Configuration of HostBridge VSAM Files

This article is intended to assist the systems programmer that is tasked with maintaining HostBridge.  It provides information about the various VSAM file that HostBridge uses, how they are used, and suggestions for configuring the files in your CICS environment.

Following is a list of the VSAM files used by HostBridge, showing how they are used both in development and in production.

CICS File Handle (DDNAME)ProductDescriptionProductionDevelopment
HBCONFIGHB.jsStores HB.js configuration parameters.Updated by the HBSM transaction by the systems programmer.  Most customers allow this file to be updated in production only in exceptional conditions.  The contents are usually REPROed in from their QA or staging environments when the region is down. If you anticipate the need for different configurations between regions, then this file should not be shared between regions.Updated via the HBSM transaction by the systems programmer or developer.
Script Repositories (HBSCRIPT, HBUTILS, custom defined)HB.jsStores compiled HB.js scripts and source files.Updated via the Eclipse IDE or batch Promote utility.  Most customers do not allow these files to be updated in production.  The contents are usually REPROed or Promoted in from their QA or staging environments when the region is down.  These files should be read only in most customers' production environments.Updated constantly by developers using the Eclipse IDE.
Script Repositories (MSCRFILE, MSCRLIB, MSCRHTML, custom defined)HBXStores compiled HBX scripts and source files.  Many customers have moved off of HBX and onto HBJS.  Check with your developers to see if HBX is still in use at your site.Updated via the Eclipse IDE or batch Promote utility. Most customers do not allow these files to be updated in production. The contents are usually REPROed or Promoted in from their QA or staging environments when the region is down. These files should be read only in most customers' production environments.Updated constantly by developers using the Eclipse IDE.
HBSCREENBase, HBX, HB.jsStores screen meta data.  Used for unique CICS development environments, IDEAL, CA/TELON etc.Updated via batch job.  Updates will not be available to CICS until the file is closed and reopened.  Most customers do not allow this file to be updated in production.  The contents are usually REPROed in from QA or staging environments when the region is down.Updated via batch job. Updates will not be available to CICS until the file is closed and reopened.  Updated as needed when screens are changed.
HBSTATSBase, HBX, HB.jsStores HostBridge performance statistics.Defined and enabled by the systems programmer using batch procedures and the HBSM transaction.  Use of statistics gathering will degrade performance in the production environment, and therefore should be used only under the direction of HostBridge support.  Defined and enabled by the systems programmer using batch procedures and the HBSM transaction.
HBJSLOGHB.jsStores log information generated from HB.js services.Updated by execution of HB.js scripts, used for logging and/or debugging.  CICS write to VSAM can be relatively expensive, be sure you limit the number of writes.  The file must be defined as writable and, if not shared via an FOR, must be unique for each CICS region where HostBridge is used.Updated by execution of HB.js scripts. The file must be defined as writable and, if not shared via an FOR, must be unique for each CICS region where HostBridge is used.
All  other filesVariousVariousRead only.  Updated only when the region is down, usually when HostBridge is upgraded.Read only. Updated only when the region is down, usually when HostBridge is upgraded.

Here are some decision points that you should consider when configuring the HostBridge files for your various environments (development, QA, staging, production):

  • Do I already have or want a File Owning Region (FOR)?  Using an FOR with CICS Tables provides all of the data integrity and has the highest performance of any of the possible configurations.  If you already have an FOR, use it; it will provide you with the highest performance and flexibility.
  • Do I need to update the HostBridge files in the environment while the region(s) are active?  Specifically, is it possible that I might have emergency updates to production services or configuration, updates that would have to be made with the region(s) active?  If not, then you should define all of the HostBridge files as read only to the regions where no updates are to be performed.
  • If I do need to make updates, can all updates be made from a single region?
  • If I do need to make updates in multiple regions, do I want to use RLS instead of an FOR?