metadata early warning system

[Tom Scavo]

On Mon, Apr 2, 2018 at 2:29 PM, Cantor, Scott <cantor.2 at osu.edu> wrote:
> My general feeling is that if there's a logging deficiency in noting refresh failures clearly enough, or impending expiration or whatever, we should get that corrected

Okay. I'm not sure if I should continue the discussion here or in
jira. First let me try to clarify:

Support for @creationInstant implies a bit more than improved logging.
I think it boils down to these three items:

1) Modify the behavior of boolean attribute
MetadataProvider/@requireValidMetadata: If @creationInstant exists and
is in the future, the metadata is not valid

2) Add attribute MetadataProvider/@freshnessInterval (to complement
@expirationWarningThreshold, which is misnamed [1])

3) Add filter MetadataProvider/RequireTimestamps (or add a boolean
attribute to the RequiredValidUntil filter) that requires
@creationInstant in addition to @validUntil

Items (1) and (2) are straightforward but item (3) may require a bit
more effort, I don't know.

> I think that's more useful than going outside the system to come up with something that generally isn't a problem in most cases.

HTTP conditional requests give the illusion the file has changed so
you wouldn't know if there's a problem until it's too late. The only
way to know for sure is to parse the metadata.

Thanks,

Tom

[1] https://issues.shibboleth.net/jira/browse/OSJ-236