backoff times must be integer values despite documentation saying otherwise

[sand7000]

What version of gRPC and what language are you using?

grpcio 1.62.1
grpcio-tools 1.62.1

What operating system (Linux, Windows,...) and version?

ubuntu 22

What runtime / compiler are you using (e.g. python version or version of gcc)

Python 3.10.12

What did you do?

I set the options for my insecure channel like this:

service_config_json = json.dumps(
    {
        "methodConfig": [
            {
                # To apply retry to all methods, put [{}] in the "name" field
                "name": [
                    {"service": "helloworld.Greeter", "method": "SayHello"}
                ],
                "retryPolicy": {
                    "maxAttempts": 5,
                    "initialBackoff": "0.01s",
                    "maxBackoff": "0.06s",
                    "backoffMultiplier": 1.5,
                    "retryableStatusCodes": ["UNAVAILABLE"],
                },
            }
        ]
    }
)

I see the error:

INVALID_ARGUMENT: errors validating service config: [field:methodConfig[0].retryPolicy.initialBackoff error:Not a duration (not a number of seconds); field:methodConfig[0].retryPolicy.maxBackoff error:Not a duration (not a number of seconds)]

I tried several values for initialBackoff and only integer values run without error. This contradicts this provided example:

https://github.com/grpc/grpc/blob/master/examples/python/retry/retry_client.py

[gnossen]

Hi @sand7000 . Thanks for the report!

We can't actually reproduce on our end -- non-integers work just fine with this example. In fact, by copy-pasting your json above, it still works. I'm wondering if you have a weird character accidentally added. For example, if a zero-width space ends up in your duration string somehow, this is the error you will see. Please take another look and see if there are weird characters hanging around.

[sand7000]

Verified and corrected. Thanks very much!