Instrumentation Trends

Instrumentation for tracking service behaviors is continuing its evolution. There are several ways of leveraging the instrumentation after the basic system is installed.

Adaptability

Adding adaptable measuring strategies reduces loads and adjusts the granularity as needed. There are minimal changes while service delivery is operating without problems. However, as problems arise, the instrumentation can shift into other modes. If an active collector detects a service outage, it can shorten the interval it uses for virtual transactions to measure the duration of the outage. After service availability is restored, it uses a longer time interval.

Collaboration

Collectors are beginning to collaborate with each other as well as with external management applications. Measurements between pairs of collectors help determine overall compliance and simplify problem isolation (see the sidebar in this chapter for more information).

Tighter Linkage for Passive and Active Collection

Within virtual transactions, the act of mapping to actual transactions is known as fidelity, and it is a limitation of active measurement techniques. High fidelity measurements increase in value because the virtual transactions reflect actual behavior. For example, a virtual transaction using a single database query will not shed much light on the actual behavior of a transaction using multiple databases.

The value of passive collectors in consumer-based network access systems (such as those used for desktops and wireless devices) is in the depth and breadth of the coverage. Each application and subtransaction can be captured. Aggregating this information gives detailed activity breakdowns that can be used in selecting the appropriate virtual transactions to use. Segmenting the information by location, customers, or other criteria offers higher fidelity to customer activities.