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diff --git a/docs/userguide/Deployment_Guideline.rst b/docs/userguide/Deployment_Guideline.rst deleted file mode 100644 index 7d3b018..0000000 --- a/docs/userguide/Deployment_Guideline.rst +++ /dev/null @@ -1,452 +0,0 @@ -This document will provide an overall framework for the high availability -deployment of NFV system. It will also continiously update to include HA -deployment guidelines and suggestions for the releases of OPNFV. - -********************************************************************* -Overview of High Available Deployment of OPNFV -********************************************************************* - -In this section, we would like to discuss the overall HA deployment of NFV system. -Different modules, such as hardware,VIM,VMs and etc, will be included, and HA -deployment of each single module will be discussed. However, not all of these HA -schemes should be deployed in on system at the same time. For the HA deployment of -a single system, we should consider the tradeoff between high availability and the -cost and resource to leverage. - - -Architecture of HA deployment -================================================================== - -This section intends to introduce the different modules we should consider -when talking about HA deployment. These moduels include the Hardware -(compute, network, storage hardware), the VIM, the hypervisor, VMs and VNFs. -HA schemes for these different moduels should all be considered when deploying -an NFV system. And the schemes should be coordinated so that the system can make -sure to react in its best way when facing failure. - -The following picture shows the the architecture of HA deployment based on the -framework from ETSI NFV ISG. - -.. figure:: Overview.png - :alt: Architecture for HA Deployment - :figclass: align-center - - Fig 1. Architecture of HA Deployment based on the Framework of ETSI NFV ISG - -HA deployment topology -================================================================== - -This section will introduce the HA deployment topology for an NFV system. -The topology explained in this section is to support the software -cluster of OPNFV platform, which we will discuss in detail in section1.3. - -The typical topology of deployment OPNFV platform should include at -least the controller nodes, and the compute nodes. Depend on the request of -the users, standalone network nodes or storage nodes can be added into this -topology. The simplest HA deployment of OPNFV only include the control nodes. Further -HA schemes can be provided to the compute nodes, the network nodes and the storage -nodes, according to the requirement of services deployed on the NFV system. -Figure 2 shows the deployment topology, in which the controller nodes are all in -a cluster, and the compute nodes can be in another cluster. - -The control node cluster here is to provide HA for the controller services, so -that the services on the control node can successfully failover when failure -happens and the service can continue. The cluster service should also provide -automatic recovery for the control nodes. For OPNFV, the control node cluster -should include at least 3 nodes, and should be an odd number if the cluster -management system use quorum. This may change if we use different cluster -management schemes though. - -The compute node clusters is responsible for providing HA for the services running -on the compute nodes. These services may include agents for openstack, host os, -hypervisors. Such cluster is responsible for the recovery and repair -of the services. However, compute node cluster will certainly bring complexity to -the whole system, and would increase the cost. There could be multiple solutions -for the compute cluster, e.g., senlin from openstack. - -There could be other HA solutions for the compute nodes except for cluster. Combination -of congress and doctor can be one of them, in which doctor provides quickly notification -of failure to the VIM, and congress provides proper recovery procedure. In such scheme, -the compute nodes are not recovered by the cluster scheme, but recovered under the -supervision of VIM. - -.. figure:: topology_control_compute.png - :alt: HA Deployment Topology of Control Nodes and Compute Nodes - :figclass: align-center - - Fig 2. HA Deployment Topology of Control Nodes and Compute Nodes - -When the cloud is supporting heavy network traffic, which is often the case for the data -plane services in the Telecom scenarios, it is necessary to deploy standalone network -nodes for openstack, so that the large amont of traffic switching and routing will not -bring extra load to the controller nodes. In figure 3, we add network nodes into the -topology and shows how to deploy it in a high available way. In this figure, the -network nodes are deployed in a cluster. The cluster will provide HA for the services -runing on the network nodes. Such cluster scheme could be the same with that of the -compute nodes. - -On thing to be notify is that all hosts in the NFV system should have at least two NICs -that are bonded via LACP. - -.. figure:: topology_control_compute_network.png - :alt: HA Deployment Topology of Control Nodes and Compute Nodes and Network Nodes - :figclass: align-center - - Fig 3. HA Deployment Topology of Control Nodes, Compute Nodes and network Nodes - -The HA deployment for storage can be different for all different storage schemes. We will -discuss the detail of the storage HA deployment in section 1.3.3 - -Software HA Framework -================================================================== - -In this section, we introduce more details about the HA schemes for a complete NFV system. - -Openstack Controller services (Openstack services) --------------------------------------------------------- - -For the High Availability of OpenStack Controller nodes, Pacemaker and Corosync are -often used. The following texts are refering from the HA guideline of OpenStack, which -gives an example of solution of HA deployment.