tag:blogger.com,1999:blog-8249436894380089801.post3777671138075537132..comments2008-02-20T14:57:57.075-03:00Corinoreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8249436894380089801.post-62569914071509244312008-02-20T13:40:00.000-03:002008-02-20T13:40:00.000-03:00I think the biggest issue that I have seen with consolidation is that each app stores and formats the data slightly differently. Thus consolidating legacy data is an expensive data warehousing migration task.<BR/><BR/>The data services layer is supposed to solve this issue but there has not been much product development that I have seen yet. Perhaps the most promising is a metadata langauge called JUMP. The open-source effort on sourceforge (project jumper http://sourceforge.net/projects/jumper) holds some promise that the industry might actually agree on an open-standard.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8249436894380089801.post-69021857471465371522007-03-12T12:57:00.000-04:002007-03-12T12:57:00.000-04:00The car analogy obscures some of the reason why the one-app-one-server model developed and has persisted.<BR/><BR/>It's really more like having 5 over-achieving spoiled brats who can't be in the same room for 5 minutes without starting a fight/international incident, and who also have 80-hour weeks between dance, band, karate, school plays, and toastmasters.<BR/><BR/>The apps really did not get along well - in fact, they still don't. Despite all the promises of .NET and Java about everything running beautifully side-by-side in parallel versions, DLL hell is still a very real place. And that's not even bringing in issues of performance or hardware requirements.<BR/><BR/>But the biggest issue is not compatibility or performance, but uptime. Again, despite all the promises, Windows servers still need to be rebooted fairly often when apps are changed (and before the MS-hate starts, note that this is mostly the fault of the app developers, not Microsoft...). If your services have 5x9 uptime requirements (99.999%), you really don't want to have to take an outage on Service A, which is not being changed, just because it happens to be installed on the same server as Service B.<BR/><BR/>So there were good reasons for the one-server-one-app policy, many of which continue to be true today.<BR/><BR/>And that is why VMWare and Microsoft's Virtual Server are huge topics in server consolidation. Virtualization was the first technology since Windows NT started the explosive proliferation of servers to provide a real chance at getting servers back to efficient usage of hardware resources.<BR/><BR/>Virtualization isn't a silver bullet, though. There are a lot of issues to consider when virtualizing a server environment - all the same kinds of things mentioned above: performance, uptime, security, compliance. When executed by people with the proper expertise, it yields great results, but it's by no means trivial.Jeff Cnoreply@blogger.com