Charles Yang

CS370

Second Assignment

11/14/2011

Slice-Based Facility Architecture

After first time reading of SFA (Slice-Based Facility Architecture), I still can’t understand SFA. This is a hard topic, but I got some of ideas after reading over few times. Also I think SFA is a great system to work on when we try to do programming and it gives covers everything of basic concept we need to know. Those concepts also can become more complex when we move to next level, but it gives general ideas that show functional part of SFA. In addition, SFA is something like UML and RMI that we did in the class. In conclusion, the SFA is taking about its principle, usages and users to run the SFA systems.

The SFA has four users, owners, operators, researchers (and developers) and principle investigators. Owners are like an owner of a website who has creates the rule of its website and force all website visitors to follow the rule, so it is the top user in the system. For example, to create a network that connects different people from all over the world together. Operators are playing the role of the owner’s worker who helps to keep website updated and running well. Because the limit of workers, the owner also the play the role of operators. Researchers are kinds of complicate in it role because its can do jobs from operators and other’s job. There are simple ways to explain which it is likes a forum manager who keep the forum running well and he also can add/delete some function by higher-level’s permit. Then the investigators are using for verifying the researchers.

The most important two key abstractions defined by SFA are components and slices. A component is uses to collect resources like CPU or memory and controlled by component manager which defines the functions for users and manages the allocation of resources to different users. A slice is distributed set of virtual machines resources, and working in a combined mode continuously. Also each slices, there only run a service or an application. The slice is only work in the name that bound to a group user, which means those services will be runnable by calling the name of those slices. The slice must be registered and connect to the users before it instantiated and instantiated be running. We one have to register the slice once and the set of user can change anytime. This is kind of like the RMI registry that we have to open and put it available for user once, and the users can be acceptable to the RMI server and running the code. In addition, there are two different respective. The way of showing the services operation is available on the researchers. Second, the consumers of the service (operator) have to show what services run on here. In general, the slice is like the function or the method in the java that we can call it by its name.

The SFA defines three principals which are management authority, slice authority and user. A management authority is the service provider that has to be stable and acceptable by the policies. A slice authority is the response of the service in each slice and behaves appropriate. A user is playing in one or more role to run in the server. For example, a researcher wants to test the service in a slice. Or an operator wants to manage some services under a slice.

The SFA defines global identifiers (GID) are the set of objects that makes up the system. GIDs form a basis for a correct and secure system that conform the GID is acceptable to process. For example, it is like a method caller with the parameters in java language.

GID = (PublicKey ABC, Lifetime)

This is a simple GID that holds the private key corresponding to PublicKey in the GID. ABC is Universally Unique Identifier and it stays the same as PublicKey and it will change as PublicKey change. The Lifetime tells people how long do this GID valid, because GID needs to refresh periodically. In this case, we can use PublicKey and ABC in different functionalities. We can change PublicKey rather than ABC to imply that all objects under PublicKey change. In details, if we change ABC, other PublicKey wont changes but others change when we change PublicKey.

. A registry maps human-readable names (HRN) to GIDs, and others to reach specific object. Furthermore, a registry is like a website address that can call the website and the link to access the method. Also it can use with different level of that website like an administrator or a user. The global registry is the entire of the registry information. The authority registry is just one level of the global registry corresponding to a slice. And a registry severs who insert the new authority register.

The registry of SFA is “kind of similar” to the registry of RMI. They both have registry. In the SFA proposed, a resource could be a Java functional method exposed for an external call via Java RMI (Remote Method Invocation), a software/hardware interface, a software/hardware processing unit for signal processing. Therefore to access the Java RMI server registered through the Java RMI client stub and Java rmiregistry. RMI allows the RMI server side resource be called by the RMI client side stub. As the RMI client stub can be repeated and the distribution of different locations, which is equivalent to a presence in different locations of resources point. Also the Java Socket added security feature which make RMI more secure. BioAPI architecture framework is basically a resource as services which can be found mostly rely on a registry registration services.

The SFA defines four key data types in addition to GIDs

• A resource specification (RSpec): it tells us what the resource is clearly.

• Registry Record: it uses the facts about the object of system.

An example from SFA PDF:

Record = (HRN, GID, Type, Info)

Where HRN and GID are as defined in Section 4,

Type = SA | MA | Component | Slice | User

And

Info = (PI [ ], Organization), if Type = SA

Info = (Owner [ ], Operator [ ], Organization), if Type = MA

Info = (URI, LatLong, IP, DNS), if Type = Component

Info = (URI, Researcher [ ], InitScript), if Type = Slice

Info = (PostalAddr, Phone, Email, AuthTokens[ ]), if Type = User

• Ticket: is “issued” by component to bind resource to ticket holder at some point in time. Also it may change back or split (passing resource to another).

• Credentials: a credentials allow user to give more specification in a slice

The interface is the main function in the SFA and we have three different term:

• Registry Interface: Has six operations. Those are uses to pass the message from different actors with return of credential.

Register (Credential, Record)

Remove(Credential, Record)

Update(Credential, Record)

Record = Resolve(Credential, HRN, Type)

Record[ ] = List(Credential, HRN, Type)

Credential = GetCredential(Credential, HRN, Type)

• Slice Interface: After the slice register, every user will have right to use the operation on components to instantiate and provision the slice

> Instantiating a Slice: four operations: we can create and delete a slice of ticket.

GetTicket(Credential, RSpec)

RedeemTicket(Ticket)

ReleaseTicket(Ticket)

CreateSlice(Credential, RSpec)

> Provisioning a Slice: we can split ticket without being encapsulated in a ticket and update a slice.

NewTicket = SplitTicket(Ticket, GID, RSpec)

LoanResources(Credential, GID, RSpec)

UpdateSlice(Credential, RSpec)

• Controlling a Slice (four control operations): all four operations are with the credential as the parameter. The stopslice is to delete the slice and stop all running threads. Startslice is to reboot a slice. And Resetslice is just deleting and re-create the slice. Last Deleteslice is for delete a slice.

StopSlice(Credential)

StartSlice(Credential)

ResetSlice(Credential)

DeleteSlice(Credential)

• Slice Information (three informational operations): three operations to get the information of a slice.

SlicesNames[ ] = ListSlices(Credential)

RSpec = ListComponents(Credential)

RSpec = GetSliceResources(Credential)

• Component Management Interface is use to configure component and support the interface.

SFA is an open and worldwide to allow users to easily access the resource over the network. Also access the local components and facility.