With the new version of SQL server 2014 there are a lot of options possible for DR or some extra Configuration options.
In the Old days there was only a failover option in SQL active/passive or if you had multiple instances you could run a instance on every node this could be seen as active/active. en yes mirroring was also an option.
But now the naming is different and there are a lot more configuration options. Remember “ my SQL is running on bare metal much faster “ eh this is not that long ago. Configurations with a Scale-out file server is not yet common but more and more configurations are using it. Now that SQL Server 2014 can store on CSV. In the following 3 blog post I will show you how to create all this bottom up. easy playground. A lot of terms will pass along like FCI WSFC Azure CSV, FTW SQL LOL
But the Two main options on SQL for clustering are :
AlwaysOn Failover Cluster Instances (SQL Server)
AlwaysOn Availability Groups (SQL Server)
Failover cluster instance (FCI) is in short the old active/passive configuration – Protection level SQL Server / instance
As part of the SQL Server AlwaysOn offering, AlwaysOn Failover Cluster Instances leverages Windows Server Failover Clustering functionality to provide local high availability through redundancy at the server-instance level—a failover cluster instance (FCI).
An FCI is a single instance of SQL Server that is installed across Windows Server Failover Clustering nodes and, possibly, across multiple subnets. On the network, an FCI appears to be an instance of SQL Server running on a single computer, but the FCI provides failover from one Windows Server Failover Clustering node to another if the current node becomes unavailable.
An FCI can leverage AlwaysOn Availability Groups to provide remote disaster recovery at the database level.
As the “SQL Server (MSSQL001)” is installed on two nodes the instances and the DB are fault tolerant but needs shared storage
This is a AlwaysOn Failover Cluster Instances (SQL Server) FCI solution.
When a SQL Server instance is configured to be an FCI (instead of a standalone instance), the high availability of that SQL Server instance is protected by the presence of redundant nodes in the FCI. Only one of the nodes in the FCI owns the Windows Server Failover Clustering resource group at a time. In case of a failure (hardware failures, operating system failures, application or service failures), or a planned upgrade, the resource group ownership is moved to another Windows Server Failover Clustering node. This process is transparent to the client or application connecting to SQL Server and this minimize the downtime the application or clients experience during a failure.
The following lists some key benefits that SQL Server failover cluster instances provide:
Protection at the instance level through redundancy
Automatic failover in the event of a failure (hardware failures, operating system failures, application or service failures)
The AlwaysOn Availability Groups feature is a high-availability and disaster recovery solution that provides an enterprise level alternative to database mirroring. An availability group supports a failover environment for a discrete set of user databases, known as availability databases, that fail over together. An availability group supports a set of read-write primary databases and one to four sets of corresponding secondary databases.
Deploying AlwaysOn Availability Groups requires a Windows Server Failover Cluster. To be enabled for AlwaysOn Availability Groups, an instance of SQL Server must reside on a Windows Server Failover Cluster node, and the Windows Server Failover Cluster and node must be online. Furthermore, each availability replica of a given availability group must reside on a different node of the same Windows Server Failover Cluster.
AlwaysOn Availability Groups supports cross-cluster migration of availability groups for deployments to a new Windows Server Failover Clustering. A cross-cluster migration moves one availability group or a batch of availability groups to the new, destination WSFC cluster with minimal downtime.
By implementing AlwaysOn SQL Server FCI an availability replica can be hosted by either a standalone instance of SQL Server or an FCI instance. Only one FCI partner can host a replica for a given availability group.
AlwaysOn Availability Groups does not depend on any form of shared storage. However, if you use a SQL Server failover cluster instance (FCI) to host one or more availability replicas, each of those FCIs will require shared storage as per standard SQL Server failover cluster instance installation.
You might need to configure a Windows Server Failover Clustering (WSFC) cluster to include shared disks that are not available on all nodes. For example, consider a WSFC cluster across two data centers with three nodes. Two of the nodes host a SQL Server failover clustering instance (FCI) in the primary data center and have access to the same shared disks. The third node hosts a stand-alone instance of SQL Server in a different data center and does not have access to the shared disks from the primary data center. This WSFC cluster configuration supports the deployment of an availability group if the FCI hosts the primary replica and the stand-alone instance hosts the secondary replica.
The following lists some key benefits that AlwaysOn Availability Groups provide ( depends on your configuration ):
As the screenshot shows it hold a availability group with a listner. The configuration is only visible in the SQL server manager
This sounds great new options more but how to configure them and how about Azure In the next post I will show you how to create all this.
In the following I created a Cluster connected to azure with a Site to Site VPN. And will show you the HA options this will be in several steps else it would be a long post.
