ARM 4.0 Metric Gauges [ARM 4.0 Metrics]

A gauge value can go up and down, and it can be positive or negative. More...

Classes
interface	org.opengroup.arm40.metric.ArmMetricGauge32
	Implements a 32-bit integer gauge. More...
interface	org.opengroup.arm40.metric.ArmMetricGauge32Definition
	Marks a metadata binding. More...
interface	org.opengroup.arm40.metric.ArmMetricGauge64
	Implements a 64-bit integer gauge. More...
interface	org.opengroup.arm40.metric.ArmMetricGauge64Definition
	Marks a metadata binding. More...
interface	org.opengroup.arm40.metric.ArmMetricGaugeFloat32
	Implements a 32-bit floating-point gauge. More...
interface	org.opengroup.arm40.metric.ArmMetricGaugeFloat32Definition
	Marks a metadata binding. More...

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Detailed Description

A gauge value can go up and down, and it can be positive or negative.

This is the IETF RFC 1155 definition of a gauge. A gauge should be used instead of a counter when it is not meaningful to sum up the values over an interval. An example is the amount of memory used. If the amount of memory used over 20 transactions in an interval is measured and the average usage for each of these transactions was 15MB, it does not make sense to say that 20*15=300MB of memory were used over the interval. It would make sense to say that the average was 15MB, that the median was 12MB, and that the standard deviation was 8MB. The values can be averaged, maximums and minimums per transaction calculated, and other kinds of statistical calculations performed.

ARM supports three gauge types:

• 32-bit integer: org.opengroup.arm40.metric.ArmMetricGauge32
• 64-bit integer: org.opengroup.arm40.metric.ArmMetricGauge64
• 32-bit floating-point: org.opengroup.arm40.metric.ArmMetricGaugeFloat32 The floating-point standard is IEEE 754 (the same as the Java language).