Foglight 7.3.0 - Administration and Configuration Guide

Working with Derived Metrics

In addition to building topology models at run-time using the data collected from monitored systems, Foglight has a unique capability to apply pre-defined calculations to the collected metrics. Metric calculations are typically scoped to specific parts of the topology and their values can change over time. They can be reused in expressions to simplify their syntax and speed up system deployment.

A metric is a specific value that is measured over time. There are two types of metrics in Foglight: raw metrics and derived metrics. Raw metrics are collected directly from your monitored environment and sent to the Foglight Management Server. Derived metrics are calculated from one or more raw or derived metrics. They are scoped to a topology type and can optionally be scoped to specific objects of that type. Many derived metrics come included with Foglight and installed cartridges. If none of the existing derived metrics meet your needs, you can create a new one and add it to the derived metric collection.

There are many reasons why it can be useful to create derived metrics. For example, creating derived metrics can make managing rules simpler by reusing metric expressions.

You can create and manage derived metrics using the Manage Derived Metrics dashboard. A typical installation can include a large number of rules. The Manage Derived Metrics dashboard lists all derived metrics that exist in your environment, and allows you to drill down to derived metric definitions. To access this dashboard, from the navigation panel, click Dashboards > Administration > Data > Derived Metrics.

To obtain additional diagnostics about derived metric behavior and how they affect your monitoring environment, use the Derived Metrics Diagnostics dashboard. From here, drill down to a specific derived metric and explore the objects that are affected by the derived metric, or find out how many times a derived metric has been calculated against a specific object. This can help you understand derived metric behavior and debug any problems associated with a particular derived metric. To access this dashboard, in the Administration dashboard, click Metrics Diagnostics in the Data column.

For more information, see the following topics:

Working with Metric Thresholds

Threshold levels in metrics are useful in situations when you need to reference a specific metric value multiple times, for example in derived metrics or rules. Each metric can have one threshold associated with it. A threshold is always associated with a threshold level. Threshold levels refer to a particular state of monitoring entities, such as agent states, alarm severities, and others. Each threshold level includes a unique set of threshold bound levels that are specific to that level. For example, the threshold level AgentState comes with several bound levels that relate to agent states, such as Running and Collecting Data.

Creating a threshold involves selecting a metric and defining values for threshold bounds. A bound level value can be a constant value, a registry variable, or another metric of the same topology type. As data is sampled, Foglight evaluates the metrics for which thresholds are defined, matching their run-time values with bound-specific values in pre-defined order, and performs actions when specific bound levels are reached.

You can create and manage thresholds using the Manage Thresholds dashboard. To access this dashboard, from the navigation panel, click Dashboards > Administration > Data > Manage Thresholds.

For more information, see the following topics:

Analyze Activity Levels with IntelliProfile

Foglight uses the IntelliProfile technology to estimate the system performance and help with system monitoring and planning. IntelliProfile uses data collected during a desired time period and generates a baseline operating range based on the collected metrics.

NOTE: You can only use this feature after installing a baseline cartridge that contains definitions for a selected metric property. Agent developers can write baseline cartridges. For more information about metric thresholds, see Working with Metric Thresholds.

A baseline establishes expected data patterns for a given time period. Baselines are periodically evaluated during IntelliProfile learning cycles, to reflect changes in data patterns.

During operating cycles, IntelliProfile compares incoming data for those metrics that have IntelliProfile threshold levels configured. Metric threshold states reflect the degree of deviation from the baseline, and can indicate potential performance bottlenecks. If there are any rule conditions that evaluate threshold states for such metrics, Foglight can generate alarms when a metric enters a certain threshold state.

IntelliProfile settings can be viewed and managed using the IntelliProfile dashboard. To access this dashboard, from the navigation panel, click Dashboards > Administration > Data > IntelliProfile.

For more information, see the following topics:

Working with Foglight Registry Variables

The Foglight registry is a collection of variables. Their values can be used for evaluation or comparison in monitoring entities and thus often determine evaluation outcome and triggered actions. The Foglight registry is not related to the host’s OS registry (for example, the Windows registry).

Rule conditions, for example, and their expressions can reference registry variables. A registry variable can have a global value that is available to all topology types and objects. It can also have one or more values associated with specific topology types or objects, or calendar dates. For example, your organization can have different administrators looking after different hosts. To configure Foglight to send host-related emails to appropriate recipients, scope the SYSADMIN variable to the monitored host instances and associate an email address with each host.

Many registry variables come included with Foglight and installed cartridges, including AvailabilityCritical, AvailabilityFatal, AvailabilityTarget, and many others. If the existing registry variables do not meet your needs, you can create a new one and add it to the registry variable collection.

You can create and manage registry variables using the Manage Registry Variables dashboard. To access this dashboard, from the navigation panel, click Dashboards > Administration > Rules & Notifications > Manage Registry Variables.

To find out the value of a registry variable for a particular topology type or object during a specific time period, use the Check Registry Value dashboard. To access this dashboard, from the navigation panel, click Dashboards > Administration > Rules & Notifications > Check Registry Value.

For more information, see the following topics: