14 October 2002GGF6 / CGS-WG1 Working with CIM Ellen Stokes

14 October 2002GGF6 / CGS-WG2 Agenda CIM refresher Managed Object Format (MOF) –What is MOF –Working with MOF Model guidance Extending the CIM schema Using a CIMOM Mapping CIM to other representations –XML –LDAP

14 October 2002GGF6 / CGS-WG3 CIM Refresher CIM is one of the approaches in the industry for enabling the management of real world managed objects 4 pieces –Modeling language and syntax (MOF – Managed Object Format –Management schema (core, common, extension) –Protocol to encapsulate syntax and schema (XML/HTTP) –Compliance document, but no test suites CIM object managers (CIMOM) are implementations, but not part of the CIM standard –The Open Group’s Pegasus project is producing a CIMOM reference implementation jointly with DMTF Interop WG API for CIMOM access by applications (by The Open Group)

14 October 2002GGF6 / CGS-WG4 Managed Object Format (MOF) Modeling Language & Syntax Meta schema is formal definition of the model –Terms are defined to express model, usage, and semantics –Constructs class (abstract, concrete, association), property, method qualifiers, references, initializers, instance declarations compiler directives (locale & namespace info) Managed Object Format (MOF) is the language used to describe management information – –Textual form –Derived from IDL (Interface Definition Language) from The Open Group –Can be encoded in Unicode (UCS-2) or UTF-8

14 October 2002GGF6 / CGS-WG5 ManagedElement (in MOF) // ================================================================== // ManagedElement // ================================================================== [Abstract, Version ("2.7.0"), Description ( "ManagedElement is an abstract class that provides a common " "superclass (or top of the inheritance tree) for the " "non-association classes in the CIM Schema.") ] class CIM_ManagedElement { [MaxLen (64), Description ( "The Caption property is a short textual description (one-" "line string) of the object.") ] string Caption; [Description ( "The Description property provides a textual description of " "the object.") ] string Description; [Description ( " A user-friendly name for the object. This property allows " "each instance to define a user-friendly name IN ADDITION TO its " "key properties/identity data, and description information. \n" " Note that ManagedSystemElement's Name property is also defined " "as a user-friendly name. But, it is often subclassed to be a " "Key. It is not reasonable that the same property can convey " "both identity and a user friendly name, without inconsistencies. " "Where Name exists and is not a Key (such as for instances of " "LogicalDevice), the same information MAY be present in both " "the Name and ElementName properties.") ] string ElementName; };

14 October 2002GGF6 / CGS-WG6 Working with MOF MOF is text No tools available to help create MOF –Disregard the MOF Editor located at the tools URL below – it doesn’t work Use your favorite text editor Read the CIM spec; look at examples Use the existing CIM schema as template for developing your schema Use a MOF compiler to check for syntax errors (Intel CIM compatibility checker) – CIM certification test suite beta release (use same tools URL above)

14 October 2002GGF6 / CGS-WG7 Model Guidance Understand what’s already modeled –Mostly at structural, device, and OS levels –Current schema doesn’t do cluster and distributed environments justice Model managed/manageability information; if it’s not useful for management, then don’t model it Remember CIM normalizes everything (small pieces) and defines relationships between all the pieces; follow suit Don’t assume that your schema automatically subclasses from managedElement (the root of all CIM schema) just because you’re developing a new schema –Reuse, subclass from, and integrate with existing schema elements Use a UML tool to do schema design –Visualization helps to show how your new schema fits with existing CIM schema Above all, there is no right or wrong way – modeling is an art!

14 October 2002GGF6 / CGS-WG8 Extending the CIM Schema Subclass from existing schema –CIM provides basic building blocks, for example, there is job schema from which the job submission interface model can be derived Reuse properties Integrate with existing models –May require changes to existing schema –Try to limit to no changes, but if changes needed, use the ‘deprecated’ qualifier to indicate how changed Use the existing qualifiers: –‘experimental’ to delineate what new and may change until firm –‘version’ to indicate from CIM version this new schema is built Qualifiers provide a way to introduce additional semantics –But beware, other systems will ignore these extensions if they don’t recognize them (but won’t crater system) Don’t add new data types – this breaks CIM compatibility –Can sometimes add new data type by introducing a new qualifier, for example, octetstring, to further qualify the format of a string property

14 October 2002GGF6 / CGS-WG9 Management Environment CIM Object Manager HTTP Server provider … Management Application Resources Schema + instance repository CIM/HTTP Operations Provider interface Pegasus, SNIA

14 October 2002GGF6 / CGS-WG10 Using a CIMOM Download Pegasus and follow instructions

14 October 2002GGF6 / CGS-WG11 Mapping: CIM to XML A Metaschema Mapping in which the XML schema is used to describe the CIM metaschema, and both CIM classes and instances are valid XML documents for that schema. –CIM DTD is used to describe in a generic fashion the notion of a CIM class or instance. CIM element names are mapped to XML attribute or element values, rather than XML element names. –MOF is encapsulated in XML so there is no additional work to describe new/changed CIM schema in XML. CIM/XML spec – Example CIM/XML – and locate link for xml representation of CIMv2.7http:// Tool to generate XML representation –

14 October 2002GGF6 / CGS-WG12 Mapping: CIM to LDAP DEN/DSP0100.pdfhttp:// DEN/DSP0100.pdf Not one-size-fits-all, but rather a set of guidelines / alternatives / strategies for mapping CIM to LDAP –Classes –Associations –Data types