Posted by: Colin Smith
70-443, Certification, Education, Training
This chapter is all about cosolidation and multiple instances. Not a very long chapter but a great read. I have to say that this cleard up some misconceptions on my part and I really enjoyed the chapter. This chapter talks about instance design and consolidation strategy. I must say that I was a firm believer in one instance per appliction. This works great for keeping things seperate and that way I can give a named instance to each application. Easy to know what instance I need to look at when the application team calls with an issue. This however is not so great when you think about the resources on the server. You can install multiple instances on one server in order to condolidate hardware but at what cost. Each instance needs its own resources and unless you need to have seperation for security purposes it may make more sense to host multiple application Databases on on instance. You will be able to save resources and have more applications running from less servers. This will save a ton of money in hardware and software licensing. You still need to know what each database is doing so you can make sure not to overload the server. remember that you have DISK IO, Memory and other things that will come into play. For instance, each connection to the instance will take about 500 KB of Ram. The more databases that your instance is hosting, the more connections you will have and the more RAM you will be using. Make sure to take all that into consideration when doing your consolidation or instance design.