Draft Escalator Requirement v0.4 ================================ Authors: -------- | Jie Hu (ZTE, hu.jie@zte.com.cn) | Qiao Fu (China Mobile, fuqiao@chinamobile.com) | Ulrich Kleber (Huawei, Ulrich.Kleber@huawei.com) | Maria Toeroe (Ericsson, maria.toeroe@ericsson.com) | Sama, Malla Reddy (DOCOMO, sama@docomolab-euro.com) | Zhong Chao (ZTE, chao.zhong@zte.com.cn) | Julien Zhang (ZTE, zhang.jun3g@zte.com.cn) | Yuri Yuan (ZTE, yuan.yue@zte.com.cn) | Zhipeng Huang (Huawei, huangzhipeng@huawei.com) | Jia Meng (ZTE, meng.jia@zte.com.cn) | Liyi Meng (Ericsson, liyi.meng@ericsson.com) | Pasi Vaananen (Stratus, pasi.vaananen@stratus.com) 1. Scope -------- | This document describes the user requirements on the smooth upgrade function of the NFVI and VIM with respect to the upgrades of the OPNFV platform from one version to another. Smooth upgrade means that the upgrade results in no service outage for the end-users. This requires that the process of the upgrade is automatically carried out by a tool (code name: Escalator) with pre-configured data. The upgrade process includes preparation, validation, execution, monitoring and conclusion. | ==[MT] While it is good to have a tool for the entire upgrade process, but it is a challenging task, so maybe we shouldn't require automation for the entire process right away. Automation is essential at execution.== | ==[hujie] Maybe we can analysis information flows of the upgrade tool, abstract the basic / essential actions from the tool (or tools), and map them to a command set of NFVI / VIM's interfaces.== The requirements are defined in a stepwise approach, i.e. in the first phase focusing on the upgrade of the VIM then widening the scope to the NFVI. The requirements may apply to different NFV functions (NFVI, or VIM, or both of them) . They will be classified in the Appendix of this document. 2. General Requirements Background and terminology -------------------------------------------------- ==[MT] At the moment 2.1-2.3 seem to be more background sections than requirements. Should we rename this part?== 2.1 Terminologies and definitions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - **NFVI** is abbreviation for Network Function Virtualization Infrastructure; sometimes it is also referred as data plane in this document. - **VIM** is abbreviation for Virtual Infrastructure Management; sometimes it is also referred as control plane in this document. - **Operators** are network service providers and Virtual Network Function (VNF) providers. - **End-Users** are subscribers of Operator's services. - **Network Service** is a service provided by an Operator to its End-users using a set of (virtualized) Network Functions - **Infrastructure Services** are those provided by the NFV Infrastructure and the Management & Orchestration functions to the VNFs. I.e. these are the virtual resources as perceived by the VNFs. - **Smooth Upgrade** means that the upgrade results in no service outage for the end-users. - **Rolling Upgrade** is an upgrade strategy that upgrades each node or a subset of nodes in a wave rolling style through the data centre. It is a popular upgrade strategy to maintains service availability. - **Parallel Universe** is an upgrade strategy that creates and deploys a new universe - a system with the new configuration - while the old system continues running. The state of the old system is transferred to the new system after sufficient testing of the later. - **Infrastructure Resource Model** ==(suggested by MT)== is identified as: physical resources, virtualization facility resources and virtual resources. - **Physical Resources** are the hardware of the infrastructure, may also includes the firmware that enable the hardware. - **Virtual Resources** are resources provided as services built on top of the physical resources via the virtualization facilities; in our case, they are the components that VNF entities are built on, e.g. the VMs, virtual switches, virtual routers, virtual disks etc ==[MT] I don't think the VNF is the virtual resource. Virtual resources are the VMs, virtual switches, virtual routers, virtual disks etc. The VNF uses them, but I don't think they are equal. The VIM doesn't manage the VNF, but it does manage virtual resources.== - **Visualization Facilities** are resources that enable the creation of virtual environments on top of the physical resources, e.g. hypervisor, OpenStack, etc. 2.2 Upgrade Objects ~~~~~~~~~~~~~~~~~~~ 2.2.1 Physical Resource ^^^^^^^^^^^^^^^^^^^^^^^ | Most of the cloud infrastructures support dynamic addition/removal of hardware. A hardware upgrade could be done by removing the old hardware node and adding the new one. This will not be in the scope of this project. | ==[MT] Does this mean that we are excluding firmware upgrades too?