FileBackedHTTPMetadaProvider fetch/refresh frequency determined by ?

[Baron Fujimoto]

We have a MetadataProvider of type FileBackedHTTPMetadataProvider defined
for the InCommon Federation defined in our relying-party.xml config file.
The only duration-ish attribute set for this MetadataProvider is

<MetadataFilter xsi:type="RequiredValidUntil"
     maxValidityInterval="P28DT0H0M0.000S" />

Since we aren't explicitly setting maxRefreshDelay, I assume it should be
using its default value of 4H, but the timestamp on the saved metadata
file indicates that it appears to be saved/refreshed just once daily.  What
am I missing that determines the frequency that the metadata file is
saved or refreshed for this MetadataProvider?

I've been using this Shibboleth Wiki page as a reference:

<https://wiki.shibboleth.net/confluence/display/SHIB2/IdPMetadataProvider>

-- 
Baron Fujimoto <baron at hawaii.edu> :: UH Information Technology Services
minutas cantorum, minutas balorum, minutas carboratum desendus pantorum