SQL Server Admin 2014 :: AlwaysOn Availability Group Configuration
Jun 17, 2015
What I asked for: Three Windows Server 2012 R2 machines with independent storage running a SQL Server 2014 AlwaysOn Availability Group. DB1 would be the primary, DB2 would be a synchronous replica, and DB3 would be a remote asynchronous replica.
What I was given: a two-node Windows Server 2012 R2 WSFC to run SQL Server 2014 Enterprise with shared storage and a third (remote) Windows Server 2012 R2 machine with independent storage, also with SQL Server 2014 Enterprise, to host an AlwaysOn Availability Groups asynchronous replica.
DB1 and DB2 (as Cluster1) share an E: drive. The remote DB3 has its own E: drive. Initially, DB3’s E: drive was claimed as a cluster resource and I couldn’t even see it. I’ve had several ugly days trying to make this work and have temporarily given up, installing DB3 as a standalone SQL Server that is no longer part of the WSFC and pointing everything towards that (it was originally a third node in the WSFC).
Is it possible to create an AlwaysOn Availability Group with nested clusters (i.e. create the AOAG with Cluster1 and DB3 and somehow ignore the individual nodes that comprise Cluster1)?
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?
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?
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.
We are looking at going down the High Availability Always On route. However we have some concerns around the lack of support for MSDTC. In short we are concerned that developers may introduce functionality either on purpose or by mistake that uses the or escalates the Query’s to the MSTDTC. As this could result in database splitting.
Understand that this will be a moot point in SQL 2016 but for 20122014 is it possible to disable the MSDTC to protect against this and run High Availability Always On. ? Does it just need to be disabled on the SQL Server or does it need to be done on the application server ?
Recently after turning on trace I restarted the sql services on a box which is configured for automatic failover availability groups. The ag has not failed over to other node. The other node was in resolving state. When the restarted server is back, the AG went back to that server. I checked the sys.availability groups field for failover property failure condition level, it's set to 1 which means service restarts should initiate the failover.
I setup an availability Group. (Only 2 servers - Primary And secondary) -- 21 , 22
I also define an listener . IP .. 23
1- In First step I connected To Listener (23) And in a while I inserted A record to a table .
While 1=1 insert into Tbl_T1(f1,f2) Values (1,2)
2- in second, I Stop the primary .
- I expected this while whitout disconnect, continue.
3- The while code stopped whit this message :
Msg 64, Level 20, State 0, Line 0 A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The specified network name is no longer available.)
4- I execute again the script, And it worked in new primary.
My questions :
1- is the listener disconnected between switched primary and secondary ? OR have we data loss between switching?
2- I did some huge update on Primary that fill the Log fiel space. And in last Update I got this error :
Msg 9002, Level 17, State 2, Line 27
The transaction log for database 'Your_DB' is full due to 'LOG_BACKUP'.
Is this (Fill All space) a reason to switch primary? Or not ?
I'm running a primary and secondary on sql server 2012 enterprise edition on windows server 2012, and it runs fine except when a network outage occurs.
Then the handshaking keeps failing, the databases on the replica show as not synchronizing and the only way to fix this is to reboot both primary and secondary.
We keep getting 3520's, etc. on the DR error log
How to eliminate all these prod reboots?
I increased query connection timeouts to 60, but saw no change.
We are currently using 2008 environment. We do have an SSIS Package running. The package used to run everyday and take the production server full backups and restore into the another server. Then do some delete commands and do some updates in that database on that server (We have some sensitive data other than Production we have to run that scripts in any environment). After run all those delete statements another team will read the data from that database.
We are planning to migrate to 2014 and set up always on and use the replica as the source. In this case how the package will work?
How to change that SSIS package. With the 2014 always on we are directly reading the data there is no backups to restore then how to run the delete statements?
I am trying to create a job that runs against my High Availability listener server.
It is a fairly simple SQL statement in the job - execute tsql.
When I try and run the job I get the error:
Executed as user: NT SERVICESQLAgent$SQL2014A. The target database ('BB_Prod') is in an availability group and is currently accessible for connections when the application intent is set to read only. For more information about application intent, see SQL Server Books Online. [SQLSTATE 42000] (Error 978). The step failed.
I thought there was a way to run a select statement as a job against the listener? The tsql step is only a select.
Is there a way to pass in the application intent = readonly as part of my SQL statement?
I would like to setup replica for one of the databases for reporting. The current environment is a 2 node cluster(active/passive). I would like to add a 3rd node that can server as a secondary replica. The secondary replica will be on asynchronous commit mode.
The database that needs to have alwayson setup has column level encryption enabled.
