Failover cluster vs Availability Groups

I am trying to understand the advantages of FCI over AG and vice versa. I have read several articles but none talks about when one should use FCI over AG or AG over FCI.
Basically I am going to make a SharePoint farm and for that I need to decide whether I should go for FCI or AG. Any help is appreciated.

Failover cluster is an instance protection level and
Availability Groups is a database protection level.
>>>>2. We can overcome this problem by using RAID (correct me if I am wrong)
Can you expand a little bit? What RAID configuration did you mean? How RAID protects you from let me say network issue caused failover?
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So isn't instance level protection better than database level protection because in instance level, databases are automatically protected?
My understanding of RAID is if some thing happens to primary SAN then the other secondary SAN will takes its place depending on RAID configuration!?

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WSFC Cluster and Availability Group Alert Variables

Is there a way to include the SQL instance name and/or the server name(s) in the alert for Cluster offline and Availability Group offline alerts?
Usually the Full Path Name contains the server name, but for these alerts the server name is nowhere to be found. The WSFC Cluster offline and Availability Group offline alerts (there could be others) only show the Cluster or Availability Group name
(For Full Path Name and Source). There's no info in the alert about the SQL instance name or the server(s) associated with the Cluster/Availability Group. This isn't very helpful and doesn't make the alert very useful if you have a lot of clusters and availability
groups that you manage. Sure, you can get the info from the Diagram View, but that means you have to login to the console, find the alert and open another view...not very useful if you need relevant data quickly to try to resolve the issue.

Hi Yan,
Thanks for the link, but none of those actually supply the name of the server of the Cluster or Availability group that generated the error. I thought the Full Name might work, but it doesn't. I also tried the Windows Computer host under the General section
($Target/Host/Property[Type="Windows!Microsoft.Windows.Computer"]/NetworkName$), and that just generates an error when you
try to save the Channel (it says it failed to verify module reference). The alerts are kind of useless unless we can identify the servers. Why? Well, we have some staging servers and some production servers that have Clusters and Availability groups that have
the same name, so when an alert gets generated there's no way to tell which Cluster or Availability group it relates to.
Anyone have a way to include the server info in the Cluster and Availability group alerts?

How to install SSAS Cluster instance with Always On availability group(Standalone database instance) in same windows cluster servers

We have requirement like to Install the SSAS as Cluster instance where SQL Server Database engine was installed with Always On availability group.Please help me to how configure it
Currently we have following configuration in Current steup.
Node1 and Node2 are in windows cluster
Node1 has SQL Server Database engine Instance1 as Standalone
Node2 has SQL Server Database engine Instance2 as Standalone
Instance1 and Instance2 configured for Always On availability group with Listener.
Now we have to steup SSAS instance with High availibilty. I know we have only option is to install cluster SSAS instance.
Can some one provide information below.
1. How to steup Cluster SSAS instance in this servers.
2. Is this will have any dependancy on exisiting Listner name.
3. Is this affects the availiblity groups, if SSAS instance failed over to another node.
Thanks in Advance
Sriram

You will need to have SSAS installed as a clustered instance with shared storage. Refer to the whitepaper from this MSDN article
How To Cluster SQL Server Analysis Services
Availability Group is in it's own Role/Resource Group. When you create the clustered SSAS, it will create its own Role/Resource Group. This means that it will require its own virtual network name and virtual IP address and will not affect the existing Availability
Group. You can also have it on the existing Availability Group if you want to. However, you need to decide if you want SSAS to failover with the Availability Group or not. Your design choices will depend on that decision.
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Do SameSubnetDelay or SameSubnetThreshold setting need restart windows failover cluster ?

Hi ,
I set SameSubnetDelay=2000 and SameSubnetThreshold = 10,but after a failover, when i check the cluster log, we still found SameSubnetDelay and SameSubnetThreshold use default setting.
So i want to konw do these settings need restart windows failover cluster core resource group to take effect?
Our windows version: Windows 2008 R2 SP1
Many thanks.

