double idealLoad() {
            double queryCpuFraction = queryFraction();
            // Assumptions: 1) Write load is not organic so we should not increase to handle potential future growth.
            //                 (TODO: But allow applications to set their target write rate and size for that)
            //              2) Write load does not change in BCP scenarios.
            return queryCpuFraction * 1/growthRateHeadroom(at) * 1 / trafficShiftHeadroom(at) * idealQueryCpuLoad +
                   (1 - queryCpuFraction) * idealWriteCpuLoad;
        }
Ideal cpu load must take the application traffic fraction into account.
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/ClusterModel.java