What HostBridge is and What it Can Do
Products| by Jerry Rackley

We routinely get calls from HostBridge customers, asking if our solution has certain features, functions or capabilities.  The most frequent answer I give is “yes, and your HostBridge license allows you to do that.” These inquiries create doubt about how well we’re getting the message out about what HostBridge does.  In fact, we get a little introspective as a result of these inquiries, which causes us to change our standard slide set or update our website to ensure that everyone knows what we do.  It is good for us to think through how we communicate all the value that HostBridge provides in making CICS applications available via APIs or services. Think of HostBridge as the “Swiss Army Knife” of CICS integration, modernization, and orchestration.

HostBridge allows you to integrate anything inside of CICS with anything outside of CICS, without having to make any changes to your mainframe applications.  This may seem like an overly broad capabilities statement, but it really doesn’t say enough.  To detail all that HostBridge can do would take more space and time than you, the reader, have patience for.  Instead, I’ll describe the things I know our customers are already doing and a few things they could do.  I’ll focus on our HostBridge Base XML and HB.js solutions, as that is where most of the activity is, and I’ll start with a short description of each solution.

HostBridge Base XML allows our customers to programmatically exercise a CICS application that was only meant to run on a terminal.  What does that mean?  There are many (really, very many) applications written to run under CICS that were only meant to run at a terminal where a human operator has to supply the input and interpret the output.  If you want to reuse the program logic built into these applications without the benefit of HostBridge, you must either:

  1. Use a screen scraper to wrapper them
  2. Rewrite them to remove the terminal interactions

Neither approach has tremendous appeal: screen scraping is very brittle, and rewriting applications is time-consuming and costly. It is no exaggeration to say there are hundreds of millions of dollars invested in these types of transactions across multiple enterprises and across multiple industries.  These transactions are still capable of fulfilling the business needs of the company but they have an interface that no one wants to use.

The HostBridge Base XML solution provides a way to continue exploiting the business logic within these applications through external programs and apps, without having to change the existing CICS applications.  HostBridge essentially provides an API that non-mainframe applications can exploit. For some of our customers this capability has saved millions of dollars in costs by allowing them to avoid rewriting applications.

HostBridge Base XML does not alter or change the logic or flow of these “visual transactions”; it just puts a programmatic interface on them.  You still have to have write code that walks through each screen, filling in the fields, validating the output, making the decisions that the human operator formerly made.  But HostBridge makes doing this possible without relying on screen-scraping approaches, by instead using server-side JavaScript, which is where the HB.js solution comes into play.

HB.js is a JavaScript engine running inside CICS, right alongside to the CICS applications that are the integration targets.  Using HB.js with HostBridge Base XML, a developer or enterprise architect can do anything an operator can do and anything a CICS program can do, all by writing JavaScript.  HB.js can exercise any existing transaction (by using HostBridge Base XML) or call any CICS API.  You could, if you chose to, write new CICS transactions in JavaScript using HB.js! The implications of this are huge: finally, non-mainframe developers can use a language they know and like to write new CICS transactions.

Additionally, HB.js is the connector to the outside world that allow clients/servers/applications to talk to the host, to invoke these new services you have created. Here’s a diagram that attempts to distill how Hostbridge goes about making CICS applications available via APIs or services:

The list of things you use HostBridge to do is lengthy, so here, in no particular order, is my attempt to compile that list.

  • Leverage/use existing security/auditing/logging
  • Create new security models (but you don’t have to)
  • Allow CICS transactions to be part of the Splunk or other SIEM ecosystem
  • Expose CICS transactions as web services
  • Work with DB2
    • Expose DB2 data with web services
    • Dynamic SQL, stored procedures
  • Work with VSAM
    • Read/Write
    • Expose as web services
  • Work with MQ
  • Invoke web services on the internet or an intranet, COBOL programs running in CICS calling web services using HB.js
  • Use nearly any API style
    • SOAP, XML, JSON, Restful, ATOM, URL query string, HTML, text, CSV, etc.
  • Write new functionally using JavaScript
  • Write new CICS transactions using JavaScript
  • Send mainframe email
  • Leverage MRO
    • Run transactions in any region
    • Load balancing
    • High availability
  • Any client/application platform can invoke/use your CICS applications (Literally anything: Java, .Net, Apache, Tomcat, WebSphere, Adobe Reader, Excel Spreadsheets, etc.)
  • Encrypt any or all conversations (SSL)
  • Authenticate and authorize users using host security systems and/or host application data for web applications
  • Submit batch jobs
  • Trigger timed events in CICS
  • HostBridge services can be triggered by CICS Events
  • HostBridge service can trigger CICS Events
  • Read/write/delete TSQueues
  • Read/write TDQueues
  • HostBridge services can be triggered by TDQueue writes
  • Call CICS programs
    • Channels and containers
  • Call non-CICS programs
  • Run CICS programs in batch
  • Run batch programs in CICS
  • Act as a web server
    • HTML
    • Images
    • Client side JavaScript
  • Authenticate conversations with
    • Basic authentication
    • Client Certificates (x.509)
    • Trusted Host
    • No authentication
  • Interact with real terminals with or without BMS maps
  • Invoke nearly any CICS API (if you need one we don’t support, we will add it)
  • Push data real time out of CICS
  • Gather CICS statistics
  • Publish dashboards
  • Bidirectional data replication

There’s even more that HostBridge can do, and our customers are constantly finding new ways to create innovative integrations with our software. If you have questions about anything we’ve discussed here, please contact us.

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