Journal of Network and Systems Management, Vol. 7, No. 1, 1999

1064-7570 / 99/ 0300-0127$16.00 / 0 Ó 1999 Plenum Publishing Corporation

127

Report

Edited by Paul Brusil

An Enterprise CORBA Application ManagementArchitecture

Conor Doherty1 and Thomas Usl Èander1

1. INTRODUCTION

The Common Object Request Broker Architecture (CORBA) [1] is a set of speci-

® cations by the Object Management Group (OMG) that de® nes inter-operability

of objects written in different languages and executing on different operating

systems. Object Request Broker (ORB) un-manageability has tended to restrict

deployments of enterprise CORBA-based applications [2].

This article reports on the results of the European Strategic Program in

Research and Development of Information Technology (ESPRIT) Management

Services for Object Oriented Distributed Systems (MAScOTTE) project [3].

MAScOTTE developed an architecture and facilities for management of multiple

vendor ORBs and CORBA applications. To support vertically integrated enter-

prise network, system, and CORBA application management, the MAScOTTE

CORBA management facilities are easily integrated with network and system

management applications via a Simple Network Management Protocol (SNMP)

or a Common Management Information Protocol (CMIP) gateway. The MAS-

cOTTE management facilities and a CMIP gateway have been implemented and

veri® ed in a video-on-dem and application.

2. CORBA MANAGEMENT ARCHITECTURE

The MAScOTTE CORBA management architecture supports management

of CORBA object services, common facilities, application objects, and ORB core

[1]. See Fig. 1. Application objects, services and facilities are managed by the

management of the objects that provide their principal interfaces. Principal inter-

faces are extended by appropriate operations that grant access to management

1 Fraunhofer-IITB, Fraunhoferstrasse 1, D-76131, Karlsruhe, Germany. E-mail: {doherty,us1}@iitb.

fhg.de

Doherty and Usl Èander128

information and realize control of managed objects. Extensions are achieved by

single inheritance of managed information interfaces by the objects. In our work

we have de® ned the term CORBA Managed Object (CMO) to mean special

objects used for management purposes and an object whose interfaces have been

extended with management interfaces.

The MAScOTTE management architecture is based on management facili-

ties that may be accessed directly by a pure CORBA-based management appli-

cation or via CMIP or SNMP gateways. The management architecture does not

support CORBA based management of SNMP or CMIP agents.

We have de® ned CORBA Management facilities as the common facilities

that provide management information and management control procedures to

management applications to enable them to monitor and control CMOs. CMOs

are organized into a Management Information Base (MIB) that is accessed by a

management application using management protocol requests to CORBA man-

agement facilities. The CORBA MIB contains information on clients, servers,

object implementations, object types, object instances, object request broker

core, (basic) object adapters, and connection resources.

CORBA management facility interfaces are de® ned for fault (e.g., object

destruction event), performance (e.g., request rate per second to a server), and

Fig. 1. The MAScOTTE CORBA management architecture.

CORBA Application Management Architecture 129

con® guration (e.g., ® le system path to server binary) management of appli-

cations and ORB infrastructure. Management information is provided to the

management facilities via CORBA operation calls to CORBA management

agents.

2.1 Scaleable CORBA Management Information Base

The CORBA MIB structure is based on an object decomposition and an

object re® nement hierarchy. While an ORB provides distribution transparency

for remote pointers, an ORB is composed of segments of micro-kernel attach-

ments and/ or stubs connected to processes running on different processors. Man-

aging an ORB requires management of these ORB segments. The CORBA MIB

is decomposed into ORB segments. Each ORB segment has an ORB core seg-

ment, an Object Adapter segment and application component. The following

types of CMOs are contained in the CORBA MIB:

ORB infrastructure managed objects:

ORB core composed of instances of ORB core segments,

ORB core segment de® ned by a machine boundary,

object adapter composed of instances of object adapter segments,

object adapter segment de® ned by a machine boundary.

CORBA application components:

object instance container (e.g., a basic object adapter),

application object type,

application object instance.

The CORBA MIB is designed to map to CMIP concepts (for scaleability).

The CORBA MIB supports vertically integrated enterprise network, system, and

CORBA application management. The class structure of the MIB is based on

a combination of the above CORBA MIB containment class hierarchy with the

managed sets interfaces de® ned in the X /Open Common Management Facilities

speci® cation. The root class of the MIB is a managed set member class. The

managed sets set class provides operations for creation of hierarchical sets of

CMOs from the MIB member classes.

In addition to the hierarchical ORB segment and CMO type decomposition

hierarchy, a MIB re® nement hierarchy provides a mechanism to specify different

re® nement or scope levels of a management information processing context to

support horizontal CORBA management integration. Vendor-speci ® c implemen-

tation management information is integrated by inheritance from the standard

MIB decomposition class hierarchy. This extends a standard CORBA MIB to a

vendor-speci® c enhanced CORBA MIB.

