Recovery :: Which Replica Becomes Primary When Availability Group Fails Over
Jul 16, 2015
I have 3 synchronous AlwaysON replicas: A, B and C. A is primary, B and C are secondary and both are set to Automatic recovery. How can I understand, which of them (B or C) will become primary when A goes offline? Well, Actually my final DB system should support following configuration:
1) Normally - A is primary B and C are sync secondary.
2) if A fails, B automatically becomes primary, C remains Sync secondary.
3) if A goes online, it becomes primary again
4) C becomes primary only after A and B fail (and there still should be cluster quorum!)
As I understood, first of all i should configure quorum the following way: A-0, B-1, C-1, folder-witness-1.
The problem, again, is: I cannot understand how to configure which replica becomes primary when AG fails over.
need to migrate a cluster with an AG dtabases to new data center cluster with AG.
I was wondering if is possible to do mirroring on top of the AG configuration? or what other options could be to migrate a cluster that has 3 nodes and setup the ag databases to a new datacenter.
Setting up a test AlwaysOn Availability Group for one database.
However, whenever I restore the database to the replica server and join it, it ends up with my user account as the owner of the database.
Obviously I do not want a user account as the database owner, but since it is read-only I cannot modify it directly. If I were able to fail the AG over to the replica, I could change the owner then, but I cannot due to business requirements. this AG is to essentially serve as a replacement to log shipping.
I tried doing the backups and restores using EXECUTE AS login = 'sa', and yet it still shows up as my user account.
As per our client requirement we want to set synchronization time from primary replica to secondary replica after 20 minutes. Is it possible in MSSQL AlwaysOn Availability Groups in SQL Server 2012?
i am preparing for always on with multiple instant.is there any consideration with multiple instant ? with each instant shall i create new availability group?
We're having an issue with an AG where the the log backup does not appear to truncate the log. symptoms..Run full backupRun transaction log backup DBCC Loginfo shows all VLFs with a status of 2sys.databases.log_reuse_wait_desc says LOG_BACKUPOPENTRANS indicates no open trans.All backups are being run on the primary.
SQL 2012 EnterprisePrimary server and 2 x secondary serversWindows 2012 R2
I have removed one of the database from availability group by mistake. Luckily I am still operational with primary server. database on secondary servers are on restoring mode.
I have done full backup of database from primary (prod) server and restored on secondary servers with no recovery when I add database into availability group I get an error message log missing what is the best method to achieve and add database again into availability group.
Note I cannot restore database on primary server as it is on production
How do I add my second (secondary) node in my AlwaysOn Availability Group, after adding my head node, and the secondary node is a virtual machine. See based on the attached file if it is the correct way?
I am in the process of rolling out a pair of SQL 2014 servers. I have setup an Availability Group, Listener and databases. It's my understanding that I will be giving the listener name to our developers so that they can do their work. In testing, I noticed that If I am using Studio Manager and connected to the the AG using the listener name, when I setup a user in security the user is only added to the active primary node. Is there a way to add a user to both servers in one shot instead of having to install on both servers?
In our(my company) current design we want to switch from failover clustering to Always On as high availibility solution.
I am currently testing the availiblity Group Listener function and have two questions regarding this.
First of all, is it possible to connect to a a listener by just using its "name" instead of "name,port", it is for our users very inconvenient to start using ports. If this is possible, where can I find information on how to configure this?
Second, is it possible to use the Availiblity Group Listener as loadbalancer or in combination with a loadbalancer to split the users over two or more nodes?*note we don't use azure.
I need to move files for a lot of databases that are all part of an AG. I've used the method at the bottom of this link with success on a small test DB.
I have a web server that is on our DMZ subnet and I have a sql 2014 database server with Always on Availability Groups that is on our internal domain subnet.The failover cluster is on the internal domain subnet as well. I am trying to connect a web application, that is working off the .net 2.0 framework, to an SQL Server 2014 database using the Always on Availability Group Listener.
The connection strings works perfect with the named instance of the sql server but when I try to use the Availability Group listener it timed out. I did some research online and was led to believe that increasing the connection time would resolve it. I did that and got a different error pertaining to a successful connection but an error occurred during the login process (Provider: TCP Provider, error: 0 - The specified network name is no longer available.)
I just want to connect to an Availability Group Listener on the domain subnet. I have rules in the firewall to allow all services for the IP of the Listener. I switch back to the named instance of the same server and it works flawlessly. I have also connected to the Listener while running the application on the same subnet as the sql server without an issue. I have tried the IP instead of the Listeners name and still received the same error on the DMZ subnet. I'm running on Windows Server 2012 R2 on all servers.
The Web Server is using IIS 8.5..All Physical Machines except the replicas and webserver are virtual machines.All Static IPs involved.As mentioned all SQL Servers are 2014.
I have an active passive cluster on my primary Data center in NY and have a DR Active / passive SQL Cluster in TX. These are two separate clusters in the same domain using the same SQL server credentials.Both clusters host an active / passive SQL instance. Lets call it SQLNY(Primary) and SQLTX (DR). I want to enable always On Availability group within the two SQL Instances SQLNY and SQLTX. The listener will be SQLAG which will be used by the Application to connect to the SQL instance. Is there a practical way to implement this? This will not only give me instant fail over within the NY (Primary) but also give me the flexibility to fail over to TX. I am using SQL 2014 Enterprise Edition on both clusters.
