private void addMetricsHandlers() {
        addMetricsHandler(METRICS_V2_HANDLER_CLASS, METRICS_V2_HANDLER_BINDING_1, METRICS_V2_HANDLER_BINDING_2);
        addMetricsHandler(PROMETHEUS_V1_HANDLER_CLASS, PROMETHEUS_V1_HANDLER_BINDING_1, PROMETHEUS_V1_HANDLER_BINDING_2);
   }
The heap size % of total memory available to the JVM process.
config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainerCluster.java