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Difference between revisions of "Federated Cloud Technology"

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#REDIRECT [[Federated_Cloud_Architecture]]
 
{{Under_construction}}
 
= Cloud Federations =
 
EGI Federated Cloud provides the services and technologies to create federation of clouds (community, private or public clouds) that operate according to the preferences, choices and constraints set by its members and users. The EGI Cloud Federations are modeled around the concept of an abstract Cloud Management stack subsystem that is integrated with components of the EGI Core Infrastructure and that provides a set of agreed uniform interfaces within the community it provides services to.
 
The '''EGI Cloud federation''' (see figure below) is an hybrid cloud composed by public, community and private clouds, all supported by the '''EGI Core Infrastructure Platform''' services. The EGI Federated Cloud is composed by multiple “realms”, each realm having homogeneous cloud management interfaces and capabilities. A '''cloud realm''' is a subset of cloud providers exposing homogeneous cloud management interfaces and capabilities. The '''Open Standards Cloud Realm''' supports the usage of open standards for its interfaces and is completely integrated with the EGI Core infrastructure Platform. A '''Community Platform''' provides community-specific data, tools and applications which can be supported by one or more realms.
 
[[Image:Federated_Cloud_Model.png|thumb|center|600px|Federated Cloud Model]]
 
Despite the large diversity in the type of cloud realms, a relatively small number of building blocks (or federator services) can be identified in almost all of them. These services turn individual clouds into a federation. The sections below describe these common services and the EGI solutions provided for them.
 
= Integrated interfaces or user environments =
 
Cloud systems must provide a set of interfaces through which users and user applications can interact with the services offered. In case of an IaaS cloud federation these interfaces offer compute, storage and network management capabilities. The interfaces can be harmonised across all participating cloud providers - in which case the providers are responsible for implementing the agreed standard - or can be native at the different sites. In this latter case, libraries or portals can hide heterogeneity from the users and can translate user requests to diverse native formats.
 
EGI Federated promotes the use of open standards for providing a uniform interface and behaviour across different providers: OCCI for management of compute resources and CDMI for management of storage. The [[Federated_Cloud_APIs_and_SDKs|Federated Cloud APIs and SDKs page]] describes from a user point of view how these interfaces can be used.
 
== OCCI ==
 
The [http://occi-wg.org/ Open Cloud Computing Interface (OCCI)] is a RESTful Protocol and API designed to facilitate interoperable access to, and query of, cloud-based resources across multiple resource providers and heterogeneous environments. The formal specification is maintained and actively worked on by OGF’s OCCI-WG.
 
The [[Federated_Cloud_VM_Management|VM Management]] scenario page contains further details on the support for OCCI on different Cloud Management Stacks.
 
=== Implementations ===
 
;[https://github.com/gwdg/rOCCI rOCCI - A Ruby OCCI Framework]
:Provides OCCI support for various Cloud Management Frameworks, including OpenNebula
 
;[https://github.com/EGI-FCTF/occi-os OCCI-OS]
:OpenStack OCCI interface
 
;[https://github.com/openstack/ooi ooi]
:New implemenation of OCCI for OpenStack, upcoming release
 
<!--
;snf-occi
:OCCI implementation for synnefo
-->
 
== OpenStack Nova ==
 
OpenStack sites of the EGI Federated Cloud can provide access through the native OpenStack API. The OpenStack API documentation is available at [http://developer.openstack.org/ OpenStack developer pages]. EGI Federated Cloud supports the usage of the [http://developer.openstack.org/api-ref-compute-v2.1.html Compute (nova) v2.1 API]. The [[Federated_Cloud_APIs_and_SDKs|Federated Cloud APIs and SDKs page]] describes how to use this API in the EGI resources.
 
== CDMI ==
 
The [http://www.snia.org/cloud SNIA Cloud Data Management Interface (CDMI)] defines a RESTful open standard for operations on storage objects. Semantically the interface is very close to AWS S3 and MS Azure Blob, but is more open and flexible for implementation.
 
CDMI offers clients a way for operating both on a storage management system and single data items. The exact level of support depends on the concrete implementation and is exposed to the client as part of the protocol.The design of the protocol is aimed both at flexibility and efficiency. Certain heavyweight operations, e.g. blob download, can be performed also with a pure HTTP client to make use of the existing ecosystem of tools. CDMI is built around the concept of Objects, which vary in supported operations and metadata schema. Each Object has an ID, which is unique across all CDMI deployments.
 
