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SQL Alwayson Question

July 8, 2019, 11:16 pm
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Hello,

i have setup an SQL 2016 AlwaysOn.My databases are in sync and when i manually move to secondary node or even i do a reboot my databases are online to the secondary,working as expected.

My main question is if i unplug the Ethernet cable for testing from the primary node should the databases get online to the secondary?Because when i shut the network i get a resolving error for the listener and my databases are offline to the primary.The secondary node does not change to primary.

Is the Ethernet problem an acceptable test for the SQL and if it is how i can resolve my problem?

Thank you!


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CSV over MPIO or Virtual Fiber Channel ?

July 9, 2019, 6:22 am
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Hello Experts,

Appreciate advice on configuring SQL clusters 2016 in a virtual environment.

i am comparing performance and limitations between CSV over MPIO or Virtual Fiber Channel for SQL Storage DB & Logs

Wondering if any of you tried both technologies ?

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IS_CLUSTERED not showing Clustered Instance in "sys.dm_server_services"

July 10, 2019, 11:23 pm
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Hi,

I have a many clustered instances installed on a Windows Server 2012 Failover Cluster. For my SQL 2016 instances and some SQL 2012 instances, the IS_CLUSTERED and CLUSTER_NODENAME from the dmv "sys.dm_server_services" show "N" and Null respectively.

However, the "SELECT SERVERPROPERTY('IsClustered')" correctly displays a "1".

I am running both queries as a SYSADMIN.

Any ideas? Am I encountering some sort of bug?

Regards

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Always on Availability Group Listener

July 11, 2019, 7:05 am
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Hi,

My SCOM is not able to listen the Always on listener everything is configured.

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After removing the secondary replica from the availability group, Database has become unavailable and showing resolving status

July 12, 2019, 4:25 am
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We have Always on availability group configuration with 2 nodes/replica

When i am removing the secondary replica from availability group, the data base has become in-accessible and showing resolving status.

Is there any way we can use the data base of server after removing it from group ?

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SQL AG script deleting DB's Automatically

June 25, 2019, 9:43 am
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Hi All:

We are in the process of creating our own scripts, when ever the application creates new database, the DB will be add to Alwayson group and its working fine for us.

Today, we are planning to add one more check.

For some-reason, if the secondary replica having same database - we want to delete it.

Is it possible to delete it from Link server?

Link server already created with @notename in below script.

When we try to delete manually also, not working using link server.

Drop database [linkservername]..[test1234]

=====================================
Error:
Msg 102, Level 15, State 1, Line 43
Incorrect syntax near '.'
==================================

This is what we are trying to with hard luck, any suggestions.

     declare @avagroupname  nvarchar(128)='',
             @tsql_restore  nvarchar(1000)='',
             @tsql_hadr     nvarchar(255)='',
             @debug int,
             @dbname nvarchar(255)='';
begin

set @dbname = 'test1234';
set  @debug = 1;
set @avagroupname='AG2016'

-- if there is a same database on the secondary node , will be deleted first
        -- get the note list
       declare @notename nvarchar(128)
       select  top 1 @notename= dh.replica_server_name from  sys.availability_replicas dh join sys.dm_hadr_availability_replica_states dap
       on dh.group_id= dap.group_id and dh.replica_id=dap.replica_id join sys.availability_groups ag
       on ag.group_id=dap.group_id where role=2 and ag.name =@avagroupname  order by dh.replica_server_name desc
       print @notename
       --end
        --while @@ROWCOUNT>0 --and @notename  is not null
          --  begin
            print 'test';
                 set @tsql_restore=N'
                     exec (''if exists (select * from sys.databases where name='''''+@notename+'..'+@dbname+N''''')
                     drop database '+@notename+'..'+@dbname+N'';
                    
                    
                 if @debug>0  print @tsql_restore
                   exec (@tsql_restore)
                    
                     ---
                      
                    
                 select  top 1 @notename= dh.replica_server_name from  sys.availability_replicas dh join sys.dm_hadr_availability_replica_states dap
                  on dh.group_id= dap.group_id and dh.replica_id=dap.replica_id join sys.availability_groups ag
                  on ag.group_id=dap.group_id where role=2 and ag.name =@avagroupname and dh.replica_server_name<@notename   order by dh.replica_server_name desc
            --end

end
=================

Thanks,
Satish Kumar

Thanks, Satish Kumar. Please mark as this post as answered if my anser helps you to resolves your issue :)


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Always on strategy across data centers

July 13, 2019, 6:07 am
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I have an application that needs to have two instances installed, one in each of our remote data centers. Both application servers will expect to point to a common listener and will manage the database semantics internally.

