Limit to the number of Vhosts under one entityID?

Peter Schober peter.schober at
Mon Nov 24 05:45:38 EST 2014

* Barry Johnson <CYCLIST at> [2014-11-21 16:22]:
> Does anyone know if there is an upper limit to how many distinct
> virtual hosts can be supported under one entityID?   Assuming we add
> the appropriate ACS endpoints to the metadata could an SP
> theoretically support hundreds of virtual hosts?   

Univie has more than 1300 Shib-enabled vhosts in their mass-hosting
web environment (one ACS URL for every TLS-enabled vhost; there also
are non-TLS vhosts), most on a single entityID, IIRC.
So far no issues with that, AFAIK, but I'm not involved with that

Univie also used signed requests instead of ACS URL checking with a
single campus SP, but that was only as a workaround since the non-Shib
SP implementation was broken and generated dynamic ACS URLs in its
authn request, mis-using unique ACS URLs to track relay state, or
something like that. Not sure that SP is still being used.

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