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SQL Server Always ON AG on Azure between 2 Region with Global VNET Peering

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Hi Team,

Thanks in Advance,

============================================

Let me first explain my environment

I've Region 1 which is my primary region and Region 2 which is my DR Region on Azure.

I've 2 SQL Servers in Region 1, with Basic Load balancer for Listener and configured in Sync Mode of Always ON AG.

I'm planning to create a Standard Load Balancer in DR Region for listener, and connecting the primary and secondary site using Global VNET Peering. 

As the secondary region will only be used for DR, once my all/primary servers goes down in azure region then my DR region SQL Server will be reachable to the web app. we've parallel web app deployed in DR Region so that it can connect to the SQL Node in DR Region for DB.

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I've few queries related to SQL Always ON AG on Azure VM between 2 Region.

As per the below article (Link 1), it is mentioned that we've to create VPN Gateway between the region for connecting the 2 VNET on Azure.

The limitation for not using the global vnet peering in sql always on AG in multi region deployment was that in global vnet peering resources in one region cannot connect to the Load balancer of the other region. (Mentioned in Link 2)

As the above limitation is removed if we use Standard Load balancer in DR Region (Link 3),I've 2 queries

Link 1 : https://docs.microsoft.com/en-us/azure/virtual-machines/windows/sql/virtual-machines-windows-portal-sql-availability-group-dr

Link 2 : https://docs.microsoft.com/en-us/azure/virtual-network/virtual-network-peering-overview#requirements-and-constraints

Link 3 : https://azure.microsoft.com/en-in/updates/global-vnet-peering-now-supports-standard-load-balancer/

Query 1 :

If I use Global VNET PEERING to connect the region 1 and Region 2 with Basic Load Balancer on Both the ends for listener

Currently, resources/web apps in Region 1 will never connect to the DR SQL as we've web app/resources in Region 2 deployed which will connect to the SQL Node 3 in DR Region (When failover happens and my Primary Region is down). So does the limitation mentioned in the Link 2 applies in my scenario of DR? 

In the above query 1, does SQL Node 1 or 2 in region 1 utilizes the listener IP/Load balancer on the DR Region for replication? or for any other reason? I believe Listener IP on LB is only used for the client connectivity.

I assume if i would have any web app from region 1 connecting to SQL Node 3 in DR region then the above limitation (Link 2)would have come into picture. But as we have web app in DR region deployed and will connect to the DR SQL Node at the time of failover/region down scenario then it would not make any impact and the limitation of global vnet peering does not applies to my scenario.

Query 2 :

If i create standard load balancer for listener in Region 2, and use Global VNET Peering to connect primary and DR VNET (Region 2). Does that help me in any ways? or overcome any blockers? and Will i be able to deploy SQL Always ON AG between 2 region/ multi region successfully?




Is MSSQL failover Cluster (Active/Passive) will support to encrypted shred disks (RDM)

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Hi All,

We have built the active-passive SQL fail over cluster successfully (Node& Disk majority) , prior cluster disk encryption,  the SQL failover cluster services moving successfully between the nodes & SQl & MSDTC services coming online automatically on nodes.

Due to some security compliance, We need to do encrypt the cluster disks + OS disks (~ $C & $D,) ( third party vendor ), but post encryption, the SQL cluster is not fail over as expected  and disks are taking more time to coming online & initializing , And then it’s leading SQL cluster fail over services failed , Once disks are initiated & coming online, then need  to bring SQl failover services manually online.

 

  • Is MSSQl failover shared disks will support encryption or not
  • What are parameters need to change in SQL failover cluster services to bring services online automatically if encrypted the cluster disks (RDM)

 

Thank you in advance



Regards, Kiron

SQL Always ON AG DR on azure VM using Async Commit.