Our DBA is saying there is no deployment strategy that can create an available scenario across both data centers such that either application server can operate simultaneously on the same listener due to latency. Traffic across DC's typically see's 5ms latency which to me seems far too low to be concerned.

Can anyone share some guidance from their experience?

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SQL Server AlwaysON - SQL 2016

July 13, 2019, 7:49 pm
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Hi

We have 2 node-cluster in each datacenter (HA) and then have geo-red fail-over to the other site. The Always ON was recommended by our customer. But can we have alternate solution in place of Always ON in order to save license costs but achieve the required functionality ?

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Sql Server AG and FCI query

July 14, 2019, 11:19 pm
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Hi there,

We have a web application working fine with sql server 2008 - 2016 but want to know if we need to change anything on the web application side to if we want to get web application work  Sql sever configured with AG or FCI.

Thanks,

Ghanshyam

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HA cluster and AG

July 15, 2019, 1:42 am
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HI,

What is the benefit of having AG  rather  than having cluster 

Thanks

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SQL Server Always On Cluster

July 15, 2019, 6:25 am
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Hi,

I am going to create a AlwaysOn Cluster with 4 nodes (2 nodes A & B in one data center and another 2 nodes C & D in another data center).
Here A will be Primary Active Node, B will be sync replica while C & D will be async replica. Every year for almost a month we will do the manual fail over and C will be the Primary replica, D will be sync replica and A & B will be async replica.

Here my question is: Which quorum configuration will be best: 
1. No Quorum
2. File Share
3. Azure Storage Share

& How many SQL Servers will be licensed?

All thoughts are welcome. 


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SQL Always ON

July 15, 2019, 7:57 pm
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Hi

SQL Version: SQL 2017 Ent edition

I have 4 VM's (VM1 Prod DB and VM2,VM3,VM4 replica of Prod that is HA/DR DB servers).

- VM1, VM2 are hosted on DC1 and VM3, VM4 are hosted on DC2.
- VM1 and VM2 are in windows fail-over cluster (A-A cluster): Cluster Name-> DC1_cluster
- VM3 and VM4 are in windows fail-over cluster (A-A cluster): Cluster Name-> DC2_cluster

Is it possible to configure SQL Always ON from VM1 to VM2, VM3 and VM4 DB servers? If it's not possible, what is the alternative solution for HA/DR?

I have two clusters. As per Windows team, it's not possible to add 4 VM's in same cluster because the VM's are hosted on different DC.


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1 DNS A record, 2 ip addresses and 2 servers windows cluster for Always on SQL

October 8, 2018, 9:58 pm
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so 1 DNS = SQLDNS

1 IP 10.10.10.1/30

2 IP 10.10.10.2/30

So this is my war at work. They have SQL always on set up, ip 1 & 2 are set up as active and stand-by but pointing to same dns A record. It keeps flipping between ip's because of the round robin default rule in dns server. I've read that if disabled it can cause problems. reverse lookup for secondary ip fails as either it is not configured or just because of the state of the interface being stand-by mode which means it does not reply to pings until ip 1 is actually down.

I am a network guy so easy on me on the clustering, SQL HA or DNS specifics..., I know a bit of all but no expert.

Thanks in advance to all 

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SQL LICENSE

July 17, 2019, 4:41 am
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HI,

If I  have connection string  using a local user account in sql  and connected to  the db , If I am going for user license , how many user licenses are required 

Thanks

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Alwayson AG failover mean gaceful failover

July 19, 2019, 11:18 pm
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Hi  Expert

We have 2016 R2 EE Alwayson and some clarification on fail over AG. We have async and sync setup

Q1. When we execute  following command does it mean it does graceful failover or not. The reason is let say application submit batch jobs . While running in the DB,  we do plan failover step.  In this situation  the batch job lost of acknowledgement whom to send back to "who submit the job" .

Do we need to setup  extra configuration to achieve this or it already satisfied .

Q2 What will happen to connected sessions? will be continued with survival replica or need a "reconnect" again and session id will be new one.     

Expert advise is highly appreciate. 

  

:Connect node 

ALTER AVAILABILITY GROUP [AG name] FAILOVER;

GO



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Always on Availability Group

July 20, 2019, 12:27 pm
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I have two SQL nodes where AG is configured and two SCOM machines when i provide listener name it goes ok!

but when i check that i can connect with my DB the folder does not show up it shows local drives and no

specific firewall Ports are opened.

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AlwaysOn Best configuration to do

July 21, 2019, 11:32 pm
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Hello,

I have installed on a sandbox an AlwaysOn Cluster. However, as it is a first time, I am not sure about my configuration and have some question. 

