Systems admin Michael Gildersleeve wishes for 100% uptime and wonders whether virtualization will bring him closer or further away from that goal. It seems to him that virtualization options only cover one server at a time. “What if I need to do an OS update or patch, or what if some critical hardware fails?” he asks. In that case, he feels a bit more comfortable with a cluster than with virtualization.
Gildersleeve is evaluating high-availability options for virtual machines. VMware’s High Availability (VMware HA) is on his list, but he’s not sure whether that product will work well with his legacy software. He’s also not sure whether HA is as mature and robust as other products on the market.
I’m answering his call for more information. I hope that you will too, either by commenting on this post or emailing me at firstname.lastname@example.org.
Gildersleeve works for a company that has a Progress database running on a Unix server. Hundreds of Windows clients and Web applications are attached to that database and server through Progress Brokers via service file ports. “I need to provide 365 by 24 by 7 uptime,” Gildersleeve said. “With our new Web business, East and West Coast facilities, and vendors managing our stock and replenishment, we need to be available all of the time.”
He wants to run his database across at least two servers, in a setup like an Oracle Real Application Cluster. He continued:
This would allow me to upgrade the OS, reboot a server or take a server down for maintenance without affecting the database or the users. So far I have only found solutions that will give me a two- to five-minute downtime between switching from one server to another.
Yes, Gildersleeve has looked a little at server virtualization. He’s evaluating server virtualization options and VMware HA to see whether he can reduce the downtime to nil.
What I have seen so far is that if I upgrade my Progress app to v10 (Progress OpenEdge), and then move to two Integrity servers running High Availability, that if one server fails or if we need to do maintenance on a server, we can manually switch to the second server; but the problem with this is that my users will feel the switch because I will need to bring one server down. They will need to log out and in again to the app, or whatever needs to be done to bring the ready server into production mode.
Gildersleeve is willing to evaluate Sun Microsystems options, if they are truly viable for running Progress. Microsoft operating systems are out of the question.
In his evaluations, Gildersleeve has come up with a lot of questions, and he’s looking for advice from HA experts. Can you provide some advice and share your experiences by commenting on this post or emailing me a email@example.com?