Author Archives: Martin Packer

(Originally posted 2015-12-22.) WLM will give up on an unachievable goal, eventually. Recently I came across a customer who didn’t know this and for whom this was a big problem.[1] This customer, like many others, was running heavily constrained for CPU. [2] But it does have consequences. In this particular case they had defined twoContinue reading “Overdoing It”

(Originally posted 2015-12-19.) After writing Reviewing The Situation I got thinking. [1] I’ve known for a long time the WLM Policy (XML) has timestamps in it. The thought was “maybe there’s value in doing timestamp analysis”. Here is a fragment of a real customer policy, showing a resource group definition: It’s pretty easy to read.Continue reading “WLM Policy Timestamp Analysis”

(Originally posted 2015-12-14.) I might have written about this before but it’s such a nebulous subject Web searches don’t enable me to tell. In any case it’s a subject worth reviewing every now and then. The subject is “when to review your WLM policy”. I’ve written extensively on how to look at a policy. WhileContinue reading “Reviewing The Situation”

(Originally posted 2015-12-10.) I’ve been very lucky (and kept busy and challenged) these last two months. In addition to my usual case load of customer situations I’ve had the enormous privilege of participating in the ITSO 2015 Mainframe Topics tour. I’ve presented whole-day sessions on Performance and Availability in five cities: Amsterdam, Paris, Warsaw, ViennaContinue reading “Thanks In Five Languages – ITSO 2015 Tour”

(Originally posted 2015-12-07.) Not to be confused with Notational Velocity. A recent customer situation reminded me of how our code calculates velocity. It’s worth sharing with you. The standard way of calculating velocity is to compute (Using Samples)/(Using Samples + Delay Samples) and convert to a percentage by multiplying by 100.[1] The numbers are allContinue reading “A Note On Velocity”

(Originally posted 2015-12-05.) It’s very early days for Twitter Polls but I think they have promise. So here’s a post on my experience with them in their infancy. [1] The point of writing about it is twofold: To encourage others to try it – both as a pollster and as a respondent[2]. To encourage TwitterContinue reading “Twitter Polls: An Early View”

(Originally posted 2015-11-30.) In IRD And Hiperdispatch – Wrong ’Em Boyo I briefly mentioned the concepts of Parking and Unparking. It wasn’t appropriate to cover them in depth there. So I’ll talk about them now, focusing on the RMF instrumentation. But first a brief discussion on Parking versus IRD Logical Processor Management. IRD could –Continue reading “A Parked Topic”

(Originally posted 2015-11-27.) Applying the maxim “the customer is always right” this week revealed a bug in my analysis code. It also gave me the opportunity to write about how RMF sees the interaction between IRD Weight Management and Hiperdispatch.[1] But let me start with some brief, basic information about the technologies in question. IfContinue reading “IRD And Hiperdispatch – Wrong’Em Boyo”

(Originally posted 2015-11-22.) Sometimes a little visual tweak can make all the difference. This post is about one such case. Actually the code change to achieve it was quite complex but the visual rearrangement is simple. I have a number of customers with Integrated Coupling Facility (ICF) processor pools with both dedicated and shared CouplingContinue reading “A Picture Of Dedication”

(Originally posted 2015-11-16.) It's that time of year when I start to think about writing conference presentations for user groups and conferences in 2016. Already I have three in mind, with varying degrees of sketchiness. Their working titles are: He Picks On CICS Fun With DDF So You Want To Be A Better Performance Specialist?Continue reading “Good Things Come in Threes?”