EBOOST - Enhanced Boost

Enhanced Definition

EBOOST, or Enhanced Boost, is a z/OS capability that allows certain general-purpose processor (CP) work to execute on specialty engines, primarily **System z Integrated Information Processors (zIIPs)**, under specific conditions. Its primary purpose is to optimize resource utilization and potentially reduce software costs by shifting eligible workload from CPs to zIIPs, especially during periods of high CP utilization or for specific zIIP-eligible work that has "spilled over" to CPs. EBOOST (Enhanced Boost) is an IBM z/OS feature that provides temporary, on-demand processor capacity for specific workloads without increasing the software charges associated with that additional capacity. It allows customers to leverage unused or temporarily activated processor resources for eligible tasks, optimizing resource utilization and cost management within the mainframe environment.

Key Characteristics

- Specialty Engine Utilization: Leverages available capacity on zIIPs to execute work that would typically run on general-purpose CPs.
- Workload Eligibility: Primarily applies to zIIP-eligible work (e.g., Java workloads, certain database functions) that has exceeded the dedicated zIIP capacity or other specific CP workloads.
- Dynamic Activation: EBOOST is dynamically engaged by z/OS, often influenced by Workload Manager (WLM) policies and current system utilization.
- Cost Optimization: Aims to reduce the impact of boosted workloads on Millions of Service Units (MSU) consumption, thereby potentially lowering software licensing costs.
- Performance Enhancement: Can improve overall system throughput and response times by distributing workload across more processor resources.
- System-Managed: The decision to boost work is typically made by the operating system and WLM, requiring minimal manual intervention once configured.

Use Cases

- Managing Peak Workloads: During periods of high CP utilization, EBOOST can offload eligible work to zIIPs, preventing CP capping and maintaining service levels.
- Optimizing Java Workloads: Ensures that Java applications running on z/OS (e.g., in a Liberty profile or WebSphere Application Server) can utilize zIIPs more extensively, even if dedicated zIIPs are fully occupied.
- Controlling MSU Growth: By moving eligible work from CPs to zIIPs, EBOOST helps manage the growth of general-purpose CP utilization, which directly impacts software charges.
- Improving Throughput for Database Operations: Certain database functions (e.g., DB2 utility processing, IMS functions) that are zIIP-eligible can benefit from EBOOST during high demand.

Related Concepts

EBOOST is intrinsically linked to zIIPs (and historically zAAPs), as it extends their utility beyond strictly zIIP-eligible work. It works in close conjunction with Workload Manager (WLM), which defines service classes and goals, influencing when and which workloads are candidates for boosting. Understanding EBOOST is crucial for Capacity Planning as it impacts the effective utilization of processor resources and directly influences MSU consumption, a key factor in software licensing costs. Monitoring tools like SMF and RMF are essential for observing EBOOST activity and its impact.

Best Practices:

WLM Configuration: Ensure Workload Manager (WLM) service definitions are accurately configured to identify and classify EBOOST-eligible workloads, allowing z/OS to effectively manage boosting.
Continuous Monitoring: Utilize RMF and SMF data to monitor zIIP and CP utilization, EBOOST activity, and its impact on workload performance and MSU consumption.
Capacity Planning Integration: Incorporate EBOOST's potential benefits into your capacity planning models to optimize hardware investments and software licensing costs.
Understand Eligibility: Stay informed about which specific workloads and software versions are eligible for EBOOST to maximize its effectiveness.
Regular Review: Periodically review EBOOST's effectiveness and WLM policies, as workload characteristics and system configurations evolve.