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?
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 RelatedIs it possible to create a cluster configuration, where 2 (or more) SQL Server instances running on different servers will simultaneously serve the same database attached to the same storage? Something like this:
Instance A Instance B Instance C
(active) (active) (active)
| /
| /
| /
SAN for Database and Quorum
The point would be to improve reliability and performance at the same time. All nodes would share load. If a node fails, the other nodes still work and take over the load.
I know a failover cluster can be done, where 1 instance is active and others are passive (active/passive) which improves reliability, but in this configuration just 1 instance is serving at the same time.
(As far as I understand, the active/active configuration is meant to run different databases on 2 (or more) instances such that the databases on a failing node are taken over by any other instances in the cluster.)
Can we make SQL 2012 Always ON over the normal SQL Cluster 2012.
View 3 Replies View RelatedWe 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).
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 RelatedHow can we change the backup replica in Always on Cluster. I am not able to take backup because of this.
View 7 Replies View RelatedWe 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.
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 ?
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 RelatedWe are planning to change all IPs of PRODUCTION Failover Cluster Setup. In my cluster setup ... we have 2 Physical Nodes with windows-2008, Roles are MSDTC and SQL-2008R2.
IP change for:
1. Both Nodes(Physical)
2. MSDTC
3. SQL Server
4. windows Cluster
So Almost... All IPs are going to change.
Im DBA here, I need to take care of SQL cluster and MSDTC. But I haven't performed this activity before.So I'm worrying about Impacts and consequences of this change. steps how should I perform this activity.
I have a 2012 AlwaysOn DB Mirroring environment set up with two nodes. Both have 5 installs of SQL named instances.
The issue we are having is when we patch one server and fail everything over, some of the applications will error. Some of the applications had to have their web.config files updated with hostinstance name because it seems to not work with DNS.
Two servers are configured with Windows 2008 / SQL server 2012 utililizing Always-On for HA. We need to upgrade both servers to Windows 2012 / SQL Server 2014 with minimum downtime(Time for Always-On failover). The upgrade to SQL 2014 is straight forward with for minimum downtime.The Windows upgrade(2008 -> 2012) is the problem. From what I have observed and read in blogs.The Windows node to be upgraded must be removed from the Windows cluster before the node can be upgraded to Win 2012.A Win 2008 and Win 2012 node can not reside in the same cluster. If this is true then the only option I can think of is to dump the DB on WIN 2008 server and restore on Win 2012. This is an outage(time it takes to dump and restore).Is there any other method to upgrade these two nodes utilizing Always-On of some other method without downtime?
View 2 Replies View RelatedI 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.
View 4 Replies View RelatedHow many maximum database's can we have in AlwaysON Availability Group?
View 3 Replies View RelatedHI There
We had an existing 2 node active / active cluster, 1 running a default instance of Sql Server 2005 Enterprise Edition 9.0.3152 (SP2 + Hotfixes) and the other running a named instance of the same version.
We recently added 2 new nodes to the cluster, they were successfully added and we tested the cluster group failover successfuly to the new nodes.
Last night we tried to install Sql Server 2005 Enterprise edition on the new nodes.
I followed to proper proceudure of modifying the installation for both instances and selecting the 2 new nodes to apply them to. This went 100%. Sql Server 2005 successfully installed for both instances on the 2 new nodes, all log files were successful.
We then tried to apply SP2, we tried the following:
1. We ran SP2 from the active node, but when we go to the screen to select what you want to apply SP2 too we could not select anything, if you clicked on database engine the message said that these instances were already at a later version and we could not proceed. This is how i successfully applied SP2 to the original 2 node cluster but it does not work for additional nodes to an exisitng cluster.
This is also what all the documentation we could find said, refer to SP2 release notes under the topic "Failover Cluster Installation", it is also the method we found when googling.
2. We then tried what is described under SP2 release notes "Rebuild a SQL Server 2005 SP2 Failover Cluster Node".
We ran SP2 from the new nodes while they were passive, but when we got the screen where you select what to apply the SP2 too we could not select database engine the message at the bottom said that SP2 must be run from the active node and that we were attempting it from the passive node, this is what we tried in step 1 described above.
