st...@trainersfriend.com (Steve Comstock) writes: > Well, I just tried to do some online credit card account maintenance > with my Capital One card, and got the message 'System Unavailable'. I > called tech support and they said they were doing maintenance on the > system. Regular weekend maintenance. > > At 2:00 on a Friday afternoon? Does anyone know if they are using > mainframes for their online / web based work? Sheesh! Someone should > teach them they can use mainframes and do maintenance while the system > keeps running!
we were doing (IBM's) HA/CMP ... this is old post about early jan92 ha/cmp cluster scaleup meeting in Ellison's conference room http://www.garlic.com/~lynn/95.html#13 within a few weeks, the cluster scaleup is transferred, announced as ibm supercomputer and we were told we couldn't work on anything with more than four computers ... prompting us to leave a few months later. some old ha/cmp cluster scaleup email http://www.garlic.com/~lynn/lhwemail.html#medusa two of the other people at the Ellison meeting also leave and join small client/server startup responsible for something called "commerce server". we get brought in as consultants because they wanted to do payment transactions on the server; the startup had also invented this technology called "SSL" they want to use; the result is now frequently called "electronic commerce". Part of the effort was figuring out how to use "SSL" for the browser/webserver payments (we also had to audit all this companies selling "SSL" domain name digital certificates) as well as transactions between webservers and the payment gateway (sits between the internet and payment networks). For no-single-point-of-failure, the payment gateway had multipe connections into the internet and the webservers (talking to payment gateway) had to support multiple DNS A-records (translated domain name to multiple different ip-addresses). However, I didn't have final sign-off for the browser support ... and could only recommend that they implement multiple A-record support. They said it was too complex. I gave tutorials, they said it was too complex. I provided them example client code from 4.3Tahoe, they said it was too complex (it was more than year later before they supported multiple A-record support). An early commerce server was major sporting goods operation that was doing national football tv advertisement on sundays ... and were expecting big upswing in traffic during half-time. This was when major ISPs still scheduled maintenance on Sundays. Even though, their server had multiple connections to different parts of the internet ... if the ISP router for the first IP-address in the DNS record was down for maintenance ... it would effectively have the webserver off the air. in any case, there can be dozen's of components between a browser and backend processor that holds the account record. backend systems holding account records still are typically mainframes ... but they can have all sorts of non-mainframe intermediate components between the backend mainframe and any internet webafied interface. the configurations I would put together were no-single-point-of-failure ... even for pure web ... but others may have not been so careful. While still at IBM doing HA/CMP ... I had also coined marketing terms "disaster survivability" (to differentiate from disaster/recovery) and "geographic survivability". They then asked me to do section for the corporation's continuous availability strategy document ... but it got pulled when both Rochester (as/400) and POK (mainframe) complained they couldn't meet the requirements. misc. past posts mentioning availability http://www.garlic.com/~lynn/submain.html#available go out and try a point-of-sale transaction on the card ... it will typically go through components that are frequently pure legacy (although increasing percentage are transitioning to internet for point-of-sale ... even with backend still mainframe). "off-peak" for many web components also tend to different than backend ... with web-use spiking during non-normal working hrs (weekends and off-shift when people are mostly not at work). -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
