When the DNS Lookup is unsuccessful with result "TRY_AGAIN = 2", a false negative result might occur

[canilsenlogiq]

Pull Request Description

When the DNS Lookup is unsuccessful(BdxlLocator.class, BusdoxLocator.class) with result TRY_AGAIN = 2, a Locator cannot throw NotFoundException.class, as the participant may be registered in PEPPOL, and we do not want false-negative results.

We (Logiq AS) made our own version of the vefa-peppol for Oxalis where we logged and looked for occurrences of false negatives. We found that multiple times a day the lookup resulted in TRY_AGAIN = 2 where the participant was actually registered in PEPPOL.

I have changed so that a TRY_AGAIN = 2 unsuccessful lookup results in a LookupException, and have included the error string into the resulting exception message, DNS-Lookup-Err: %.

Consequences of the change:

• Users of will see an increase in LookupExceptions.
• Reduction in false-negative lookup results (NotFoundExceptions).
• Anyone that does string matching of the LookupException exception message might need to alter their logic, as the returning exception message is changed.
  • I can return the exception message back to the previous exception message if the risk is to high.

Type of Pull Request

• [ ] New feature/Enhancement - non-breaking change which adds functionality
• [X] Bug fix
• [ ] Breaking change (Require Major version change?)

[aaron-kumar]

This commit handle false positive with detailed lookup exception message. Thanks @canilsenlogiq

Additional changes required will be committed via another commit (@aaron-kumar )

[matrad4307]

We have the same problem on our side. When can we expect a new release version that includes the fix for this bug?

[aaron-kumar]

@matrad4307 : I have applied fix https://github.com/OxalisCommunity/vefa-peppol/commit/d6a1c0fe14f866989347a1156e8e12e2d79199e0 on top of this pull request. Currently we are doing QA testing of upcoming release. You can expect new release with this and other necessary changes & functionality in 2-3 weeks.