3. This was a last resort. We were advised to try failing over the instance to the new node and then running SP2. Personally i thought this was a bad idea, one should never fail over a instance of sql server to a node with incompatible binary versions and secondly when we installed sql server on the new nodes a warnng popped up before hand stating that the instances were at a later version and that the new nodes must be at this version before attempting fail over. I thought that sql would not even start, to my surprie we successfully failed over the sql group to the new node, when we ran SP2 it looked good we could select the database engine on the new node to apply SP2 too, BUT after clicking next after a few seconds the SP2 installation just closed, NO INFORMAITONAL MESSAGES NO ERRORS NO WARNINGS it just closed an never came back.
I had never seen this happen on a cluster before, needless to say this made me very nervous so we failed the sql group back to the original nodes and gave up.
PLEASE can some tell me how to apply SP2 to 2 new nodes in a 4 node cluster all methods descibed in SP2 release notes and other documentation as descibed above in step 1 and 2 do not work !
Thank You
I'm setting up a cluster to test a new deployments of SQL2K14 on a WSFC cluster (W2K12R2). Starwinds VS. the built in iSCSI service?Will either one allow me to build a cluster consisting of two nodes? Do I need to dedicate a third node to run the iSCSI storage?
View 4 Replies View RelatedI can't seem to install SQL Server 2005 (x64 version) on an x64 Win2k3 two node cluster.
I get all the way through the configuration and setup fails because it cannot start a task on the remote node. The error message indicates to check the task scheduler log file, which I have and I cannot find any 'errors' in the file.
Google/MSDN/Technet turn up nothing on multiple searches. Has anyone else run into this problem?
My installation account is a local admin on both machines, so is the sql cluster account. For the life of me I cannot figure out what's different for an x64 install vs 32bit....
Hello,
We currently have a 2 node Active/Passive 2 named instance SQL 2000 cluster. We will be chaning the configuration to Active/Active, basically moving 1 instance to the passive node (so we can take advantage of the resources on the passive node).
We would also like to add 3 nodes to the cluster making it a 5 node SQL cluster. What we are thinking of doing is basically making it an Active/Active/Active/Active with the 5th server being passive. The question I have is will I be able to add and install the 3 new nodes without having to redo the SQL cluster? Should I install the two new active nodes with the default SQL instace or do I have to install SQL with named instances? (actually I think the named instances is the way to go but then I wouldn't be posting here if I was sure about the answer).
Thx!
-Albert-
I believe to configure maximum number of replicas it is required to have 5 nodes (1 Primary & 4 Secondary replicas). But how many databases can be included in one availability group, it think it is 32767. When I am referring to below URL it is mentioned something like "An availability group supports a set of read-write primary databases and one to eight sets of corresponding secondary databases. " What does this 'sets' means, is that maximum limit for only eight databases or maximum groups should be eight?
[URL] ....
My question is, I'd like my actual cluster to have 4 servers. The virtual server that will be running SQL 2005 will only be installed on 2 of those nodes. Will this work or do I have to split my cluster in to 2 to meet the SQL Server 2005 2 node failover limitation? A basic config for the cluster would be like below....
ClusterSQLNode
Active SQL 2005 Server
ClusterExchNode
Active Exchange Server
ClusterAppNode
Active Application Server
ClusterFailoverNode
Failover SQL 2005
Failover Exchange
Failover Application
Will SQL 2005 install in a 4 server cluster if I only install it on to two of the nodes? Any potential gotchas?
Can we add physical nodes and VMs to windows cluster?
View 7 Replies View RelatedHi There
I have found no real documentation on this, so any links would be greatly appreciated.
We have an existing 2 node active active cluster.
A default and and named instance SS2005 Enterprise Edition are installed on the cluster.
Recently we acquired new hardware, 2 servers, which we added to the cluster so we now have a 4 node cluster.
The 2 new nodes have OS etc installed.
Now i have installed sql on a new multi node cluster, i have upgraded sql server in an existing cluster BUT i have never installed sql on an existing cluster for new nodes for multiple instances.
Now i presume you simply run the install on one of the new nodes, do this for a default instance, selecting both 2 new nodes to installl on. And do this again for the named instance.
But in the past I have never been promoted for which nodes to install sql on, it simply does all the nodes BUT i do not want this.
And how will the cluster know where the binary files are for each instance on the new nodes?
In a nutshell, how do i install sql server 2005 for 2 new nodes in an existing 4 node cluster for multiple instances ?
