Only save main session by default with cloudpickle when dataflowrunner.

[claudevdm]

Please add a meaningful description for your change here

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Mention the appropriate issue in your description (for example: addresses #123), if applicable. This will automatically add a link to the pull request in the issue. If you would like the issue to automatically close on merging the pull request, comment fixes #<ISSUE NUMBER> instead.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

To check the build health, please visit https://github.com/apache/beam/blob/master/.test-infra/BUILD_STATUS.md

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI or the workflows README to see a list of phrases to trigger workflows.

[gemini-code-assist]

Summary of Changes

Hello @claudevdm, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a more intelligent default behavior for the save_main_session pipeline option within Apache Beam, specifically targeting pipelines executed on the Dataflow runner with cloudpickle. By automatically setting save_main_session to True under these conditions, the change aims to reduce manual configuration and improve the out-of-the-box experience for users. It also refines the command-line argument handling by removing a now-redundant flag.

Highlights

• Default save_main_session for DataflowRunner: When using cloudpickle with the DataflowRunner, the save_main_session option will now default to True if it has not been explicitly set by the user. This aims to simplify configuration for common Dataflow use cases.
• Removal of --no_save_main_session flag: The explicit command-line argument --no_save_main_session has been removed, streamlining the pipeline option parsing and reducing redundancy.
• New Runner API method: A new method, cloudpickle_save_main_session_by_default(), has been added to the base Runner class, allowing individual runners to specify their preferred default behavior for save_main_session when cloudpickle is in use.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[Abacn]

We can use the existing PipelineOptionsValidator.is_service_runner() in the check here

beam/sdks/python/apache_beam/options/pipeline_options.py

Line 1801 in 2cf0930

if pickle_library in ['default', 'cloudpickle']:

to set default value.