Now let's turn our attention to the enhancements that affect availability for SQL Server 2012. Now understand SQL Server 2012 continues to offer you a number of different availability functionalities that we've all kind of gotten addicted to, that we like. One of those is Database Mirroring. Then there's Log Shipping and then Replication. Now these have kind of become staples in the SQL Server Administrative Availability world. They are still here, we have not lost them. Log Shipping especially, really neat functionality, a lot of people do a lot of different cool things with this. Replication is admittedly one of those technologies, some administrators love this, wouldn't live without it, others you just mention Replication and they start to throw furniture and scream and lose control and you have to call people to come help. So let's talk about the Four Availability Enhancements that I'm going to focus on here. And keep in mind before I talk about this, there are other enhancements and you need to go, kind of do some reading and check in those. But these are the ones that are getting all the attention, those are typically the ones that get tested on pretty strongly. So first of all AlwaysOn Availability Groups, this is a new functionality in 2012, notice AlwaysOn, one word, that is not a typo, it's not a misprint. Microsoft is, is kind of branding this particular functionality for good reason, it looks pretty cool, we'll talk about it more in a minute. AlwaysOn Fail-Over Clustering Instances or FCI, then there's support for Windows Server Core and then a Neat New Tool called Recovery Adviser. So let's dig into the AlwaysOn Availability Groups. The bottom line with this is it let's multiple databases fail-over as a single unit. It's almost like a transaction based fail-over. So if we've got one database that fails but we've got three other databases that are closely related to this one for whatever reason, they fail-over as a single unit. And this functionality AlwaysOn will support up to four what Microsoft calls Secondary Replicates. Now these are replicas of your primary SQL Server. And here is the cool part, two of these can be configured as synchronous. Now the other two will be asynchronous okay, which means updates are going to happen separately and there's going to be maybe a little bit of a lag time. But synchronous means it's happening at the same time, they are synchronized. And so you're going to have, if you have two of these, then you have three basically identical copies at all times. Now all your Secondary Replicas whether they are synchronous or asynchronous are active and readable. Now you can't update them but you can read from them, but look what that gives you. You can go to one of the secondaries and you can do your backups there, so you are offloading backups off your primary database production server. You can run reporting off of one of these backups. The big thing here, most of your report queries are large and involved and they are slow to process. You can offload that onto one of the secondaries. Any adhoc querying, we're just trying to bang out queries to get information to run tests whatever, that is historically a notoriously not efficient, poorly done, you know, all those kinds of things. The kind of deal we executed and then realize, oh wait a minute I shouldn't of done that. That can be done on an offloaded basis on a secondary replica. Now here's the term that CEOs and COs love, AlwaysOn Availability will provide Zero Data Loss Protection and that is huge. The next one I want to talk about AlwaysOn Fail-Over Cluster Incidences or FCI. This is really just enhanced Fail-Over Clustering. It now allows you to Fail-Over Clustering onto multiple subnets. That means the subnet can be local or remote and in English that means I can now Fail-Over Clustering in geographically separate locations and that's the ultimate insecurity in our world today. Then the Fail-Over Clustering has been improved. You get faster start up and recovery, once a Fail-Over Occurrence does happen and that's always a big deal, and you also have improved Cluster Health Detection Policies. There is nothing more frustrating than to take the time and the effort and the man hours and the sweat insanity to build cluster, get it working, test it. Then in a real world scenario when one side fails, the other side doesn't pick up. It usually helps you to find a job somewhere else, it's, it's just a not good deal. So anyway support for the Windows Server Core, SQL Server 2012 can now be installed on Windows Server Core. Now just as a little refresher here, Windows Server Core is a stripped down version of Windows Server. No bells and whistles, no graphical user interfaces, it's all Command Line, but it's a lean and mean version of Windows Server. A lot of people virtualize this and is part of availability to put SQL Server on that, because it can be much more efficiently managed, moved around. That sort of thing. And then the last one is, this Recovery Adviser. This is a New Visual Interface Tool that helps you kind of watch and police and understand where you are in a database restore process. And if you've got a lot of Transaction Logs and that sort of thing, it can get confusing, this thing will help you get through that without losing your sanity, causing data problems and that sort of thing. So we'll talk about that some more later on in the course. But that's kind of the basic availability enhancements. Make sure you get some hands on with each one of these and just tinker with it a little bit because I am sure you're going to see questions about this functionality on the exam.
| Course: | Microsoft SQL Server 2012 Admin (70-462) |
| Author: | Mark Long |
| SKU: | 34342 |
| ISBN: | 978-1-61866-048-0 |
| Release Date: | 2012-06-18 |
| Duration: | 9 hrs / 99 lessons |
| Work Files: |
Yes |
| Captions: | No |
| Compatibility: |
Vista/XP/2000, OS X, Linux QuickTime 7, Flash 8 |