== 2.2.2 Virtual Resources ^^^^^^^^^^^^^^^^^^^^^^^ | Virtual resource upgrade mainly done by users. OPNFV may facilitate the activity, but suggest to have it in long term roadmap instead of initiate release. | ==[MT] same comment here: I don't think the VNF is the virtual resource. Virtual resources are the VMs, virtual switches, virtual routers, virtual disks etc. The VNF uses them, but I don't think they are equal. For example if by some reason the hypervisor is changed and the current VMs cannot be migrated to the new hypervisor, they are incompatible, then the VMs need to be upgraded too. This is not something the NFVI user (i.e. VNFs ) would even know about.== 2.2.3 Virtualization Facility Resources ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Based on the functionality they provide, virtualization facility resources could be divided into computing node, networking node, storage node and management node. | The possible upgrade objects in these nodes are addressed below: (Note: hardware based virtualization may considered as virtualization facility resource, but from escalator perspective, it is better considered it as part of hardware upgrade. ) **Computing node** #. OS Kernel #. Hypvervisor and virtual switch #. Other kernel modules, like driver #. User space software packages, like nova-compute agents and other control plane programs | Updating 1 and 2 will cause the loss of virtualzation functionality of the compute node, which may lead to data plane services interruption if the virtual resource is not redudant. | Updating 3 might result the same. | Updating 4 might lead to control plane services interruption if not an HA deployment. **Networking node** #. OS kernel, optional, not all switch/router allow you to upgrade its OS since it is more like a firmware than a generic OS. #. User space software package, like neutron agents and other control plane programs | Updating 1 if allowed will cause a node reboot and therefore leads to data plane services interruption if the virtual resource is not redudant. | Updating 2 might lead to control plane services interruption if not an HA deployment. **Storage node** #. OS kernel, optional, not all storage node allow you to upgrade its OS since it is more like a firmware than a generic OS. #. Kernel modules #. User space software packages, control plane programs | Updating 1 if allowed will cause a node reboot and therefore leads to data plane services interruption if the virtual resource is not redudant. | Update 2 might result in the same. | Updating 3 might lead to control plane services interruption if not an HA deployment. **Management node** #. OS Kernel #. Kernel modules, like driver #. User space software packages, like database, message queue and control plane programs. | Updating 1 will cause a node reboot and therefore leads to control plane services interruption if not an HA deployment. Updating 2 might result in the same. | Updating 3 might lead to control plane services interruption if not an HA deployment. 2.3 Upgrade Span ~~~~~~~~~~~~~~~~ | **Major Upgrade** | Upgrades between major releases may introducing significent changes in function, configuration and data, such as the upgrade of OPNFV from Arno to Brahmaputra. | **Minor Upgrade** | Upgrades inside one major releases which would not leads to changing the stucture of the platform and may not infect the schema of the system data. 2.4 Upgrade Granularity ~~~~~~~~~~~~~~~~~~~~~~~ 2.4.1 Physical/Hardware Dimension ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Support full / partial upgrade for data centre, cluster, zone. Because of the upgrade of a data centre or a zone, it may be divided into several batches. The upgrade of a cloud environment (cluster) may also be partial. For example, in one cloud environment running a number of VNFs, we may just try one of them to check the stability and performance, before we upgrade all of them. 2.4.2 Software Dimension ^^^^^^^^^^^^^^^^^^^^^^^^ - The upgrade of host OS or kernel may need a 'hot migration' - The upgrade of OpenStack’s components i.the one-shot upgrade of all components ii.the partial upgrade (or bugfix patch) which only affects some components (e.g., computing, storage, network, database, message queue, etc.) | ==[MT] this section seems to overlap with 2.1.== | I can see the following dimensions for the software - different software packages - different funtions - Considering that the target versions of all software are compatible the upgrade needs to ensure that any dependencies between SW and therefore packages are taken into account in the upgrade plan, i.e. no version mismatch occurs during the upgrade therefore dependencies are not broken - same function - This is an upgrade specific question if different versions can coexist in the system when a SW is being upgraded from one version to another. This is particularly important for stateful functions e.g. storage, networking, control services. The upgrade method must consider the compatibility of the redundant entities. - different versions of the same software package - major version