Add exponential backoff to HTTPQueue put

[lantiga]

What does this PR do?

This PR adds exponential backoff to posts to the HTTP queue, for added resiliency on the works.
The PR introduces https://github.com/litl/backoff as a dependency.

In general, I think we need to encourage developers to take backoff strategies into account whenever they consume APIs.

Although the backoff package has been released 8 months ago, so it's not moving fast, it is quite ideal for our purposes.

It's very minimal. Not a lot of code and we can easily fix it ourselves. No transitive dependencies.

It has a clean design:

• you can associate backoff to specific exceptions or predicates, so it's very flexible
• you can control every aspect of backoff, not just how many retries and how long to retry, but also conditions on when to give up, and hooks to be called when it's backing off and retrying

So given the low risk and the high convenience, I recommend adding this dependency to our package.

Before submitting

• Was this discussed/agreed via a GitHub issue? (not for typos and docs)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure your PR does only one thing, instead of bundling different changes together?
• Did you make sure to update the documentation with your changes? (if necessary)
• Did you write any new necessary tests? (not for typos and docs)
• Did you verify new and existing tests pass locally with your changes?
• Did you list all the breaking changes introduced by this pull request?
• Did you update the CHANGELOG? (not for typos, docs, test updates, or minor internal changes/refactors)

PR review

Anyone in the community is welcome to review the PR.
Before you start reviewing, make sure you have read the review guidelines. In short, see the following bullet-list:

Reviewer checklist

• Is this pull request ready for review? (if not, please submit in draft mode)
• Check that all items from Before submitting are resolved
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cc @Borda

[github-actions]

⚡ Required checks status: All passing 🟢

Groups summary

🟢 lightning_app: Tests workflow

Check ID	Status
app-pytest (macOS-11, lightning, 3.8, latest)	success	✅
app-pytest (macOS-11, lightning, 3.8, oldest)	success	✅
app-pytest (macOS-11, app, 3.9, latest)	success	✅
app-pytest (ubuntu-20.04, lightning, 3.8, latest)	success	✅
app-pytest (ubuntu-20.04, lightning, 3.8, oldest)	success	✅
app-pytest (ubuntu-20.04, app, 3.9, latest)	success	✅
app-pytest (windows-2022, lightning, 3.8, latest)	success	✅
app-pytest (windows-2022, lightning, 3.8, oldest)	success	✅
app-pytest (windows-2022, app, 3.8, latest)	success	✅

These checks are required after the changes to src/lightning/app/core/queues.py, tests/tests_app/core/test_queues.py, requirements/app/base.txt.

🟢 lightning_app: Examples

Check ID	Status
app-examples (macOS-11, lightning, 3.9, latest)	success	✅
app-examples (macOS-11, lightning, 3.9, oldest)	success	✅
app-examples (macOS-11, app, 3.9, latest)	success	✅
app-examples (ubuntu-20.04, lightning, 3.9, latest)	success	✅
app-examples (ubuntu-20.04, lightning, 3.9, oldest)	success	✅
app-examples (ubuntu-20.04, app, 3.9, latest)	success	✅
app-examples (windows-2022, lightning, 3.9, latest)	success	✅
app-examples (windows-2022, lightning, 3.9, oldest)	success	✅
app-examples (windows-2022, app, 3.9, latest)	success	✅

These checks are required after the changes to src/lightning/app/core/queues.py, requirements/app/base.txt.

🟢 lightning_app: Docs

Check ID	Status
make-doctest (app)	success	✅
make-html (app)	success	✅

These checks are required after the changes to src/lightning/app/core/queues.py, requirements/app/base.txt.

🟢 mypy

Check ID	Status
mypy	success	✅

These checks are required after the changes to requirements/app/base.txt, src/lightning/app/core/queues.py.

🟢 install

Check ID	Status
install-pkg (ubuntu-22.04, app, 3.8)	success	✅
install-pkg (ubuntu-22.04, app, 3.10)	success	✅
install-pkg (ubuntu-22.04, fabric, 3.8)	success	✅
install-pkg (ubuntu-22.04, fabric, 3.10)	success	✅
install-pkg (ubuntu-22.04, pytorch, 3.8)	success	✅
install-pkg (ubuntu-22.04, pytorch, 3.10)	success	✅
install-pkg (ubuntu-22.04, lightning, 3.8)	success	✅
install-pkg (ubuntu-22.04, lightning, 3.10)	success	✅
install-pkg (ubuntu-22.04, notset, 3.8)	success	✅
install-pkg (ubuntu-22.04, notset, 3.10)	success	✅
install-pkg (macOS-12, app, 3.8)	success	✅
install-pkg (macOS-12, app, 3.10)	success	✅
install-pkg (macOS-12, fabric, 3.8)	success	✅
install-pkg (macOS-12, fabric, 3.10)	success	✅
install-pkg (macOS-12, pytorch, 3.8)	success	✅
install-pkg (macOS-12, pytorch, 3.10)	success	✅
install-pkg (macOS-12, lightning, 3.8)	success	✅
install-pkg (macOS-12, lightning, 3.10)	success	✅
install-pkg (macOS-12, notset, 3.8)	success	✅
install-pkg (macOS-12, notset, 3.10)	success	✅
install-pkg (windows-2022, app, 3.8)	success	✅
install-pkg (windows-2022, app, 3.10)	success	✅
install-pkg (windows-2022, fabric, 3.8)	success	✅
install-pkg (windows-2022, fabric, 3.10)	success	✅
install-pkg (windows-2022, pytorch, 3.8)	success	✅
install-pkg (windows-2022, pytorch, 3.10)	success	✅
install-pkg (windows-2022, lightning, 3.8)	success	✅
install-pkg (windows-2022, lightning, 3.10)	success	✅
install-pkg (windows-2022, notset, 3.8)	success	✅
install-pkg (windows-2022, notset, 3.10)	success	✅

These checks are required after the changes to src/lightning/app/core/queues.py, requirements/app/base.txt.

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Thank you for your contribution! 💜

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[ethanwharris]

LGTM!