SQL 2012 :: Multi-Site AlwaysOn Failover Cluster
Oct 6, 2014
We are implementing a multi-site (Windows Server Failover Cluster) WSFC to enable Always On between our primary and DR site. We are not going to use SQL clustered instances. We are not planning to use shared disks. Each node is running a standalone instance of SQL 2012.
I have successfully configured a 3 node multi-site Windows failover cluster with no shared storage. For quorum, I have defined a File Share Witness (FSW). The FSW has voting rights and is in the DR site. The setup looks like this –
WSFC –
•Node A – Site #1 (voting right = 1)
•Node B – Site #1 (voting right = 1)
•Node C – Site #2 (voting right = 0)
•FSW – Site #2 (voting right = 1)
Again - There are no shared disks in our setup. We are not going to use SQL clustered instance. We are going to use Always On with these 3 nodes.
SQL Always On –
•Node A – Site #1 (Primary Replica)
•Node B – Site #1 (Readable Secondary)
•Node C – Site #2 (Readable Secondary)
All the setup including the “availability group” works properly under this setup. However, a failover to site #2 under DR situation is not working and I know why but don’t know what needs to be done to fix the problem.
The following works fine –
•Automatic failover between nodes A and B (same site – site #1)
•Forced failover to node C in site #2 provided at least one of the nodes in site #1 is up (non – DR situation) - this will ensure the cluster is up
The following is not working –
•Forced failover to node C in site #3 when both nodes in site #1 are lost (true DR situation) – This is because the cluster is not up at this point.
I know I have to bring the cluster up somehow and I have not been able to do so by restarting the cluster service.
I tried to run the command to start cluster service.
Question –
How can I FORCE the cluster to come up in Site #2 on node C when it has no voting rights?
I have always worked with even number of nodes and shared disks with traditional clustering. I am not sure what needs to be done in this scenario with 3 nodes and a FSW.
View 3 Replies
ADVERTISEMENT
Apr 3, 2014
I'm looking for a solution to have cross data center automatic failover in the event of a data center loss for highly critical databases. I would like to have local HA and also automatic failover to the DR site. This does not seem possible with AlwaysOn.
Is my only option for automatic cross data center failover to build a node in one data center and a node in the other data center with a node/FS at a third data center in order to maintain quorum? I'd like to have local HA in the mix but that doesn't seem possible.What pattern for the highest data security and also availability?
View 5 Replies
View Related
Sep 30, 2015
How can we find the cluster failover count in always on ?
As my AG is configured as synchronous mode , AG went offline and we manually restarted the AG service when we check the properties on AG role they r in default setting ?
View 0 Replies
View Related
May 3, 2013
When I fail an availability group between subnets, I am finding that the DNS entry in DNS is staying. So what happens is the Availablity Group listener has 2 records in DNS, one for each IP. This causes the App to timeout at times, since DNS will return either of the two IP's.
View 9 Replies
View Related
Oct 29, 2015
1. Once fail over to secondary replica, what will happen to connected session in primary node? can the session fail over to secondary seamlessly or need to re-login. what happen committed transactions which has not write to disk.
2. Assume I have always on cluster with three nodes, if primary fails, how second node make write/ read mode.
3. after fail over done to 2nd secondary node what mode in production(readonly or read write).
4. how to rollback to production primary ,will change data in secondary will get updated in primary.
View 5 Replies
View Related
Oct 29, 2015
1. In alwaysON fail over cluster, Once fail over to secondary replica, what will happen to connected session in primary node? can the session fail over to secondary seamlessly or need to re-login. what happen committed transactions which has not write to disk.
2. Assume I have always on cluster with three nodes, if primary fails, how second node make write/ read mode.
3. After fail over done to 2nd secondary node what mode in production(readonly or read write).
4. How to rollback to production primary ,will change data in secondary will get updated in primary.
View 3 Replies
View Related
Nov 17, 2015
OS - Windows 2012 R2 Standard Edition.
DB - SQL 2012 Enterprise edition
Total 3 nodes participates for AO setup, 2 Nodes for Local HA and 1 Node for another datacenter for DR. All the 3 Nodes are same domain name and member.
1. Local First 2 Nodes are same subnet XXX.XX.44.XX
2. DR Node another subnet XXX.XX.128.XX
Does it require to add two different IP address while creating cluster name? Not using shared disk SAN storage etc.. I am using Node majority quorum witness setting for failover.
View 10 Replies
View Related
Jun 30, 2015
we have to build high availability SQL 2012 cluster for VDI and we have two options. One option is to build a server cluster with combination of failover and mirroring and other option is to build failover cluster with AlwaysOn.We are not sure which option to chose. We have contacted Microsoft support to provide us some documents and instructions for failovermirroring combination but they have send us instructions for AlwaysOn option.
What would be best way to build high availability cluster for VDI? Also, since first option is very complicated.
View 5 Replies
View Related
May 22, 2015
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
View 8 Replies
View Related
Apr 27, 2015
We have two locations in US, I am thinking of having 2 node SQL cluster for Lync 2010, I alardy have One DB server running in one location, now we got new site where we are planning to have one more DB for redundancy.
