Evangelizing Mainframe
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IMS V15 Offers Security, Performance Enhancements

IBM IMS has been around since 1968, and will be celebrating its 50th birthday on Aug. 14 next year. It comes in two parts—there’s the database part (IMS DB) and there’s the Transaction Manager part (IMS TM, which some people call IMS DC). And coming soon to a data center near you will be Version 15.

IMS DB is a hierarchical database that has survived for the past 49 years because it made access to large amounts of stored data very fast. Over the years there have been three variants of this type of database:

  • “Full Function” databases, which were derived from the DL/I databases developed in 1968. The data is stored using VSAM or OSAM.
  • “Fast Path” databases are optimized for extremely high transaction rates, and come in two types—Data Entry Databases and Main Storage Databases.
  • High Availability Large Databases are an extension of full function databases that provide better availability, better handling of extremely large data volumes and online reorganization to support continuous availability.
IMS TM uses a messaging and queuing paradigm, and can access data in Db2 if required. And transactions can start from many different devices, with the responses being sent back to these devices.

So, what’s left for IBM to add to this remarkable and venerable piece of software that became available to order on October 27 this year?

It has enhanced security, what IBM called managing risk. Following IBM’s announcement of the z14 mainframe with its pervasive encryption facilities, IMS V15 running on a z14, can help to simplify compliance certifications by allowing IBM z/OS data set encryption of IMS data with minimal CPU overhead and no application changes. IMS V15 also helps users to better manage security and compliance, from providing support for building greater security into mobile solutions to helping to track and report on mobile workloads.

IMS V15 also provides support for leveraging RACF password enforcement and other RACF features critical for end-to-end security in a connected mainframe environment. There’s a new IMS Connect option for RACF statistics gathering for IMS DB clients. This is the OD RACF ST= parameter, which can be added to the ODACCESS statement of the HWSCFGxx configuration PROCLIB member. There’s also support for additional RACF special characters in passwords.

Transactions initiated in distributed environments use authentication/identity mechanisms that are different from those used in z/OS, which can lead to the user’s distributed identity being lost. IMS V15 provides an enhancement to propagate the original user identity to IMS for auditability and accounting purposes (not for authentication or authorization).

IMS V15 can also amplify an organization’s business efficiency in a number of ways. A Java Virtual Machine (JVM), in either a Java message processing or a Java batch processing dependent region can use 64-bit storage, which provides for more efficient memory management with Java applications and ensures that all Java applications will run under IMS control. It’s now possible to track JVM usage statistics with the new SMF29S2 record. Plus users can dynamically configure Java environment variables and options with a new DD statement (//STDENV DD) in the dependent region start-up JCL. This gives better security, flexibility and control over environment settings for the JVM by moving configuration parameters from the DFSJVMEV and DFSJVMMS members of the PROCLIB data set into several partitioned sequential data sets that are referenced by the //STDENV DD statement.

There are also performance and tuning enhancements. For example, the IMS logger leverages DFSMS Media Manager, which enables the use of hardware features that maximize performance. New efficiencies in External Subsystem Attach Facility (ESAF) connection thread management help reduce the overhead on IMS connections to the external subsystem. IMS V15 also offers broader support for dynamic change and increased potential for growth with scalability and high-availability improvements.

There are also enhancements to simplify system administration, including simplified system management capabilities, which reduce reliance on the IMS system definition process, simplify dynamic resource definition, and help to keep IMS trouble free. The maximum number of ports in IMS Connect is increased from 50 to 200. New QUERY TRACE and UPDATE TRACE commands enhance the usability of IMS type-2 traces.

And by using workload reporting for mobile transactions, sites are able to distinguish their mobile workload from the rest of their IMS transactions, and that can help them to control costs.

Read the full software announcement.

IMS has clearly stood the test of time and is in no way reliant on its past successes. It’s making use of the latest developments in mainframe technology, while at the same time making it easier to connect IMS systems to distributed sources and maintaining the security of everything at all times. IMS still has a great future ahead of it.

Trevor Eddolls is CEO at iTech-Ed Ltd, an IT consultancy. A popular speaker and blogger, he currently chairs the Virtual IMS and Virtual CICS user groups. He’s editorial director for the Arcati Mainframe Yearbook, and was an IBM Champion between 2009 and 2016.

Posted: 11/21/2017 12:00:17 AM by Trevor Eddolls

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