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Hi Team,

I've one requirement of creating a DR using SQL Always ON AG with Async commit. I've gone through the below link but it is a mixture of 2 SQL Node in primary region with Sync Commit and 3rd SQL Node in Async Commit.

https://docs.microsoft.com/en-us/azure/virtual-machines/windows/sql/virtual-machines-windows-portal-sql-availability-group-dr

Do we have any article for only Async commit in the DR Region/ Secondary Region?

Is this possible first of all and Will there be any LB in the primary Region? any guidance.

Catalog missing from Linked Server

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We recently configured Linked Servers (Sql Server 2016 Ent).Everything is working fine.

But today userdb missing from LinkedServer only default catalog are showing.

I logged in with SA user. How to add missing DB back to Catalog?


Shrink/purge Huge transaction log - MS SQL 2014 Always on High Availability

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I have a MS SQL 2014 Always on High Availability cluster with one primary and two secondaries. The transaction log sizes for the different databases has grown so large(3 TB), and the disk size cannot be extended beyond 4 TB. The DB is set up for Full recovery model. 

Now we need to reduce the transaction log size. Maximum log duration needed is one week. We need to reduce/shrink/purge these transaction logs with less performance impact and no down time.

I have used DBCC SHRINKFILE previously, but not sure this will lock transaction, block writes and hence a down time for customers.

DBCC SHRINKFILE (logfilename, EMPTYFILE)

Looking for suggestions on reducing the transaction log size without a down time for customers.


SQL cluster configuration

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Hi All,

We have a SQL fail over cluster(Passive-Active) which consist of two server nodes and is used to hold the DBs for our SharePoint environment.I ran into an issues where someone mistakenly altered the cluster configuration settings.It took the great part of a day but I and a colleague of mine where able to put back the correct settings to bring the cluster back. Since then I have been investigating the best way to recover a cluster in situations like this and worse. 

Firstly may I know if there is a configuration file that highlights all the clusters original settings? If so, may I know where it is usually located.

Secondly,could you clearly point me to a document or explain how I would backup the configuration for a cluster and how I would restore it?

Many thanks,

Dom

Has anyone successfully setup AlwaysON Availability group on Windows 2016 datacentre using Azure Hyper-V VM

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I have been struggling to resolve the issue in my current environment and i am not able to fix the issue.  I have tried everything that is available in net but nothing is working.  Once again I am giving my problem definition

Environment

2 SQL VM - Windows 2016 Datacenter

2 SQL server 2016 enterprise version

1 Listener VM Windows 2016

My setup runs fine when Primary VM is primary , I can connect to my primary server using Listener IP from any other VMs with no issue.  The problem starts when i move my PRimary to Secondary VM,  It only connected from my Secondary VM using Listener and not connecting from any other machine.  I am getting following error 

C:\windows\system32>sqlcmd -S EMCPRODSQLCAP -E
Sqlcmd: Error: Microsoft ODBC Driver 13 for SQL Server : TCP Provider: The wait operation timed out.
.
Sqlcmd: Error: Microsoft ODBC Driver 13 for SQL Server : Login timeout expired.
Sqlcmd: Error: Microsoft ODBC Driver 13 for SQL Server : A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online..

C:\windows\system32>

If this issue does not fix I may lose my contract.  I am having strong feeling that I may be hitting a bug in this,

best archi using mirroring F5 and DNS

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hello,

I have 2 datacenter sql server 2012 configured.

  • on site 1: 2 nodes with microsft clustering
  • site 2: 2 nodes with microsft clustering
  • synchronous mirroring configured between the 2 clusters, Witness on the datacenter that is running the active instance

 I would like to enhance this design, what do you think about

  1. if I create a VIP for witness so it will point always to an active witness server
  2. DNS round robin entru for witness

ð Combine 1 and 2

Thanks


An error occurred while validating access to Azure from cluster node - winHTTP use automatic configuration script

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Hello,

I'm trying to setup a Cloud Witness in Failover Cluster Manager and getting this error:

An error occurred while validating access to Azure from cluster node

I have created my Storage account name, endpoint and access key but the Windows servers don't have direct Internet access.  IE is configured via GPO to use automatic configuration script.  I have not been able to figure out how I can configure winHTTP to use automatic configuration script.  Is this possible? 

