tag:blogger.com,1999:blog-6806654330436722244.post8205043118229192258..comments2024-03-24T17:11:57.814-07:00Comments on Catterall Consulting: For Ultra-Fast DB2 Recovery, Don't RecoverRobert Catterallhttp://www.blogger.com/profile/12629696535422235653noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-6806654330436722244.post-84340666510098095742008-06-09T15:25:00.000-07:002008-06-09T15:25:00.000-07:00That's an excellent question, and it speaks to the...That's an excellent question, and it speaks to the complexity of making the "ultra-availability" system work. I believe that the functionality about which you're inquiring could be built into the system. Presumably, the network routers that get requests to either site A or site B could do so based on an algorithm provided by the user. It could be that one could update a factor in this routing equation by way of a message sent to the routers, and it's possible that the factor adjustment could be automated through programs running on app servers that would poll back-end data servers to check on their load status (I have to believe that there's a workload management API on the mainframe, and their may be such an API for LUW platforms, as well). If the DB2 data server's "degree of busyness" gets above some threshold, the app server sends a message to the router, and the request-routing is altered accordingly.<BR/><BR/>Sorry to be a little short on details here. I'm thinking that a good bit of user programming would be required here, but it may be that some router and/or app server vendors have done at least some of this for you.Robert Catterallhttps://www.blogger.com/profile/12629696535422235653noreply@blogger.comtag:blogger.com,1999:blog-6806654330436722244.post-32966742314192143902008-06-08T09:38:00.000-07:002008-06-08T09:38:00.000-07:00Hi RobInteresting article.One question: Using two ...Hi Rob<BR/>Interesting article.<BR/>One question: Using two identical data repositories would allow the non-DR aspect to be successful and also share the workload during the other 99.99% availability to give better load balancing.<BR/>If one of the systems becomes busier than the other however, is there any way the calling application can check the 'health' of each data server before sending the request in? Almost like a WLM environment which sits on the application server and 'talks' to the WLM environments on each of the data servers.<BR/>Thanks for any advice<BR/>SimonAnonymousnoreply@blogger.com