Database Reference
In-Depth Information
Load balancer(s)
The high availability system's architecture usually depends on load balancer appli-
ances. These come in two types: first Layer 4/Local Server Load balancer/Local
Traffic Manager (L4/LSLB/LTM), also known as local load balancers; and second
Layer 7/Global Server Load Balancer (L7/GSLB/GTM), also known as global load
balancers. In small implementations only local load balancers are implemented as
the hot standby pair, that means, only one takes the active traffic at a given time.
The multisite implementations (both physical and logical sites) also known as multi
data center deployments are required to implement the combination of global load
balancers and local load balancers. The global and local load balancers are the key
components to achieve the availability uptime SLAs of 99.99 percent or 99.999 per-
cent.
Compute resource(s)
In a nutshell, the Oracle SOA Suite is a standard-based J2EE application deployed
on the Oracle WebLogic Server Platform. It is also important to implement redundant
componentsforloadbalancingandfailoveroptionsattheweb,application,anddata-
base tier to meet the high availability requirements. The availability uptime SLAs of
99.9 percent or more needs each tier in compute resources to get the redundant
component even for a minimal load. You may decide not to implement the redundant
component at the database tier due to the cost but one needs to at least implement
a standby node for database failover.
