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Questions tagged [high-availability]

High-availability technologies mask the effects of hardware or software failure, so that perceived downtime for users and applications is minimized.

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SQL AlwaysOn & System Center Configuration Manager TP 4 1601

Recently Microsoft released Technical Preview 4 for Configuration Manager (1601). Per TechNet, "Configuration Manager now supports using a SQL Server AlwaysOn availability groups to host the ...
Adam's user avatar
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3 votes
0 answers
100 views

Mysterious alwaysOn breakage on SQL Server 2012

I've just bumped into a new situation regarding alwaysOn availability. We have a setup with a large database (terabyte range) with one primary and one secondary replica. Geographically the servers are ...
Kahn's user avatar
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2 votes
1 answer
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Getting "PAGEIOLATCH_SH" on a Named Replica of a HyperScale Database in Azure?

I have a monitoring query that populates a dashboard. It was created to monitor the transactions that occur on the primary replica. To avoid overloading the Primary Replica, I created a Named Replica. ...
Heliot's user avatar
  • 19
2 votes
0 answers
93 views

Alwayson fn_hadr_backup_is_preferred_replica takes a long time to return results

Our 2 nodes full sync mode Alwayson cluster has 20 databases which allocated into 4 different AG groups (9, 6, 3, 2). We set backup preference as on 'preferred secondary'. Find out that ...
Andrew An's user avatar
2 votes
2 answers
505 views

behavior of a Sql Server availability group listener and a jdbc client during a failover?

i have a question about the behavior of the AG listener during a failover... when the failover happens, I realize that all the connections on both primary and secondaries are closed. if the client ...
user2180778's user avatar
2 votes
0 answers
9k views

Issue: Data synchronization state of availability database is not healthy

I have a sqlserver 2017 cluster (sql server 14.0.3026.27) with two secondary nodes set with Availability Mode = Synchronous commit. The server has 8 databases that are replicated on the secondary ...
boggy's user avatar
  • 427
2 votes
0 answers
988 views

REQUIRED_SYNCHRONIZED_SECONDARIES_TO_COMMIT for Readscale AG failover

I have 2 node Readscale AG setup where each node is on a different data center. I want to know if SET (REQUIRED_SYNCHRONIZED_SECONDARIES_TO_COMMIT = 1); needs to be run even after setting both the ...
buddinggeek's user avatar
2 votes
1 answer
228 views

What is the difference between sys.dm_hadr_ tables and sys.availability_groups / sys.availability_replicas?

Browsing around some sys tables, I see: sys.dm_hadr_availability_replica_cluster_nodes.group_name = sys.availability_groups.name and sys.dm_hadr_availability_replica_cluster_nodes....
youcantryreachingme's user avatar
2 votes
0 answers
291 views

2 SQL 2019 Servers with High Availability Linux with a shared Linux SQL Express 2019 Witness

Is it possible to have two SQL Always on High Availability servers in datacentre A replicating to two servers in datacentre B with one Witness using Express with two availability groups (one for each ...
Waihibeachian's user avatar
2 votes
1 answer
851 views

Mirroring on-premise SQL Server to AWS EC2 SQL Server

Trying to mirror an on-premise SQL Server instance to EC2 instance, but not much information is available on this topic. The closest one I managed to find is: Implement SQL Server High Availability ...
Jimson James's user avatar
2 votes
1 answer
2k views

Add shared folder to AlwaysOn AG Failover

We have setup a 2 node Synchronous AG with automatic failover to provide HA for our ERP application (Dynamics GP) The GP desktop client loads a number of shared reports and dictionaries from a file ...
Jeremie's user avatar
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2 votes
0 answers
53 views

Unexplained connections from one SQL server to another

I just installed 2 SQL Server 2016 Enterprise and configured a High Availabilty Group. As a test object for the HA-Group I used a database I restored from another server. It's a database called "...
Hans Lindahl's user avatar
2 votes
0 answers
51 views

Asynchronous Availability Group Secondary Verify Up To Date with Primary Before Backup

I was wondering if there was a way to include a verification step before a backup on a secondary replica under asynchronous commit mode in availability groups to verify that the secondary replica is ...
Travis's user avatar
  • 21
2 votes
0 answers
50 views

