Policy-Based Management


Automation is a key attribute of an effective Service Level Management (SLM) system. Stringent SLA compliance criteria reduce the time cushion that administrators might have had. One of the compliance criteria mentioned in Chapter 2, "Service Level Management," is a demand for higher availability. If management staff members are left to deal with high rates of change and growing complexity, the resolution times are unacceptable. Automated management tasks are the only way to add speed and to deal with complexity.

Note, however, that automated tasks are also of concern to administrators because they are taking actions and making changes at a faster rate than humans can maintain. A policy-based management system is an attempt to leverage automation while constraining actions.

Policies are sets of rules that define and constrain the actions the management system takes in different situations. Table 7-1 shows the various levels of rules that might be involved in a policy-based system. The rules are defined from the business level downward. Each rule level supports the goals of the levels above and depends on lower levels to achieve those goals.

Table 7-1. Multi-Level Rules

Level

Focus

Business rules

Business goals, such as protecting revenue

Service rules

Defining service quality metrics for end-user services

Infrastructure rules

Defining service quality metrics for infrastructure services

Element rules

Defining quality metrics for elements

Management system rules

For internal tasks, such as monitoring


As an example, consider that infrastructure rules might involve establishing special routes for low-latency network traffic or allocating more servers behind a load-balancing switch. Those infrastructure rules depend in turn on the proper element configurations.

Management system rules govern internal management processes, such as monitoring. Monitoring processes have targets, polling and heartbeat frequency, threshold values for alerts, and steps to take when there are failures in the instrumentation system.

Many policies are activated when a potential or actual service disruption is passed along by an alert from the real-time event manager. Other policies are activated in response to changes in the SLA statistics.

Policy-based management has a learning curve. Simple policies save staff time and effort and are usually implemented first. More sophisticated policies are implemented as the management team gains experience and learns how to extend policies more deeply into business processes and to more areas in the managed environment.

Policy-based management is the systematic creation of policies that drive the management system to maintain the highest service quality.




Practical Service Level Management. Delivering High-Quality Web-Based Services
Practical Service Level Management: Delivering High-Quality Web-Based Services
ISBN: 158705079X
EAN: 2147483647
Year: 2003
Pages: 128

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