(http://docs.openstack.org/ha-guide/) - -At its core, a cluster is a distributed finite state machine capable of co-ordinating the startup and recovery -of inter-related services across a set of machines. For OpenStack Controller nodes, a cluster management system, -such as Pacemaker, is recommended to use to provide the following metrics. - -1, Awareness of other applications in the stack - -2, Awareness of instances on other machines - -3, A shared implementation and calculation of quorum. - -4, Data integrity through fencing (a non-responsive process does not imply it is not doing anything) - -5, Automated recovery of failed instances - -Figure 4 shows the details of HA schemes for Openstack controller nodes with Pacemaker. - -.. figure:: HA_control.png - :alt: HA Deployment of Openstack Control Nodes based on Pacemaker - :figclass: align-center - - Fig 4. HA Deployment of Openstack Control Nodes based on Pacemaker - -High availability of all stateless services are provided by pacemaker and HAProxy. - -Pacemaker cluster stack is the state-of-the-art high availability and load -balancing stack for the Linux platform. Pacemaker is useful to make OpenStack -infrastructure highly available. Also, it is storage and application-agnostic, -and in no way specific to OpenStack. - -Pacemaker relies on the Corosync messaging layer for reliable cluster -communications. Corosync implements the Totem single-ring ordering and -membership protocol. It also provides UDP and InfiniBand based messaging, -quorum, and cluster membership to Pacemaker. - -Pacemaker does not inherently (need or want to) understand the applications -it manages. Instead, it relies on resource agents (RAs), scripts that -encapsulate the knowledge of how to start, stop, and check the health -of each application managed by the cluster.These agents must conform -to one of the OCF, SysV Init, Upstart, or Systemd standards.Pacemaker -ships with a large set of OCF agents (such as those managing MySQL -databases, virtual IP addresses, and RabbitMQ), but can also use any -agents already installed on your system and can be extended with your -own (see the developer guide). - -After deployment of Pacemaker, HAProxy is used to provide VIP for all the -OpenStack services and act as load balancer. HAProxy provides a fast and -reliable HTTP reverse proxy and load balancer for TCP or HTTP applications. -It is particularly suited for web crawling under very high loads while -needing persistence or Layer 7 processing. It realistically supports tens -of thousands of connections with recent hardware. - -Each instance of HAProxy configures its front end to accept connections -only from the virtual IP (VIP) address and to terminate them as a list -of all instances of the corresponding service under load balancing, such -as any OpenStack API service. This makes the instances of HAProxy act -independently and fail over transparently together with the network endpoints -(VIP addresses) failover and, therefore, shares the same SLA. - -We can alternatively use a commercial load balancer, which is a hardware or -software. A hardware load balancer generally has good performance. - -Galera Cluster, or other database cluster service, should also be deployed -to provide data replication and synchronization between data base. Galera -Cluster is a synchronous multi-master database cluster, based on MySQL and -the InnoDB storage engine. It is a high-availability service that provides -high system uptime, no data loss, and scalability for growth. The selection -of DB also will have potential influence on the behaviour on the application -code. For instance using Galera Clusterl may give you higher concurrent write -perfomance but may require a more complex conflict resolution. - -We can also achieve high availability for the OpenStack database in many different -ways, depending on the type of database that we are using. There are three -implementations of Galera Cluster available: - -1, Galera Cluster for MySQL The MySQL reference implementation from Codership; - -2, MariaDB Galera Cluster The MariaDB implementation of Galera Cluster, which is -commonly supported in environments based on Red Hat distributions; - -3, Percona XtraDB Cluster The XtraDB implementation of Galera Cluster from Percona. - -In addition to Galera Cluster, we can also achieve high availability through other -database options, such as PostgreSQL, which has its own replication system. - -To make the RabbitMQ high available, Rabbit HA queue should be configued, and all -openstack services should be configurd to use the Rabbit HA queue. - -In the meantime, specific schemes should also be provided to avoid single point of -failure of Pacemaker. And services failed should be automaticly repaired. - -Note that the scheme we described above is just one possible scheme for the HA -deployment of the controller nodes. Other schemes can also be used to provide