View 5 Replies
View Related
Feb 18, 2014
I´ve been reading that SQL Server 2012 Always On is dependent on having a Windows Failover Cluster setup. Is that correct ?
View 6 Replies
View Related
Dec 10, 2014
I have setup SQL AlwaysOn between primary and DR data centers. Here is the setup:
Primary data center: Server1 (Primary), Server2 (Sync Commit Secondary), Server3 (ASync Commit Secondary)
DR data center: Server4 (ASync Commit Secondary)
Data synchronization and manual failover works fine. But, sometimes, the AlwaysOn cluster automatically fails over to Sync Commit Secondary on Primary data center. Here is the error message from Failover Cluster Manager->Cluster Events:
"Cluster has missed two consecutive heartbeats for the local endpoint xx.xx.xx.yy:~3343~ connected to remote endpoint xx.xx.xx.zz:~3343~"
"Cluster has lost the UDP connection from local endpoint xx.xx.xx.yy:~3343~ connected to remote endpoint xx.xx.xx.zz:~3343~"
I had our network engineer check all connections multiple times and he confirmed everything is fine. But he was also able to confirm (using monitoring tools) that right at the time of a failover, there is almost 2GB worth of traffic going from Primary Server to DR server. That happens every time. I had checked the times of all failovers and there is no job or process occuring that will produce 2GB worth of data. Also, this happens regardless of which server is primary.
Even though the failover works fine, this unexpected automatic failover due to missed heartbeats are occurring often (2-3 times a month).
Here is the list of errors from the Cluster Validation Report:
Under Network Section, I see the following error messages in Red:
Validate Network Communication
Network interfaces Server4 (DR) - SAN_Team and Server1 (Primary) - SAN_Team - VLAN 20 are on the same cluster network, yet address xx.xx.xx.pp is not reachable from xx.xx.xx.yy using UDP on port 3343.
Network interfaces Server4 (DR) - SAN_Team and Server2 (Secondary) - SAN_Team - VLAN 20 are on the same cluster network, yet address xx.xx.xx.qq is not reachable from xx.xx.xx.yy using UDP on port 3343.
[Code] ....
View 7 Replies
View Related
Jan 27, 2015
So I have 2 servers S1 & S2.
Database Group 1 = L1 with Primary S1 and Secondary S2
Database Group 2 = L2 with Primary S2 and Secondary S1
For 99% of the time the 2 groups of databases are not related. For the 1 procedure that does move data from L1 to L2 something like
Update L2.DB.Owner.Table
set flag = 1
Whare a = 0
On S1 I have a linkedServer with connection to L2.
If I have a failover I cannot have L2 on S2 as they are essentially the same server.
How to I use the 2 groups hand in hand.
View 0 Replies
View Related
Jun 16, 2014
If there is a history kept somewhere of failover events of a database in an AO group? I have 2 replicas with automatic failover and I'm looking for a history of failovers.
View 0 Replies
View Related
Oct 27, 2015
An automatic failover set exists. This set consists of a primary replica and a secondary replica (the automatic failover target) that are both configured for synchronous-commit mode and set to AUTOMATIC failover.Configured the both AG Group database automatic failover and synchronous-commit mode.But automatic Failover failed also Cluster service not started automatically at Node2. It got connected through AO Listerner after starting Node1. As below SQL Error log during shutdown Node1
Date,Source,Severity,Message
10/27/2015 10:44:20,spid37s,Unknown,AlwaysOn Availability Groups: Waiting for local Windows Server Failover Clustering node to come online. This is an informational message only. No user action is required.
10/27/2015 10:44:20,spid37s,Unknown,AlwaysOn Availability Groups: Local Windows Server Failover Clustering node started.
[code]....
what need to be change existing AO configuration?
View 9 Replies
View Related
Mar 28, 2014
What happens when an automatic failover occurs, in a two server AlwaysOn Availability Group configuration, where the secondary replica is configured as read-only?
Will it only allow read-only connections, or will it become read-write and can accept INSERT, UPDATES and DELETES when assigned the new role as Primary?
Is it correct that adding a third server/node, that just acts as passive and should be used for automatic failover, to support true HADR, would NOT need another license .. and that licenses would only be required for the previous Primary and Secondary (Read-Only) replicas?
View 3 Replies
View Related
Aug 17, 2015
More often than not, I typically don't touch DTC on clusters anymore; however on a project where the vendor states that it's required. So a couple things here.
1) Do you really need DTC per instance or one for all?
2) Should DTC be in its own resource group or within the instance's group?
2a) If in it's own resource group, how do you tie an instance to an outside resource group? tmMappingSet right?
View 9 Replies
View Related
Aug 17, 2015
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.
View 6 Replies
View Related
Mar 17, 2014
How many nodes can you have in a cluster with SQL 2012 alwaysOn.
I understand that availability groups are limited to 5 nodes but if you had a 10 node cluster and decided to create multiple availability groups using various nodes within the 10 nodes but never exceeding 5, is that possible?
Or is there a counter or some validation from SQL AlwaysOn that actually hard limits to a grand total of 5 nodes in a cluster?