There are 4 CDMI objects most relevant in the context of EGI’s Federated Cloud:
* '''Data object''': Abstraction for a file with rich metadata.
* '''Container''': Abstraction for a folder. Export to non-HTTP protocols is performed on the container level. Container might have other containers inside of them.
* '''Capability''': Exposes information about a feature set of a certain object. CDMI supports partial implementation of the standards by defining optional features and parameters. In order to discover what functionality is supported by a specific implementation, CDMI client can issue a GET request to a fixed url: /cdmi_capabilities.
* '''Domain''': Deployment specific information.
 
Attachment of the storage items to a VM can often be performed more efficiently using protocols like NFS or iSCSI. CDMI supports exposing of this information via container metadata. A client can make use of this information to attach a storage item to a VM over an OCCI protocol.
 
=== Implementations ===
 
TBC
 
= Virtual Machine Image Management =
 
In a distributed, federated Cloud infrastructure, users will often face the situation of efficiently managing and distributing their VM Images across multiple resource providers. Users need a catalogue of Virtual Machine images (VMIs) that are usable on the IaaS cloud provider sites and encapsulate those software configurations that are useful and relevant for the given community. (Typically pre-configured scientific models and algorithms). To maximise usability of VMIs across cloud sites the images should be in a format that’s supported at every federation member site (Or at least can be converted to such formats). Users also need  a system that automatically replicates VMIs from the VMI catalogue to the federation member sites, as well as removes them when needed. Automated replication can ensure consistency of capabilities across sites and is very often coupled with a VMI vetting process to ensure that only properly working, and relevant VMIs are replicated to the cloud sites of the community
 
== AppDB Cloud MarketPlace ==
 
The [https://appdb.egi.eu/ EGI AppDB] service has been extended to a Virtual Appliance Marketplace. This brings about a new category of software entries, called Virtual Appliances (VAs), which are, in all practical manners, clean-and mean virtual machine images designed to run on a virtualization platform, that provide a software solution out-of-the-box, ready to be used with minimal or no set-up needed within the EGI Federated Cloud infrastruture.
 
== HEPiX image lists ==
 
AppDB's Virtual Appliance Marketplace provides the ground for managing and publishing versioned repositories of virtual appliances, in a way that integrates with the existing HEPiX [https://github.com/hepix-virtualisation/vmcaster VMCaster] / [https://github.com/hepix-virtualisation/vmcatcher VMCatcher] framework, currently in use by the EGI.
 
Research Communities ultimately create and update VM Images (or delegate this functionality). The Images themselves are stored in Appliance repositories that are provided and managed elsewhere, typically by the Research Community itself. A representative of the Research Community then generates a VM Image list (or updates an existing one) using AppDB. Federated Clouds Resource Provider then subscribe to changes in VM Image lists by regularly downloading the list from AppDB, and comparing it against local copies. New and updated VM Images are downloaded from the appliance repository referenced in the VM Image list into a local staging cache and, where required, made available for further examination and assessment.
 
Ultimately, Cloud resource Providers will make VM Images available for immediate instantiation by the Research Community.
 
= Single Sign-On for users =
 
SSO Ensures that users of the federation needs to register for access only once before they can use the federated services. Single sign-on is increasingly implemented in the form of identity federations in both industry and academia.
 
== Virtual Organisation Management & AAI ==
 
Within EGI, research communities are generally identified and, for the purpose of using EGI resources, managed through “Virtual Organisations” (VOs). The Open Standards Cloud Realm uses these VOs for authorization and authentication. Three VOs must be supported at every Resource Provider in the realm:
* [http://operations-portal.egi.eu/vo/view/voname/ops <code>ops</code> VO], used for monitoring purposes;
* [http://operations-portal.egi.eu/vo/view/voname/dteam<code>dteam</code> VO], used for testing purposes by site operators; and
* [http://operations-portal.egi.eu/vo/view/voname/dteam <code>fedcloud.egi.eu</code> VO], a catch-all VO that provides resources to users for a limited period of time (6 months initially) for protopying and validation.
 
Resource Providers may support additional VOs in order to give access to other user communities.
 