I have a situation where I have two servers in SQL Server 2012 R2 AlwaysOn Availability Group. One is primary and the other one being secondary. I am only running SharePoint Database on it.I have run out of space on the primary server and about to run out of space at the secondary server. I have tried shrinking database transaction log files, but it returns an error that it cannot be shrunk as the database is in the AlwaysOn Availability Group.
Questions: 1. Several forums suggest that databases need to taken out of AlwaysOn Availability Group in order for the shrinking to work properply? 2. Would it have any impact on the database if it is taken out of availability group and then added back?
I have a SQL 2014 SP1 set of servers with two asynchronous copies of an availability group. One of the asynchronous sites is down and SQL can no longer replicate the changes. I need to understand how long SQL Server can continue this way before the secondary replica will no longer be able to catch up. I assume this is really tied to the transaction log on the primary replica but would like it clarified.
I'm just starting to work with AlwaysOn Availability and WSFC.
I have in my environment (in Azure) a DC, WSFC and to SQL instances, so I have 3 nodes in my Failover Cluster:
WSFC SQL1 SQL2
If I simulate failure by shutting down one of the SQL boxes my Availability group seamlessly fails over to the other SQL instance - which is great.
However, I'm starting to look into the workings of the Quorum, my envt has the default settings and when I shutdown both of my SQL servers I expected the Cluster itself to go offline as 2 out of the 3 votes will be negative, but the Cluster is still up - Screenshot below when SQL1 and SQL2 are shutdown:
Going through the Wizard (but not changing anything) it shows following config:
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 am setting up a new pair of SQL 2014 enterprise servers in HA using Availability Groups. One of the servers is located here in our local datacenter (10.0.1.x) and the other SQL server is in our remote datacenter(172.16.1.x). I was able to setup the Windows Failover Custer without much issue. I setup the AG but when I try to setup the listener. I get the following error. I have setup an IP for both networks on the listener. I have confirmed that there is not any DNS records created for AG listener name. But I still get this error.
Environment: SQL Server 2014 on Windows Server 2012 R2.
We have our availability group configured and working. However, when we try to connect to the AG listener from a remote server, we have to use the fully qualified domain name (FQDN) to connect. We'd like to be able to connect just using the host name. Interestingly, ping actually resolves the IP correctly for either.
I have getting issues when i am creating listener for always On . Error shown as below
Can not bring the Windows server fail over cluster (WSFC) resources online. (Error Code 5942). The WSFC service may not be running or may not be accessible in its currents states, or the WSFC resources may not be in a state that could accept the request.
For information about this error code see "system error code" in windows development documentation
The attempt to create network name and IP address for the listener is failed. The WSFC service may not be running or may not be accessible in its currents states or the value provide for the network name and IP address may be incorrect. Check the state of the WSFC cluster and validate network name and IP address with network administrator. (Microsoft SQL Server error 41066) ...
I have 2 SQL Server replicas configured on SQL Server 2012 AlwaysOn. e.g. SQL1 & SQL2.
I have configured backup job on both SQL Server with the following statement. and the job occurs every 10 minutes.
•declare @DBNAME sysname,@sqlstr varchar(500) set @DBNAME = 'dba' IF (sys.fn_hadr_backup_is_preferred_replica(@DBNAME)=0) BEGIN --Select 'This is not the preferred replica, exiting with success';
[Code] ...
I turned off SQL2 for Windows maintenance. So there is only SQL1 is online. Afterwards. I checked the backup folder and didn't see any new backup files was created after SQL2 was offline. I rerun the job. It still doesn't backup database on the Primary Replica. Then I searched on SQL Server Book online. It says
Prefer Secondary
Specifies that backups should occur on a secondary replica except when the primary replica is the only replica online. In that case, the backup should occur on the primary replica. This is the default option.
According to what it says, it should backup on the Primary Replica.
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 have a requirement to build SQL environment which will give us local high availability and disaster recovery to second site. We have two sites- Site A & Site B. We are planning to have two nodes at Site A and 2 nodes at Site B. All four nodes will be part of same Windows failover cluster. We will build two SQL Cluster, InstanceA will be clustered between the nodes at Site A Server and InstanceB will be clustered between the nodes at Site B, we will enable Always On Between the InstanceA and InstanceB and will be primary owner where data will be written on InstanceA and will be replicated to InstaceB. URL....Now we want we will have instanceC on the Site B and data will be writen from the application available on Site B, will be replicated to the instance on the Site A as replica.
We have a vendor that is exposing our database via a High Availability replica. They are geographically far away from us though so we would like to extract portions of the database over to our side for our reporting /warehousing purposes. I was curious if it is possible to setup snapshot replication on a high availability group?
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 have Active Active Cluster with 2 nodes , on the first node I can execute the queries, but when I trying to execute query or just open a DB to see the tables I getting error:"The Database XX is not accessible. (ObjectExplorer)".
I'm getting an error adding Replica to SQL AlwaysOn failover cluster in the new availability group wizard. When I enter the name of the target node (secondary replica) server and press connect, I get the following:
A network-related or instance-specific error occurred while establishing a connection to SQL Server.
The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 2) The system cannot fine the file specified
The SQL Browser service is up and running on the target. I am using an Azure VM for my SQL instance. This cluster spans geographies from our on-premise site to Azure via a VPN. This is a multi-subnet cluster. I'm attempting to create a new AG from the primary replica node and the target is a node on Azure called SSASNodeAz03.
[URL]
Full error:
Connect to Server Cannot connect to ssasnodeaz03
Additional information: A network-related or instance-specific error occurred while establishing a connection to SQL Server.
The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 2) The system cannot fine the file specified
