[FLINK-15431][CEP] Add numLateRecordsDropped/lateRecordsDroppedRate/watermarkLatency in CepOperator

[libenchao]

What is the purpose of the change

This pr adds numLateRecordsDropped/lateRecordsDroppedRate/watermarkLatency metric in CepOperator.

Brief change log

adds numLateRecordsDropped/lateRecordsDroppedRate/watermarkLatency

Verifying this change

This change added tests and can be verified as follows:

CEPOperatorTest. testCEPOperatorLateRecordsMetric

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, Yarn/Mesos, ZooKeeper: (no)
• The S3 file system connector: ( no)

Documentation

• Does this pull request introduce a new feature? (no)

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Automated Checks

Last check on commit 51c9f2e (Sat Dec 28 12:22:54 UTC 2019)

Warnings:

• 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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• ❓ 1. The [description] looks good.
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• ❓ 3. Needs [attention] from.
• ❓ 4. The change fits into the overall [architecture].
• ❓ 5. Overall code [quality] is good.

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CI report:

• 51c9f2e Travis: SUCCESS Azure: SUCCESS
• 95a3307 Travis: SUCCESS Azure: SUCCESS

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[libenchao]

@flinkbot run travis

[libenchao]

@flinkbot run travis

[dawidwys]

Hi @libenchao I added a comment in the corresponding JIRA. Let's discuss the scope of the changes there first.

[libenchao]

@dawidwys Thanks for your response.
I have updated pr according to the discussion in JIRA.