Lawrence Livermore National Laboratory Gary Kumfert UCRL-PRES-235389 Lawrence Livermore National...

Lawrence Livermore National Laboratory

Gary Kumfert

UCRL-PRES-235389

Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, CA 94551

This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344

Top Ten Reasons Why The CCA Specification Is NOT Ready for 1.0

11 October, 2007

2UCRL-PRES-235389 Gary Kumfert, LLNL


Motivation

Yes, this is a David Letterman-style “Top 10 List”• It is meant to be fun• But there are real issues that need to be addressed

Each item will...• have a 1-2 slide explanation• recommend actions

Expect many other issues to come out• all issues will be captured/tracked • on a wiki or Roundup or some combination



Top 10 Reasons: Why CCA Is Not Ready For 1.0

10. Need to Implement CCA Review Board & Maturity Model




Motion 53 on Quorum • Passed Unanimously on May 8, 2007

1. Establishes a multi-stage specification maturity process

2. Institutes ad hoc task forces with charters, lifespan, documentation trail and named chair

3. Creates CCA Review Board (CCARB) to oversee quality of the specification and constitute & dissolve task forces

Motion 54 on Quorum now:

• Approves CCARB nominated by the Chair• Posted & Seconded Oct 2, 2007• Voting Ends Oct 23, 2007



Stages Of Specification Maturity


Completion Criteria:• Actually seat a CCARB• Have at least one task force go through entire process (Not

EventServices, which is too far ahead)• Have CCARB & histogram of all task forces (past and present)

accessible from cca-forum.org

Env & Toolkit Groups

Initiatives & Internal Apps

Tutorial & Outreach

TaskForce IdeaDraft

CandidateFinal




9. SIDL Spec Should Not Be Preprocessed by Autoconf




9. SIDL Spec Should Not Be PreProcessed By Autoconf

Proposed Changes:• Abandon pre-Babel 1.0 compatibility• Abandon “variable version” specifications• Rename files to cca-v.v.v.sidl• Post all official versions prominently on cca-forum.org

@GOVCCA_SIDL_START_0@

package gov {

/** Common Component Architecture. ... */

package cca version @CCASPEC_VERSION@ {




...

cca-spec-babel/cca.sidl.in




8. Exceptions Need Redesign






Enumerated error codes are poor design• Classic C++-tran• Not extensible

CCAException clutters almost every method signature Proposed Changes:

• Develop a hierarchy of exception types that are meaningful• Incorporate Babel’s implicit sidl.RuntimeException• Let BabelRMI worry about the Network Errors

enum CCAExceptionType {

Unexpected=-1, Nonstandard=1, PortNotDefined=2,

PortAlreadyDefined=3, ..., NetworkError=12 }

interface CCAException extends sidl.BaseException {

CCAExceptionType getCCAExceptionType();

}cca-spec-babel/cca.sidl.in




7. Need EventService, CommandLineService, & MPIService







These are all year 1 deliverables for TASCS EventService – on track

• Chair: Steve Parker• Blocked by CCARB formation

MPIService – stalled• Need a Chair• de facto implementations exist in frameworks

CommandLineService – stalled• Need a Chair• Needed by

MPIService (probably) Python? possible see Babel Issue 530




6. Replace Parameter{Get,Set}Listener & ConnectionEventService With EventService When It Passes







6. Replace Parameter{Get,Set}Listener & ConnectionEventService With EventService

We already have event-like services specific to• When port connections are made and broken• When parameters are set or read from

ParameterPort

Proposed Changes• Simplify spec by making all events through

EventService• Demonstrate EventService handling these system

events in a framework before final approval




5. Parameter Port Is Too Complex









158 methods Entire CCA 0.8.2 specification• 66 methods – core spec• 92 methods – ports

63 methods are just for ParameterPort & friends.

01

111122

385

4112

12

171233

3523

11

0 10 20 30 40

PortCCAException

ServicesComponent

ComponentReleaseComponentID

TypeMismatchExceptionTypeMap

AbstractFrameworkConnectionID

ComponentClassDescriptionGoPort

ConnectionEventConnectionEventListenerConnectionEventService

BuilderServiceComponentRepository

ServiceProviderServiceRegistry

BasicParameterPortParameterPort

ParameterPortFactoryParameterGetListenerParameterSetListener

# Methods Per SIDL Interface

Core

Spec




4. Need Concept of a SubAssembly









4. Need Concept of a Subassembly. Including Multiplicities, Nests, & Interconnects

Provides a Recursive Composability Model for Components

Component 2

Port 3 Port C

Component 1

Port 2 Port B

Port 1 Port A

Component 2

Port 5

Port 4 Port D

SubAssembly 1

SubAssembly 1

Port 3 Port D

Port 1 Port A

Two views of

the same thing




3. Comments Are Long, Inconsistent, Out-of-Sync, Occasionally Wrong, & Sometimes Even Snide











/** ... This version of the Port is so simple that mere mortal component writers could implement it...

*/

Describing BasicParamterPort

/** ...

* ::gov::cca::Services_Interface *svc = 0;

* svc = fwk->getServices( “instance0”, “AppDriver”, 0);

*/

A supposed C++ example in AbstractFramework’s doc-comment.

40 Line Introduction to ParameterPort

Doccomments appearas: • plain text • Javadoc • HTML.

createInstance( ... gov.TypeMap properties);

setComponentProperties( ..., gov.TypeMap map); }

Inconsistent naming conventions (e.g. from BuilderServices)




2. CCA Conformance is Under-Defined











Finding right balance between “inclusive” and “technically meaningful.”• Distributed Frameworks• CCA-Lite• The Rogue Ruby Implementer

Proposed Changes:• Define some hierarchy of conformance• Commit to some consistent vernacular that audience will

understand

•

2. CCA Conformance is Under Defined

“Compliance” to technical specification implies expectation of: • “interoperability” (e.g. IPv4, USB 1.1, 802.11g, etc.), or at least • “compatibility” (e.g. at source code level: MPI or POSIX).

“CCA-Compliant” should not deviate from this norm.




1. CCA Manual












1. CCA Manual

THE COMMON COMPONENT

ARCHITECTURE

Completely revised for1.0 standards compliance

IN A NUTSHELLThe Official Guide

O’SMILEY

1 st Edition

Over a dozen copies in print

Fission Ares and Crag Pottswith A. Lotta Uddavolks



So What Now?

Proposal• Gathering these 10, plus many others • CCARB should decide on Roundup, wiki, or both

More Info:• Understanding the CCA Specification through Decaf

(in process of updating to CCA 0.8.2 & Babel 1.0)




1. CCA Manual










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