Our infrastructure is a stretch cluster on 2 sites with a 3rd site as Witness. I have installed one SQL server (MSSQL 2016 SP2) on each site with my Quorum server on the Witness. Each SQL server have been installed with one instance:

  • SANDBOX01 -> MSSBOX01
  • SANDBOX02 -> MSSBOX02

Both SQL have been added in a Windows Failover Cluster using the Microsoft Fail over feature with the Quorum configuration. 

1) Question: Is there something to configure in the Failover Cluster to make it better? Or a key element to monitor to be sure that everything works as it should?

Then I have put the Failover Cluster in the SQL configuration on both servers. 

Now for the SQL configuration:

I have created a new Availability Group using the Wizard. I had to modify my databases in “Recovery Full” to be able to add my Database. And did my full backup.

2) Question: Is there a best practice about databases in AlwaysOn. Should all databases in one Instance be in the AlwaysOn or will it work the same with only some databases selected? I am talking about performances and such. 

I have configured that our two servers should be in “Automatic Failover” with readable secondary. Then I have created our “Listener”. 

3) Question: As I understand correctly, the listener will be the port of entry for the SQL systems to redirect all sql request to the servers (if primary is down, go to secondary). As the second server is up in read mode, is there a way to have all write request go to primary and all the read request to the secondary in an auto way?

As a first Initialization, I have configured it in “join only” as we have two different Instance name and then restored the database on the other replica. Everything seems to be working fine.

I have tested what happens when I crash one server and it redirect, as it should.

I have a few other question:

4) Question: For our production environment, we have a database that is published (in “Transactional” mode). Is it possible to add it in an AlwaysOn Cluster? How about the configuration? As the replication is based on a server and not the cluster. How will it work (if we say the replication is configured on the first server and it crashed to let the secondary take after)?

5) Question: Is there something to configure special to make it work better? Or something I should know?

6) Question: What about the backup, how should I backup my AlwaysOn Database? I use Avamar as client.

Thank you for taking the time to read me and to answer,

Best Regards,

Jon


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Two AlwaysOn AG clusters: 2014 and 2017

July 23, 2019, 2:04 pm
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Just starting to think about migrating 2014 AG cluster to 2017.  2014 cluaster is the classic 2 HA node + 1 DR node.  We need to maintain the 2014 because it's hosting apps.  We want to introduce a 2017 cluster, but we want to minimize expense of hardware.  Can 2017 be install side-by-side on the the 2014 DR node, and that node serve as DR for both 2014 and 2017 clusters? Not even sure that makes sense, but need to ask.  Thx.

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Powershell Script to Install SQL server 2016 Service pack on Always-on and standalone servers

July 24, 2019, 8:46 am
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Hi Friends,

I am new to PowerShell we have 300+ SQL database servers and we have to install latest service pack\CU for every 3 months for all servers including production, pre-prod and dev\test as well but this task is very tedious every 3 months and resource and time consuming process I am looking to automate this task with below listed activities.

1. Script to copy the installation files to all destination servers

2. Invoke\executes the executable with the silently .

3. Run the report after some time, which shows us updated service pack

All of my production servers are configured 3 node cluster and all dev\test are standalone but in production and lower environment I have multiple instances in every server can you please help me to get code.

Thanks,

Srini.B 

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Clustered role 'xxxx-AG' has exceeded its failover threshold

November 4, 2014, 7:31 am
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I am getting the following error in cluster manager. I have an AG listener but it will not start in cluster manager

Log Name:      System
Source:        Microsoft-Windows-FailoverClustering
Date:          11/4/2014 7:17:51 AM
Event ID:      1254
Task Category: Resource Control Manager
Level:         Error
Keywords:      
User:          SYSTEM
Computer:      
Description:
Clustered role 'xxx-AG' has exceeded its failover threshold.  It has exhausted the configured number of failover attempts within the failover period of time allotted to it and will be left in a failed state.  No additional attempts will be made to bring the role online or fail it over to another node in the cluster.  Please check the events associated with the failure.  After the issues causing the failure are resolved the role can be brought online manually or the cluster may attempt to bring it online again after the restart delay period.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-FailoverClustering" Guid="{BAF908EA-3421-4CA9-9B84-6689B8C6F85F}" />
    <EventID>1254</EventID>
    <Version>0</Version>
    <Level>2</Level>
    <Task>3</Task>
    <Opcode>0</Opcode>
    <Keywords>0x8000000000000000</Keywords>
    <TimeCreated SystemTime="2014-11-04T15:17:51.897163400Z" />
    <EventRecordID>7748</EventRecordID>
    <Correlation />
    <Execution ProcessID="1608" ThreadID="4936" />
    <Channel>System</Channel>
    <Computer></Computer>
    <Security UserID="S-1-5-18" />
  </System>
  <EventData>
    <Data Name="ResourceGroup">OPSDB-AG</Data>
  </EventData>
</Event>


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