Overview

Given that the monitoring framework supports the exposure of application health to infrastructure such as load balancers, it’s a short hop to considering the potential of the framework for human control of whether a service is in status or not.

InOutServiceMonitor

This monitor provides the ability to manually move a service between OK and FAIL in order to control whether it’s in service or not. Configuration is simple in spring:

<bean name="inOutServiceMonitor" class="com.sportex.betex.monitor.service.InOutServiceMonitor"> <constructor-arg index="0" value="MyMonitorName"/> <constructor-arg index="1" value="/etc/bf-blah/service-monitor.status"/> </bean>

The functionality of the monitor is simple:

• Default status is OK
• Status can be changed via the boolean JMX property inService.
• When the status is changed via the JMX property, then it’s written to the file specified in the constructor so it’s persisted between restarts.
• If the file is not found, the status is the default (OK).

Supporting AvB testing

Once you’ve got to grips with in/out of service control, then it’s reasonably easy to build up more complex arrangements, such as enabling AvB testing:

{yuml:type=class|dir=td} PingController 1->OverallStatus 1 PingController 1-note: Exposed on /webpingA via your spring config PingController 2->OverallStatus 2 PingController 2-note: Exposed on /webpingB via your spring config OverallStatus 1->MonitorRegistry 1 OverallStatus 2->MonitorRegistry 2 MonitorRegistry 1->InOutServiceMonitor 1 MonitorRegistry 2->InOutServiceMonitor 2 MonitorRegistry 1->SharedMonitor 1 MonitorRegistry 1->SharedMonitor 2 MonitorRegistry 1->SharedMonitor 3 MonitorRegistry 2->SharedMonitor 1 MonitorRegistry 2->SharedMonitor 2 MonitorRegistry 2->SharedMonitor 3 {yuml}

Or even AvB testing with a legacy webping for other traffic:

{yuml:type=class} PingController 1->OverallStatus 1 PingController 1-note: Exposed on /webpingA via your spring config PingController 2->OverallStatus 2 PingController 2-note: Exposed on /webpingB via your spring config PingController 3->OverallStatus 3 PingController 3-note: Exposed on /webping via your spring config OverallStatus 1->MonitorRegistry 1 OverallStatus 2->MonitorRegistry 2 OverallStatus 3->MonitorRegistry 3 MonitorRegistry 1->InOutServiceMonitor 1 MonitorRegistry 2->InOutServiceMonitor 2 MonitorRegistry 1->SharedMonitor 1 MonitorRegistry 1->SharedMonitor 2 MonitorRegistry 1->SharedMonitor 3 MonitorRegistry 2->SharedMonitor 1 MonitorRegistry 2->SharedMonitor 2 MonitorRegistry 2->SharedMonitor 3 MonitorRegistry 3->SharedMonitor 1 MonitorRegistry 3->SharedMonitor 2 MonitorRegistry 3->SharedMonitor 3 {yuml}