Thanks for your reply.
After set up new values for these two settings , i checked the values use "cluster /prop " command, it indeed show new values.
But after a sql server cluster instance failover, i checked the cluster log to find the cause of failover ,in the cluster log it showed default values for these settings. There were two times like this.
I will keep watching this, and next time i will post the setting values and cluster log.

How to Perform Forced Manual Failover of Availability Group (SQL Server) and WSFC (Windows Server Failover Cluster)

I have a scenario with the three nodes with server 2012 standard, each running an instance of SQL Server 2012 enterprise, participate in a
single Windows Server Failover Cluster (WSFC) that spans two data centers.
If the nodes in the primary data center are unavailable due to data center outage. Then how I can able to access node in the WSFC (Windows Server Failover Cluster) in the secondary disaster recovery data center automatically with some script.
I want to write script that can be able to check primary data center by pinging some IP after every 5 or 10 minutes.
If that IP is unable to respond then script can be able to Perform Forced Manual Failover of Availability Group (SQL Server) and WSFC (Windows Server Failover Cluster)
Can you please guide me for script writing for automatic failover in case of primary datacenter outage?

please post you question on failover clusters in the cluster forum. THey will explain how this works and point you at scipts.
You should also look in the Gallery for cluster management scripts.
¯\_(ツ)_/¯

How to Perform Forced Manual Failover of Availability Group (SQL Server) and WSFC (Windows Server Failover Cluster) with scrpiting

I have a scenario with the three nodes with server 2012 standard, each running an instance of SQL Server 2012 enterprise, participate in a
single Windows Server Failover Cluster (WSFC) that spans two data centers.
If the nodes in the primary data center are unavailable due to data center outage. Then how I can able to access node in the WSFC (Windows Server Failover Cluster) in the secondary disaster recovery data center automatically with some script.
I want to write script that can be able to check primary data center by pinging some IP after every 5 or 10 minutes.
If that IP is unable to respond then script can be able to Perform Forced Manual Failover of Availability Group (SQL Server) and WSFC (Windows Server Failover Cluster)
Can you please guide me for script writing for automatic failover in case of primary datacenter outage?

You are trying to implement manually what should be happening automatically in the cluster. If the primary SQL Server becomes unavailable in the data center, it should fail over to the secondary SQL Server automatically. Is that not working?
You also might want to run this configuration by some SQL experts. I am not a SQL expert, but if you have both hosts in the data center in a cluster, there is no need for replication between those two nodes as they would be accessing
the database from some form of shared storage. Then it looks like you are trying to implement Always On to the DR site. I'm not sure you can mix both types of failover in a single configuration.
FYI, it would make more sense to establish a file share witness in your DR site instead of placing a third node in the data center for Node Majority quorum.
. : | : . : | : . tim

Perform Forced Manual Failover of Availability Group (SQL Server 2012) and WSFC (Windows Server Failover Cluster)

I have a scenario with the three nodes with server 2012 standard, each running an instance of SQL Server 2012 enterprise, participate in a
single Windows Server Fail-over Cluster (WSFC) that spans two data centers.
If the nodes in the primary data center are unavailable due to data center outage. Then how I can able to access node in the WSFC (Windows Server Fail-over Cluster) in the secondary disaster recovery data center automatically with some script.
I want to write script that can be able to check primary data center by pinging some IP after every 5 or 10 minutes.
If that IP is unable to respond then script can be able to Perform Forced Manual Fail-over of Availability Group (SQL Server) and WSFC (Windows Server Fail-over Cluster)
Can you please guide me for script writing for automatic fail-over in case of primary data-center outage?

+1 to David's comment. I would not suggest to run a script automatically. During such failover you might have data loss and decision has to be made with business owners during disaster.
During such situation, you need to start cluster service in force quorum mode (/fq switch) and then perform manual failover of AG to DR site.
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Cluster failover but Availability Group do not

We recently had an issue where a file share was unavailable. It caused the cluster to failover. However, the Availability Group did not failover. The application was trying to connect to the secondary database which it couldn't since the failover had not
happened. We are set up using Quorum with a File Share Witness. We have manually failed this over successfully. Any ideas on why the Availability Group did not failover would be most appreciated. We do not have any experts in this area so please help us figure
out where to look.

