Object Request Broker

Object Request Broker
Name	Object Request Broker
Alt	ORB
Purpose	Distributed object middleware
Developer	Various vendors and standards bodies
Introduced	1990s
License	Proprietary and open-source

Object Request Broker is middleware that enables communication between software objects in distributed computing environments by mediating requests and responses across heterogeneous systems. It provides location transparency, interface definition, and invocation semantics to allow components developed for Sun Microsystems, IBM, Microsoft, Oracle Corporation, and BEA Systems to interoperate. By hiding network, language, and platform differences, it facilitates integration among systems such as Unix, Windows NT, Linux, VMS, and Mac OS-based servers.

Overview

Object Request Broker technology emerged to address interoperability among components created by vendors like Digital Equipment Corporation, Hewlett-Packard, and Siemens and to support distributed applications across networks such as ARPANET, Internet, and corporate intranets. It relies on interface specifications typically produced using standards groups such as the Object Management Group and influenced design choices at organizations including Xerox PARC, Bell Labs, and Sun Microsystems laboratories. ORBs abstract marshalling, transport, and dispatch so developers from Microsoft Research, IBM Research, AT&T Laboratories, and NASA could focus on business logic. Major deployments occurred in sectors involving AT&T, Siemens AG, General Electric, Siemens Healthcare, and Motorola.

Architecture and Components

Architecturally, ORBs comprise an object adapter, naming and trading services, and stubs/skeletons generated from Interface Definition Languages by tools from vendors like Borland, Rational Software, and Wind River Systems. Key components include a request broker core, object adapters inspired by designs at Sun Microsystems and Digital Equipment Corporation, and a repository service comparable to systems from Oracle Corporation and Microsoft. Complementary services include a naming service patterned after ideas from Xerox PARC and a transaction service reflecting work at IBM and Sun Microsystems. Development environments integrating ORBs often involved toolchains from Eclipse Foundation, Visual Studio, NetBeans, and JetBrains.

Communication Models and Protocols

ORB communication supports multiple models such as synchronous invocation, asynchronous callbacks, and publish/subscribe; these models were formalized by standards bodies including the Object Management Group and influenced messaging from vendors like TIBCO, Progress Software, and Solace Systems. Protocol stacks commonly employed for ORB transport include TCP/IP implementations used in products from Cisco Systems and Juniper Networks and mapping layers influenced by the IETF and IEEE working groups. The Common Object Request Broker Architecture mapping to Internet protocols was shaped by collaborations with industry players such as Sun Microsystems, IBM, and HP Labs. Interoperability efforts referenced implementations from Oracle Corporation, Microsoft, and Red Hat.

Implementations and Standards

Prominent implementations originated from companies and projects including Sun Microsystems (with technology research spanning SunOS), IBM (with products deployed in z/OS environments), Oracle Corporation (post-acquisition strategies), and open-source projects hosted by communities around Apache Software Foundation and Free Software Foundation. Standards and specifications were promulgated by the Object Management Group, with contributions from corporations like HP, Siemens, TIBCO, and Nokia. Vendor-specific ORBs were commercialized by firms such as BEA Systems, Iona Technologies, and VisiBroker-affiliated teams. Academic prototypes and experimental systems were developed at institutions including Massachusetts Institute of Technology, Stanford University, Carnegie Mellon University, University of California, Berkeley, and MIT Lincoln Laboratory.

Security and Transaction Management

Security models for ORBs integrated authentication, authorization, and confidentiality mechanisms using standards championed by organizations such as IETF and OASIS, and deployed technology from RSA Security, Symantec, and Entrust. Transaction management combined two-phase commit protocols developed through collaborations among IBM, Oracle Corporation, and Microsoft and leveraged mapping to transaction monitors like BEA Tuxedo and IBM CICS. Secure transport layers incorporated TLS implementations influenced by work at OpenSSL and applied in systems managed by VeriSign and DigiCert. Auditing and compliance features were often aligned with regulatory regimes affecting Wall Street firms and institutions such as Federal Reserve systems.

Performance and Scalability Considerations

Performance tuning for ORBs addressed marshalling efficiency, thread pools, connection multiplexing, and load balancing; practices were informed by experiences at Amazon.com, eBay, Google, and Facebook with distributed systems research from Google Research and Facebook AI Research. Scalability strategies drew on clustering technologies from Red Hat, VMware, and Citrix Systems as well as caching patterns from projects at Akamai Technologies and Cloudflare. Benchmarking used suites and tools originally developed by groups like SPEC, TPC, and academic labs at UC Berkeley and Stanford. High-availability deployments incorporated replication architectures similar to those used by Netflix, Twitter, and LinkedIn.

Historical Development and Usage Examples

The historical evolution of ORBs reflects contributions from the Object Management Group and major vendors including Sun Microsystems, IBM, Microsoft, and Oracle Corporation, with early commercial uptake by Telecom Italia and financial institutions including Goldman Sachs and Morgan Stanley. Case studies include integration projects at British Telecom, distributed control systems at Siemens, and mission-critical applications at NASA and European Space Agency. Academic and industrial research that shaped ORB design involved teams at MIT, Stanford University, CMU, Bell Labs, and Xerox PARC, influencing later middleware like Web Services stacks, gRPC, and RESTful architectures. The lifecycle of ORB technology informed standards work at OMG and transitions in enterprise middleware practiced by Accenture, Deloitte, and Capgemini.

Category:Distributed computing