- 11.1 Workload Distribution Architecture
- 11.2 Resource Pooling Architecture
- 11.3 Dynamic Scalability Architecture
- 11.4 Elastic Resource Capacity Architecture
- 11.5 Service Load Balancing Architecture
- 11.6 Cloud Bursting Architecture
- 11.7 Elastic Disk Provisioning Architecture
- 11.8 Redundant Storage Architecture
- 11.9 Case Study Example
11.5 Service Load Balancing Architecture
The service load balancing architecture can be considered a specialized variation of the workload distribution architecture that is geared specifically for scaling cloud service implementations. Redundant deployments of cloud services are created, with a load balancing system added to dynamically distribute workloads.
The duplicate cloud service implementations are organized into a resource pool, while the load balancer is positioned as either an external or built-in component to allow the host servers to balance the workloads themselves.
Depending on the anticipated workload and processing capacity of host server environments, multiple instances of each cloud service implementation can be generated as part of a resource pool that responds to fluctuating request volumes more efficiently.
The load balancer can be positioned either independent of the cloud services and their host servers (Figure 11.10), or built-in as part of the application or server’s environment. In the latter case, a primary server with the load balancing logic can communicate with neighboring servers to balance the workload (Figure 11.11).
Figure 11.10 The load balancer intercepts messages sent by cloud service consumers (1) and forwards them to the virtual servers so that the workload processing is horizontally scaled (2).
Figure 11.11 Cloud service consumer requests are sent to Cloud Service A on Virtual Server A (1). The cloud service implementation includes built-in load balancing logic that is capable of distributing requests to the neighboring Cloud Service A implementations on Virtual Servers B and C (2).
The service load balancing architecture can involve the following mechanisms in addition to the load balancer:
- Cloud Usage Monitor – Cloud usage monitors may be involved with monitoring cloud service instances and their respective IT resource consumption levels, as well as various runtime monitoring and usage data collection tasks.
- Resource Cluster – Active-active cluster groups are incorporated in this architecture to help balance workloads across different members of the cluster.
- Resource Replication – The resource replication mechanism is utilized to generate cloud service implementations in support of load balancing requirements.