SQL 2012 :: Database Can't Be In Two Availability Groups
Jun 30, 2014
I been trying to learn availability groups since I have not implemented it.
From my understanding you can have more than one group.
Lets pretend we have two groups in one instance:
1. Accounting
2. Engineering
From my understanding you can't make a database in two AG because it wouldn't make sense.
But lets pretending there is one database that both are used by accounting and engineering.
Would you have to make a third AG for future fail overs so that other databases in the other two group don't failover when not needed because when you fail over an AG all the databases inside it fail over.
From what I understand, one SQL Server 2012 instance can host multiple availability groups. That should allow, for example, the following situation - one SQL Server 2012 instance containing three primary replica databases - each one part of a different availability group - and each availability group's secondary replica located on a separate SQL Server 2012 instance.
Can you have three SQL Server 2012 instances, each with one primary replica database and have all three secondary replica databases on one SQL Server 2012 instance? So instead of, as above, going from 1 primary server to 3 secondary servers, this time we're going from 3 primary servers to 1 secondary server? The one secondary server would then contain all three secondary replicas for each of the 3 separate primary replicas.
This would mean that the single server (where all three secondary replicas reside) was part of three separate Windows Server Failover Clustering clusters.
We had 3 Availability Groups set up in SQL 2012 last year but they were poorly named so I am just looking to rename them but there doesn't seem to be any command for it that I can find.Can they not be renamed once created? I guess I could just create new ones and move the DB's into them but just thought I would check!
I have several 2012 availability groups running on a cluster. I have one database that is bulk loaded every 30 minutes. The DB is about 1 GB in size. To be on the availability group it has to be set to full recovery mode, but simple or even bulk would obviously be better. Is there a better way to handle the transaction log size other than to run a backup after each bulk load causing extra overhead? With mirrors you could use simple, but since those are going away . . .
We have some tables that are bulk-loaded every day and they do not have RI to the other tables in the database.
To ease pressure on the logs, I had the idea of spinning them off to another database on the same AG in simple or bulk-load recovery model and using synonyms to point to them so the code base would not need changing.
I know an earlier bug in 2005 existed that basically made the query analyzer ignore indexes if a table was accessed via a synonym.
We have multiple SQL 2012 SQL servers setup in an alwaysOn availability groups. Where should we schedule the re-index? We have Server1 as the primary and 2 secondaries Server2 and Server3. Are their any tricks to have it run on which ever one is the primary?
Prod - shared storage between server 1 and 2 Server1: clustered SQL instance with availability group as primary Server2: Passive server for clustered instance of PROD
DR - shared storage between server 1 and 2 Server1: Clustered SQL instance with availability group as replica Server2: Passive server for clustered instance of DR
Approach 2: Using replicated SAN Prod - Server 1: Standalone instance with availability group as Primary Server 2:Standalone instance with availability group as replica
DR - Server 1: Offline until Disk group 1 (Prod server 1) has been broken and brought online at DR Server 2: Offline until Disk group 2 (Prod server 2) has been broken and brought online at DR
Both these approaches will work wont they? I have only built and played with normal availability groups across servers, not mixing it with clustered instance replicated SAN
I inherited a SQL 2012 Ent server sitting on a 2008R2 server using AlwaysOn High Availability, two nodes.
Available Mode: Synchronous commit Failover Mode: Manual Connection in Primary role: Allow all connections Readable secondary: No seesion timeout: 10
Somebody decided to give SQL server priority boost so I need to change this ASAP. So I plan on doing the following.
1. Manually fail over to the secondary, which does not have the priority boost set to true 2. change the setting 3. restart the service 4. Manually fail over
My question is with the service restart. How does SQL handle if the DB changes on the new primary while the secondary is having the service restarted. Where can I see if the DB are sync again or if not where are they in the sync process.
I have configured replication between Always ON Availability Groups (Listener) (PUBLISHER), remote distributor to XYZ SUBSCRIBER...with above link ...
Now, I want to know how to replicate Data from XYZ SERVER a PUBLISHER to Always ON Availability Groups (Listener) (SUBSCRIBER)? Distributor Database being on XYZEX:
XYZ SQL SERVER as PUBLISHER, and DISTRIBUTOR to Always ON Availability Groups (Listener) SUBSCRIBER...
