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diff --git a/Section_5_VIM_HA.rst b/Section_5_VIM_HA.rst deleted file mode 100644 index ac16515..0000000 --- a/Section_5_VIM_HA.rst +++ /dev/null @@ -1,133 +0,0 @@ - -This section about VIM High availability - -============================ -5 VIM High availability -============================ -The VIM in the NFV reference architecture contains all the control nodes of OpenStack, SDN controllers -and hardware controllers. It manages the NFVI according to the instructions/requests of the VNFM and -NFVO and reports them back about the NFVI status. To guarantee the high availability of the VIM is -a basic requirement of the OPNFV platform. Also the VIM should provide some mechanism for VNFs to achieve -their own high availability. - -5.1 Architecture requirement of VIM HA ---------------------------------------- -The architecture of the control nodes should avoid any single point of failure and the management -network plane which connects the control nodes should also be redundant. Services of the control nodes -which are stateless like nova-API, glance-API etc. should be redundant but without data synchronization. -Stateful services like MySQL, Rabbit MQ, SDN controller should provide complex redundancy policies. -Cloud of different scale may also require different HA policies. - -Requirement: ------------- -- In small scale scenario active-standby redundancy policy would be acceptable. - -- In large scale scenario all stateful services like database, message queue, SDN controller - should be deployed in cluster mode which support N-way, N+M active-standby redundancy. - -- In large scale scenario all stateless services like nova-api, glance-api etc. should be deployed - in all active mode. - -- Load balance nodes which introduced for all active and N+M mode should also avoid the single point - of failure. - -- All control node servers shall have at least two network ports to connect to different networks - plane. These ports shall work in bonding manner. - -- Any failures of services in the redundant pairs should be detected and switch over should be carried out - automatically in less than 5 seconds totally. - -- Status of services must be monitored. - - -5.2 Fault detection and alarm requirement of VIM --------------------------------------------------- -Redundant architecture can provide function continuity for the VIM. For maintenance considerations -all failures in the VIM should be detected and notifications should be triggered to NFVO, VNFM and other -VIM consumers. - -Requirement: ------------- -- All hardware failures of control nodes should be detected and relevant alarms should be triggered. - OSS, NFVO, VNFM and other VIM consumers can subscribe these alarms. - -- Software on control nodes like OpenStack or ODL should be monitored by the clustering software - at process level and alarms should be triggered when exceptions are detected. - -- Software on compute nodes like OpenStack/nova agents, ovs should be monitored by watchdog. When - exceptions are detected the software should be restored automatically and alarms should be triggered. - -- Software on storage nodes like Ceph, should be monitored by watchdog. When - exceptions are detected the software should be restored automatically and alarms should be triggered. - -- All alarm indicators should include: Failure time, Failure location, Failure type, Failure level. - -- The VIM should provide an interface through which consumers can subscribe to alarms and notifications. - -- All alarms and notifications should be kept for future inquiry in VIM, ageing policy of these records - should be configurable. - -- VIM should distinguish between the failure of the compute node and the failure of the host HW. - -- VIM should be able to publish the health status of the compute node to NFV MANO. - -5.3 HA mechanism of VIM provided for VNFs ------------------------------------------- -When VNFs deploy their HA scheme, they usually require from underlying resource to provide some mechanism. -This is similar to the hardware watchdog in the traditional network devices. Also virtualization -introduces some other requirements like affinity and anti-affinity with respect to the allocation of the -different virtual resources. - -Requirement ------------- -- VIM should provide the ability to configure HA functions like watchdog timers, - redundant network ports and etc. These HA functions should be properly tagged and exposed to - VNF and VNFM with standard APIs. - -- VIM should provide anti-affinity scheme for VNF to deploy redundant service on different level of - aggregation of resource. - -- VIM should be able to deploy classified virtual resources to VNFs following the SAL description in VNFD. - -- VIM should provide data collection to calculate the HA related metrics for VNFs. - -- VIM should support the VNF/VNFM to initiate the operation of resources of the NFVI, such as repair/reboot. - -- VIM should correlate the failures detected on collocated virtual resources to identify latent faults in - HW and virtualization facilities - -- VIM should be able to disallow the live migration of VMs and when it is allowed it should be possible - to specify the tolerated interruption time. - -- VIM should be able to restrict the simultaneous migration of VMs hosting a given VNF. - -- VIM should provide the APIs to trigger scale in/out to VNFM/VNF. - -- When scheduler of the VIM use the Active/active HA scheme, multiple scheduler instances must not create - a race condition - -- VIM should be able to trigger the evacuation of the VMs before bringing the host down - when *maintenance mode* is set for the compute host. - -- VIM should configure Consoleauth in active/active HA mode, and should store the token in database. - -- VIM should replace a failed VM with a new VM and this new VM should start in the same initial state - as the failed VM. - -- VIM should support policies to prioritize a certain VNF. - -5.4 SDN controller -------------------- -SDN controller: Distributed or Centralized - -Requriements -------------- -- In centralized model SDN controller must be deployed as redundant pairs. - -- In distributed model, mastership election must determine which node is in overall control. - -- For distributed model, VNF should not be aware of HA of controller. That is it is a - logically centralized - system for NBI(Northbound Interface). - -- Event notification is required as section 5.2 mentioned. - |