First I will give technical details on one of SAP systems I support:
1) CI/Oracle DB runs on 8CPU/32GB memory Unix Server
2) 2 Unix application servers, each with 4 CPUs/16GB of memory
ST06 (information gathered by SAPOSCOL) regularly shows almost 99% CPU idle on one of application servers. Other application server shows 70+% CPU idle every hour; DB server shows at least 65% idle every hour. I observe this behavior all 7 days a week.
Currently busniess users are not experiencing any performance issues.Based on statistics I reported above, I should ideally be working on reducing the number of application servers to meet Green IT objectives. Instead I am working on adding on one more Unix application server with 4 CPUs/16GB of memory.
Why?
Last year we implemented an application using web application templates and decided to use BI Java stack for displaying data using graphs and charts. This application basically reads 10-15 records from BI Cache, uses IGS to draw charts/graphs and displays them in Portal. This was first portal based application at this customer site. Technically this is not Portal-centric application; all work is done at ABAP/IGS level. We, technical team, used quick sizing tool last year and estimated that we would need 3 application servers using very limited information we had at that time. The estimation was done before the application went live. As no design documentation existed, technical team used the best judgement while repsonding to Quick Sizer's questions.
After application went live, the technical team analyzed its flow and concluded that it was not resource-intensive application. It has been in production for 6+ months and no performance issues have been reported. And one of 2 application servers is not being used 99+% time. Other two servers are showing 50+% idle time. Unfortunately the business/development team is not ST06-literate. They are interested in implementing 3rd server as per last year's recommendations.
As this year's TechEd theme is "Sustainability and Green IT", I thought I will share my challanges in implementing Green IT. I guess not adding a third server may seem a drop in ocean of redundent resources; however I believe eliminating little drops of such redundent resources would go a long way in building mighty "green" world.