This is my first deployment of an always on availability group for SQL 2014 and I'm trying to get my custom backup procedure to handle all databases appropriately depending on the primary group. Basiscally I want the system databases and all databases that don't participate in the availability group to be backed up on both nodes and those that do participate backed up ONLY on the primary server. I've looked at the sys.fn_hadr_backup_is_preferred_replica funcation, but would like to only have to test for a single databases existance in the availability group. If the one database is in the group, only backup the system databases and those that don't participate, otherwise backup everydatabase. This would be the case for both full backups and transaction logs.
I've got an availability group with multiple databases, replicating to multiple secondary servers. On one of the secondary servers, some of the databases are not synchronising, and when we try re-establish the sync we get an LSN error. I can't see any obvious way to re-establish only one database on one secondary without affecting all databases on that secondary or affecting that database on all secondary nodes.
The options I seem to have are to either remove the database and then re-add it, in which case this affects all secondary replicas, or to remove the secondary replica and add it, in which case all the DBs are added.
We are planning to upgrade our production servers from mirroring to alwayson. Our current mirror setup gives the advantage that it can failover a single database.To have a similar setup in alwayson we are probably going to create an availability group per database. Any other disadvantage in this except for the extra initial configuration work?
I'm looking at using Cluster Shared Volumes on a new Windows Server 2012/SQL Server 2014 cluster. Each instance is going to be configured to use cluster shared volumes. Is there any reason why Availability Groups couldn't be used in conjunction with Cluster Shared Volumes.
I am planning to have AlwaysON Availability Group setup between Server 1 and Server 2
Server 1 -->Publisher-->2014 SQL Enterprise edition-->Windows Std 2012 --> Always on Primary Replica Server 2 -->Publisher(when DR happens)-->2014 SQL Enterprise edition-->Windows Std 2012 --> Secondary Primary Server 3 -->Subscriber-->2012 SQL Enterprise edition-->Windows Std 2012 --> NOT involved in Always ON Server 4 -->Subscriber-->2012 SQL Standard edition-->Windows Std 2012 --> NOT involved in Always ON Server 5(VM)-->Distributor-->2012 Standard edition-->Windows Std 2012-->not involved in Always ON
i know Publisher and subscribers can be mix match of 2014 and 2012 rom the above scenarios can i use (VM)SQL2012 std. as Distributor ? while publisher is being SQL 2014 ent.?
Discovered that a geo-spatial AlwaysOn HA database (1 of 4) was not synchronizing as at a point in time earlier in the day. Suspend Data Movement appears to be working perpetually without finishing. The SQL Server services is in a Pending Changes state after an attempt to restart it from SQL Configuration Manager. The Cluster Dashboard says it is in a Not Synchronizing state, with only the one database in question having a yellow triangle, all 3 others show green.
The warning for the cluster is:At least one availability database on this availability replica has an unhealthy data synchronization state. If this is an asynchronous-commit availability replica, all availability databases should be in the SYNCHRONIZING state. If this is a synchronous-commit availability replica, all availability databases should be in the SYNCHRONIZED state. There is no abnormal data movement from the primary to the seconday.The warnings for the unhealthy database are:
The data synchronization state of this availability database is unhealthy. On an asynchronous-commit availability replica, every availability database should be in the SYNCHRONIZING state. On a synchronous-commit replica, every availability database should be in the SYNCHRONIZED state.Either a database administrator or the system has suspended data synchronization on this availability database.So how to get this database back to synchronizing state?
The MSDN doc makes it sound like after a failover of the primary, the CDC data won't "keep working" on the secondary unless you "To allow the logreader to proceed further and still have disaster recovery capacity, remove the original primary replica from the availability group using ALTER AVAILABITY GROUP <group_name> REMOVE REPLICA. Then add a new secondary replica to the availability group."
We have a few CDC tracked tables that we use and the general idea of AlwaysOn I thought was to minimize all the overhead and let things "just work" so your apps just connect and the listener re-routes everything where it needs to go.
It looks like to get this working properly an automated job /trigger would have to wait for a failover event and then kick off tasks to remove and re-add the replica and perhaps start up the CDC job on the secondary?
