Reference Guide

Note that the info parameter provides information about the newly-connected datapath, and the
isHybrid parameter indicates whether the controller is configured for hybrid mode or not.
Such a component must register with the controller service to have its callback invoked at the
appropriate times:
controller.registerInitialFlowContributor(this);
Metrics Framework
The fundamental objectives to be addressed by the metering framework are as follows.
•
Support components that are part of the HP VAN SDN Controller Framework and
applications that are not.
•
Make metrics simple to use.
•
Support the creation and updating of metrics within the controller and from outside, to
accommodate apps that have external components but want to keep all of their metric data
in one repository.
•
Support several metric types:
 Counter
 Gauge
 Rolling counter
 Ratio gauge
 Histogram
 Meter
 Timer
•
Designed to be robust
 Maintains functionality when the controller stops and restarts
 Maintains functionality when the metering framework stops and restarts, but the
controller does not
•
Support persistence of data over time on different time scales.
•
Support display of specified metrics via JMX.
•
Support authorization-based REST access to persisted data over time.
External View
The overarching purpose of metering support is to provide a centralized facility that application
developers can use to track metric values over time, and to provide access to the resulting time
stamped values thereafter via REST. The use of this facility, as shown in the following conceptual
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