I have had a strange request from management as to how far apart we can move our production systems. I know there are limitations on how far the (in this case) two systems (and two coupling facilities) can be apart and I've dug up an old IBM Redbook on the issue where they did tests with a sysplex at 0, 20, 40, 60 and 80 kms apart. Physical limitations (eg. FICON) don't seem to be an issue. We are a CICS and DB2 shop so the manual certainly addressed issues that we might see but it is dated 2008 so has anything changed since then? CICS and DB2 have moved on a long way in that time.
I was thinking of saying up to 10km but this is really a finger in the air value. Maybe it's only 5 and maybe its 20 or 30. Can we just throw CPU and memory at it as I would think we would have a lot more transactions running at the same time with some (but not all apparently) having extra delays incurred? The transaction increases suggested in that manual are milleseconds and these days (with all the distributed systems involved) the users are happy to get 10 second response times. Admitted this can involve many, many transactions behind the scenes from the application servers to populate their crowded browser screens. Gone are the days of data-entry pools and sub-second responses. What I was wondering is there anyone out there with real life experience on this kind of activity. How far apart do people run their sysplex systems? What gotchas sprang up to relieve them of their sanity? Any pointers would be gratefully appreciated. Regards, Alan Watthey From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of IBM-MAIN automatic digest system Sent: 03 January 2018 8:00 am To: [email protected] Subject: IBM-MAIN Digest - 1 Jan 2018 to 2 Jan 2018 (#2018-2) ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