We are trying to build HA and DR environment, combining AG and FCI. So we have 3 servers added to a cluster, 2 of them sharing the same storage and working as ACTIVE-PASSIVE cluster instance. The other server has a stand alone instance with its local storage, with the same drivers letters as the cluster instance.
Between the Active FCI and the Stand Alone, we set up an Availability Group. They are running fine, except by the listener. When the stand alone instance owns the Primary Replica, I am able to access the SQL Server instance by the listener, but when the Primary Replica is owned by the FCI, I can't reach the database by the listener (name or IP).
I've opened the same ports in both servers, it hasn't worked though.
I'm doing a certification process using AlwaysOn, and was using the link below, and on the lower 90 hotfix, and instead of downloading one by one, and then upgrade one by one updates, is there any way to make it more faster or practical, or unfortunately have to do this one by one, so the download as the update? This rollup contains the latest version of the Windows system files that are updated after the release of SP1. URL...
We are having a conversation at work and the subject of load balancing with SQL came up. Right now we are running SQL Server 2014 on four (4) machines. I am using a AlwaysOn with Availability Groups (AG). Now I know that we can scale out the reading in AG by allowing the secondary serves to receive reads.
Is there a way to be able to do this with writes? Can I have in essences 2 masters that some how reconcile with each other? We are expecting a huge amount of writes in the near future and we need a way for SQL to handle the amount of traffic we are expecting with out any issues.
I explored the possibility of Peer - to - Peer replication; however, it seems that it would be more work if we are constantly making updates to the database scheme.
we currently use Backup Scripts from Ola Hallengren, It Says Full (non copy-only) and differential backups are performed on the primary replica. Full(Copy-only) backups and transaction log backups are performed on the preferred replica.
we currently do FULL(COPY_ONLY) Backup everyday and LOG Backups for every 15 min, is there any performance benefit on running the FULL (non copy-only) on the preferred replica .
I am planning to have AlwaysON Availability Groups setup between Server 1 and Server 2
Server 1 -->Publisher-->2014 SQL Enterprise edition-->Windows Std 2012 --> Always on Primary Replica
Server 2 -->Publisher(when DR happens)-->2014 SQL Enterprise edition-->Windows Std 2012 --> Secondary Primary
Server 4 as Subscriber
Server X as Remote Distributor ..
If i create Publications on Server1 (primary replica) to subscriber 4 servcer, will the publication be created automatically in Secondary Replica Server2 ? or do i have to create manullay using GUI/T Sql on Both Servers?
I am planning to have AlwaysON Availability Groups setup between Server 1 and Server 2
Server 1 -->Publisher-->2014 SQL Enterprise edition-->Windows Std 2012 --> Always on Primary Replica Server 2 -->Publisher(when DR happens)-->2014 SQL Enterprise edition-->Windows Std 2012 --> Secondary Primary Server 4 as Subscriber Server X as Remote Distributor ..
as of now , In the event of Disaster happens on Node 1 i will have to manage JOBS on Node 2 (backups, Maintenance, replication, day-day other Jobs)..Is there a way i can call all jobs to run from a remote server which executes on Active NODE(which ever is active)? so that in the event of disaster happens on node1, when node 2 becomes online and i don't have to do anything with SQL Agent or jobs on Node 2?
I am setting up a 3 node cluster as part of an availability group.Initially I tested failover between nodes using SQL Management Studio and everything failed over successfully when I stopped a node, and I was still able to write queries. I started to test with an application which connects using an SQL user and whenever I would switch nodes, I would get login failed. I believe the cause of this issue is because the server logins SID's which are tied to the database are different than the server logins on the other nodes which resulted in login failed.how can I ensure that the server logins SID's are the same between nodes? Is there a way of copying this over or how is this supposed to be done? I read a little about contained databases where I could just set the login on the database itself vs. creating a server login but I would rather not go down that route.
I want two write a small script to determine which is the currently active (primary) server in the AG.
Right now, I see that using SELECT * FROM SYS.dm_hadr_availability_replica_states I can determine the role. However, when the server goes down and switches to the secondary node, I don't believe that the role changes (or does it?). How do I determine which is the active node?