Availability listener are a good way of providing a fault tolerance for the client and in addition providing read-intent or read-only access to the secondary replicas. If you need it, you can go through these documentations. They show the why and how to
set them up. If you have any additinal questions let me know.
http://msdn.microsoft.com/en-us/library/hh213417.aspx
Always make sure to configure AG relevenat parts through SSMS not the cluster Service manager itself. There are some points that you might want to tweak in the cluster manager, but most parts should be configured (and for most cases they are sufficient)
in the SQL Server related tools (SSMS)
-Jens
Jens K. Suessmeyer http://blogs.msdn.com/Jenss

Reporting Services as a generic service in a failover cluster group?

There is some confusion on whether or not Microsoft will support a Reporting Services deployment on a failover cluster using scale-out, and adding the Reporting Services service as a generic service in a cluster group to achieve active-passive high
availability.
A deployment like this is described by Lukasz Pawlowski (Program Manager on the Reporting Services team) in this blog article
http://blogs.msdn.com/b/lukaszp/archive/2009/10/28/high-availability-frequently-asked-questions-about-failover-clustering-and-reporting-services.aspx. There it is stated that it can be done, and what needs to be considered when doing such a deployment.
This article (http://technet.microsoft.com/en-us/library/bb630402.aspx) on the other hand states: "Failover clustering is supported only for the report server database; you
cannot run the Report Server service as part of a failover cluster."
This is somewhat confusing to me. Can I expect to receive support from Microsoft for a setup like this?
Best Regards,
Peter Wretmo

Hi Peter,
Thanks for your posting.
As Lukasz said in the
blog, failover clustering with SSRS is possible. However, during the failover there is some time during which users will receive errors when accessing SSRS since the network names will resolve to a computer where the SSRS service is in the process of starting.
Besides, there are several considerations and manual steps involved on your part before configuring the failover clustering with SSRS service:
Impact on other applications that share the SQL Server. One common idea is to put SSRS in the same cluster group as SQL Server. If SQL Server is hosting multiple application databases, other than just the SSRS databases, a failure in SSRS may cause
a significant failover impact to the entire environment.
SSRS fails over independently of SQL Server.
If SSRS is running, it is going to do work on behalf of the overall deployment so it will be Active. To make SSRS Passive is to stop the SSRS service on all passive cluster nodes.
So, SSRS is designed to achieve High Availability through the Scale-Out deployment. Though a failover clustered SSRS deployment is achievable, it is not the best option for achieving High Availability with Reporting Services.
Regards,
Mike Yin
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Cannot add multiple members of a failover cluster to a DFSR replication group

Server 2012 RTM. I have two physical servers, in two separate data centers 35 miles apart, with a GbE link over metro fibre between them. Both have a large (10TB+) local RAID storage arrays, but given the physical separation there is no physical shared storage.
The hosts need to be in a Windows failover cluster (WSFC), so that I can run high-availability VMs and SQL Availability Groups across these two hosts for HA and DR. VM and SQL app data storage is using a SOFS (scale out file server) network share on separate
servers.
I need to be able to use DFSR to replicate multi-TB user data file folders between the two local storage arrays on these two hosts for HA and DR. But when I try to add the second server to a DFSR replication group, I get the error:
The specified member is part of a failover cluster that is already a member of the replication group. You cannot add multiple members for the same cluster to a replication group.
I'm not clear why this has to be a restriction. I need to be able to replicate files somehow for HA & DR of the 10TB+ of file storage. I can't use a clustered file server for file storage, as I don't have any shared storage on these two servers. Likewise
I can't run a HA single DFSR target for the same reason (no shared storage) - and in any case, this doesn't solve the problem of replicating files between the two hosts for HA & DR. DFSR is the solution for replicating files storage across servers with
non-shared storage.
Why would there be a restriction against using DFSR between multiple hosts in a cluster, so long as you are not trying to replicate folders in a shared storage target accessible to both hosts (which would obviously be a problem)? So long as you are not replicating
folders in c:\ClusterStorage, there should be no conflict.
Is there a workaround or alternative solution?

