Hi, This issue has been discussed again and again, I would like to clarify my idea and your comments will be very appreciated. Suppose we want to provide a server which is: 1) Hosting 1,000,000 members' profile. Each member's disk quota is 5MB. Which means we need at least 5,000GB (5 TeraGB) disk space. 2) Assume the concurrent accessing to a URL is 1000 request/per second 3) Assume all the requests retrieve dynamic content. 4) We want to leverage the power of Zope which means all the pages should be rendered by zope. The priciples I would like to verify are: 1) Some database (RDBMS) should be used instead of FileStorage for ZODB. 2) The ZEO should be used for constructing a cluster computing. 3) The Apache should be the front end instead of ZServer. 4) The PCGI should be the connection between Apache and Zope. 5) I shouldn't create static instance into the ZODB but query the external database. 6) The "Cache" of zope is useless since all the responses are dynamic rendered. By the way, how much will this kind of system costs, regardless the hardware? Iap, Singuan