IdP startup issues

[Joel Goguen]

All of our MetadataProvider entries are defined as FileBackedHTTPMetadataProvider types. This is causing us issues with starting up the IdP; whenever any one or more metadata sources is unavailable, the IdP refuses to start entirely even if the defined backingFile exists. Is there some way (preferably without external cron jobs) we can have automatically-updating MetadataProvider definitions but not have the IdP fail to start when a metadata source can't be reached?

As an example, here's one of our MetadataProvider definitions that has failed more than a few times: 
<MetadataProvider id="Desire2Learn" xsi:type="FileBackedHTTPMetadataProvider"
                xmlns="urn:mace:shibboleth:2.0:metadata"
                metadataURL="http://lms.unb.ca/Shibboleth.sso/Metadata"
                backingFile="/opt/shibboleth-idp/metadata/desire2learn.xml" maxRefreshDelay="PT1H0M0.000S" />

Is there some change to this or to the IdP configuration I can make to avoid issues on startup if the metadataURL can't be reached but the backingFile exists?

-- 
Joel Goguen
Developer
Enterprise Solutions
Information Technology Services
University of New Brunswick
Email: joel.goguen at unb.ca
Phone: (506) 453-4872
Fax: (506) 453-3590