  In a multi-tenant service network, multiple virtual service networks (VSNs),
one for each tenant, coexist on the same service network. The tenants
themselves need to be able to dynamically create and customize their own VSNs
to support their initial and changing functional and performance requirements.
These tasks are problematic for them due to: 1) platform-specific knowledge
required, 2) the existence of a large number of customization options and their
dependencies, and 3) the complexity in deriving the right subset of options. In
this paper, we present an approach to enable and simplify the tenant-driven
customization of multi-tenant service networks. We propose to use feature as a
high-level customization abstraction. A regulated collaboration among a set of
services in the service network realizes a feature. A software engineer can
design a customization policy for a service network using the mappings between
features and collaborations, and enact the policy with the controller of the
service network. A tenant can then specify the requirements for its VSN as a
set of functional and performance features. A customization request from a
tenant triggers the customization policy of the service network, which
(re)configures the corresponding VSN at runtime to realize the selected
features. We show the feasibility of our approach with two case studies and a
performance evaluation.