Yes, I read that series. But it doesn't address the issue. The article is about making a DFSR target highly available. That won't help me here.
I need to be able to use DFSR to replicate files between two different servers, with those servers being in a WSFC for the purpose of providing other clustered services (Hyper-V, SQL availability groups, etc.). DFSR should not interfere with this, but it
is being blocked between nodes in the same WSFC for a reason that is not clear to me.
This is a valid use case and I can't see an alternative solution in the case where you only have two physical servers. Windows needs to be able to provide HA, DR, and replication of everything - VMs, SQL, and file folders. But it seems that this artificial
barrier is causing us to need to choose either clustered services or DFSR between nodes. But I can't see any rationale to block DFSR between cluster nodes - especially those without shared storage.
Perhaps this blanket block should be changed to a more selective block at the DFSR folder level, not the node level.

SQL AlwaysOn Availability Group modifies preferred owner node on move/failover

I have a two node Windows Server 2012 R2 failover cluster with two SQL Server 2012 Enterprise AlwaysOn Availability groups configured. Within the cluster I have configured a preference order on which node a AlwaysOn Availability Group should run.
Get-ClusterGroup -Name "AlwaysOn1" | Set-ClusterOwnerNode -Owners "node1","node2";
Get-ClusterGroup -Name "AlwaysOn2" | Set-ClusterOwnerNode -Owners "node2","node1";
After configuring the preference and retrieving the preference order it is configured as it should be. When I do a failover the preference order is adjusted to first the node it currently runs on and second the other node instead of leaving the preference
order as it was. It doesn't matter if I use the PowerShell "Move-ClusterGroup" or the "ALTER AVAILABILITY GROUP [AlwaysOn1] FAILOVER" T-SQL command. From the cluster log it is shown that the preference is modified after the resource
has been moved.
INFO [GUM] Node 2: executing request locally, gumId:15859, my action: /rcm/gum/SetGroupPreferredOwners, # of updates: 1
INFO [RCM] rcm::RcmGum::SetGroupPreferredOwners(AlwaysOn1,<vector len='2'>
The default groups within the cluster "Available Storage" and "Cluster Group" keep their preference setting when configured (only configured for testing to verify it has to do with the SQL Server Availability Group resource type).
The Windows Server 2012 R2 servers are updated using the latest Windows Updates and SQL 2012 has build number 11.0.5556.
For other cluster groups which I have configured in the past like file, Hyper-V (used for affinity to get VM's which have a lot of traffic between them within the same virtual switch to reduce latency and additional hops. it would be nice if vNext will have
a affinity option for cluster groups besides the anti-affinity within the current version)
I would like to know if someone could explain why the SQL Server Availability Group resource always modifies the group preference. I might understand this with a three node cluster where the first two are running in Synchronous commit mode and the third
one in Asynchronous commit mode.
Thanks in advance,
Dennis van den Akker

Hi Dennis van den Akker,
Do not use the Failover Cluster Manager to manipulate availability groups, for example:
Do not add or remove resources in the clustered service (resource group) for the availability group.
Do not change any availability group properties, such as the possible owners and preferred owners. These properties are set automatically by the availability group.
Do not use the Failover Cluster Manager to move availability groups to different nodes or to fail over availability groups. The Failover Cluster Manager is not aware of the synchronization status of the availability replicas, and doing so can lead to extended
downtime. You must use Transact-SQL or SQL Server Management Studio.
The related KB:
Failover Clustering and AlwaysOn Availability Groups (SQL Server)
https://msdn.microsoft.com/en-us/library/ff929171.aspx
The similar thread:
SQL Server Clustering 2008 (Multi Node)
https://social.msdn.microsoft.com/Forums/sqlserver/zh-CN/c35fe863-3fed-4a6e-830b-b79aa032c198/sql-server-clustering-2008-multi-node?forum=sqldisasterrecovery
Best Regards,
Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact [email protected]