Doherty and Usl Èander130

2.2. CORBA Agent Facility

The CORBA agent facility provides access to the CORBA MIB structure

of CMOs for object instances, servers, clients, ORB core and object adapters

from information received from CORBA management agents communicating

with instrumented ORBs and CORBA applications. Object management infor-

mation is exposed to CORBA management agents by the CMO Interface Def-

inition Language (IDL) interfaces. The CORBA agents store attributes of the

CMOs and containment relationships between them and implement CMO man-

agement operations.

2.3. Noti® cation and Logging Facility

The noti® cation and logging facility provide ® ltering and logging of man-

agement events on top of the CORBA event service. The noti® cation facility

provides synchronous noti® cation of management events between event suppli-

ers and event customers. Management event customers may specify event ® lters.

Events are automatically logged by the noti® cation facility and event logs may

be browsed by clients. The noti® cation facility supports pre-de® ned event types

for object creation /deletion, threshold, exception, and application failure events.

2.4. Application De® nition Facility

The application de® nition facility supports the de® nition and con® guration

of CORBA applications. When an application is installed the application de® ni-

tion facility inserts information on the installed instances of objects, the proces-

sors on which they are installed and any attribute values (e.g., installation path)

set during the installation into object descriptions. When the application is exe-

cuted, the application de® nition facility compares the static object description

with the dynamic model of CMOs provided by the CORBA agent to determine

if objects of an application are correctly loaded on processors.

2.5. Discovery Facility

A CORBA discovery facility reads the containment hierarchies of all

instances of the CORBA agent, usually one per processor. The facility enables

a management application to update its view of currently existing CMOs. The

facility is also used during initialization of the CMIP to Internet InterORB Pro-

tocol (IIOP) gateway in order for the gateway to construct the CMO graph.

CORBA Application Management Architecture 131

2.6. CMIP to IIOP Gateway

To demonstrate vertical integration of enterprise CORBA application man-

agement with enterprise system and network management tools, a prototype

CMIP to IIOP MIB translation gateway was implemented for Bull’ s OpenMaster

system management platform [3]. The gateway translates Common Management

Information Service (CMIS) operations into IDL calls on CMOs.

The gateway arranges the CMOs in a hierarchical MIB containment tree that

supports scoping of a search CMO sub-tree root, scoping of search depth and

level, and ® ltering by assertions about values of attributes in scoped CMOs. The

gateway transfers CMO operation and noti® cation information, provides struc-

turing facilities to enable operations to be performed on multiple CMOs, and

supports multiple responses to con® rmed linked operations.

3. CONCLUSIONS

The CORBA management architecture was demonstrated on December 17,

1997 by management of a video-on-demand pilot at the Centro Studi e Labora-

tori Telecomunicazioni (CSELT) in Turin, Italy. The CSELT video-on-dem and

application pilot was based on Digital Audio-Visual Council and Telecommuni-

cations Information Networking Architecture (TINA) standards. In the demon-

stration, Iona Technologies’ Orbix CORBA product was instrumented and man-

aged by Bull OpenMaster system management product. The Orbix instrumenta-

tion formed the basis for the subsequent release of the OrbixManager product.

The demonstration tested the gateway, agent, facilities and instrumentation on

an operational system with ten servers. Several fault recovery scenarios were

demonstrated.

The architecture and facilities are being adopted by TeleManagement Forum

(formerly the Network Management Forum) in a Telecommunications Network

Management Application Component project. This project aims to develop mod-

ular network management functionality using Bellcore Intelligent Network archi-

tecture principles of loosely coupled distributed computing over CORBA. The

management architecture and facilities are also being incorporated into the spec-

i® cation of the Advanced Information Technology (AIT) for European manufac-

turing industry integration platform.

ACKNOWLEDGMENTS

We are grateful to our colleague Hajo Brunne Fraunhofer-IITB and to our

partners in Bull, European Space Agency, Mari, Iona Technologies and CSELT

for carrying out much of the work described in this report in ESPRIT project

20804.

Doherty and Usl Èander132

REFERENCES

1. Object Management Group, The common object request broker / internet inter-operability protocol

2.2 speci® cation, February 1998. http: / / www.omg.org / corba / corbaiiop.htm .

2. Thomas Usl Èander, User requirements and state-of-the-art in managing CORBA-based applica-

tions,º Journal of Network and Systems Management , Vol. 6, No. 1, pp. 459±463, 1997.

3. ESPRIT MAScOTTE Project http: / / www.esa.int / MAScOTTE.

Conor Doherty received a BSc in computer science from University College of Dublin in

1988 and a Ph.D. in computer science from Aston University in 1996. He has worked on distributed

system, statistical, and robotic projects. He is a research scientist in Fraunhofer-IITB.

Thomas Usl Èander studied Computer Science at the University of Karlsruhe, Germany. Since

1987, he has been involved in numerous international research and industrial projects in the domain

of network and systems management, covering both Internet, SNMP, ISO, CMIP, and CORBA. He is

a manager of a research group in Fraunhofer -IITB in Karlsruhe concerned with telematics platforms.