Thank you!


Rumi

SQL Server AlwaysON cannot failover if you changed default port number

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Hello,

I have installed 3 nodes SQL Server 2016 with AlwaysON (2 nodes for HA- in same Location + 1 node for DR- in different Location)

I have changed SQL Servers' s default port number (different than 1433). When I want to failover to secondary Availability Groups, I cannot. Because on the Failover screen, SSMS would like to connect to Secondary node using default port number and it can not allow to change port number like "ipadress,portnumber". Due to it cannot connect to secondary node, I cannot failover to secondary.

Is it a bug or can i have some wrong settings?

Thank you!

After failover from 2014 to 2016 replica and removal of 2014 replica from the AG, it remains in a resolving state.

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Hello.

We are upgrading our environment  from SQL 2014 to SQL 2016.

We are doing this by adding a SQL 2016 server to the existing availability groups that consist on SQL 2014 servers and failing them over. Once the failover is complete the AG complains about to 2014 boxes which is expected. We then remove the old 2014 replica.

However, when we access the old 2014 replica we can still see the AG listed in "resolving" state. If you look at the AG on the new 2016 box it does not list to 2014 box.

If we delete the AG directly on the 2014 box it will delete the AG entirely (including on the 2016 box).

Has anyone else seen this behavior and if so, do you know how to get rid of the AG on the 2014 box. Sadly we have to keep the 2014 box as we do still have some other databases on it for the moment.

I have googled this and have not found any threads with this issue to date.

Thanks in advance.

SQL AlwaysON best practices - backup and restore

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Hi ,

We are planning to setup AlwaysON availabiliy group between onprem SQL and Azure IaaS SQL server. 

The question I have around is , taking backup and restoring it onto cloud sql server before starting the AG setup. 

whats the best practice here? how can I reduce the DB downtime? My approach is something like below. 

1. Take full backup

2. copy it to cloud server and restore it with no recovery mode. 

3. once the setup is complete, take a T-Log backup and restore it with recovery mode. 

Whether AlwaysON sync takes care of all the changes made to the DB during the setup and replicates it? 

Do I need to perform point#3? 

WHole idea is to setup the whole thing with minimal downtime. 

Kindly help. 


Redo log error

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Recently face this redo log issue,

Error: 3456, Severity: 21, State: 1.

Could not redo log record (14215667:937684:2), for transaction ID (1:-1187662913), on page (1:61242908), allocation unit 51745774043136, database 'Strorage' (database ID 12). Page: LSN = (14215534:4612217:6), allocation unit = 51745774043136, type = 1. Log: OpCode = 3, context 1, PrevPageLSN: (14215603:96348:132). Restore from a backup of the database, or repair the database.

Always On Availability Groups data movement for database 'Strorage' has been suspended for the following reason: "system" (Source ID 2; Source string: 'SUSPEND_FROM_REDO'). To resume data movement on the database, you will need to resume the database manually. For information about how to resume an availability database, see SQL Server Books Online.

During redoing of a logged operation in database 'Strorage', an error occurred at log record ID (14215667:937684:2). Typically, the specific failure is previously logged as an error in the Windows Event Log service. Restore the database from a full backup, or repair the database.

I have re-stored the backup, however would like to know why it is happening and how can i stop it from happening.. where can i check for logs. Can please advise on this.

The package execution returned DTSER_FAILURE (1).