View 6 Replies
View Related
Nov 13, 2014
Can we make SQL 2012 Always ON over the normal SQL Cluster 2012.
View 3 Replies
View Related
May 19, 2015
We have an existing SQL Server 2012 Enterprise cluster with 2 nodes (active-active) and uses Windows 2008 R2 OS. We are looking for a way to increase HA as well as offload backups to secondary server and it was suggested that AlwayOn could be an option.
The questions I have are:
1) Is it possible to turn on AalwaysOn feature on an existing cluster?
2) If yes to above, does the secondary replica need to exist as a node on the same cluster or can it be on a completely different cluster?
3) If the secondary replica is on the same cluster (i.e. we add a 3rd node to existing 2 node cluster), can that node be provisioned with storage from a completely different SAN? (i.e. Node 1 and Node 2 accesses LUNs on SAN1 and Node 3 accesses LUNs on SAN2).
View 9 Replies
View Related
Mar 29, 2014
I have virtualbox installed on my notebook. For testing purpose, is it possible to setup SQL Server Fail-Over cluster using virtual box? I don't have a shared storage. How can I simulate that?
View 1 Replies
View Related
May 5, 2014
How to create a SQL 2012 Failover cluster using VMs?
View 9 Replies
View Related
May 6, 2014
How can we change the backup replica in Always on Cluster. I am not able to take backup because of this.
View 7 Replies
View Related
Jan 21, 2015
I am trying to create a failover cluster without the log shipping in 2012 as i've done it with a static instance with some database.Is the "AlwaysON" feature the solution when an application creates random and numerous databases within the instance and we need a failover scenario ?
View 9 Replies
View Related
Mar 21, 2014
I'm reading up on Always on and I am confused what is the difference between AlwaysOn Availability Groups and AlwaysOn Failover Cluster Instances.
View 3 Replies
View Related
Apr 17, 2014
I had a cluster running on 3 nodes (windows failover cluster) with server 2012 and SQL server 2012 running in the cluster. Well, I thought I'd just go ahead and rename all 3 of the hosts with new hostnames and it apparently broke the cluster pretty bad. Now when I open failover cluster manager I cannot see anything nor can I connect to the cluster object in AD. I re-named all of the hosts back to their original names but that didn't work.
View 5 Replies
View Related
Aug 6, 2015
I am new to SQL Server 2012 clustering.I added a new instance to one of the two nodes.when I try to move it to the other node it fails.Do I need to install it on both?If so, what options do you install on the second node?
View 7 Replies
View Related
Sep 18, 2014
I know now that AlwaysOn feature HAS to be installed/configured on a Windows Clustering environment, BUT the secondary replicas, like the Disaster recovery replica residing in a different Data Center HAS to be also in a Windows Clustering environment or can it reside on a SINGLE SQL Server INSTANCE?.
View 6 Replies
View Related
Oct 13, 2014
In QA we have a two-node cluster with four instances of sql. In trying to add a fifth, I was given an IP address already in use so the install hung.
I removed it from the cluster but it is still there in the registry etc on the node I was working on.
I read about using the maintenance tab of the sql server install to "remove a node" but the terminology is confusing. To me a node is a physical server and an instance is an instance of sql server -- not the same at all but they are often referred to as the same thing.
I definitely don't want to remove one of the servers from the cluster.
View 1 Replies
View Related
Feb 18, 2015
I am trying to install SQL Server 2012 onto an already configured and validated windows failover cluster (server 2012) but the process is hanging after installing the setup files.
The last entry in the log is:
running discovery on remote machine
and I've left it hanging like this for 4 hours and nothing happens.
View 2 Replies
View Related
Jun 7, 2015
I Config Ha-Alwayson on 2 test servers . In addition, was defined a listener for them.i can connect to them from the listener and in directly. I did manual Failover and it worked.However all connection to all servers (primary and secondary and listener) was breaked. I expected my connection To The listener, be stable. But How can I test the Auto failover mechanism? I run this scenario :
1- I filled all free space from the primary server else a bit.
2- And run on it a Huge Update to fill remain free space.
3- MeanWhile I Run an insert command into listener IP. (in a while Loop)
I expected :
>>> After run update or in middle of it , The primary server face to a problem. (Full Log file). And This was happened.
>>> After I expected The Failover act and change Primary And Secondary.And My insert commands Continues without Break Or Continue On new server After some Seconds
But It didn't Happend.Both Of 2 Command are stoped !!!!! And auto failover didnt act. I tryed To create a manual fail on primary server . I Tried to Offline the main database in primary server.
Then
1- What is the meaning Of fail that Auto failover act about it ?
2- In which scenario I can Test It ?
View 9 Replies
View Related
Jun 30, 2015
I have a 3 node 2014 AlwaysOn setup. The primary and secondary are set for automatic failover. The third node, of course, is manual (until 2016). The 2 nodes with are automatic are sitting in one datacenter, the third is in another. If the first datacenter was to go down, I would manually have to failover to the third node? What's the normal process here for having two datacenters and ensuring the availability group is always available?
View 3 Replies
View Related