But along the choices there are a lot of options that can be a problem with your configuration or maybe not the best option. And maybe you need a 3th party product the get the job done. Like Datakeeper my fellow Cluster MVP David Bermingham is SteelEye’s Director of Product Management.
In the next part I will start with AlwaysOn Failover Cluster Instances (SQL Server) Followed By AlwaysOn availability group (SQL Server) and Azure Failovers.
Just for the fun I recorded a movie on the installation of Windows Server 2012 R2 . I thought just a quick recording and done but as it turns out it took longer than I expected, I made a typo in the script or clicked the wrong script or forgot to clean out my netbios name. then you gona build failsafe items in the scripts and they will be shown as errors because some items are already be set and can’t set twice.
The basic Idea was record a quick movie of an unattended installation of a SQL cluster in a few minutes is this possible yes it cab be done in les than 15 minutes. installation of the OS , Cluster with full Storage validation and a two node SQL cluster based on normal disk and a two node cluster based on CSV.
Eh in 15 minutes two full SQL nodes. just for fun.
when I was building this lab and thought recording in one piece is no fun I can never use the items in one piece and the movie size is bigger.
So I created every step in a single movie file, with sound and created one big movie with some speeding steps in it.
First the Windows Installation movie. ( did you know the Cluster validation process with full Storage testing took longer than the Complete installation from OS and SQL server
So the OS installation the Windows version choice can be avoided by pre-staging the VM’s and I like to choose my disk size not very disk in my OS is the same. nor do I set a name ,IP and domain join the VM in one pass. I like to be flexible and do this step by step. and for demo’s is is nicer to show.
Watch this new video I made http://youtu.be/UyqNY5JyE9k
Windows Server 2012 R2 unattended SQL Server 2014 Cluster installation On Clustered Shared Volumes
The SQL installation on CSV and adding the node to the normal SQL on disk took 7 minutes. The installation on the Disk was about 4 minutes slower.
Who said that clustering was hard
The scripts what I used are all available I already posted this on my blog. See my blog post on the SQL Server 2014 installation.
There are a lot of good blog post about how to setup your Availability group, in two blog post I will try to break the basic setup and will show you what you should not do in your production environment. Just because you can does not mean I should do this.
This blog post will also show you most common errors and how to fix them and where to find the errors, but in the end you will have a working two node cluster and one Availability group
First how to setup an Availability group to make things more complex there are multiple instances, see how they look Naming convention is really important when you do complex configurations. an typo is quickly made!
Deploying AlwaysOn Availability Groups requires a Windows Server Failover Clustering (WSFC) cluster. To be enabled for AlwaysOn Availability Groups, an instance of SQL Server must reside on a WSFC node, and the WSFC cluster and node must be online. Furthermore, each availability replica of a given availability group must reside on a different node of the same WSFC cluster. The only exception is that while being migrated to another WSFC cluster, an availability group can temporarily straddle two clusters.
AlwaysOn Availability Groups relies on the Windows Failover Clustering (WSFC) cluster to monitor and manage the current roles of the availability replicas that belong to a given availability group and to determine how a failover event affects the availability replicas. A WSFC resource group is created for every availability group that you create. The WSFC cluster monitors this resource group to evaluate the health of the primary replica.
The quorum for AlwaysOn Availability Groups is based on all nodes in the WSFC cluster regardless of whether a given cluster node hosts any availability replicas. In contrast to database mirroring, there is no witness role in AlwaysOn Availability Groups.
The overall health of a WSFC cluster is determined by the votes of quorum of nodes in the cluster. If the WSFC cluster goes offline because of an unplanned disaster, or due to a persistent hardware or communications failure, manual administrative intervention is required. A Windows Server or WSFC cluster administrator will need to force a quorum and then bring the surviving cluster nodes back online in a non-fault-tolerant configuration.
Primary on an FCI with a replica on a different FCI
I have a lot of SQL instances and this all runs on a two node Cluster and not all instances are installed on both nodes to trick the installation and to show you the errors you can expect.
Enabling the AlwaysOn and you can see the Difference the new AG Wizard is not grayed out any more .
Starting the Wizard and on system Databases it wil not work AG will only work on your own DB !
You must make a full backup of your DB before you start ( this is always handy )
Now we can add a new replica Check the Server and as it is a Cluster you can not set it to automatic failover.
We do setup a Data share for the replication
Now that we have completed the wizard we do the validation and go for the finish.
An Error ? checking the location ?? eh what should the DB be on the same location ?? not all my SQL server Cluster are the same and are not using all the drive letters. and as I choose to do this on the same cluster ( not supported ) I can not give the other instance the same drive letter. but hat if I had an other cluster and even then I did not have the same Drive letter. Is there a wizard bypass some where. Wizards are nice If you have a default installation. If not Plan B.
