Juan M.Gienini


HostBridge: JavaScript Engine & Base XML

HB.js is server-side JavaScript for CICS® applications and IBM z Systems™ data assets. It is the only JavaScript/JSON-based integration solution for the mainframe. Both a development facility and runtime engine, HB.js provides all the capabilities z Systems customers need to rapidly develop and deploy reusable Web services and/or scripts.
HB.js is zIIP-enabled, runs inside CICS, and supports:
- CICS terminal-oriented (visual) transactions
- BMS, non-BMS, 3270, and CA application types
- COMMAREA (non-visual) programs
- DB2®, VSAM™, DL/I, Datacom®, and other data assets
- Connectivity via HTTP, LINK/EXCI, Enhanced WebSphere MQ
- Extended Multi-Region Operation (MRO)
- Other CICS and z/OS tools and technologies.
Use Cases
With HB.js, you can:
- Orchestrate CICS terminal-oriented transaction micro flows as single services
- Orchestrate and aggregate transactions, programs (e.g., COMMAREA), and data into single composite services
- Integrate anything mainframe with anything distributed – Web and mobile applications, cloud architectures, service-oriented architectures (SOAs), other enterprise applications, etc.
- Create dynamic object-oriented applications that simplify and revitalize legacy applications for modern environments. HB.js fully supports a wide range of object-oriented scripting/Web services types and protocols, including JavaScript, JSON, XML, SOAP, SOAP 1.2, RESTful services, Ajax, Atom, HTML, and E4X (ECMAScript for XML).
With HB.js, developers can incorporate complex CICS transaction micro flows that can involve interaction with dozens or even hundreds of screens into a single, reusable Web service. Integrating these micro flows using sub-optimal, middle-tier integration technologies has serious performance implications because they require a full request-response cycle with the mainframe for each transaction. HB.js executes the entire transaction sequence on the mainframe, orchestrating and aggregating all relevant data and returning a single response, typically with sub-second response times.
Development Environment
Developers can use HB.js to expose z Systems apps and data using the same high-performance, industry-standard technologies used by today’s leaders in mobile, web, and cloud computing. The HostBridge Eclipse Integrated Development Environment (IDE) allows developers to easily and rapidly author, test, and deploy HB.js scripts/Web services. The IDE includes HB Transaction Explorer, a graphical display that precisely replicates CICS screens. Using this tool, developers can navigate live terminal-oriented CICS application micro flows to develop highly reliable integration scripts/services.
New, Composite Apps
HB.js customers are reinventing complex legacy applications as modern composite apps by leveraging JavaScript’s object-oriented capabilities to write new, dynamic applications within a Web services application architecture.

HostBridge: Base XML

HB Base XML automatically converts CICS transactions to XML, making CICS integration-ready to any distributed application, including web, mobile, service-oriented architectures (SOA), and cloud architectures. HostBridge-generated XML conforms to a predictable document structure from which data is easily extracted. Customers can write web services with this XML, or do so in combination with the JavaScript generated by the HostBridge JavaScript Engine (HB.js). The HostBridge Eclipse IDE exploits this XML, letting developers easily and quickly author, test, and deploy integration scripts and web services. HostBridge Base XML is zIIP-enabled.
Advantage: Performance
HostBridge delivers the highest-performance integration for CICS and z/OS mainframe resources, because it runs on the mainframe. Integrations that run in the middle-tier must execute a full network transit and request-response cycle between the distributed system and mainframe for every transaction. The result is request/response latency, slower response times, and higher mainframe CPU demands. In high-volume environments, these differences ae significant and directly impact the speed and efficiency of business processes.
Advantage: Reliability
Integrations based on screen-scraping technology rely on row and column coordinates to rigidly “map” mainframe output to distributed systems. Changes to host applications that alter screen locations cause screen-scraping integration to fail because they can no longer map fields to target applications. HostBridge doesn’t use screen-scraping, and instead uses screen and field names as metadata to control interactions and remote presentation. For this reason, HostBridge integrations are not brittle, because changes to a host application’s row and column locations has no effect on output or integrations.
Advantage: Fidelity
HostBridge preserves originating CICS data and business logic when it converts CICS data to XML, essentially wrapping it in metadata. This approach ensures that data, screens, and logic are simply and exactly reproduced. The way HostBridge uses screen and field names to identify and navigate screens enables HostBridge to replicate source applications and data without distortion.
Key Features
HostBridge exploits CICS and z Systems tools and technologies, including the Link3270 Bridge, as well as industry-standard transports, protocols, and languages to enable mainframe integration using these features:
- SOAP/REST Support: Integrate CICS applications as formal or informal web services, enabling applications to invoke CICS transactions as web services in both loosely coupled and tightly coupled systems.
- HTTP Interface: Distributed applications can invoke CICS applications directly using HTTP requests over TCP/IP. Any application capable of sending a URL and receiving an XML document can access CICS data. This standard approach maximizes integration flexibility.
- LINK Interface (ECI/EXCI): Mainframe applications with existing COMMAREA interfaces can utilize HostBridge’s XML output abilities.
- Standards-Based: Developers can integrate CICS transactions as Web services with their existing knowledge, lowering development time and costs.
- Security: HostBridge works securely with and within IBM-provided components supporting standard mainframe security systems such as RACF, ACF/2, and TopSecret. HostBridge also supports SSL and digital certificates, and IP address host name inclusion/exclusion lists.

Origin: HostBridge 2018