changes - they may introduce incompatibilities. Even when there are backward compatibility requirements changes may cause issues at graceful rollback - minor version changes - they must not introduce incompatibility between versions, these should be primarily bug fixes, so live patches should be possible - different installations of the same software package - using different installation options - they may reflect different users with different needs so redundancy issues are less likely between installations of different options; but they could be the reflection of the heterogeneous system in which case they may provide redundancy for higher availability, i.e. deeper inspection is needed - using the same installation options - they often reflect that the are used by redundant entities across space - different distribution possibilities in space - same or different availability zones, multi-site, geo-redundancy - different entities running from the same installation of a software package - using different startup options - they may reflect different users so redundancy may not be an issues between them - using same startup options - they often reflect redundant entities==== 3.5 Upgrade duration ~~~~~~~~~~~~~~~~~~~~ As the OPNFV end-users are primarily Telco operators, the network services provided by the VNFs deployed on the NFVI should meet the requirement of 'Carrier Grade'. In telecommunication, a "carrier grade" or"carrier class" refers to a system, or a hardware or software component that is extremely reliable, well tested and proven in its capabilities. Carrier grade systems are tested and engineered to meet or exceed "five nines" high availability standards, and provide very fast fault recovery through redundancy (normally less than 50 milliseconds). [from wikipedia.org] "five nines" means working all the time in ONE YEAR except 5'15". We have learnt that a well prepared upgrade of OpenStack needs 10 minutes. The major time slot in the outage time is used spent on synchronizing the database. [from ' Ten minutes OpenStack Upgrade? Done! ' by Symantec] This 10 minutes of downtime of OpenStack however did not impact the users, i.e. the VMs running on the compute nodes. This was the outage of the control plane only. On the other hand with respect to the preparations this was a manually tailored upgrade specific to the particular deployment and the versions of each OpenStack service. The project targets to achieve a more generic methodology, which however requires that the upgrade objects fulfill ceratin requirements. Since this is only possible on the long run we target first upgrades from version to version for the different VIM services. **Questions:** #. | Can we manage to upgrade OPNFV in only 5 minutes? | ==[MT] The first question is whether we have the same carrier grade requirement on the control plane as on the user plane. I.e. how much control plane outage we can/willing to tolerate? | In the above case probably if the database is only half of the size we can do the upgrade in 5 minutes, but is that good? It also means that if the database is twice as much then the outage is 20 minutes. | For the user plane we should go for less as with two release yearly that means 10 minutes outage per year.== | ==[Malla] 10 minutes outage per year to the users? Plus, if we take control plane into the consideration, then total outage will be more than 10 minute in whole network, right?== | ==[MT] The control plane outage does not have to cause outage to the users, but it may of course depending on the size of the system as it's more likely that there's a failure that needs to be handled by the control plane.== #. | Is it acceptable for end users ? Such as a planed service interruption will lasting more than ten minutes for software upgrade. | ==[MT] For user plane, no it's not acceptable in case of carrier-grade. The 5' 15" downtime should include unplanned and planned downtimes.== | ==[Malla] I go agree with Maria, it is not acceptable.== #. | Will any VNFs still working well when VIM is down? | ==[MT] In case of OpenStack it seems yes. .:)== 2.5.1 The maximum duration of an upgrade ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | The duration of an upgrade is related to and proportional with the scale and the complexity of the OPNFV platform as well as the granularity (in function and in space) of the upgrade. | [Malla] Also, if is a partial upgrade like module upgrade, it depends also on the OPNFV modules and their tight connection entites as well. 2.5.2 The maximum duration of a rollback when an upgrade is failed - this should be about rollback duration ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | The duration of a rollback is short than the corresponding upgrade. It depends on the duration of restore the software and configue data from pre-upgrade backup / snapshot. | ==[MT] During the upgrade process two types of failure may happen: | In case we can recover from the failure by undoing the upgrade actions it is possible to roll back the already executed part of the upgrade in graceful manner introducing no more service outage than what was introduced during the upgrade. Such a graceful rollback requires typically the same amount of time as the executed portion of the upgrade and impose minimal state/data loss.