cluster -management and monitoring. - -SDN controller services ---------------------------------------- - -SDN controller software is data intensive application. All static and dynamic data has -one or more duplicates distributed to other physical nodes in cluster. Built-in HA schema -always be concordant with data distribution and built-in mechanism will select or -re-select master nodes in cluster. In deployment stage software of SDN controller -should be deployed to at least two or more physical nodes regardless whether the -software is deployed inside VM or containner. Dual management network plane should -be provided for SDN controller cluster to support built-in HA schema. - -Storage ----------------------------------------- -Depending on what storage scheme deployed, different HA schemes should be used. The following -text are refering from the Mirantis OpenStack reference architecture, which provides suggestions -on the HA deployment of different storage schemes. - -1, Ceph - -Ceph implements its own HA. When deploying it, enough controller nodes running the Ceph Monitor -service to form a quarum, and enough Ceph OSD nodes to satisfy the object replication factor are -needed. - -2, Swift - -Swift API relies on the same HAProxy setup with VIP on controller nodes as the other REST -APIs. For small scale deployment, swift storage and Proxy services can be deployed on the -controller nodes. However, for a larger production environment, dedicated storage nodes, in -which two for swift proxy and at least three for swift storage, are needed. - - - -Host OS and Hypervisor ---------------------------------------- - -The Host OS and Hypervisor should be supervised and monitored for failure, and should be -repaired when failure happens. Such supervision can based on a cluster scheme, or can -just simply use controller to constantly monitor the computer host. Figure 6 shows a -simplified framework for hypervisor cluster. - -When host/hypervisor failure happens, VMs on that host should be evacuated. However, -such scheme should coordinate with the VM HA scheme, so that when both the host and the -VM detect the failure, they should know who should take responsibility for the evacuation. - - -.. figure:: HA_Hypervisor.png - :alt: HA Deployment of Host OS and Hypervisor - :figclass: align-center - - Fig 5. HA Deployment of Host OS and Hypervisor - -Virtual Machine (VM) ---------------------------------------- - -VM should be supervised and monitored for failure, and should be repaired when failure -happens. We can rely on the hypervisor to monitor the VM failure. Another scheme can be -used is a cluster for the VM, in which failure of VMs in one cluster can be supervised -and will be repaired by the cluster manager. Pacemaker and other cluster management -schemes can be considered for the VM cluster. - -In case when VNFs do not have HA schemes, extra HA scheme for VM should be taken into -consideration. Such approach is kind of best effort for the NFV platform to provide HA -for the VNF service, and may lead to failure copy between VMs when VNF fails. Since the -NFVI can hardly know of the service runing in the VNF, it is imporssible for the NFVI -level to provide overall HA solution for the VNF services. Therefore, even though we -mention this scheme here, we strongly suggest the VNF should have its own HA schemes. - -Figure 6 gives an example for the VM active/standby deployment. In this case, both the -active VM and the standby VM are deployed with the same VNF image. When failure happens -to the active VM, the standby VM should take the traffic and replace the active VM. Such -scheme is the best effort of the NFVI when VNFs do not have HA schemes and would only -rely on VMs to provide redundancy. However, for stateful VNFs, there should be data copy -between the active VM and standby VM. In this case, fault for the active VM can also be -copied to the standby VM, leading to failure of the new active VM. - -.. figure:: HA_VM.png - :alt: VM Active/Standby Deployment - :figclass: align-center - - Fig 6. VM Active/Standby Deployment - -Virtual Network Functions (VNF) ---------------------------------------- - -For telecom services, it is suggested that VNFs should have its own built-in HA schemes -or HA schemes implemented in VNF Managerhave to provide high available services to -the customers. HA schemes for the VNFs can based on cluster. In this case, OpenSAF, -pacemaker and other cluster management services can be used. - -HA schemes for the VNFs should be coordinate with the lower layer. For example, it -should be clear which level will take responsibility for VM restart. A suggested -schemes could be, the VNF layer should be responsible for the redundancy and failover -of the VNFs when failure happens. Such failover should take place in quite a short -time (less then seconds). The repairing procedure will then take place from upper -layer to lower layer, that is, the VNF layer will first check if the failure is at -its layer, and should try to repair itself. If it fails to repaire the failure, -the failure should escalate to lower layers and let the NFVI layer to do the repair -work. There could also be cases that the NFVI layer has detected the failure and will -repair it before the escalation. These functions should be complished by the coordination -of all different component, including the VNFM, VIM, VNFs and NFVI. - -In the meantime, the VNFs can take advantage of API the hypervisor can provide to -them to