there's no consumer plugin for this feature yet. Because the response format is not encapsulated. Currently on trasnport layer there's only a json string in the response. Ideally we want a ResultSet or DataFrame like response for clients to access data. An issued is created w.r.t this.
2. This change is to the request model, which is the input of the SQL/PPL engine. Having it separated into 2 repos is not development friendly. E.g, the CI will fail for sure, because CI only pulls against released common-utils

Description

Add a transport layer for handle PPL request. This will expose transport interface for inter-plugin communication. The existing Rest layer handler is also being refactored to make use of the transport layer

• Create TransportPPLQueryAction

• refactored RestPPLQueryAction to service as a route layer, moved the query request handling logic to TransportPPLQueryAction.

• Register action and handler in SQLPlugin

• Refactored PPLQueryRequest to be writable, for the transport layer commuication

• Create transport response model that currently holds a string response.

• Add common-utils as dependency, since the request/response models will be exposed in common-utils for other plugin to consume as well.

• TODO:

  1. Request and response format are strings for now.(may need modification in future version, especially response format)
  2. Implement transport interface for SQL, in a similar manner

Issues Resolved

#521

CI/CD

• The CI is failing because of the pending PR in common-utils
• [Fixed]local build failed because of jarhell caused by ml-commons. Raised another PR in their repo to fix. Fix jarhell of common-utils ml-commons#328

| java.home: /Library/Java/JavaVirtualMachines/jdk-14.0.2.jdk/Contents/Home
| examining directory: /Users/szhongna/Desktop/Projects/OpenSearch/sql/integ-test/build/classes/java/test
| examining directory: /Users/szhongna/Desktop/Projects/OpenSearch/sql/integ-test/build/resources/test
| examining jar: /Users/szhongna/Desktop/Projects/OpenSearch/sql/sql-jdbc/build/libs/opensearch-sql-jdbc-2.0.0.0.jar
| examining jar: /Users/szhongna/Desktop/Projects/OpenSearch/sql/sql-jdbc/build/libs/opensearch-sql-jdbc-1.2.0.0.jar
| Exception in thread "main" java.lang.IllegalStateException: jar hell!
| class: org.opensearch.jdbc.ResultSetImpl
| jar1: /Users/szhongna/Desktop/Projects/OpenSearch/sql/sql-jdbc/build/libs/opensearch-sql-jdbc-2.0.0.0.jar
| jar2: /Users/szhongna/Desktop/Projects/OpenSearch/sql/sql-jdbc/build/libs/opensearch-sql-jdbc-1.2.0.0.jar
|       at org.opensearch.bootstrap.JarHell.checkClass(JarHell.java:317)
|       at org.opensearch.bootstrap.JarHell.checkJarHell(JarHell.java:212)
|       at org.opensearch.bootstrap.JarHell.checkJarHell(JarHell.java:99)
|       at org.opensearch.bootstrap.JarHell.main(JarHell.java:83)

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':integ-test:jarHell'.
> Process 'command '/Library/Java/JavaVirtualMachines/jdk-14.0.2.jdk/Contents/Home/bin/java'' finished with non-zero exit value 1

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

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.