Thursday, August 01, 2019

DevOps is Coming to Db2 for z/OS


Mainframe development teams are relying on DevOps practices more extensively, bringing the need to incorporate Db2 for z/OS database changes into the toolset that is supporting their software development lifecycle (SDLC).

But most mainframe professionals have only heard a little about DevOps and are not really savvy as to what it entails. DevOps is an amalgamation of Development and Operations. The goal of DevOps is to increase collaboration between developers and operational support and management professionals, with the desired outcome of faster, more accurate software delivery.

DevOps typically relies on agile development, coupled with a collaborative approach between development and operations personnel during all stages of the application development lifecycle. The DevOps approach results in small and frequent code changes and it can significantly reduce the lead time for changes, lower the rate of failure, and reduce the mean time to recovery when errors are encountered. These are all desirable qualities, especially as organizations are embracing digital transformation driven by the 24/7 expectations of users and customers to access data and apps at any time from any device.

The need to be able to survive and thrive in the new digital economy has caused organizations to adopt new and faster methods of developing, testing and delivering application software. Moving from a waterfall software development methodology to an agile methodology is one way that organizations are speeding the time-to-delivery of their software development. Incorporating a DevOps approach is another.

Instead of long software development projects that may not deliver value for months, or perhaps even years (common using the Waterfall development methodology) an agile DevOps approach delivers value quickly, and then incrementally over time. DevOps enables the continuous delivery of new functionality demanded by customers in the digital economy.

Succeeding with DevOps, however, requires a cultural shift in which all groups within IT work in collaboration with one another, and where management endorses and cultivates this cultural change. Because DevOps relies upon incremental development and rapid software delivery, your IT department can only thrive if there is a culture of accountability, collaboration, and team responsibility for desired business outcomes. Furthermore, it requires solid, integrated automated tooling to facilitate the SDLC from development, through testing, to delivery. Creating such an environment and culture can be challenging.

With DevOps the result will be a constantly repeating cycle of continuous development, continuous integration and continuous deployment. This is typically depicted graphically as the infinity symbol such as in Figure 1 (below).

Figure 1 - continuous development, integration and deployment


Note, however, that this particular iteration of the DevOps infinity graphic calls out the participation of both the application and the database. This is an important, though often lacking, detail that should be stressed when adopting DevOps practices.

The Mainframe and DevOps

The adoption of DevOps has, until now, been much slower within mainframe development teams than for distributed and cloud application development. The staid nature of mainframe development and support, coupled with a glass house mentality, and a rigid production turnover process contribute to the delayed adoption of DevOps on the mainframe. This is not surprising as mainframes mostly are used by large organizations running mission critical workloads with an aversion to any kind of change and risk-averse.

Additionally, the traditional waterfall development methodology has been used by most mainframe software developers for multiple decades, whereas DevOps is closely aligned with an agile approach, which differs significantly from waterfall.

Notwithstanding all of these barriers to acceptance of DevOps on the mainframe, mainframe developers can, and in some cases already do successfully utilize a DevOps approach. Technically speaking, the mainframe is just another platform and there is nothing inherent in its design or usage that obviates the ability to participate in a DevOps approach to application development and delivery.

What about Db2 for z/OS?

Integrating database change into the application delivery lifecycle can be a stumbling block on the road to DevOps success. Development teams focus on application code, as they should, and typically view database structure changes as ancillary to their coding efforts. In most application development projects, it is not the programmer’s responsibility to administer the database and modify database structures. But applications rely on the database being designed, implemented, and changed in accordance with the needs of the business and the code.

This means that many development projects have automated their SDLC tool chain to speed up the delivery of applications. This is the “Dev” portion of DevOps. But the requisite automation and tooling has not been as pervasively implemented to speed up the delivery of database changes. This is the “Ops” portion of DevOps. And this is changing.

A big consideration is that the manner in which change is applied to applications differs from how database changes are applied. That means each must be managed using different techniques and probably different tools. When an application program changes, the code is compiled, and the load module is migrated from test to production. The old load module is saved for posterity in case the change needs to be backed out, but the change is a wholesale replacement of the executable code.

Database changes are different. The database is an entire configuration in each environment and changes get migrated. There is no wholesale replacement of the database structures. DDL commands are issued to ALTER, DROP, and CREATE the changes to the database structures as needed.

From the perspective of database changes on Db2 for z/OS, DBAs need the ability to modify all the database objects supported by Db2 for z/OS. Supporting Db2 for z/OS using DevOps requires tooling that understands both Db2 for z/OS and the DevOps methodology and toolchain. And the tooling must understand how changes are made, as well as any underlying changes that may be required to effectively implement the database change. Some types of database changes are intrusive, requiring a complicated series of unloads, metadata captures, drops, creates, loads, and additional steps to implement. The tooling must be capable of making any of these changes in an automated way that the DBA trusts.

Fortunately, for organizations adopting DevOps on the mainframe with Db2, there is a solution for integrating Db2 database change into the DevOps toolchain: BMC AMI DevOps for Db2. BMC AMI DevOps for Db2 integrates with Jenkins, an application development orchestration tool, to automatically research and determine database schema change requirements, to streamline the review and approval process, and to safely implement the database schema changes making development and operations teams more efficient and agile.  

1 comment:

DevOps said...

very useful information, the post shared was very nice
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