GH-150: adjust feign retryer configuration (#151)

[francoisledroff]

Description

Configure Retries in Feign utility:

• retry calls maximum 3 times (5 before)
• enlarge the maximum waiting period to 4s (1s before)
• use a larger base interval of 1s (100ms before)

Related Issue

#150
#151

Motivation and Context

This would better tune calls retries. We do not want in general to retry too much, and we want more time between each of the calls to wait for the called system to recover. Note that even in case of a retry after header present in the response, the maximum waiting period will be used in place of the time specified in the response to place the next call when lower:

 if (e.retryAfter() != null) {
        interval = e.retryAfter().getTime() - currentTimeMillis();
        if (interval > maxPeriod) {
          interval = maxPeriod;
        }

which is ok to protect the service for hanging up for too long. 4s seems like a reasonable time to wait before retrying and eventually fail, also, the maximal waiting period that can be calculated with the given parameters by the exponential backoff strategy fits the maximum as well.

Another solution would be the approach proposed here: #149

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[francoisledroff]

don't you think we should allow the users to specify the retries through conf here ?
same as for the log level see #146

[nicdard]

done :)