Integration modules are available for each Cloud Management Framework that been developed by the task members. Configuring these modules into a provider’s cloud installation will allow members of these VOs to access the cloud. The user retrieves a VOMS attribute certificate from the VOMS server of the desired VO (currently, Perun server for <code>fedcloud.egi.eu</code> VO) and thus creates a local VOMS proxy certificate. The VOMS proxy certificate is use in subsequent calls to the OCCI endpoints of OpenNebula or OpenStack using the rOCCI client tool. The rOCCI client directly talks to OpenNebula endpoints, which map the certificate and VO information to local users. Local users need to have been created in advance, which is triggered by regular synchronizations of the OpenNebula installation with Perun.
 
In order to access an OpenStack OCCI endpoint, the rOCCI client needs to retrieve a Keystone token from OpenStack Keystone first. The retrieval is transparent to the user and automated in the workflow of accessing the OpenStack OCCI endpoint. It is triggered by the OCCI endpoint rejecting invalid requests and sending back an HTTP header referencing the Keystone URL for authentication. Users are generated on the fly in Keystone, it does not need regular synchronization with the VO Management server Perun.
 
Generic information about how to configure VOMS support for the supported Cloud Management Frameworks is available at [[MAN10]]. Information to how to add the support for a new Virtual Organisation on the EGI Federated Cloud can be found at [[HOWTO16]].
 
 
= Service Registry =
 
The Service Registry contains general information about the providers participating to the infrastructure and their capabilities. The registry provides the ‘big picture view’ about the federation for both human users and online services (such as service monitors).
 
== GOCDB ==
 
EGI’s central service catalogue is used to catalogue the static information of the production infrastructure topology. The service is provided using the GOCDB tool that is developed and deployed within EGI. To allow Resource Providers to expose Cloud resources to the production infrastructure, a number of service types are available:
* <code>eu.egi.cloud.accounting</code>
* <code>eu.egi.cloud.storage-management.cdmi</code>
* <code>eu.egi.cloud.vm-management.occi</code>.
* <code>eu.egi.cloud.vm-metadata.marketplace</code>
* <code>eu.egi.cloud.vm-metadata.vmcatcher</code>
* <code>eu.egi.cloud.vm-metadata.appdb-vmcaster</code>
* <code>org.openstack.nova</code>
 
All providers '''must''' enter cloud service endpoints to GOCDB in order to enable integration with other operational tools.
 
Higher level broker services also have its own service types:
* <code>eu.egi.cloud.broker.compss</code>
* <code>eu.egi.cloud.broker.proprietary.slipstream</code>
* <code>eu.egi.cloud.broker.vmdirac</code>
 
Further information about GOCDB can be find on the following page: [[GOCDB/Input System User Documentation]].
 
 
Special rules apply for the following service types:
 
=== eu.egi.cloud.storage-management.cdmi ===
 
'''Endpoint URL''' field must contain the following info:
 
http[s]://hostname:port
 
=== eu.egi.cloud.vm-management.occi ===
 
'''Endpoint URL''' field must contain the following info:
 
https://hostname:port/?image=&lt;image_name&gt;&amp;resource=&lt;resource_name&gt;
 
Both &lt;image_name&gt; and &lt;resource_name&gt; cannot contain spaces. These attributes map to os_tpl and resource_tpl respectively.
 
=== org.openstack.nova ===
 
'''Endpoint URL''' field must contain '''Keystone URL''' (https://hostname:port/url) with the following additional info:
 
<nowiki>https://hostname:port/url?image=&lt;image_uuid&gt;&amp;resource=&lt;flavor_name&gt;</nowiki>
 
Both &lt;image_name&gt; and &lt;flavour_name&gt; cannot contain spaces.
 
= Information system =
 
The information system provides a real-time view about the actual capabilities and load of federation participants. The information system can be used by both human users and online services.
 
== BDII and GlueSchema ==
 
Users and tools can discover the available resource in the infrastructure by querying EGI information discovery services. The common information system deployed at EGI is based on the Berkeley Database Information Index (BDII) with a hierarchical structure distributed over the whole infrastructure.
 
The information system is structured in three levels: the services publish their information (e.g. specific capabilities, total and available capacity or user community supported by the service) using an OGF recommended standard format, [http://www.ogf.org/documents/GFD.147.pdf GLUE2]. The information published by the services is collected by a Site-BDII, a service deployed in every site in EGI. The Site-BDIIs are queried by the Top-BDIIs - a national or regional located level of the hierarchy, which contain the information of all the site services available in the infrastructure and their services. NGIs usually provide an authoritative instance of Top-BDII, but every Top-BDII, if properly configured, should contain the same set of information.
 
