Progress of virtualization technology in recent years
made it easy to build cache server in the Cloud. It became
possible to increase Web service capacity using virtual cache
servers. However, expected responsiveness can not be gained
with insufficient cache servers against load. In contrast, costs
will increase by surplus resources with too many cache servers
against load. Therefore, we have been developing a distributed
Web system suitable for the Cloud adjusting the number of
Web servers according to load of them to reduce running
cost. This research aims to imprement the scaling mechanism
for the distributed Web system. It has three functions: load
monitoring function, cache server management function and
destination setting function. This paper describes these