The lease timeout between avaiability group and the Windows Server Failover Cluster has expired

Hi,
I am having some issues where I get a lease timeout from time to time. I have a Windows 2012 Failover Cluster with 2 nodes and 2 SQL 2012 Always-on Availability Groups. Both nodes
are a physical machines and each node is the primary for an AG.
From what I understand if
the HealhCheckTimeout
is exceeded without the signal exchange the lease is declared 'expired' and the SQL Server resource dll reports that the SQL Server availability group no longer 'looks alive' to the Windows cluster manager. Here are the properties I have setup
which are the default settings:
LeaseTimeout - 20000
HealthCheckTimeout - 30000
VerboseLoging - 0>
FailureConditionLevel – 3
Here are the events that occur in the Application Event Viewer:
Event ID 19407:
The lease between availability group 'AG_NAME' and the Windows Server Failover Cluster has expired. A connectivity issue occurred between the instance of SQL Server and the Windows Server Failover
Cluster. To determine whether the availability group is failing over correctly, check the corresponding availability group resource in the Windows Server Failover Cluster.
Event ID 35285:
The recovery LSN (120881:37533:1) was identified for the database with ID 32. This is an informational message only. No user action is required.
SQl server logs are too long to post in this box but I can send them if you request.
The AG is setup to failover automatically but it did not failover. I am trying to figure out why the lease timed out. Thanks.

From what I've been able to find out, this is due to an issue with the procedure sp_server_diagnostics. It sounds like the cluster is expecting this procedure to regularly log good status "Clean" in the log files, but the procedure is designed not
to flood the logs with "Clean" messages, so only reports changes, and does not make an entry when the last status was "Clean" and the current status is "Clean". The result is that the cluster looks to be unresponsive. However, once it initiates
the failover, the primary machine responds, since it was never really down, and the failover operation stops.
The end result is that there really never is a failover, but the database becomes unavailable for a few minutes while this is resolved.
I'm going to try setting the cluster's failure condition level to 2 (instead of 3) and see if that prevents the down time.
blogs.msdn.com/b/sql_pfe_blog/archive/2013/04/08/sql-2012-alwayson-availability-groups-automatic-failover-doesn-t-occur-or-does-it-a-look-at-the-logs.aspx

New SQL Server Failover Cluster Installation - No disk is available to select in section "Cluster Disk Slection"

Hello Everyone,
I am in a deep need for your help regarding the problem I am facing.
I am doing a New SQL Server Failover Cluster Installation in a virtual server that is part of a failover cluster. I am able to complete all the steps successfully but, when I reach the point where I am supposed to select the shared disk that will
be included in the SQL server resource cluster group, I don't find any disk in the list (as u can see in the figure below).
I have already created the a 2 nodes failover cluster and added 3 disks (1 as a witness in Quorum and 2 other available storage).
No roles were created, 2 nodes are available and 1 network is there in the cluster.
If u take a look at the message it say: "The search for mount points failed. Error: the system cannot find the path specified". What is this and how can I solve this issue??
Thanks in advance for your support and looking forward for your valuable feedbacks.
Mark as answer if it was an answer for you question.. Please don't hesitate to ask for any further help..

Dear Ashwin,
I have granted the privileges mentioned in the link you provided as below:
Act as Part of the Operating Sywstem = SeTcbPrivileg
  Bypass Traverse Checking = SeChangeNotify
  Lock Pages In Memory = SeLockMemory
  Log on as a Batch Job = SeBatchLogonRight
  Log on as a Service = SeServiceLogonRight
  Replace a Process Level Token = SeAssignPrimaryTokenPrivilege
I was not able to solve the problem by giving these privileges to the domain account I am using to install SQL.
Mark as answer if it was an answer for you question.. Please don't hesitate to ask for any further help..