== | ==[MT] Requirement: It should be possible to roll back gracefully the failed upgrade of stateful services of the control plane. | In case we cannot recover from the failure by just undoing the upgrade actions, we have to restore the upgraded entities from their backed up state. In other terms the system falls back to an earlier state, which is typically a faster recovery procedure than graceful rollback and depending on the statefulness of the entities involved it may result in significant state/data loss.== | **Two possible types of failures can happen during an upgrade** #. We can recover from the failure that occured in the upgrade process: In this case, a graceful rolling back of the executed part of the upgrade may be possible which would "undo" the executed part in a similar fashion. Thus, such a roll back introduces no more service outage during an upgrade than the executed part introduced. This process typically requires the same amount of time as the executed portion of the upgrade and impose minimal state/data loss. #. We cannot recover from the failure that occured in the upgrade process: In this case, the system needs to fall back to an earlier consistent state by reloading this backed-up state. This is typically a faster recovery procedure than the graceful rollback, but can cause state/data loss. The state/data loss usually depends on the statefulness of the entities whose state is restored from the backup. 2.5.3 The maximum duration of a VNF interruption ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Since not the entire process of a smooth upgrade will affect the VNFs, the duration of the VNF interruption may be shorter than the duration of the upgrade. In some cases, the VNF running without the control from of the VIM is acceptable. | ==[MT] Should require explicitly that the NFVI should be able to provide its services to the VNFs independent of the control plane?== | ==[MT] Requirement: The upgrade of the control plane must not cause interruption of the NFVI services provided to the VNFs.== | ==[MT] With respect to carrier-grade the yearly service outage of the VNF should not exceed 5' 15" regardless whether it is planned or unplanned outage. Considering the HA requirements TL-9000 requires an ent-to-end service recovery time of 15 seconds based on which the ETSI GS NFV-REL 001 V1.1.1 (2015-01) document defines three service availability levels (SAL). The proposed example service recovery times for these levels are: | SAL1: 5-6 seconds | SAL2: 10-15 seconds | SAL3: 20-25 seconds== | ==[Pva] my comment was actually that the downtime metrics of the underlying elements, components and services are small fraction of the total E2E service availability time. No-one on the E2E service path will get the whole downtime allocation (in this context it includes upgrade process related outages for the services provided by VIM etc. elements that are subject to upgrade process).== | ==[MT] So what you are saying is that the upgrade of any entity (component, service) shouldn't cause even this much service interruption. This was the reason I brought these figures here as well that they are posing some kind of upper-upper boundary. Ideally the interruption is in the millisecond range i.e. no more than a switchover or a live migration.== | ==[MT] Requirement: Any interruption caused to the VNF by the upgrade of the NFVI should be in the sub-second range.== ==[MT] In the future we also need to consider the upgrade of the NFVI, i.e. HW, firmware, hypervisors, host OS etc.== 3. Functional Considerations ---------------------------- 3.1 Requirement of Escalator's Basic Actions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This section describes the basic functions may required by Escalator. 3.1.1 Preparation (offline) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is the design phase when the upgrade plan (or upgrade campaign) is being designed so that it can be executed automatically with minimal service outage. It may include the following work: #. Check the dependencies of the software modules and their impact, backward compatibilities to figure out the appropriate upgrade method and ordering. #. Find out if a rolling upgrade could be planned with several rolling steps to avoid any service outage due to the upgrade some parts/services at the same time. #. Collect the proper version files and check the integration for upgrading. #. The preparation step should produce an output (i.e. upgrade campaign/plan), which is executable automatically in an NFV Famawork and which can be validated before