We report our experiences on application development with the open source OpenAIS
framework, which is an implementation of the standard Application Interface Specification
(AIS) issued by the Service Availability Forum. Our focus is put on integrating existing
(legacy) applications or services into the AIS framework (where the source code of
these services is not available) in order to make such services highly available.
This is achieved by using Proxy components, which are responsible for managing the
High Availability (HA) lifecycle of legacy services (called proxied components). We
estimate the availability of legacy services as provided by using redundant proxy
and proxied components in the OpenAIS framework on a benchmark service architecture.
Furthermore, as the AIS standard does not contain any recommendation on business-related
communication, in the paper, we propose to use communication mediation to forward
requests to service provider components and responses back to the service consumers.