works

[BenCowen]

Type of Change

This is a bit of a workaround for "custom retries" (i.e. retrying via modal.Retries on some exceptions, and circumventing retries on other, more fatal errors). It's based on this demo I made for Achira last year, and I'm bringing it up again because another customer asked for it here.

The demo follows a scripted sequence of errors that requires each function execution to "know" which iteration it's on. This is accomplished with a modal.Dict but could potentially simplify this by perhaps choosing a random error? (but then, it's random)

• New example for the GitHub repo

Monitoring Checklist

• Example is configured for testing in the synthetic monitoring system, or lambda-test: false is provided in the example frontmatter and I have gotten approval from a maintainer
  • [X Example is tested by executing with modal run, or an alternative cmd is provided in the example frontmatter (e.g. cmd: ["modal", "serve"])
  • Example is tested by running the cmd with no arguments, or the args are provided in the example frontmatter (e.g. args: ["--prompt", "Formula for room temperature superconductor:"]
  • Example does not require third-party dependencies besides fastapi to be installed locally (e.g. does not import requests or torch in the global scope or other code executed locally)

Documentation Site Checklist

Content

• Example is documented with comments throughout, in a Literate Programming style
• All media assets for the example that are rendered in the documentation site page are retrieved from modal-cdn.com

Build Stability

• Example pins all dependencies in container images
  • Example pins container images to a stable tag like v1, not a dynamic tag like latest
  • [] Example specifies a python_version for the base image, if it is used
  • --> currently just using default image, should i add .debian_slim(add_python=...)?
  • Example pins all dependencies to at least SemVer minor version, ~=x.y.z or ==x.y, or we expect this example to work across major versions of the dependency and are committed to maintenance across those versions
    • Example dependencies with version < 1 are pinned to patch version, ==0.y.z

Outside Contributors

You're great! Thanks for your contribution.

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[BenCowen]

Might also want SDK's blessing on this (hence @thomasjpfan tag)?

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 2 additional findings.

[thomasjpfan]

Do we have a list of exceptions that we'll retry? Do users want to configure their function so they can control when their retries?

I'm thinking of:

@app.function(retries=modal.Retries(max_retries=5, initial_delay=1.0)) 
def my_func():
    try:
        my_custo_funcdtion()
    except MyCustomException as exc:
        raise ModalRetriableError(...) from exc  # signal to model that we want to retry.
       

[BenCowen]

Do users want to configure their function so they can control when their retries

I have only gotten this request twice in the last year, so possibly not often enough to dedicate engineering...

Do we have a list of exceptions that we'll retry

Right now, retries are configured based on task status, and there is no exception filtering.