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diff --git a/docs/release/userguide/feature.userguide.rst b/docs/release/userguide/feature.userguide.rst new file mode 100644 index 0000000..0a32270 --- /dev/null +++ b/docs/release/userguide/feature.userguide.rst @@ -0,0 +1,294 @@ +.. This work is licensed under a Creative Commons Attribution 4.0 International License. +.. http://creativecommons.org/licenses/by/4.0 + +Abstract +======== +This user guide document provides the users with: + +1. Short description of Promise project and key features implemented in +Danube. + +Promise description +=================== +Promise is a resource reservation and management project to identify NFV related +requirements and realize resource reservation for future usage by capacity +management of resource pools regarding compute, network and storage. + +The following are the key features provided by this module: + +* Capacity Management +* Reservation Management +* Allocation Management + +Promise capabilities and usage +============================== +The Danube implementation of Promise is built with the YangForge data modeling +framework [#f2]_ , using a shim-layer on top of OpenStack to provide +the Promise features. This approach requires communication between +Consumers/Administrators and OpenStack to pass through the shim-layer. The +shim-layer intercepts the message flow to manage the allocation requests based +on existing reservations and available capacities in the providers. It also +extracts information from the intercepted messages in order to update its +internal databases. Furthermore, Promise provides additional intent-based APIs +to allow a Consumer or Administrator to perform capacity management (i.e. add +providers, update the capacity, and query the current capacity and utilization +of a provider), reservation management (i.e. create, update, cancel, query +reservations), and allocation management (i.e. create, destroy instances). + +Detailed information about Promise use cases, features, interface +specifications, work flows, and the underlying Promise YANG schema can be found +in the Promise requirement document [#f1]_ . + +Promise features and API usage guidelines and examples +------------------------------------------------------ +This section lists the Promise features and API implemented in OPNFV Danube. + +Note: The listed parameters are optional unless explicitly marked as "mandatory". + +Reservation management +^^^^^^^^^^^^^^^^^^^^^^ +The reservation management allows a Consumer to request reservations for +resource capacity. Reservations can be for now or a later time window. +After the start time of a reservation has arrived, the Consumer can issue +create server instance requests against the reserved capacity. Note, a +reservation will expire after a predefined *expiry* time in case no +allocation referring to the reservation is requested. + +The implemented workflow is well aligned with the described workflow in the +Promise requirement document [#f1]_ (Section 6.1) except for the +"multi-provider" scenario as described in :ref:`multi-provider` . + +.. _create-reservation: + +*create-reservation* +"""""""""""""""""""" + +This operation allows making a request to the reservation system to reserve +resources. + +The operation takes the following input parameters: + +* start: start time of the requested reservation +* end: end time of the requested reservation +* capacity.instances: amount of instances to be reserved +* capacity.cores: amount of cores to be reserved +* capacity.ram: amount of ram in MB to be reserved + +Promise will check the available capacity in the given time window and in case +sufficient capacity exists to meet the reservation request, will mark those +resources "reserved" in its reservation map. + +*update-reservation* +"""""""""""""""""""" + +This operation allows to update the reservation details for an existing +reservation. + +It can take the same input parameters as in *create-reservation* +but in addition requires a mandatory reference to the *reservation-id* of the +reservation that shall be updated. + +*cancel-reservation* +"""""""""""""""""""" + +This operation is used to cancel an existing reservation. + +The operation takes the following input parameter: + +* reservation-id (mandatory): identifier of the reservation to be canceled. + +*query-reservation* +""""""""""""""""""" + +The operation queries the reservation system to return reservation(s) matching +the specified query filter, e.g., reservations that are within a specified +start/end time window. + +The operation takes the following input parameters to narrow down the query +results: + +* without: excludes specified collection identifiers from the result +* elements.some: query for ResourceCollection(s) that contain some or more of these element(s) +* elements.every: query for ResourceCollection(s) that contain all of these element(s) +* window.start: matches entries that are within the specified start/ +* window.end: end time window +* window.scope: if set to 'exclusive', only reservations with start AND end time + within the time window are returned. Otherwise ('inclusive'), all + reservation starting OR ending in the time windows are returned. +* show-utilization: boolean value that specifies whether to also return the + resource utilization in the queried time window or not + +Allocation management +^^^^^^^^^^^^^^^^^^^^^ + +*create-instance* +""""""""""""""""" + +This operation is used to create an instance of specified resource(s) for +immediate use utilizing capacity from the pool. *Create-instance* requests can +be issued against an existing reservation, but also allocations without a +reference to an existing reservation are allowed. In case the allocation +request specifies a reservation identifier, Promise checks if a reservation +with that ID exists, the reservation start time has arrived (i.e. the +reservation is 'active'), and the required capacity for the requested flavor is +within the available capacity of the reservation. If those conditions are met, +Promise creates a record for the allocation (VMState="INITIALIZED") and update +its databases. If no *reservation_id* was provided in the allocation request, +Promise checks whether the required capacity to meet the request can be +provided from the available, non-reserved capacity. If yes, Promise creates a +record for the allocation with an unique *instance-id* and update its +databases. In any other case, Promise rejects the *create-instance* request. + +In case the *create-instance* request