The placebo effect of a mainframe IPL.

Long gone are the days of weekly IPLs or is it? Believe it or not weekly IPL of the mainframe is still very much real. When I think of mainframe modernization, I realize its more mindset than myth. The weekly IPL being necessary is still believed by some companies. While that was the case 15 years ago a solid system does not need a weekly IPL.

There was a time when IPLs were a weekly necessity. The system had its memory leaks and weekly clean up was necessary. Today the Z series and the latest ZOS has solved several of these issues. Gone are the days of 100% CPU crippling your system. Well, if you have updated your system. However, business leaders are not necessarily up to date on technology and heard that it was necessary to do an IPL every week.

The second instance of IPL’s being no longer necessary is time change. DB2 as well as other subsystems do not do well when the log goes back in time. So the catch all was to IPL the system and leave it down for over an hour. While it works it’s a very dated model and with good planning you could shutdown certain subsystems and use that time for other purposes.

The third is your system has hit an issue and its uncertain how to resolve the issue. While there are cases where an IPL is the best option a lot of times it is not. Why is it the option in certain cases? One is the lack of familiarity between started tasks. Siloed employees who only work with one of the started tasks a lot of times will not understand how they interact. The biggest issue is companies invest in DR planning but not emergency planning. We plan to lose a data center but there is no “issue planning” what if this started task has issues – how do you resolve that.

The mindset of the leaders leads to the third happening way to often. IPLs was the fix all 10 years ago. The lack of industry standards and best practices backed by the community does not help. Having industry standards and best practices assembled by industry leaders would help mold the mindset of business leaders. It is tangible to the point that they retain the information more. Many times, I battle old thinking because the mindset is this is the way we have always done it.

The problem is most companies do not have a single touch IPL. An IPL can take 30-60 minutes and is an active task for at least one staff. IPLs in general are stressful because the system needs to be up and in the correct state. In a break fix situation, it is very likely that staff that never IPLs the system is doing the IPL which means the stress level goes up significantly higher. Almost no company is doing emergency IPL training either. Adding this training would reduce some of the stress levels.

The bottom line is IPLs are a waste of money and a big drain on mainframe Managed Service Providers. The typical IPL Window is between Friday evening and Monday morning. Poor IPL maintenance makes them more stressful. Operations working nights and weekends feel detached from business hour staff. Remote work makes a larger gap which causes less to be reported. The question is how many staff hours a month do you want to spend on IPLs. The fewer you do the more you have to “practice”. It is silly to not plan for emergencies. Yet it is common practice which leads to the IPL being the best medicine.