execution. - The upgrade campaign should not be referring to scalable entities directly, but allow for adaptation to the system configuration and state at any given moment. - The upgrade campaign should describe the ordering of the upgrade of different entities so that dependencies, redundancies can be maintained during the upgrade execution - The upgrade campaign should provide information about the applicable recovery procedures and their ordering. - The upgrade campaign should consider information about the verification/testing procedures to be performed during the upgrade so that upgrade failures can be detected as soon as possible and the appropriate recovery procedure can be identified and applied. - The upgrade campaign should provide information on the expected execution time so that hanging execution can be identified - The upgrade campaign should indicate any point in the upgrade when coordination with the users (VNFs) is required. ==[hujie]Depends on the attributes of the object being upgraded, the upgrade plan may be slitted into step(s) and/or sub-plan(s), and even more small sub-plans in design phase. The plan(s) or sub-plan(s) my include step(s) or sub-plan(s).== 3.1.2 Validation the upgrade plan / Checking the pre-requisites of System( offline / online) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | The upgrade plan should be validated before the execution by testing it in a test environment which is similar to the product environment. | ==[MT]However it could also mean that we can identify some properties that it should satisfy e.g. what operations can or cannot be executed simultaneously like never take out two VMs of the same VNF. | Another question is if it requires that the system is in a particular state when the upgrade is applied. I.e. if there's certain amount of redundacy in the system, migration is enabled for VMs, when the NFVI is upgraded the VIM is healthy, when the VIM is upgraded the NFVI is healthy, etc. | I'm not sure what online validation means: Is it the validation of the upgrade plan/campaign or the validation of the system that it is in a state that the upgrade can be performed without too much risk?== | Before the upgrade plan being executed, the system heathly of the online product environment should be checked and confirmed to satisfy the requirements which were described in the upgrade plan. The sysinfo, e.g. which included system alarms, performance statistics and diagnostic logs, will be collected and analyized. It is required to resolve all of the system faults or exclud the unhealthy part before executing the upgrade plan. | ==[hujie] Text merged.== 3.1.3 Backup/Snapshot (online) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ For avoid loss of data when a unsuccessful upgrade was encountered, the data should be backuped and the system state snapshot should be taken before the excution of upgrade plan. This would be considered in the upgrade plan. Several backups/Snapshots may be generated and stored before the single steps of changes. The following data/files are required to be considered: #. running version files for each node. #. system components' configuration file and database. #. image and storage, if it is necessary. ==[MT] Does 3 imply VNF image and storage? I.e. VNF state and data?== | ==[hujie] The following text is derived from previous "4. Negotiate with the VNF if it's ready for the upgrade"== | Although the upper layer, which include VNFs and VNFMs, is out of the scope of Escalator, but it is still recommended to let it ready for a smooth system upgrade. The escalator could not garanttee the safe of VNFs. The upper layer should have some safe guard mechanism in design, and ready for avoiding failure in system upgrade. 3.1.4 Execution (online) ^^^^^^^^^^^^^^^^^^^^^^^^ | The execution of upgrade plan should be a dynamical procedure which is controlled by Escalator. | ==[hujie] Revised text to be general.== #. It is required to supporting execution ether in sequence or in parallel. #. It is required to checke the result of the execution and take the action according the situation and the policies in the upgrade plan. #. It is required to execute properly on various configurations of system object. I.e. stand-alone, HA, etc. #. It is required to excecute on the designated different parts of the system. I.e. physical server, virtualized server, rack, chassis, cluster, even different geographical places. 3.1.5 Testing (online) ^^^^^^^^^^^^^^^^^^^^^^ | The testing after upgrade the whole system or parts of system to make sure the upgraded system(object) is working normally. | ==[hujie] Revised text to be general.== #. It is recommended to run the prepared test cases to see if the functionalities are availiable without any problem. #. It is recommended to check the sysinfo, e.g. system alarms, performance statistics and diagnostic logs to see if there are any abnormal. 