Other Questions,
* Do I need to backup and restore the service master key on secondary server in order to have the column level encryption to work on secondary server? * What would be preferred Quorum settings? * What is the setting for 'readable secondary' for primary and replica db? * What should be the setting for 'Connections in Primary Role' for primary and replica db? * We are trying to setup without a Listner. Do I need to setup AG Listener? Can the application exclusively use the [secondary instance name].[replica DB name] without a listener?
I have a database that is part of AlwaysOn that is filling up the transaction log drive even though I have a daily full backup and transaction logs set for every 2 hours. The backups are going from both the primary and secondary replica backuping up to the shared disk and I have the backup preferences set to the primary.
When I try to shrink the log I get 'The transaction log for database 'DB' is full due to 'LOG_BACKUP''. I have to manually backup the trans log and then shrink, why the maintenance plan backups aren't doing this even though they are "working".
We had a big issue today during maintenance work in our SQL environment.
So our environment: - 2x SQL Server 2014 Enterprise on Windows Server 2012 R2 (SRV1 and SRV2) -- Both Hyper-V VMs on different Hosts -- Both configured to an Windows Failover Cluster and AlwaysOn Availability Group (AG1) -- AG Listener: AG1_lis -- No shared storage (each Hyper-V Host has its own local storage) -- Asynchronous Mode -- SRV1 is primary, SRV2 is secondary SQL node
What happened? - Shutting down Windows on SRV2 due hardware maintenance - Cluster goes offline, AG1 goes offline -- Error message: "Stopped listening on virtual network name 'AG1_lis'." -- Error message: "The availability group database "DatabaseXY" is changing roles from "PRIMARY" to "RESOLVING" because the mirroring session or availability group failed over due to role synchronization."
Results? - AG1_lis wasn't available for our applications and they stopped working properly because database connection was lost!
I think, I HOPE, this is not the normale behaviour when one node is shutting down (especially the secondary node!)
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 .
We have a 2 node clustered instance(SQL 2014) with 26 databases and we would like to enable alwayson for one of the databases for reporting (only one secondary and do not need high availability setup). I'm thinking if the reporting application/queries can explicitly connect to the secondary database(Instance namedatabase name) without using a listener and setup the secondary in asynchronous commit mode. Read about the REDO thread blocking due to reporting workload. How does this affect if I implement the secondary in this way.
I am trying to build out an AlwaysOn AG with 2 nodes each in a different subnet (in AWS if that matters), windows 2012r2 / SQL 2014 RTM
I created a AG Listener with 2 ip address, 1 for each subnet (checked that neither ip address are used). But whenever i failover the AG to the secondary, and try and connect via the listener it fails,
I am trying to connect via SSMS from the primary instance. and just time out, If i roll over to the primary i can connect no issues, I've tried playing with the connection settings, upping the time out to 30 secs, adding the MultiSubnetFailover=true. etc but not getting any joy.
Having an annoying AG/AO problem with the read only routing side of it.
Let me give some specifics first:
2 SQL Server Instances, Not Clustered. Availability Group is named 'Ireland'
There is a primary Replica and a Secondary Replica, named:
'IrelandPrimary' and 'IrelandSecondary'
There is a listener configured with the name 'ListenIreland' on Port 14330 (the two 3's are correct)
Read Only Routing URLS are configured as follows: IrelandPrimary tcp://Ireland.dom.local:49891ALL IrelandSecondary tcp://Ireland.dom.local:49841ALL
So now my problem:
When I try to connect using the ApplicationIntent=Readonly; or even using -K ReadONLY in sqlcmd I get the error telling me that my connection was actively refused.
This is connecting to the Listener, not the instance itself - that works fine. I'm at a bit of a loss now.
To explain what I am trying to achieve is a for a connection to be redirected to the secondary replica when its set for read-intent.
I've just noticed that it only fails when I specify ApplicationIntent=ReadOnly; If I omit the Intent It connects to the read-write database instead.
How you are handling the replication of the many instance-level objects/items (logins, linked servers, server roles, database mail, operators, on and on) to the replicas in an AlwaysOn topology.
I'm especially curious about DBAs managing larger SQL Server environments. In my current environment, we have approximately 80 production SQL instances containing about 650 databases that require high availability and disaster recovery.
We use mirroring today and have a solid, home-grown solution for replicating the instance-level items from production to disaster recovery. AlwaysOn changes things a bit since we'll have multiple replicas and of course the database could be active on any one of those at any time. So my concern is about instance-level items being created in one instance but never deployed to the other instances participating in the AG group.
Is there any single TSQL query which provides below info.When did my AlwaysOn Availability group failed over and from which node it failed to which new node(i.e. replica)?