Alwayson cannot fail over using tsql

I have an Alwayson test environment with the following settings. My test goals are as follows: When SqlNod1 is primary instance, I want SqlNod2 to answer read-only queries. When SqlNod2 is primary ...
SelmanAY's user avatar
2 votes
0 answers
6k views

High availability PostgreSQL 9.3 server on Windows

I'm trying to set up PostgreSQL 9.3 server in HA mode on 2 Windows servers. Final solution should be deployed to Microsoft azure network, so there are few limitations. Since Microsoft is doing ...
Ivan Cagalj's user avatar
2 votes
0 answers
497 views

dropping and adding subscription only picking up new article on some subscribers

I have used the following script to drop aand re-add a table from a subscription so I could move replace the ntext fields with nvarchar(max) columns. the script worked fine, but when I ran the ...
DamagedGoods's user avatar
  • 2,591
2 votes
0 answers
4k views

SQL Server connection with multiSubnetFailover fails, claims mirroring is enabled

I have two SQL Server instances in an availability group. They are not mirrored. I'm trying to connect to the AG using the MS JDBC drivers (4.0) with a connection string including multiSubnetFailover=...
Joe Kearney's user avatar
1 vote
0 answers
88 views

Configuring 3:1 Failover Cluster for SQL Developer Edition on Windows Server with AWS AMI

We are in the process of configuring a 3:1 failover cluster mechanism for SQL Developer Edition hosted on Windows Server, deployed using an AWS AMI. Our objective is to ensure that if any of the three ...
Rahul's user avatar
  • 11
1 vote
1 answer
351 views

Configuring High Availability for MySQL Router in a MySQL InnoDB Cluster

I've configured a MySQL InnoDB Cluster for high availability with two servers on a Windows system (Server 1: h01xxxxxxxxx1, IP: 10.xxx.xx.61, Server 2: h01xxxxxxxxx2, IP: 10.xxx.xx.71), running ...
alaa's user avatar
  • 11
1 vote
0 answers
217 views

Multi master with some slaves vs single master with some slaves

I need some advice on architecture. I have a national database that relies on postgres and some architectural design that involves orchestrating several components, very much similar to the picture ...
padjee's user avatar
  • 187
1 vote
1 answer
362 views

SQL AAG Cluster - Diagnosing Partner Quorum Failure

Recently we had a failure of our SQL Server (2016) Always On Availability Group, where our fileshare witness node was briefly inaccessible to our two nodes due to a CPU spike. We have two SQL server ...
4oo4's user avatar
  • 111
1 vote
1 answer
48 views

Always On with multi AGs primary on each replica - Any gotcha's?

I have a bunch of Always On clusters that I manage and am really comfortable with them. I have one client who is running an Always On cluster with 2 replicas. They have 4 AG's that each have their ...
LoriB's user avatar
  • 11
1 vote
2 answers
342 views

Automatic Failover for Basic Availability Group

This will be my first project with Basic availability group so I thought would check before implementing . As per Microsoft documentation below it says we will need to have Software assurance for ...
SQL_NoExpert's user avatar
  • 1,061
1 vote
0 answers
83 views

Windows Failover Cluster/Availability Groups - Issues because all servers of one site where unreachable

we had some issues because of maintenance and hope someone can explain what happened. Our cluster looks like this: Site A: Node A1 (Quorum vote) Node A2 (Quorum vote) Node A3 (Quorum vote) Node A4 (...
NicSmith's user avatar
1 vote
0 answers
158 views

SQL Always on Availability Groups Direct Seeding

Setting up a new SQL cluster and HA using SQL Availability Groups. SQL 2019 STD 2 Node Multi Subnet Basic AG Primary Node AWS Secondary Node VMWare on premise I am using the newer Automatic Seeding ...
Stockburn's user avatar
  • 419
1 vote
0 answers
416 views

What are the available automatic failover solutions for MariaDB Master-Slave replication on Windows Server?

I am setting up a Master-Slave or Master-Master setup in MariaDB on two seperate servers running Windows Server. I also need to configure an automatic failover solution where client read requests gets ...
Lucas Teong's user avatar
1 vote
1 answer
2k views

Why availability group resource goes offline in WSFC?

Sometimes I find the AG Cluster role in offline state which results the AG in resolving state. It doesn't allow the application to access the databases during this time. And then after sometime it ...
Sree Lekha's user avatar
1 vote
0 answers
173 views

How to install PolyBase in an availability groups architecture for high availability?

