idfzos...@gmail.com (Scott Ford) writes: > Agree you 100%. Maybe they need a second pair of eyes to review the > design. I know I do and I will bet other software designers and system > programmers do. A second pair of eyes is like a Dr.'s second option.. Like > you mentioned something was missed and the easy out was a mainframe > upgrade. I agree with everyone on this one, sometimes it's lack of > experience too.
the IBM science center pioneered a lot of performance methodologies in the 60s & 70s ... hot-spot monitoring, system modeling, multiple regression analysis, etc. some of the system modeling work eventually evolves into capacity planning. One of the system models was analytical model done in APL. The APL model evolves into the "Performance Predictor" available on the world-wide sales&marketing support HONE system ... branch office could obtain customer workload and system profile data ... feed it into the "Performance Predictor" and ask "what-if" questions (aka what happens if the workload changes, system configuration changes, more disks, more memory, etc .... major objective justifying selling more hardware) Around the start of the century I ran into consultant that was making a living from performance consulting to large mainframe datacenters in Europe and the US. IBM's downturn in the early 90s, IBM was unloading some amount of its stuff ... and this consultant obtained the right to a descendent of the "performance predictor" and ran it through an APL->C language converter. We met at a large datacenter that had a 450kloc cobol program that ran evernight on 40+ max. configured mainframes (constantly being upgraded, none older than 18months, number required for application to finish in the overnight batch window). They application had a few dozen people in peformance department that had been working on it for decades ... primarily using hot-spot methodology. Hot-spot tends to shine light on sections that need logic examination for doing things better ... working primarily with logic at the "micro-level" The modeling work fed workload & system activity data and identified areas that resulted in 7% improvement. I then used multiple regression analysis with application activity data to spotlight some macro-level logic that resulted in 14% improvement. Remember that this is an application that had dedicated performance group with dozens of people that had been working with this application for decades (but primarily using "hot-spot" methodology ... that tends to focus on micro-level logic) -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
