Application failover is the big thing
Setting up high availability was one of the top priorities for Lathrop & Gage LLP CIO Ben Weinberger when he moved to the Kansas City, Mo.-based law firm from Florida-based Ruden McClosky in July 2008. Weinberger said his current firm is less likely to suffer natural disasters as his previous one, but nobody's immune to fires or power outages.
He said Lathrop is a straight Windows shop, mostly Windows 2003 with some Windows 2008. He plans to move to Exchange 2010 early next year, in hopes of setting up active-active high availability for headquarters and 12 remote offices.
Weinberger was an XOsoft customer at his former firm, and he's evaluating XOsoft and Double-Take at his new firm. He said he's paying particular attention to how they handle applications. "Everybody does replication now, but application failover is the big thing," he said.
The most important applications for Lathrop are Exchange and SQL, but Weinberger said the firm is running 300 applications. He also prefers host-based data replication over SAN-based replication.
"The advantage of host-based replication over SAN-based replication is it tends to be application aware," Weinberger said. "It knows it's running Exchange; it can check for the consistency of the database. It's also less expensive than SAN-based replication, and you're not locked into identical hardware on both sides. XOsoft seems more slick with the other components, like Assured Recovery, that lets you pause replication for testing. And with its CDP you can roll back to any point in time."
Another key to the equation is the licensing around virtual servers, said Weinberger.
"We were trying to shove as many guests onto a single host box as possible on our secondary site," Weinberger said. "We upgraded our Windows Enterprise license to Windows Datacenter to support a lot of guest virtual machines. By changing to Datacenter Edition, we could run an almost unlimited version of Windows. That was the starting point. Then we looked at what software for replication we could use.
"Double-Take has a good licensing model; you can run an unlimited number of guests. XOSoft did not. CA came back and said they would modify the licensing model so we could run 20-plus guests on a single host. Realistically, we'll probably fit 15 guests on that host. We didn't want to have to buy an individual license for every guest there, that's too much to manage aside from the cost factor."
Weinberger said he's taking a wait-and-see attitude on Exchange 2010's clustering capabilities.
"I'd love to believe that we can get it all done with the native tools, but, we won't truly know that until we see it in action," he said. "CCR/SCR in Exchange 2007 was supposed to negate that need [for third-party HA], but, it did not."
High-availability alternatives for SMBs
Cem Kursunoglu, president of San Francisco-based BayNode Technology Consulting, recommends Neverfail's high-availability software to his clients. BayNode concentrates on small- to midsized businesses (SMBs) that are almost totally Windows shops.
Kursunoglu said Microsoft's clustering is too complicated and expensive for smaller businesses, and third-party applications scale better and simplify the process. He recommends Neverfail because it integrates better with Windows applications than other alternatives.
"Depending on the customer's budget, we'll use Neverfail for offsite replication," he said. "If there's no budget, we use CCR and put the nodes in the main office and the disaster recovery [DR] site. But that requires manual tweaking if they need to switch to the DR site. Neverfail's compression technology can squeeze a lot of bandwidth. It will transfer the load from one server to the other, not just make a file transfer."
Kursunoglu also recommends Hyper-V 2 to some of his smaller clients. To keep down storage costs, he recommends they run DataCore Software Corp.'s SANmelody or Hewlett-Packard (HP) Co.'s LeftHand Networks SANiQ to turn commodity hardware into an iSCSI SAN.
"Normally if I want to protect an application server, I have to put it in a cluster or use a third-party solution," he said. "Now I can do that with this free tool [Hyper-V], and pair it up with a DataCore SAN."
Taneja Group analyst Jeff Boles agrees with Kursunoglu that third-party tools can simplify and scale clusters better than Microsoft's software, especially for off-site replication.
"You can get part of the way there with Microsoft's cluster, but it's primarily designed for in-site clustering," Boles said. "Other products have more sophisticated application capabilities. They support more nodes, a larger pool of servers -- or they massively simplify the process. Microsoft clustering historically has been complex. Products that introduce a simple layer to clustering add a lot of value."
