Service Level Management

We saw in earlier sections that using target subsystem and monitoring subsystem we can monitor any resource in a datacenter. We can see the availability of any IT resource by looking at the history of status metrics. In the traditional approach, the history of status metric is good enough to measure system performance.

In most of the datacenters today, IT systems performance is measured by Service Level Agreements (SLA). SLA includes the performance indicators to be used, thresholds for the performance indicators, and expected availability of the IT resource in terms of the performance indicators. For example, one sample SLA for a Linux host includes CPU usage and IO rate as performance indicator; it also includes acceptable thresholds for CPU and IO rate. This SLA measures the availability of Linux servers in terms of CPU usage and IO rate.

Enterprise Manager provides support for defining and monitoring service level agreements. It provides necessary backend...