3.1.6 Restore/Rollback (online) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | When upgrade is failure unfortunatly, a quick system restore or system rollback should be taken to recovery the system and the services. | ==[hujie] Revised text to be general.== #. It is recommend to support system restore from backup when upgrade was failed. #. It is recommend to support gracefull rollback with reverse order steps if possible. 3.1.7 Monitoring (online) ^^^^^^^^^^^^^^^^^^^^^^^^^ | Escalator should continually monitor the process of upgrade. It is keeping update status of each module, each node, each cluster into a status table during upgrade. | ==[hujie] Revised text to be general.== #. It is required to collect the status of every objects being upgraded and sending abnormal alerms during the upgrade. #. It is recommend to reuse the existing monitoring system, like alarm. #. It is recommend to support pro-actively query. #. It is recommend to support passively wait for notification. | **Two possible ways for monitoring:** | **Pro-Actively Query** requires NFVI/VIM provides proper API or CLI interface. If Escalator serves as a service, it should pass on these interfaces. | **Passively Wait for Notification** requires Escalator provides callback interface, which could be used by NFVI/VIM systems or upgrade agent to send back notification. | [hujie] I am not sure why not to subscribe the notification. 3.1.8 Logging (online) ^^^^^^^^^^^^^^^^^^^^^^ Record the information generated by escalator into log files. The log file is used for manual diagnostic of exceptions. #. It is required to support logging. #. It is recommended to include time stamp, object id, action name, error code, etc. 3.1.9 Administrative Control (online) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Administrative Control is used for control the privilege to start any escalator's actions for avoding unauthorized operations. #. It is required to support administrative control mechenism #. It is recommed to reuse the system's own secure system. #. It is required to avoid conflicts when the system's own secure system being upgraded. 3.2 Requirements on system object being upgraded ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | ==We can develope BPs in future from req of this section and GA for upper stream projects== | Escalator focus on smooth upgrade. In practical implementation, it might be combined with installer/deployer, or act as an independent tool/service. In either way, it requires targeting systems(NFVI and VIM) are developed/deployed in a way that Escalator could perform upgrade on them. On NFVI system, live-migration is likely used to maintain availability because OPNFV would like to make HA transparent from end user. This requires VIM system being able to put compute node into maintenance mode and then isolated from normal service. Otherwise, new NFVI instances might risk at being schedule into the upgrading node. | On VIM system, availability is likely achieved by redundancy. This impose less requirements on system/services being upgrade (see PVA comments in early version). However, there should be a way to put the target system into standby mode. Because starting upgrade on the master node in a cluster is likely a bad idea. | ==[hujie] Revised text to be general.== #. It is required for NFVI/VIM to support **service handover** mechanism that minimize interruption to 0.001%(i.e. 99.999% service availability). Possible implementations are live-migration, redundant deployment, etc, (Note: for VIM, interruption could be less restrictive) #. It is required for NFVI/VIM to restore the early verion in a efficent way, such as **snapshot**. #. It is required for NFVI/VIM to **migration data** efficiently between base and upgraded system. ==[hujie] What is exact meaning of "base" here?== #. It is recomend for NFV/VIM's interface to support upgrade orchestration, e.g. reading/setting system state ==[hujie] I am not sure if it reflect the previous text.== 4. Use Cases ------------ This section describes the use cases to verify the requirements of Escalator. 4.1 Upgrade a system with minimal configuration ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A minimal configuration system is normally depolyed for experimental or developement ussage, such as a OPNFV test bed. Althouth it dose not have large workload, but it is a typical system to be upgraded frequently. 4.2 Upgrade a system with HA configuration ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A HA configuration system is very popular in the operator's data centre. And it is a typical product environment. It always running 7 \* 24 a week with VNFs running on it to provide services to the end users. 4.3 Upgrade a system with Multi-Site configuration ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Upgrade in one site may cause service interruption to other site, if both sites are depended and sharing the same modules/data base (e.g. a keystone for both sites). If a site failure during an upgrade, the rollback missing any minimal state/data loss can cause an affect/failure to the depended site. ==Consider one site of ARNO release first. Then, multi-site in the future.