7. Annex: NFVI FaultsΒΆ

Faults in the listed elements need to be immediately notified to the Consumer in order to perform an immediate action like live migration or switch to a hot standby entity. In addition, the Administrator of the host should trigger a maintenance action to, e.g., reboot the server or replace a defective hardware element.

Faults can be of different severity, i.e., critical, warning, or info. Critical faults require immediate action as a severe degradation of the system has happened or is expected. Warnings indicate that the system performance is going down: related actions include closer (e.g. more frequent) monitoring of that part of the system or preparation for a cold migration to a backup VM. Info messages do not require any action. We also consider a type “maintenance”, which is no real fault, but may trigger maintenance actions like a re-boot of the server or replacement of a faulty, but redundant HW.

Faults can be gathered by, e.g., enabling SNMP and installing some open source tools to catch and poll SNMP. When using for example Zabbix one can also put an agent running on the hosts to catch any other fault. In any case of failure, the Administrator should be notified. The following tables provide a list of high level faults that are considered within the scope of the Doctor project requiring immediate action by the Consumer.

Compute Hardware

Fault Severity How to detect? Comment Action to recover
Processor/CPU failure, CPU condition not ok Critical Zabbix   Switch to hot standby
Memory failure/ Memory condition not ok Critical Zabbix (IPMI)   Switch to hot standby
Network card failure, e.g. network adapter connectivity lost Critical Zabbix/ Ceilometer   Switch to hot standby
Disk crash Info RAID monitoring Network storage is very redundant (e.g. RAID system) and can guarantee high availability Inform OAM
Storage controller Critical Zabbix (IPMI)   Live migration if storage is still accessible; otherwise hot standby
PDU/power failure, power off, server reset Critical Zabbix/ Ceilometer   Switch to hot standby
Power degration, power redundancy lost, power threshold exceeded Warning SNMP   Live migration
Chassis problem (e.g. fan degraded/failed, chassis power degraded), CPU fan problem, temperature/ thermal condition not ok Warning SNMP   Live migration
Mainboard failure Critical Zabbix (IPMI)   Switch to hot standby
OS crash (e.g. kernel panic) Critical Zabbix   Switch to hot standby

Hypervisor

Fault Severity How to detect? Comment Action to recover
System has restarted Critical Zabbix   Switch to hot standby
Hypervisor failure Warning/ Critical Zabbix/ Ceilometer   Evacuation/switch to hot standby
Zabbix/ Ceilometer is unreachable Warning ?   Live migration

Network

Fault Severity How to detect? Comment Action to recover
SDN/OpenFlow switch, controller degraded/failed Critical ?   Switch to hot standby or reconfigure virtual network topology
Hardware failure of physical switch/router Warning SNMP Redundancy of physical infrastructure is reduced or no longer available Live migration if possible otherwise evacuation