enhance HA. Such API may include constant health check from the hypervisor, -affinity/inaffinity deployment support. example about watchdog - -Figure 7 gives an example for the VNF HA scheme. - -.. figure:: HA_VNF.png - :alt: HA Deployment of VNFs - :figclass: align-center - - Fig 7. HA Deployment of VNFs - -********************************************************************************* -HA deployment guideline for OPNFV releases -********************************************************************************* - -In this section, we will continiously update the HA deployment guideline for the releases -of OPNFV. - -HA deployment guideline for Arno -============================================== - -Deployment Framework ------------------------------------------------ - -Figure 8 shows an overall architecture for the HA deployment of ARNO. - -.. figure:: HA_ARNO.png - :alt: HA Deployment of OPNFV ARNO release - :figclass: align-center - - Fig 8. HA Deployment of OPNFV ARNO release - -For OPNFV Arno release, HA deployment of Openstack Control Node (Openstack Juno) and ODL -controller (ODL Helium) is supported. Both deployment tools (fuel and forman)support -such HA deployment. - -For such HA deployment, the following components¡¯ failure is protected - -Software: -* Nova scheduler -* Nova conductor -* Cinder scheduler -* Neutron server -* Heat engine - -Controller hardware: -* dead server -* dead switch -* dead port -* dead disk -* full disk - - -HA test result for ARNO -------------------------------------------------- - -Two specific High Availability testcases are done on the ARNO release. These test cases -are collaboratively developed by the High Availability project and the Yardstick project. - -Both cases are excuted in the China Mobile's Lab, where ARNO SR1 release is deployed with -Fuel. - -The two testcases respectively test the following two aspects: - -1, Controll Node Service HA - -In this test, HA of "nova-api" is tested. According to the result, the service can -successfully failover to the other controller nodes within 2.36s, once failure happens -at the active node. However, the service can't repair itself automatically. more -explaination about the repair, other services are not tested yet. - -2, Control Node Hardware HA - -In this test, HA of the controller node hardware is tested. One of the hardware is -abnormally shutdown, and the service of "nova-api" is monitored. According to the test -results, the service can failover to the other controller node within 10.71 secondes. -However, the failed hardware can't automatically repair itself. - -See more details about these test cases in the Yardstick doc of "Test Results for -yardstick-opnfv-ha"(https://gerrit.opnfv.org/gerrit/#/c/7543/). - -From these basic test cases we can see that OPNFV ARNO has integrated with some HA -schemes in its controller nodes. However, its capability of self repair should be -enhanced. - -HA deployment guideline for Brahmaputra -============================================== -In the Brahmaputra release, 4 installers are provided. We will discuss about the HA -deployment of each installer. - -Apex ----------------------------------------------------- - -For the installer of Apex, all of the OpenStack services are in HA on all 3 controllers. -The services are monitored by pacemaker and load balanced by HA Proxy with VIPs. The -SDN controllers usually only run as a single instance on the first controller with no -HA scheme. - -Database is clustered with galera in an active passive failover via pacemaker and the -message bus is rabbitHA and the services are managed by pacemaker. - -Storage is using ceph, clustered across the control nodes. - -In the future, more work is on the way to provide HA for the SDN controller. The Apex -team has already finished a demo that runs ODL on each controller, load balanced to -neutron via a VIP + HA Proxy, but is not using pacemaker. Meanwhile, they are also -working to include ceph storage HA for compute nodes as well. - -Compass ---------------------------------------------------------- -TBD - -Fuel -------------------------------------------------------------- - -At moment Fuel installer support the following HA schemes. - -1)Openstackcontrollers: N-way redundant (1,3,5, etc) -2)OpenDaylight:No redundancy -3)Cephstorage OSD: N-way redundant (1,3,5, etc) -4)Networkingattachment redundancy: LAG -5)NTPredundancy: N-way relays, up to 3 upstream sources -6)DNSredundancy: N-way relays, up to 3 upstream sources -7)DHCP:1+1 - -JOID ---------------------------------------------------------- - -JOID provides HA based on openstack services. Individual service charms have been -deployed in a container within a host, and each charms are distributed in a way each -service which meant for HA will go into container on individual nodes. For example -keystone service, there are three containers on each control node and VIP has been -assigned to use by the front end API to use keystone. So in case any of the container -fails VIP will keep responding to via the other two services. As HA can be maintainer -with odd units at least one service container is required to response. - - -Reference -========== - -* https://www.rdoproject.org/ha/ha-architecture/ -* http://docs.openstack.org/ha-guide/ -* https://wiki.opnfv.org/display/availability?preview=/2926706/2926714/scenario_analysis_for_high_availability_in_nfv.pdf -* https://wiki.opnfv.org/display/availability?preview=/2926706/2926708/ha_requirement.pdf - |