Resource Providers must provide a Site-BDII endpoint that published information on the available resource following the GLUE2 schema. Even if the GLUE2 schema defines generic computing and storage entities, it was developed originally for Grid resources and can represent only partially the information needed by the Cloud users. Thus, the EGI Federated Cloud is working within the GLUE2 WG at OGF to profile and extend the schema to represent Cloud Computing, Storage and in the future Platform and Software services. The proposed extensions are currently under discussion at the WG.
EGI provides an implementation for service-level information that generates information supporting OpenStack and OpenNebula, Synnefo support is currently being added. The information is published in a different subtree (<code>Glue2GroupID=cloud</code>) so it can coexist with grid information and is easily discoverable by users.
 
Information available for each provider:
* Cloud computing resources
* Service endpoint
* Capabilities provided by the service, such as: virtual machine management or snapshot taking. The labels that identify the capabilities are agreed within the taskforce.
* Interface, the type of interface – e.g. webservice or webportal – and the interface name and version, for example OCCI 1.2.0
* User authentication and authorization profiles supported by the service, e.g. X.509 certificates
* Virtual machines images made available by the cloud provider
* Resource templates (number of cores and physical memory) allocable in a virtual machine.
 
=== Schema ===
 
'''TBC, Cloud schema specification'''
 
= Accounting =
 
Federated Accounting provides an integrated view about resource/service usage: it pulls together usage information from the federated sites and services, integrates the data and presents them in such a way that both individual users as well as whole communities can monitor their own resource/service usage across the whole federation.
 
== Usage Records, APEL and accounting portal ==
 
EGI Federated Cloud has agreed on a Cloud Usage Record -which inherits from the [https://www.ogf.org/documents/GFD.98.pdf OGF Usage record]- that defines the data that resource providers must send to EGI’s central Accounting repository.
 
Support for retrieving the accounting data in this format is available from:
* OpenNebula: https://github.com/EGI-FCTF/opennebula-cloudacc
* Openstack – https://github.com/IFCA/caso
* Synnefo provides its own internal component
 
Once generated, records are delivered via the network of EGI message brokers to the central accounting repository using APEL SSM (Secure STOMP Messenger) provided by STFC. SSM client packages can be obtained at https://apel.github.io. A Cloud Accounting Summary Usage Record has also been defined and summaries created on a daily basis from all the accounting records received from the Resource Providers are sent to the EGI Accounting Portal. The [http://accounting-devel.egi.eu/egi.php EGI Accounting Portal] also runs SSM to receive these summaries and provides a web page displaying different views of the Cloud Accounting data received from the Resource Providers.
 
= Shared Operational Practices =
 
The participating service/resource providers may share certain operational tools and practices at the level of the federation, for example use a shared system to collect availability and reliability statistics about their site, or to share and respond to security alerts. 
 
 
== EGI A/R Monitoring ==
 
Services in the EGI infrastructure are monitored via [https://argoeu.github.io/ ARGO]. Specific probes to check functionality and availability of services must be provided by service developers, The current set of probes used for monitoring cloud resources consists of:
* OCCI probes (eu.egi.cloud.OCCI-VM and eu.egi.cloud.OCCI-Context): OCCI-VM creates an instance of a given image by using OCCI, checks its status and deletes it afterwards. OCCI-Context checks that the OCCI interfaces correctly supports the standard and the FedCloud contextualization extension.
* Accounting probe (eu.egi.cloud.APEL-Pub): Checks if the cloud resource is publishing data to the Accounting repository
* TCP checks (org.nagios.Broker-TCP, org.nagios.CDMI-TCP, org.nagios.OCCI-TCP and org.nagios.CloudBDII-Check): Basic TCP checks for services.
* VM Marketplace probe (eu.egi.cloud.AppDB-Update): gets a predetermined image list from AppDB and checks its update interval.
* Perun probe (eu.egi.cloud.Perun-Check): connects to the server and checks the status by using internal Perun interface
 
Probes for CDMI and the image synchronization mechanism are currently under development. More information on cloud probes can be at [[Cloud SAM tests]].
 
Currently a [https://cloudmon.egi.eu/nagios central instance] specific to the activities of the EGI Federated Clouds Task has been deployed for monitoring test bed Results of cloud probes are visible on the [http://mon.egi.eu/myegi/sa/ central SAM interface] under profile <code>ch.cern.sam-CLOUD-MON</code> and <code>ch.cern.sam-CLOUD-MON_CRITICAL</code>.

Latest revision as of 15:18, 12 September 2019