Availability group Automatic failover

Hi
setup a simple 2 node AG, sync. (SQL 2014 enterprise on windows 2012R2 standard)
if I set it as manual failover everything works as expected. however when I switch to automatic failover and stop SQL service on the primary node the AG resource in cluster does offline and doesn't failover to secondary node.
both nodes are available to the cluster resourse.
would appreciate your feedback as to what might be the reason
Regards
Shaunt

Hi,
I would verify if Database Availability Group means AlwaysOn Availability Group.
How did you set the FailureConditionLevel?
Whether the diagnostic data and health information returned by sp_server_diagnostics warrants an automatic failover depends on the failure-condition level of the availability group. The failure-condition level specifies what failure conditions
trigger an automatic failover. There are five failure-condition levels, which range from the least restrictive (level one) to the most restrictive (level five). For details about failure-conditions level, see:
http://msdn.microsoft.com/en-us/library/hh710061.aspx#FClevel
There are two useful articles may be helpful:
SQL 2012 AlwaysOn Availability groups Automatic Failover doesn’t occur or does it – A look at the logs
http://blogs.msdn.com/b/sql_pfe_blog/archive/2013/04/08/sql-2012-alwayson-availability-groups-automatic-failover-doesn-t-occur-or-does-it-a-look-at-the-logs.aspx
SQL Server 2012 AlwaysOn – Part 7 – Details behind an AlwaysOn Availability Group
http://blogs.msdn.com/b/saponsqlserver/archive/2012/04/24/sql-server-2012-alwayson-part-7-details-behind-an-alwayson-availability-group.aspx
Thanks.
Tracy Cai
TechNet Community Support
Hi,
Thanks for the reply.
It's an AlwaysOn Availability Group.
In my test lab, I have changed the quorum configuration to a file share witness and that has allowed an automatic failover when I turn the primary replica server off (rather than power it off).
I'll take a look at the links you provided.
Regards,
Bob

2012 SQL AlwaysOn Availability Group - JDBC re-connection not happening in case of Multisubnet failover

Hi There,
Having some problem with MultiSubNet AG failover re-connection using SQL JDBC driver 4. Details given below.
SETUP:
We have a three node 2012 Windows Server Cluster, on top it we have 2012 SQL Sever AlwaysOn Availability Group.
Two nodes are in one subnet and other in a different subnet to make this as a multisubnet AlwaysOn AG.
An AG Listener is configured with a DNS name and two VIP assigned (For two subnet) to it. We were able to failover from one subnet to other using the SQL Studio successfully.
NEED:
We have a java application which will be connected to AG Listener name. In case of failover, automatic re-connection to DB/AG Listener name should happen.
For this we use "sqljdbc4.jar" and added
'multiSubnetFailover=true' in our connection string. The connection String is given below.
cURL="jdbc:sqlserver://testsqlag:1433;databaseName=SalesDB;multiSubnetFailover=true;loginTimeout=200;applicationName=MyApp";
THE PROBLEM:
In case of AG failover, driver is not trying to re-connect to the AG Listener name. Not sure how to make it work.
Is this supported in SQL Server 2012 ?
Thanks,
Krishna.

Hi Sean,
Thanks for your answer.
I looked at the link earlier, but it was not very clear that, whether the mssql jdbc driver will automatically re-connect to AG Listener name in case of failure of Primary replica which will result in Multisubnet failover. Pasted the confusing statements
from the link
http://msdn.microsoft.com/en-us/library/gg558121(v=sql.110).aspx.
Also, because a connection can fail because of an availability group failover, you should implement connection retry logic, retrying a failed connection until it reconnects.
Connecting With MultiSubnetFailover :
During a multi-subnet failover, the client will attempt connections in parallel. During a subnet failover, the Microsoft JDBC Driver for SQL Server will aggressively retry the TCP connection.
Thanks,
Krishna.

Failover cluster vs Availability Groups

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