Thanx
I have encountered issue by add a node to SQL cluster
Server 2012 R2 Datacenter version
SQL 2012 Enterprise edition
Error Status>
number of cluster nodes supported for edition - failed
I have failed to bypass with Setup /SkipRules=Cluster_VerifyForErrors /Action=AddNode
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:
My environment has a 4 node cluster , 2 in primary and 2 in sec dc. Storage is sperate for both.
Need to setup always on for 4 Instances there on the 2 nodes of the primary dc. Is there any restriction in setting up always on for multiple instances for a cluster.
I have had a serious issue with a production AlwaysOn cluster whereby the service did not successfully transition to the secondary node and I cannot find the root cause of the issue.
Some details: It is a 2 node cluster (same datacenter) with a shared disk quorum, Windows Server 2012, both are virtual machines running on VMWare vSphere 5.5. SQL Server version is 2012 Enterprise SP2 CU6
The failover occurred because of a network incident (a spanning tree recalculation caused a connection timeout between both nodes). Initial entries in the SQL Log look normal for this event, for example:
05/08/2015 11:18:06: A connection timeout has occurred on a previously established connection to availability replica 'FIN-IE-PA078' with id [6910F4A9-87E7-4836-BA79-0F41BE90266D]. Either a networking or a firewall issue exists or the availability replica has transitioned to the resolving role.
05/08/2015 11:18:06: AlwaysOn Availability Groups connection with secondary database terminated for primary database 'UserManagement' on the availability replica with Replica ID: {6910f4a9-87e7-4836-ba79-0f41be90266d}. This is an informational message only. No user action is required.
[code]....
My interpretation of this is that the cluster failover attempts failed, because the network condition still persisted. The network interruption lasted approximately 2 minutes, and I would have expected the cluster to come back online at this point, after the restart delay period as suggested in the last entry in the error log. However this did not happen.
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.
To set up AlwaysOn Feature on cluster environment how many VM's we would require.
We have already have 2 VM's for cluster but am not able to configure AlwaysOn.
I have MasterDataServices installed on a server and the database is in an AlwaysOn Availability Group.The MDM front end currently is set up incorrectly and is referencing NodeA (primary node) for its database.I want to fix this but im unsure if i should:
-point the MDM front end to the cluster name, so it wont matter what server the databsae is on?
-create an Availability Group Listner, which would also decoupple the database referenced from a particular server.
I got 5 SQL Servers 2008R2 (2x CPUs with 96-384Gb of RAM) with total 1500DBs and around 10Tb of allocated data. Now
I am forced to upgrade to 2012 and 2014, but the old hardware is overkill.
Is it possible to consolidate this to a large SQL AlwaysOn cluster?
We pros/cons could it be to have 2 or 4 nodes?
2 or 4 sockets servers?
My goal was to use ~20 cores Enterprise license on active server.
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!)
I have a 3-nodes AlwaysOn cluster (Windows Server 2008 R2 SP1 + SQL Server 2012 RTM), Node Majority quorum, the quorum vote for each node is 1.
Today the AlwaysOn AG was suddenly down due to the cluster service on node 1 stopped and can't be started.
The error in eventlog is -
The cluster database could not be loaded. The file may be missing or corrupt. Automatic repair might be attempted.
The Cluster Service service terminated unexpectedly. It has done this 2 time(s). The following corrective action will be taken in 120000 milliseconds: Restart the service.
The failover cluster database could not be unloaded. If restarting the cluster service does not fix the problem, please restart the machine.
The Cluster Service service terminated with service-specific error The system cannot find the file specified..
The error log in cluster log is -
0000156c.000008f8::2012/09/05-08:09:36.057 INFO [DM] Key RegistryMachineCluster.restored does not appear to be loaded (status STATUS_OBJECT_NAME_NOT_FOUND(c0000034))
0000156c.000008f8::2012/09/05-08:09:36.057 WARN [DM] Node 1: Failed to unload restored hive from the registry with error STATUS_INVALID_PARAMETER(c000000d)
0000156c.000008f8::2012/09/05-08:09:36.057 INFO [DM] Node 1: loading local hive
0000156c.000008f8::2012/09/05-08:09:36.057 ERR [DM] Node 1: failed to unload cluster hive, error 2.
Now the cluster service can't be started on node 1, error code 2. Looks like the clusdb in C:windowscluster is missing or corrupted. How to restore the clusdb file? And how to prevent this happen again?
All nodes were well patched, AlwaysOn and cluster related hotfixes were all installed. [URL] .... doesn't wok.