== 5. RA of Escalator ------------------ This section describes the reference architecture, the function blocks, the function entities of Escalator for the reader to well understand how the basic functions be organized. 6. Information Flows -------------------- | This section describes the information flows among the function entities when Escalator is in actions. | We should consider a generic procedure / frameworks of upgrading. And may provide a plugin interface for specialized tasks 7. Interfaces ------------- This section describes the required interfaces of Escalator. 7.1 Manual Interface (CLI / GUI) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 7.2 RESTful API ~~~~~~~~~~~~~~~ To support 3.3 Negotiate with the VNF if it's ready for the upgrade 7.3 Configuration File ~~~~~~~~~~~~~~~~~~~~~~ This section will suggest a format of the configuration files and how to deal with it. 7.4 Log File ------------ This section will suggest a format of the log files and how to deal with it. 8. Requirements from other OPNFV projects ----------------------------------------- | We have created a questionnaire for collecting other projects requirments (https://docs.google.com/forms/d/11o1mt15zcq0WBtXYK0n6lKF8XuIzQTwvv8ePTjmcoF0/viewform?usp=send_form), please advertise it. | ==[hujie] Can we force other OPNFV projects to complete the survey by using JIRA dependence?== 8.1 Doctor Project ~~~~~~~~~~~~~~~~~~ | ==Note: This scenario could be out of scope in Escalator project, but having the option to support this should be better to align with Doctor requirements.== | The scope of Doctor project also covers maintenance scenario in which 1) the VIM administorator requests host maintenance to VIM, 2) VIM will notifiy it to consumer such as VNFM to trigger application level migration or switching active-standby nodes, and 3) VIM waits responce from the consumer for a short while. - VIM should send out notification of VM migration to consumer (VNFM) as abstracted message like "maintenance". - VIM could wait VM migration until it receives "VM ready to maintenance" message from the owner (VNFM) 8.2 HA Project ~~~~~~~~~~~~~~ 8.3 Multi-site Project ~~~~~~~~~~~~~~~~~~~~~~ - Escalator upgrade one site should at least not lead to the other site API token validation failed. 9. Reference ------------ | [1] ETSI GS NFV 002 (V1.1.1): “Architectural Framework” | [2] ETSI GS NFV 003 (V1.1.1): "Terminology for Main Concepts in NFV". | [3] ETSI GS NFV-SWA001:“Virtual Network Function Architecture” | [4] ETSI GS NFV-MAN001:“Management and Orchestration” | [5] ETSI GS NFV-REL001:"Resiliency Requirements" | [6] QuEST Forum TL-9000:"Quality Management System Requirement Handbook" | [7] Service Availabilty Forum AIS:"Software Management Framework" 10. Useful Working Drafts of ETSI NFV ------------------------------------- | Access them with your own ETSI account, please DO NOT disclose the content. | [1] Migrate Virtualised Compute Resource operation @ 7.3.1.8 | ftp://docbox.etsi.org/ISG/NFV/Open/Drafts/IFA005_Or-Vi_ref_point_Spec/NFV-IFA005v070.zip | [2] Reliability issues during NFV Software upgrade and improvement mechanisms @ 8 | ftp://@docbox.etsi.org/ISG/NFV/Open/Drafts/REL003_E2E_reliability_models/NFV-REL003v030.zip Appendix -------- A.1 Impact Analysis ~~~~~~~~~~~~~~~~~~~ Upgrading the different software modules may cause different impact on the availability of the infrastracture resources and even on the service continuity of the vNFs. **Software modules in the computing nodes** #. Host OS patch ==[MT] As SW module, we should list the host OS and maybe ====its drivers as well. From upgrade persepctive do we limit host OS upgrades to patches only?== #. Hypervisor, such as KVM, QEMU, XEN, libvirt #. Openstack agent in computing nodes (like Nova agent, Ceilometer agent...) **Software modules in network nodes** #. Neutron L2/L3 agent #. OVS, SR-IOV Driver **Software modules storage nodes** #. Ceph The table below analyses such an impact - considering a single instance of each software module - from the following aspects: - the function which will be lost during upgrade, - the duration of the loss of this specific function, - if this causes the loss of the vNF function, - if it causes incompatibility in the different parts of the software, - what should be backed up before the upgrade, - the duration of restoration time if the upgrade fails | These values provided come from internal testing and based on some assumptions, they may vary depending on the deployment techniques. Please feel free to add if you find more efficient values during your testing. | https://wiki.opnfv.org/_media/upgrade_analysis_v0.5.xlsx | Note that no redundancy of the software modules is considered in the table.