SQL Clone
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Availability Group Question


Availability Group Question

Author
Message
rummings
rummings
Ten Centuries
Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)

Group: General Forum Members
Points: 1123 Visits: 461
We are running a six instance, Active\Active 2008R2 cluster. We want to go to a 2012 failover cluster. I am familiar with the SQL Server 2008 R2 cluster and how it works, but not the 2012 with the Availablity Group feature. Do you create the Availabilty Group(s) in a Failover Cluster instance and then have the option to fail the entire instance or just move the Availabilty Group to the other node? From what I read... the Availabilty Group is more like a hot standby... allowing you to move the databases in the Availability Group to another node(s). I would think the Availabilty Group would reside separate from the Failover instances.... but would like to hear it from someone that has already set this up.

Thanks!

Charlie
Sreekanth B
Sreekanth B
Ten Centuries
Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)

Group: General Forum Members
Points: 1137 Visits: 2151
SQL Server Failover Cluster Instances are not mandatory for AGs. All you need is a Windows Cluster and standalone SQL Instances to make it work(All the Servers(nodes) participating in AlwaysON AG should be part of same Windows cluster). You can build AGs on top of SQL clustered Instances as well(same as we used to do with DB Mirroring), it really depends on your business RTOs/RPOs. Consider AG as "Super Mirroring". They both work pretty much on same principals, but AG has some Super powers like "Multiple databases Failover as a single unit", "readable Secondaries" etc...

Bottom Line: SQL Server failover Clustered Instances are not required for setting up AGs.
rummings
rummings
Ten Centuries
Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)Ten Centuries (1.1K reputation)

Group: General Forum Members
Points: 1123 Visits: 461
Great! Thank you very much for the information.

Charlie
TheSQLGuru
TheSQLGuru
SSC-Dedicated
SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)

Group: General Forum Members
Points: 32309 Visits: 8674
Please don't just read a few blog posts, run a few forum questions and then set off doing AGs!!! NOTHING good will come of that! This is complex stuff with lots of caveats, provisos and gotchas!

Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service
RTaylor2208
RTaylor2208
SSCrazy
SSCrazy (2.7K reputation)SSCrazy (2.7K reputation)SSCrazy (2.7K reputation)SSCrazy (2.7K reputation)SSCrazy (2.7K reputation)SSCrazy (2.7K reputation)SSCrazy (2.7K reputation)SSCrazy (2.7K reputation)

Group: General Forum Members
Points: 2657 Visits: 1262
TheSQLGuru (11/14/2013)
Please don't just read a few blog posts, run a few forum questions and then set off doing AGs!!! NOTHING good will come of that! This is complex stuff with lots of caveats, provisos and gotchas!


I get the feeling that its a bit of a rushed out product, I have been evaluating AG's for the last 2 months and there are a number of issues I have found so far. Specifically replication. Your distribution database cannot be part of an availability group meaning really you need to host it in a seperate SQL instance and possibly used clustering to provide any sort of HA. Although there is the option to utilities 2 or more of your servers used as part of the AG solution to host an additional clustered instance with shared storage.

Subscribers are not particularly well supported either and a real pain to deal with if part of a AG.

MCITP SQL 2005, MCSA SQL 2012
Perry Whittle
Perry Whittle
SSC Guru
SSC Guru (54K reputation)SSC Guru (54K reputation)SSC Guru (54K reputation)SSC Guru (54K reputation)SSC Guru (54K reputation)SSC Guru (54K reputation)SSC Guru (54K reputation)SSC Guru (54K reputation)

Group: General Forum Members
Points: 54147 Visits: 17684
If you do join a clustered instance to an AO group you will not be able to use automatic failover.

-----------------------------------------------------------------------------------------------------------

"Ya can't make an omelette without breaking just a few eggs" ;-)
TheSQLGuru
TheSQLGuru
SSC-Dedicated
SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)SSC-Dedicated (32K reputation)

Group: General Forum Members
Points: 32309 Visits: 8674
RTaylor2208 (11/15/2013)
TheSQLGuru (11/14/2013)
Please don't just read a few blog posts, run a few forum questions and then set off doing AGs!!! NOTHING good will come of that! This is complex stuff with lots of caveats, provisos and gotchas!


I get the feeling that its a bit of a rushed out product, I have been evaluating AG's for the last 2 months and there are a number of issues I have found so far. Specifically replication. Your distribution database cannot be part of an availability group meaning really you need to host it in a seperate SQL instance and possibly used clustering to provide any sort of HA. Although there is the option to utilities 2 or more of your servers used as part of the AG solution to host an additional clustered instance with shared storage.

Subscribers are not particularly well supported either and a real pain to deal with if part of a AG.


Not sure about rushed - it's just a very difficult thing to do robustly and scalably. Leaving out replication isn't surprising. In my experience (dedicated SQL Server engine work, mostly consulting, since 6.5 first came out) very few installations use replication. Some of the issues have been addressed in patches. But again, HA/DR itself is VERY hard to do right and I have come across very few clients that had things done up correctly. And most were HORRIBLY messed up!

Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service
Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search