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Hi, I have a problem with my SQL 2005 Transactionlog backup. I get an error on the schedule job:

 

Message
Executed as user: TNET\sqlservice. Microsoft (R) SQL Server Execute Package Utility  Version 9.00.3042.00 for 32-bit  Copyright (C) Microsoft Corp 1984-2005. All rights reserved.    Started:  01:00:00  Progress: 2008-02-15 01:00:02.56     Source: {8277BBE5-6B5E-44D1-9221-17442AB5C857}      Executing query "DECLARE @Guid UNIQUEIDENTIFIER      EXECUTE msdb..sp".: 100% complete  End Progress  DTExec: The package execution returned DTSER_FAILURE (1).  Started:  01:00:00  Finished: 01:00:03  Elapsed:  2.813 seconds.  The package execution failed.  The step failed.

 

but the job goe's trough and the full backup is ok.

The version I have is 3042 and sp2. Doe's anybody regognize this?

Question about Current Vote column inside Failover Cluster Manager that is hosting AlwaysOn Databases

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Hello,

We have two node Win2k12 r2 fail-over cluster that is hosting AO synchronized databases. The synchronization is set to Synchronous commit and  manual fail-over inside SSMS. When I look at the Fail-over Cluster Manager gui-->Nodes, I see Assigned Vote column showing 1 each for the two nodes, but the Current Vote column shows 0 for the current active node or the primary replica inside SSMS and 1 vote for the secondary node. We do not have at this time a fileshare witness created, but is in the works.

Wondering why the primary node does not a voting right in the cluster configuration?

Will greatly appreciate your response.

Thanks.

Victor


Victor


Storage for Windows Server Failover Clustering with SQL Server

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If we want to deploy SQL Server as Always On Failover Cluster Instances with iSCSI as storage, we filtered out two possibilities for our data files: 

- directly use Clustered Shared Volumes (created from iSCSI)

- use SMB shares on a scale out file server that itself uses storage from iSCSI

Is there any advantage for the second solution or does this introduce an unnecessary overhead to use a file server? 

Is there any recommendation for "best" storage for SQL Server on Failover Cluster? 

Thank you for your help,

Ina

Best practice for DR design using AlwaysON

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I have AlwaysOn with a few AGs each has 3 replicas, 2 replicas are on the main site, and the third is on the DR site.

The distance between the main and DR site is 1500+ Miles.

I currently run all replicas with synchronous mode as I don't want to take a risk of losing any data in a case of disaster. Performance isn't an issue in my case, as our servers are strong and the throughput is sufficient.

Is it true to say that it is not the BP to have synchronous replicas to a far replica?

Can you please refer me to any BP documentation which will specify if a synchronous mode is not the right thing for a remote replica?

Windows failover clustering for SQL Server 2017 AlwaysOn AG?

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Hello,

Can AlwaysOn AG (SQL 2017) be configured without the need for Windows failover clustering?  Does anyone have a step-by-step configuration of AlwaysOn AG for SQL 2017?

Thank you, 


Rumi

Trouble-shooting External Load Balancer for Always On Availability Groups

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I'm reviewing some "possible" issues with Windows 2016 and above as they relate to ELB and ILB implementations. I noticed the following limitation and wondered if it had been mitigated in future releases of Windows. Any suggestions, thoughts, comments?

Configure An External Listener for Always On Availability Groups in Azure

Guidelines and limitations for external listeners

Note the following guidelines about the availability group listener in Azure when you are deploying using the cloud service public VIP address:

  • The availability group listener is supported on Windows Server 2008 R2, Windows Server 2012, and Windows Server 2012 R2.

and

Guidelines and limitations for internal listeners

The use of an internal load balancer (ILB) with an availability group listener in Azure is subject to the following guidelines:

  • The availability group listener is supported on Windows Server 2008 R2, Windows Server 2012, and Windows Server 2012 R2.

Thanks much,

Mark S


SQL replication with Availability groups

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Performance implications:

We have a SQL AG Set up for a couple of databases (Primary and Secondary)

2 database requires to be replicated.

Is it a good idea to replicate between Secondary AG database to another standalone SQL instance with replication set-up between standalone SQL instance and Secondary AG database

please, advise




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