[FLINK-20625][pubsub,e2e] Add PubSubSource connector using FLIP-27

[RyanSkraba]

What is the purpose of the change

• Help finish the PR [FLINK-20625][pubsub,e2e] Add Google Cloud Pub/Sub source connector in accordance with FLIP-27 #15152 for a new Pub/Sub connector that implements the Source API from FLIP-27

Brief change log

• Rebased [FLINK-20625][pubsub,e2e] Add Google Cloud Pub/Sub source connector in accordance with FLIP-27 #15152 on master and fixed conflicts
  • Squashed the original changes (retaining @jakob-ed's authorship)
  • Moved new classes to packages that align with the FLIP-27 KafkaSource
• Modified the E2E tests to fetch a bounded number of records from the Pub/Sub emulator

Verifying this change

Please make sure both new and modified tests in this PR follows the conventions defined in our code quality guide: https://flink.apache.org/contributing/code-style-and-quality-common.html#testing

This change added tests and can be verified as follows:

• Adds end-to-end test using the Pub/Sub emulator.

(example:)

• Added integration tests for end-to-end deployment with large payloads (100MB)
• Extended integration test for recovery after master (JobManager) failure
• Added test that validates that TaskInfo is transferred only once across recoveries
• Manually verified the change by running a 4 node cluser with 2 JobManagers and 4 TaskManagers, a stateful streaming program, and killing one JobManager and two TaskManagers during the execution, verifying that recovery happens correctly.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? yes
• If yes, how is the feature documented? docs / JavaDocs

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CI report:

• 4b8aeb8 Azure: SUCCESS

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Automated Checks

Last check on commit 4b8aeb8 (Thu Feb 17 14:10:03 UTC 2022)

Warnings:

• 1 pom.xml files were touched: Check for build and licensing issues.
• No documentation files were touched! Remember to keep the Flink docs up to date!
• This pull request references an unassigned Jira ticket. According to the code contribution guide, tickets need to be assigned before starting with the implementation work.

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• ❓ 5. Overall code [quality] is good.

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[MartijnVisser]

@RyanSkraba Thanks a lot for the PR! We're working on moving out the first connectors from the Flink repo. Have you already looked into porting the GCP Sink to the Unified Sink API by any chance?

[RyanSkraba]

Hello! I have been working on two specific Pub/Sub things (1) updating unit tests here and (2) the FLIP-143 unified sink API version. I'm currently on vacation 🏖️ so they've been progressing slowly (I haven't claimed the JIRA for this reason).

I've also been watching the elasticsearch migration. It's looking pretty good and meeting the goals of the externalization! When do you think other connectors should start moving?

[MartijnVisser]

@RyanSkraba Awesome stuff. Let me know if you want me to assign the Jira to you. I'm hoping that we'll be able to start on the other connectors in the next couple of week. We've already created a couple of new repo's, if you also think you're ready for that let me know so I can get it arranged.

[dchristle]

Hi @RyanSkraba thanks for your work on pushing this connector closer to the finish line! I'm interested in helping to test it out & get it merged. Can you outline what remaining areas need to be worked on?

[MartijnVisser]

@RyanSkraba It would indeed be nice if we can move this now to the externalized repo. @dchristle it would be great if you can help validate it so we can move it forward.

[RyanSkraba]

@MartijnVisser I've moved this to apache/flink-connector-gcp-pubsub#2! Thanks for the ping! @dchristle having some eyes check it out for validation would be the most useful next step.