[FLINK-37375][checkpointing] Checkpoint supports the Operator to cust…

[hejufang]

What is the purpose of the change

Checkpoint supports the Operator to customize asynchronous operation, thereby minimizing the blocking of the main thread and improving task throughput.

Brief change log

Add asyncOperate interface for checkpoint. Users can implement this interface to define custom asynchronous operation processing logic.

Verifying this change

This change added tests and can be verified as follows:
CheckpointWithAsyncOperateITCase

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): yes
• 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? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• 13128ac Azure: FAILURE

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[davidradl]

nit: , is seems to have a missing word. maybe , as it is

[davidradl]

I am not sure what drawing means here. Maybe simplify to the context from which a snapshot of the operator is created

[davidradl]

nit: maybe rephrase to be a little clearer.

• If you don't want to task fail, can throw a RetriableAsyncOperateException, I am not sure who the you is here.

Would the following be correct:

A RetriableAsyncOperateException thrown by this method indicates that the checkpoint has failed but the Async checkpoint operation can be retried. Other Exceptions indicate that the the checkpoint should not be retried so the task will fail.

Furthermore I think it would be better to not throw Exception on these methods, all the specific Exception types that are likely to be thrown should be explicitly on these methods to the contract is explicit. Then we can detail the appropriately for each Exception type.