Spring-boot: Handle StepRegistry connect/read timeout deprecation

[snicoll]

The read-timeout and connect-timout of StepRegistry is deprecated in favour of configuring the client yourself.

Any registry that is a StepRegistry is affected. We expose two related properties for each implementation. We should figure out what we want to do with this.

[snicoll]

IMO, we have two choices here:

• Either we call the deprecated mapping method to the config object and those two properties should be deprecated
• Or, we don't call that mapping any longer and we do whatever is the recommendation in the auto-config

[jkschneider]

@wilkinsona and I discussed this yesterday. There is another option, and that is to explicitly declare that you intend to use the HttpUrlConnectionClient when building step-based registries in Spring Boot, and set the properties on the constructor there.

DatadogMeterRegistry.builder(config)
    .httpClient(new HttpUrlConnectionClient(connectTimeout, readTimeout))
    .build();

The properties are not deprecated in this context, because it is clear that connect and read timeout mean what HUC means by connect and read timeout.

[snicoll]

Thanks Jon, Andy told me about that discussion and I believe that this is the same thing as the second option in my previous comment.

[wilkinsona]

I'm not sure that we can stop performing the mapping in 2.1 as it will be a breaking change for anyone who is using the auto-configured …PropertiesConfigAdapter …Config implementation to retrieve the connect or read timeout.

[wilkinsona]

We've decided to remove the mappings in the config adapters.

[wilkinsona]

Closing in favour of #14886.