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Dynamic Metrics

Dynamic Metrics Used In Best Node Evaluation


Dynamic metrics are registered (for required node types) in the applicationContext.xml file (RED5_HOME/webapps/streammanager/WEB-INF/applicationContext.xml).

<bean id="freeConnectionSlotsMetric"
    class="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
    <property name="metricName">
        <value>clientCount</value>
    </property>
    <property name="unit">
        <value>PERCENTAGE</value>
    </property>
    <property name="minValue">
        <value>0</value>
    </property>
    <property name="maxValue">
        <value>100</value>
    </property>
    <property name="direction">
        <value>LOWERBETTER</value>
    </property>
    <property name="metricWeight">
        <value>${instanceevaluator.streams.metricweight}</value>
    </property>
</bean>

<bean id="streamCountMetric"
    class="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
    <property name="metricName">
        <value>publisherCount</value>
    </property>
    <property name="unit">
        <value>PERCENTAGE</value>
    </property>
    <property name="minValue">
        <value>0</value>
    </property>
    <property name="maxValue">
        <value>100</value>
    </property>
    <property name="direction">
        <value>LOWERBETTER</value>
    </property>
    <property name="metricWeight">
        <value>${instanceevaluator.streams.metricweight}</value>
    </property>
</bean>

<bean id="availableMemoryMetric"
    class="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
    <property name="metricName">
        <value>availableMemory</value>
    </property>
    <property name="unit">
        <value>PERCENTAGE</value>
    </property>
    <property name="minValue">
        <value>0</value>
    </property>
    <property name="maxValue">
        <value>100</value>
    </property>
    <property name="direction">
        <value>HIGHERBETTER</value>
    </property>
    <property name="metricWeight">
        <value>${instanceevaluator.memory.metricweight}</value>
    </property>
</bean>

<bean id="subscriberCountMetric"
    class="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
    <property name="metricName">
        <value>edgeSubscriberCount</value>
    </property>
    <property name="unit">
        <value>PERCENTAGE</value>
    </property>
    <property name="minValue">
        <value>0</value>
    </property>
    <property name="maxValue">
        <value>100</value>
    </property>
    <property name="direction">
        <value>LOWERBETTER</value>
    </property>
    <property name="metricWeight">
        <value>${instanceevaluator.subscribers.metricweight}</value>
    </property>
</bean>

<bean id="restreamerCountMetric"
    class="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
    <property name="metricName">
        <value>restreamerCount</value>
    </property>
    <property name="unit">
        <value>PERCENTAGE</value>
    </property>
    <property name="minValue">
        <value>0</value>
    </property>
    <property name="maxValue">
        <value>100</value>
    </property>
    <property name="direction">
        <value>LOWERBETTER</value>
    </property>
    <property name="metricWeight">
        <value>${instanceevaluator.restreamer.metricweight}</value>
    </property>
</bean>

<bean id="serverMetricsEvaluator" class="com.red5pro.services.streammanager.nodes.component.InstanceMetricsRuleManager">

    <property name="originMetricRules">
        <list   value-type="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
            <ref bean="freeConnectionSlotsMetric"></ref>  <!-- dynamically injected metrics -->
            <ref bean="streamCountMetric"></ref>  <!-- dynamically injected metrics -->
            <ref bean="subscriberCountMetric"></ref>  <!-- dynamically injected metrics -->
        </list>
    </property>

    <property name="edgeMetricRules">
        <list value-type="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
            <ref bean="freeConnectionSlotsMetric"></ref>  <!-- dynamically injected metrics -->
            <ref bean="availableMemoryMetric"></ref>  <!-- dynamically injected metrics -->
        </list>
    </property>


    <property name="relayMetricRules">
        <list value-type="com.red5pro.services.streammanager.nodes.metrics.MetricRule">
            <ref bean="restreamerCountMetric"></ref>  <!-- dynamically injected metrics -->
            <ref bean="availableMemoryMetric"></ref>  <!-- dynamically injected metrics -->
        </list>
    </property>

</bean>

Each of the above dynamic metrics is expressed in percentage. The weight value, supplied via configuration file during initialization is attached to the max possible value (100%) for that metric. As the connection, memory load of the node increases, the overall evaluated weight for it decreases. This is then compared with the evaluated weight of other candidate nodes in the category to select the best node.

Each metric rule property listed under the serverMetricsEvaluator java bean is groups individual dynamic metrics required for evaluation of node score for a specific node type.

  • To exclude a dynamic metric from origin score calculation, omit or comment-out the metric from the 'originMetricRules' list property in the serverMetricsEvaluator bean.
  • To exclude a dynamic metric from edge score calculation, omit or comment-out the metric from the 'edgeMetricRules' list property in the serverMetricsEvaluator bean.
  • To exclude a dynamic metric from relay score calculation, omit or comment-out the metric from the 'relayMetricRules' list property in the serverMetricsEvaluator bean.

Generally you do not need to edit anything in the applicationContext file. You can control most of the required settings from the red5-web.properties file.

Refer to METRIC WEIGHTS FOR BEST NODE EVALUATION SECTION discussed in the Stream Manager Configurable Properties topic.