Database Reference
In-Depth Information
Chapter 10. Architecting
High
Availability for Business Services
Availability of business services for enterprise SOA implementations at any organ-
ization is either mission-critical or business-critical. The availability of business ser-
vices for an organization can directly impact the revenue or at least the brand value.
Architects must understand and define the high availability requirements for an ap-
plication platform in collaboration with business. The high availability is measured by
the business services uptime by the different levels of 9s such as 99.0 percent, 99.9
percent, 99.99 percent, or 99.999 percent and often referenced as availability uptime
Service Level Agreements
(
SLAs
), either with business units or external custom-
ers. The high availability for an application platform providing business services has
two dimensions to it; first systems architecture and second release and change man-
agement processes. In this chapter, our focus is to learn the high availability system's
reference architecture(s) using the Oracle SOA Suite to implement business services
with various levels of availability SLAs. The key system architecture components that
assist us in achieving high availability for business services by an application platform
are as follows:
• Shared services
• Internal services: For example, Single Sign On, Enterprise
Document Repository, and E-mail System.
• External services: For example, payment gateway, credit
scores look-ups, stocks buying and selling orders, and pickup
and delivery orders.
• Data center(s)
• Number of sites
• Network
• Power
• Load balancer(s)
• L7/GSLB/GTM
• L4/LSLB/LTM
