Shibboleth Developers

[Lukas Haemmerle <>]

Situation:
IdP or SP periodically update their metadata from a central web server
because the file changes several times a day. Let's say every hour. The
metadata file is rather large (> 100kB). Many SPs and IdPs do that.

Problem:
Central web server gets hammered with requests because Metadatatool
downloads metadata with each request, even if nothing changed. This
wastes not only resources (mainly bandwidth) on that web server but also
on the IdP/SP side.

Solution:
Metadata tool could compare the local file's size and timestamp with
that of the file on the web server by asking the web server with a HEAD
request for the 'Last-Modified' parameter. Metadatatool then only would
download the metadata file (and set its modification date to the one of
the web server's metadata file) if at least one of these parameters differ.

Of course one could write a wrapper arround metadatatool and e.g. use
curl -I http://file.to/metadata.xml to do that but it would nevertheless
be nice if there was an option for the metadatatool that would allow the
above out of the box.

What do you think?

Best Regards
Lukas

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