Ghost in the machine

What PaaS capabilities and components are required to migrate your application into the Cloud?  WSO2 announced the  WSO2 Stratos cloud middleware platform version 1.5.2 release.  Besides enhancements to 12 service components (i.e. application server, data service platform, enterprise service bus, identity service, governance service, gadgets, business activity monitoring, business process, business rules, mashups, message broker, complex event processing),  core platform enhancements include an innovative service-aware load balancer and ghost deployer.

Service-aware dynamic load balancing assigns a single load balancer node to balance message load across multiple service group instances and route requests across different service clusters. A single load balancer node or single load balancer cluster will optimize resource utilization.  A high level architecture diagram of the Stratos load balancer is presented in Figure 1.


Figure 1: Stratos Load Balancer High Level Architecture

Stratos Load Balancer
Stratos Load Balancer High Level Architecture


The ghost deployer maximizes performance and optimizes resource usage when large numbers of artifacts, or services, are deployed in the system. Instead of loading all deployable artifacts, Ghost Deployers create ghost services that correspond to the real services. A real service instance is loaded only when a message invokes the service endpoint. The ghost deployment strategy reduces memory consumption and improves system response.  A state diagram detailing ghost deployer operations is presented in Figure 2.


Figure 2:  Stratos Ghost Deployer State Diagram

Ghost Deployer
Ghost Deployer State Diagram

The two core enhancements improve the platform’s underlying Cloud architecture and differentiate the Platform as a Service offering from traditional application servers or cloud-washed middleware products.

What other core enhancements would you like to see in Stratos?  You can submit your requests into the product development pipeline through our public architecture forum.





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