In that case, you would need to
purchase an additional server to sit idle to maintain the N+1 formula.
This approach is usually applied to load balancing, but I believe it should be applied to SQL Server
clustering as well. If you have only a two-node configuration, it can be hard to justify the cost of letting
that hardware sit. As you increase the number of nodes, the potential protection provided by a node
that sits fallow can be significant. Having a spare node can still be a hard sell to management, but I??™ll
discuss some techniques to rationalize the extra hardware in Chapter 12.
Active/Active/Active/ . . .
SQL Server 2005 Enterprise Edition supports the same number of nodes as the Windows
Server version being used, which means you could have an eight-node active/active/
active/active/active/active/active/active configuration. I??™ve configured four-node clusters,
as shown in Figure 7-4, for production use, and I??™ve configured an eight-node cluster
in a test environment. Having four active nodes is complicated enough; a cluster of eight
active nodes in a production environment is enough to make your head explode (well,
mine at least).
Pages:
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361