 A key facet of multitenancy operations is Building the Network of the Future External consumer Ceilometer API system HTTP REST Rating, monitoring, w/ JSON & alarming, statistics, capacity planning Storage Publisher abstraction layer Database Collector FIGURE 16.14 OpenStack Ceilometer data/event logging architecture. overbooking of the physical resources such as CPU, memory, memory bus, and I/O. It is critical to monitor the level of overbooking and Ceilometer provides measurements to do that. CPU counters Memory usage and allocation counters Disk I/O counters Network I/O (not usually a bottleneck due to VM contention but can be used to check whether network interfaces were successfully established for the VMs). Ceilometer has plugins into SDN local controllers to monitor the east-west traffic between tenants. Additional measurements can be added since support is provided for Linux SYSSTAT utilities (also used in Nagios monitoring) and the KVM/Quick EMUlator (QEMU) hypervisor. A specific example is described below for CPU counters and memory counters (Tables 16.1 and 16.2). The above counters can be used to monitor the physical resource consumption levels of OpenStack tenants and analytics can reveal when overbooking is causing performance degradation. Nagios is used for Fault Monitoring (FM) on the Openstack and KVM hosts. Possible to do FM on guest as well. Applica VNF 1 VNF 2 VNF 3 Guest CentOS Ubuntu Hyperv vCPU,vMem, vDisk vCPU,vMem,vDis Hypervisor(KVM, ESXi) Hardwar CPU Cores Physical Disk Storage Network I/O Ceilometer will be the main tool for Performance Monitoring (PM) on both the host and the guest. FIGURE 16.15 OpenStack Ceilometer configuration in the NFV stack. Network Measurements TABLE 16.1 Ceilometer CPU Counter OpenStack Measurement Description Level Ceilometer Parameter Total time that VM was ready but could not get scheduled to run on VM level %CPU steal physical CPU Actively used CPU of the host, as a percentage of the total available Host level, cpu_util in Libvirt and CPU. Active CPU is ap