Friday, May 25, 2012

DB2 for z/OS Recovery: Getting it Right -- and Fast -- with Recovery Expert

Some people seem to be under the impression that recovery has drifted down, importance-wise, in the hierarchy of issues associated with running a DB2 for z/OS system. These folks might be thinking that, with the ever-increasing reliability of mainframe hardware, software, and storage systems, DB2 recovery operations just aren't required as often as they once were. On top of that, there's a feeling that point-in-time data recovery -- more complex than recover-to-currency -- is largely a thing of the past, owing to factors such as the increasing prevalence of round-the-clock transactional traffic accessing DB2 databases. Finally, there are the ongoing improvements in backup and recovery capabilities that are delivered with new releases of DB2 for z/OS, seen as mitigating some challenges that presented themselves in years past.

Well, these factors are indeed part of the current landscape: mainframe systems, long known for rock-solid reliability, are even more robust than before. Point-in-time data recovery is trickier when both online transactions and batch jobs update data in the same tables at the same time. DB2 for z/OS backup and recovery functionality has advanced in important ways in recent years. With all that said, however, I will tell you that recovery is as front-and-center in the world of DB2 for z/OS as it's ever been. Here's why:
  • The financial cost of downtime is escalating. It's an online world. Organizations' customers and clients demand access to data and services at all times. For some companies, the cost of data and application unavailability is measured in millions of dollars per hour.
  • The need for point-in-time data recovery is very much present in today's systems. Batch job input files still occasionally contain errors that have to be subsequently backed out of the database; furthermore, the iterative nature of application development common at many sites results in more-frequent database schema changes, and these at times need to be reversed.
  • With more options for DB2 for z/OS backup and recovery come more decisions. If there are multiple go-forward paths for a given recovery situation, which one is the best? If there are more recovery assets nowadays (e.g., system-level as well as object-level backups), how do you track and manage them?

Lots to think about. Fortunately, there is a tool available that can make you better at DB2 for z/OS recovery than you were before. As the voice-over from the beginning of the old television series, The Six Million Dollar Man, put it (yes, I'm dating myself here): "Better. Faster. Stronger." That tool is IBM's DB2 Recovery Expert for z/OS.

Recovery Expert delivers the greatest value when you need it most: 2:00 AM, data unavailable, application programs failing, phone ringing non-stop, escalation to upper management imminent. Pressure's on, cost of mistakes is high, time is absolutely of the essence. Do you even know what your recovery options are? Will you choose a good one? Are the required recovery assets in place (backups, log files, etc.)? Will you get the JCL right? Will you try to multi-thread some of the recovery processing? You can go with your gut and hope for a good outcome, or you can raise the odds of success by getting the advanced technology of Recovery Expert on your side. Fire up the GUI (browser-based starting with the recently announced 3.1 release) or the ISPF interface, point and click (or populate ISPF panel fields) to input information on the recovery task at hand, and let Recovery Expert do its thing. You'll quickly be presented with a list of alternative recovery procedures, with the best-performing option on top. Make the choice that's right for the situation (minimization of elapsed time might be your objective, or you might be focused on CPU consumption or some other aspect of the recovery operation), and leave it to Recovery Expert to build and execute the jobs that will get things done right the first time around. You even have the ability to specify a degree of parallelization for processes involved in the recovery operation. Speed and accuracy are significantly enhanced, and you get to tell the higher-ups that the problem is resolved, versus fighting through a storm of panic and stress.

Hey, and outside those 2:00 AM moments (which, I hope, are few and far between for you), Recovery Expert can deliver all kinds of value for your company. Want to reverse a database schema change without leaving behind all the associated DB2 stuff -- not only indexes and packages, but triggers, views, stored procedures, and authorizations -- that would be impacted by an unload/drop/re-create/re-load operation? Check. Want to restore an accidentally dropped table? Check. Want to accelerate the leveraging of DB2 10 features such as roll-backward recovery? Check. Want to quickly implement DB2 system-level backups to make your backup procedures much simpler and more CPU-efficient? Check. Want to assess available recovery assets to ensure that you have what you need to accomplish various recovery tasks? Check. Want to find "quiet times" in the DB2 log to which you can aim point-in-time recovery operations? Check. Want to accommodate application-based referential integrity in your recovery operations? Check. Want to translate a timestamp to which you want to restore data to the requisite DB2 log RBA or LRSN? Check. Want to create a backup that can be handed over to the IBM DB2 Cloning Tool for z/OS to clone a subsystem? Check. Want to simplify the bringing forward of your existing backup and recovery procedures as part of a migration to DB2 10 for z/OS? Check.

That's a lot of checks, and I haven't even gotten into all that's there. Believe me, Recovery Expert addresses so many needs associated with DB2 for z/OS recovery, once you start using it you may wind up wondering how you were able to get along without it. The more data you have, the more DB2 subsystems you have, the more complex and demanding your DB2 application environment is, the greater the Recovery Expert payoff. Get Recovery Expert, and get bionic with your DB2 recovery capabilities. "We have the technology..."

1 comment:

  1. There was an excellent presentation on Recovery Expert delivered via teleconference on May 23, 2012 by John Campbell of IBM DB2 for z/OS development and Anthony Ciabattoni, a Recovery Expert product specialist. If you didn't get a chance to listen to this presentation, register for the teleconference anyway (at, and you'll get an e-mail when the replay of the teleconference is available.