Changes between Version 45 and Version 46 of orca-introduction

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Timestamp:
05/09/11 21:17:53 (8 years ago)
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chase (IP: 71.65.215.83)
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  • orca-introduction

    v45 v46  
    1212Orca is based on the foundational abstraction of resource leasing. A lease is a contract involving a resource consumer, a resource provider, and one more brokering intermediaries. Each actor may manage large numbers of independent leases involving different participants. 
    1313 
    14 This document is meant to present a brief overview of ORCA arhictecture, principles and operation. For more information please refer to the ''Further Reading'' section below. 
     14This document is meant to present a brief overview of ORCA architecture, principles and operation. For more information please refer to the ''Further Reading'' section below. 
    1515 
    1616== Terminology == 
     
    1818 * Substrate - a collection of resources under specific administrative ownership. Examples of substrate are servers (virtualizable or not), network links, data sets, measurement resources.  
    1919 * Sliver - a smallest unit of some resource that is independently programmable and/or indepen- dently controllable in some resource-specific fashion. Each sliver is granted from a single substrate provider. An example of a sliver can be a Virtual Machine created inside a cloud of a specific provider. 
    20  * Slices are groupings of multiple slivers from multiple substrate providers. 
     20 * Slices are groupings of multiple slivers from multiple substrate providers.  Every sliver is allocated for exactly one slice. 
    2121 * Guest - a distributed software environment running within collection of slivers configured to order, possibly from different substrate providers. Some guests will be long-running services that require different amounts of resources at different stages of execution. The guests may range from virtual desktops to complex experiments to dynamic instantiations of distributed applications and network services. 
    2222 
     
    2828 * Authority or Aggregate Manager (AM). An authority actor controls access to some subset of the substrate components. It corresponds directly to the aggregate manager (AM) in GENI. Typically, an authority controls some set of infrastructure resources in a particular site, autonomous system, transit domain, administrative domain, or component aggregate comprising a set of servers, storage units, network elements, or other components under common ownership and control. Terminology note: the term ''site'' or ''site authority'' (e.g., a cluster site or hosting center) is often used to refer to a substrate authority/AM, as a result of our roots in virtual cloud computing. For network substrates we are using the term ''domain authority'' more often when it is appropriate. 
    2929 
    30  * Slice/Service Manager (SM) or Slice Controller. This actor is responsible for creating, configuring, and adapting one or more slices. It runs on behalf of the slice owners to build each slice to meet the needs of a guest that inhabits the slice. Terminology note. This actor was originally called a service manager in SHARP (and in the Shirako code) because the guest was presumed to be a service. As GENI has developed, we have adopted the term slice controller because the actor’s role is to control the slice, rather than the guest itself, and because in GENI the guest is an experiment rather than a service. Slice Manager (also SM) is also OK since the “controller” is properly speaking a plugin module to the actor itself.  
     30 * Slice/Service Manager (SM) or Slice Controller. This actor is responsible for creating, configuring, and adapting one or more slices. It runs on behalf of the slice owners to build each slice to meet the needs of a guest that inhabits the slice. Terminology note. This actor was originally called a Service Manager in SHARP (and in the Shirako code) because the guest was presumed to be a service. As GENI has developed, we have adopted the term Slice Manager (SM) because the actor’s role is to control the slice, rather than the guest itself, and because in GENI the guest is an experiment rather than a service. A Slice Controller is a plugin module to an SM actor, with a control policy for slices managed by that SM. 
    3131 
    32  * Broker. A broker mediates resource discovery and arbitration by controlling the scheduling of resources at one or more substrate providers over time. It may be viewed as a service that runswithin a GENI clearinghouse. A key principle in Orca is that the broker can have specific allocation power delegated to it by one or more substrate authorities, i.e., the substrate providers “promise” to abide by allocation decisions made by the broker with respect to their delegated substrate. This power enables the broker to arbitrate resources and coordinate allocation across multiple substrate providers, as a basis for federation and scheduling of complex slices across multiple substrate aggregates. Brokers exercise this power by issuing tickets that are redeemable for leases. 
     32 * Broker. A broker mediates resource discovery and arbitration by controlling the scheduling of resources at one or more substrate providers over time. It may be viewed as a service that runs within a GENI clearinghouse. A key principle in Orca is that the broker can have specific allocation power delegated to it by one or more substrate authorities, i.e., the substrate providers “promise” to abide by allocation decisions made by the broker with respect to their delegated substrate. This power enables the broker to arbitrate resources and coordinate allocation across multiple substrate providers, as a basis for federation and scheduling of complex slices across multiple substrate aggregates. Brokers exercise this power by issuing tickets that are redeemable for leases. 
    3333 
    3434[[Image(orca-arch.png, 600px)]] 
    3535 
    36 Authorities delegate resources to brokers (one authority can delegate resources to several brokers). Brokers hold the promised resources until Service Managers request them. Brokers issue tickets for resources from different authorities to a Service Manager and a Service Manager redeems those tickets at Authorities. Authorities instantiate the resource slivers and pass the control of them to the Service Manager. Pluggable control and access policies help mediate these transactions. Query interfaces allow actors to asynchronously determine the state of other actors.  
     36Authorities delegate resources to brokers (one authority can delegate resources to one or more brokers). Brokers hold the promised resources until SMs request them. Brokers issue tickets for resources from different authorities to an SM, which redeems those tickets at AMs (Authorities). AMs instantiate the resource slivers and pass the control of them to the SM. Pluggable control and access policies help mediate these transactions. Query interfaces allow actors to query the state of other actors.  
    3737 
    38 Slices are used to group resources together. A slice in a Service Manager represents resources owned by a particular user (e.g. for the purpose of an experiment). A slice in a Broker represents a portion of slivers given to a particular service manager slice from this Broker. If a Service Manager acquires resources from multiple brokers, they are not aware of each other. A slice in an authority represents the resources given by this authority to a particular service manager slice. Notice that architecturally in ORCA ''only the Service Manager knows the exact composition of the experimenter's slice''. All other actors may have only a partial view of the experimenter's slice.  
     38Slices are used to group resources together. A slice in a Service Manager represents resources owned by a particular user (e.g. for the purpose of an experiment). If a Service Manager acquires resources from multiple brokers, they are not aware of each other. A slice in an authority represents the resources given by this authority to a particular service manager slice. Notice that architecturally in ORCA ''only the Service Manager knows the exact composition of the experimenter's slice''. All other actors may have only a partial view of the experimenter's slice.  
    3939 
    4040== Naming ==