is rejected, Promise responds with a +"status=rejected" providing the reason of the rejection. This will help the +Consumer to take appropriate actions, e.g., send an updated *create-instance* +request. In case the *create-instance* request was accepted and a related +allocation record has been created, the shim-layer issues a *createServer* +request to the VIM Controller (i.e. Nova) providing all information to create +the server instance. + +The operation takes the following input parameters: + +* name (mandatory): Assigned name for the instance to be created +* image (mandatory): the image to be booted in the new instance +* flavor (mandatory): the flavor of the requested server instance +* networks: the list of network uuids of the requested server instance +* provider-id: identifier of the provider where the instance shall be created +* reservation-id: identifier of a resource reservation the *create-instance* + +The Danube implementation of Promise has the following limitations: + +* All create server instance requests shall pass through the Promise + shim-layer such that Promise can keep track of all allocation requests. This + is necessary as in the current release the sychronization between the VIM + Controller and Promise on the available capacity is not yet implemented. +* *Create-allocation* requests are limited to "simple" allocations, i.e., the + current workflow only supports the Nova compute service and + *create-allocation* requests are limited to creating one server instance at a + time +* Prioritization of reservations and allocations is yet not implemented. + Future version may allow certain policy-based conflict resolution where, + e.g., new allocation request with high priority can "forcefully" terminate + lower priority allocations. + + +*destroy-instance* +"""""""""""""""""" + +This operation request to destroy an existing server instance and release it +back to the pool. + +The operation takes the following input parameter: + +* instance-id: identifier of the server instance to be destroyed + +Capacity management +^^^^^^^^^^^^^^^^^^^ +The capacity management feature allows the Consumer or Administrator to do +capacity planning, i.e. the capacity available to the reservation management +can differ from the actual capacity in the registered provider(s). This feature +can, e.g., be used to limit the available capacity for a given time window due +to a planned downtime of some of the resources, or increase the capacity +available to the reservation system in case of a planned upgrade of the +available capacity. + +*increase/decrease-capacity* +"""""""""""""""""""""""""""" + +This operations allows to increase/decrease the total capacity that is made +available to the Promise reservation service between a specified window in +time. It does NOT increase the actual capacity of a given resource provider, +but is used for capacity management inside Promise. + +This feature can be used in different ways, like + +* Limit the capacity available to the reservation system to a value below 100% + of the available capacity in the VIM, e.g., in order to leave "buffer" in the + actual NFVI to be used outside the Promise reservation service. + +* Inform the reservation system that, from a given time in the future, + additional resources can be reserved, e.g., due to a planned upgrade of the + available capacity of the provider. + +* Similarily, the "decrease-capacity" can be used to reduce the consumable + resources in a given time window, e.g., to prepare for a planned downtime of + some of the resources. + +* Expose multiple reservation service instances to different consumers sharing + the same resource provider. + +The operation takes the following input parameters: + +* start: start time for the increased/decreased capacity +* end: end time for the increased/decreased capacity +* capacity.cores: Increased/decreased amount of cores +* capacity.ram: Increased/decreased amount of RAM +* capacity.instances: Increased/decreased amount of instances + +Note, increase/decreasing the capacity in Promise is completely transparent to +the VIM. As such, when increasing the virtual capacity in Promise (e.g. for a +planned upgrade of the capacity), it is in the responsibility of the +Consumer/Administrator to ensure sufficient resources in the VIM are available +at the appropriate time, in order to prevent allocations against reservations +to fail due to a lack of resources. Therefore, this operations should only be +used carefully. + + +*query-capacity* +"""""""""""""""" + +This operation is used to query the available capacity information of the +specified resource collection. A filter attribute can be specified to narrow +down the query results. + +The current implementation supports the following filter criteria: + +* time window: returns reservations matching the specified window + +* window scope: if set to 'exclusive', only reservations with start AND end time + within the time window are returned. Otherwise, all reservation starting OR + ending in the time windows are returned. + +* metric: query for one of the following capacity metrics: + + * 'total': resource pools + * 'reserved': reserved resources + * 'usage': resource allocations + * 'available': remaining capacity, i.e. neither reserved nor allocated + +.. _multi-provider: + +(Multi-)provider management +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +This API towards OpenStack allows a Consumer/Administrator to add and remove +resource providers to Promise. Note, Promise supports a multi-provider +configuration, however, for Danube, multi-provider support is not yet +fully supported. + +*add-provider* +"""""""""""""" + +This operation is used to register a new resource provider into the Promise +reservation system. + +Note, for Danube, the add-provider operation should only be used to +register one provider with the Promise shim-layer. Further note that currently +only OpenStack is supported as a provider. + +The operation takes the following input parameters: + +* provider-type (mandatory) = 'openstack': select a specific resource provider + type. +* endpoint (mandatory): target URL endpoint for the resource provider. +* username (mandatory) +* password (mandatory) +* region: specified region for the provider +* tenant.id: id of the OpenStack tenant/project +* tenant.name: name of the OpenStack tenant/project + +.. [#f1] Promise requirement document, + http://artifacts.opnfv.org/promise/docs/requirements/index.html + +.. [#f2] YangForge framework, http://github.com/opnfv/yangforge + |