TITLE: Microsoft SQL Server Management Studio
Checking for compatibility of the database file location on the secondary replica resulted in an error. (Microsoft.SqlServer.Management.HadrTasks)
The following folder locations do not exist on the server instance that hosts secondary replica MVPSQL201402SQL2:
So placing this on a CSV SQL server 2014
Well if drive letters is an issue SQL Server 2014 can store the DB on a CSV so no more drive letters.
And It passed the Validation that is Great.
Great thinking but.. the CSV is connected to all SQL servers So the next error is logical.
Yes the DB is already there.. what now ?
Manually Creating an Availability group for a SQL Server 2014 FCI
This sounds great but where to start ? should I bing It ? Let Me Bing That For You!
Well I Create it with a SQL script ( I’m no SQL master ) So things can be different.
However you can run this in a SQL CMD but here I do this step by Step.
I have My SQL Availibility group name, My DB name,IP, Servers
CREATE AVAILABILITY GROUP SQL001AG04
WITH (AUTOMATED_BACKUP_PREFERENCE = SECONDARY)
FOR DATABASE AG04 –, …
REPLICA ON — primary:
N’MVPSQL201401sql001′ WITH (ENDPOINT_URL = N’TCP://MVPSQL201401.mvp.local:5023′,
FAILOVER_MODE = MANUAL, AVAILABILITY_MODE = ASYNCHRONOUS_COMMIT,
BACKUP_PRIORITY = 50, SECONDARY_ROLE(ALLOW_CONNECTIONS = NO)),
N’MVPSQL201402SQL2′ WITH (ENDPOINT_URL = N’TCP://MVPSQL201402.mvp.local:5022′,
FAILOVER_MODE = MANUAL, AVAILABILITY_MODE = ASYNCHRONOUS_COMMIT,
BACKUP_PRIORITY = 50, SECONDARY_ROLE(ALLOW_CONNECTIONS = NO));
ALTER AVAILABILITY GROUP SQL001AG04
ADD LISTENER N’MVPLST01′
(WITH IP ((N’10.255.255.69′, N’255.255.255.0′)), PORT=1433);
BACKUP DATABASE AG04 TO DISK = ‘\mvpfsw01SQLAG04AG04.bak’
WITH INIT, COPY_ONLY, COMPRESSION;
BACKUP LOG AG04 TO DISK = ‘\mvpfsw01SQLAG04AG04.trn’
WITH INIT, COMPRESSION;
Now we go to the replica server and run the script below.
—————- Run this on The Replica Server!!!!!!!
ALTER AVAILABILITY GROUP SQL001AG04 JOIN;
RESTORE DATABASE AG04 FROM DISK = ‘\mvpfsw01SQLAG04AG04.bak’
WITH REPLACE, NORECOVERY, NOUNLOAD,
MOVE ‘AG04′ TO ‘E:MSSQL11.SQL001AG04.mdf’,
MOVE ‘AG04_log’ TO ‘E:MSSQL11.SQL001AG04_log.ldf';
RESTORE LOG AG04 FROM DISK = ‘\mvpfsw01SQLAG04AG04.trn’
WITH NORECOVERY, NOUNLOAD;
ALTER DATABASE AG04 SET HADR AVAILABILITY GROUP = SQL001AG04
But as You can see in the screen shot it is not working the secondary server is down.
the following error is showing : The connection to the primary replica is not active. The command cannot be processed.
A connection timeout has occurred while attempting to establish a connection to availability replica ‘MVPSQL201401sql001′ with id [F82BBD94-4F04-4B0A-8B75-28A0899F240C]. Either a networking or firewall issue exists, or the endpoint address provided for the replica is not the database mirroring endpoint of the host server instance.
Ok I did turnoff all the Firewall, checked the network set permissions now what.
Think : I have two cluster nodes both are using SQL in the script what do they have in common.
ENDPOINT_URL = N’TCP://MVPSQL201401.mvp.local:5022′
So changed it from 5022 to 5023 and it work like a charm
In the next post I will explain how to check this and how to change this
SO basically it is better to use the script that the wizard well it depends For now in the demo environment running on two different disks it is better and It would be better if the wizard ask you about drive letters or storage locations.
But manually you have more control about the setup and if something fails you can fixit before you go further. But also you have to think about a lot of issues
Next will be Part 2
More Errors and more fixes on SQL Server 2014 Failover Clustered Instance (FCI) with Step-By-Step #AlwaysOn Availability Groups #winserv #FCI