Glossary - Appistry EAF v3.8

Affinity	Affinity can be used by those applications that need some control over which worker runs the action code of the process flow. For example, the code may need access to hardware/software that is installed on a limited set of workers, or a limited number of workers have a cache of information whose construction is expensive. Affinity strategies are implemented by the fabric application developer as fabric tasks or components, and executed in the context of a process flow which uses the strategy to direct user code execution to the correct or best-fit worker.
Application Fabric	An application fabric is the layer between the application, the operating system, and hardware formed by Appistry EAF. This layer allows the application fabric developer to develop to a single, logical entity, regardless of the physical implementation and configuration of the system. The application fabric developer also does not need to focus on fail-over and fault-tolerance issues.
Assimilation	Assimilation is the process of installing a worker's operating system, drivers, or fabric system files. The fabric does this through the use of an external PXE server.
Background Task	A background task is a task that is constantly running, waiting for work, and is not called from a process flow.
Bean	Beans are reusable software components. Practically, they are classes written in the Java programming language conforming to a particular convention. They are used to encapsulate many objects into a single object (the bean), so that the bean can be passed around rather than the individual objects.
Client	A client is any application, residing inside or outside the fabric, that makes processing requests to the fabric.
Component Definition	A component definition enables Fabric developers to use their existing Java classes (POJOs) or Spring beans in the Fabric with no code changes. Developers can either call these components remotely using Fabric Spring remoting, or reference these components from process flow states to define the activity to be executed by the Fabric. The methods available to the Fabric can be explicitly defined or automatically discovered by reflection. Component definitions are a great alternative to Task definitions, but can only define Java objects.
Deploy	Deploy is the process of adding a new or updated application or configuration file to the fabric.
Exclusive	An exclusive task or component is typically resource intensive user code. For example, perhaps it takes several seconds or more, and/or consumes 80% to 100% of a worker's CPU. By declaring such a task or component as exclusive, the fabric application develop can specify that only a certain number of these tasks or components can run concurrently on each worker across the fabric.
FAR File	refer to Fabric Archive
Fabric Accessible Memory	The Fabric Accessible Memory is fabric-based storage for applications to maintain and share data for inter-fabric requests.
Fabric Archive	A Fabric Archive file, far file, is a versioned package containing java archives (jar/zip files), native code dynamic libraries (dll/so files) and other support files that can be shared between several fabric applications. This package is deployed to a running fabric. In addition, libraries listed in the far XML file will be visible to any fabric application that references that far file in its fabric application definition XML. Java jars listed in the java-libs element will be seen by the fabric application's Java class loader. Native dynamic libraries listed in the libs element will be loadable by the fabric application.
Fabric Application	A fabric application consists of a collection of process flows and tasks. It is ideally suited for service-oriented or transactional applications. The fabric application uses a compensating transaction model for ensuring the reliability of accepted requests.
Fabric Control	The fabric_ctl utility is a command line client that enables you to start and stop the entire fabric or a single worker, deploy applications and configuration files, retrieve configuration files, check the versions of fabric services and deployed applications, and query the status of the fabric and its workers.
FabricIdentifier	A FabricIdentifier is the name (or Id) given to an item in an application's XML. FabricIdentifiers are arbitrarily long sequences of alphanumeric characters (upper or lower case), hyphens (-), and underscores (_). They are case sensitive.
Fabric Keeper	The fabric keeper coordinates the distribution of new applications, application and configuration file updates, fabric system updates, operating system updates. The fabric keeper exists on all workers.
Fabric Monitor	The Fabric Monitor is a flash-based application that displays the current status of a fabric, including CPU, TPS, and worker status. Additionally, fabric region organization and detailed worker information is displayed.
Fabric Package	The fabric_pkg utility is a command line client that enables you to validate a fabric application and bundle it's files into a deployable fabric application package. Additionally, you may extract the contents of a fabric application package, or view the package contents.
Fabric User	The fabric_user utility is a command line client that enables you to add or remove user accounts to a fabric.
Fabric Worker Manager	The fabric worker manager coordinates the processing of the fabric and handles load balancing. The fabric worker manager exists on all workers to watch over the proper execution of requests and tasks.
Limited	A limited task or component is user code that the developer specifies only a certain number of instances can across an entire fabric at one time. This might be done, for example, to protect a shared resource like database connections, etc.
Log Monitor	The log_monitor utility is a command line tool that captures and displays MCAST traffic from a fabric and displays messages generated by the fabric.
Process Flow	A process flow is a declarative model of a set of activities that are to be exposed (published) by the fabric.
Process Handler	A process handler is a service running on worker. The process handler receives the request from the request handler locates task handlers to process the tasks watches the task handler's health ensures tasks are performed in the correct order determines if a task should be retried
Processing Region	A processing region is a logical grouping of workers that process requests. The maximum and minimum number of workers in a processing region is set in the fabric.cfg file. Each fabric has at least one processing region.
Region	A region is a logical grouping of workers that limit the amount of network traffic within the fabric. When a request enters the fabric, the request goes to the workers within one region and all available workers in that region offer to process the request.
Request	A request is a computing task submitted to the fabric for processing.
Request Handler	A request handler is a service running on a worker. The request handler receives requests from the client locates a process handler to process the request watches over the health of the process handler returns the result to the client
Request Region	A request region is a logical grouping of workers that listen for requests from a client and locates a worker to process the request. A fabric has only one request region. The maximum number of workers in the request region is set in the fabric.cfg file. Each fabric has at least one worker listening for requests from a client.
Spread	When you Spread something to the fabric, you distribute the file to each worker. The fabric is treated as one entity rather than individual workers, therefore if you give a file to one worker, you will be giving it to all the workers.
Spring Framework	The Spring Framework (or Spring for short) is an open source application framework for the Java platform.
Task	A task is the smallest unit of work within a fabric application. A task does not maintain a state of its own and is called by the task handlers.
Task Handler	A task handler is a service running on a worker that processes tasks.
Test Fabric	A test fabric is a small fabric that was segmented from the production fabric. A test fabric allows you to test all aspects of the application, including possible conflicts with existing fabric applications, before placing the application in the production environment.
Unlimited	An unlimited task or component is user code that any number of instances can run in a fabric on any worker at one time.
Update	Update is the process of installing a new or updated application or configuration file on each worker.
Worker	A worker is a single computer that works as a processing node within the fabric. The worker is dedicated to the fabric. No other applications run on a worker. A worker can be in only one fabric at a time. Workers in a fabric are not required to be located at the same site. Workers in the same fabric must run the same operating system, however, they are not required to be configured identically.