ESO - Garching 08 – 09 March, st ALMA Common Software Workshop ACS Container/Component Model

ALMA Project 2Garching, March 20041st ALMA Common Software Workshop Container/Component ACS container Comp My container starts and stops me and offers its services, some of which I don’t notice I only care about the Lifecycle IF of my components ACS containers in Java, Python, C++

ALMA Project 3Garching, March 20041st ALMA Common Software Workshop Component Deployable unit of ALMA software 1…many components per subsystem Functional interface defined in CORBA IDL Deployed inside a Container Well-defined lifecycle (initialization, finalization) Accessible as a plain CORBA object if required Focus on functionality with little overhead for remote communication and deployment Similar ideas in EJB,.NET, CCM

ALMA Project 4Garching, March 20041st ALMA Common Software Workshop Container Centrally handles technical concerns and hides them from application developers –Deployment, Start-up –Selection und configuration of various ORBs; here CORBA alone is much too complicated. –Selection of CORBA Services, integration with ACS Services (Error, Logging, configuration, …) –Convenient access to other components and resources New aspects will be easily integrated in the future, w/o modifying application software

ALMA Project 5Garching, March 20041st ALMA Common Software Workshop Interfaces container Comp CORBA ORBs Services lifecycle interface: init() run() cleanUp() Comp functional interface: observe() container service interface: getComponent(“other”) Logger getLogger() other ACS services Manager deployment configurations

ALMA Project 6Garching, March 20041st ALMA Common Software Workshop Tight vs. Porous Container por. container tight container Comp CORBA, ACS services Comp functional interface is intercepted by container, for logging/exception handling, security, … container manages Lifecycle and offers services, but exposes the component’s functional interface directly – less overhead

ALMA Project 7Garching, March 20041st ALMA Common Software Workshop Interactions (component activation & retrieval) C++ Container Cmp2 Cmp1 CDB deployment configurations Java Container Cmp4 Cmp3 Container IF Manager Manager IF (2) which container can run “myComp”? (0) login (3) activate(“cmp4”) returns a reference to that component (1) get(“cmp4”) Container IF CORBA stubs and skeletons are everywhere, but not shown…

ALMA Project 8Garching, March 20041st ALMA Common Software Workshop Interactions (Administration) CDB deployment configurations Container Comp2 Comp1 Cont. IF Manager Manager IF Object Explorer Client IF Admin Client Client IF IF Repository knows component IFs Generic client for any component, allows to call IF methods All about clients, containers, components