Background: I’m designing a 2 node SQL 2019 availability groups installation hosted in VMs. We would have limited (single node) usage of PolyBase. The Microsoft Docs don’t reference installation for ...
Marshall's user avatar
1 vote
0 answers
142 views

Enabling FileStream in existing clustered servers in SQL Server 2012

I have heard that enabling FileStream in an already existing clustered environment is tough. I'm working on a consolidation project and currently analyzing the impact it will have if we migrated DBs ...
dbbk's user avatar
  • 11
1 vote
1 answer
68 views

AlwaysOn Replicas set to manual but failing automatically

My two synchronous-commit SQL AO replicas are set for manual failover mode but are failing over automatically. When I look through the logs and extended events, it looks just like what would happen if ...
Matt Davis's user avatar
1 vote
1 answer
1k views

Mirroring issue with mirror server

I am running two Windows Servers 2012 R2 with SQL Server 2014 Standard Edition. I have strange issue on mirroring. I configured mirroring on for 15 databases, no Witness server. The Principal server ...
Nasar Babu Chowdary's user avatar
1 vote
0 answers
62 views

Why use Failover replica on Google Cloud RDS?

we are thinking of migrating our MySQL database from our dedicated server to a Google Cloud RDS instance. However I would like to clarify the below: 1) What is the purpose of creating a failover ...
Leonidas's user avatar
1 vote
0 answers
134 views

Adding Databases to Availability Group

I'm attempting to add databases to an existing availability group using automated seeding but I randomly receive this error: "Seeding Check Message Timeout". I'm pulling this error message from sys....
Steven Barnhill's user avatar
1 vote
1 answer
143 views

Enable Replication/CDC from High Availability Group

I am a newbie to this Replication concept and I am trying to build some scripts to automate our Build Process where we will be disabling/re-enabling Replication on a regular basis. Background: We ...
Julaayi's user avatar
  • 111
1 vote
0 answers
561 views

MHA vs Orchestrator

Im going to setup an HA solution. Im planning to use Orchestrator. But seems MHA is also doing well. If anyone already used/using any one these solutions, please suggest me to choose a right one ...
TheDataGuy's user avatar
  • 1,950
1 vote
0 answers
109 views

How do Master / Slave JDBC URL handle broken MySQL Slave?

I own the following classical MySQL 5.7 set-up : one master server one slave server The master => slave link is done though GTID. I'm monitoring the link by querying show slave status on the slave ...
Jérôme B's user avatar
1 vote
0 answers
212 views

Availability Group Always ON 2016 HADR_SYNC_COMMIT

I know it is not the best practice but we have a two node AG 2016 between two data centers. Server 1 and HQ and Server 2 at DR and they are clustered (multisubnet). AG is setup in Synchronous Commit ...
DoubleD's user avatar
  • 11
1 vote
0 answers
617 views

What is a good schema for a database where users can search for inventory availability on certain dates (such as Airbnb)?

I apologize if this is not the right venue to ask such a question. This is my first time on this site and I'm open to suggestions. I am trying to find a good schema for a database that needs to ...
Jacobo Koenig's user avatar
1 vote
0 answers
332 views

Can I run an index rebuild on a sql server HA replica or a copy the DB, and then swap with the primary?

We have a large database hosted in sql azure and we need to occasionally run maintenance tasks such as index rebuild. Pretty common of course, and we also try to minimize downtime. We use the premium ...
Clement's user avatar
  • 536
1 vote
0 answers
31 views

User-defined Policy Evaluates to True when Evaluated but False when Invoked by Test-SqlAvailabilityReplica

I created a PBM condition and policy in SSMS. The policy runs a T-SQL script using the ExecuteSql function against the Server facet to determine whether all databases that are expected to be a member ...
Craig Dawson's user avatar
1 vote
0 answers
546 views

Restore database that is part of an Availability Group

I have a few databases that were part of an Availability Group. The primary replica (production) databases were taken offline for maintenance then brought back online. the primary databases were then ...
Kefash's user avatar
  • 175
1 vote
1 answer
265 views

Automatic MYSQL failover

We have a wordpress environment however this is not a wordpress question. Our scenario is that front Ends connect to a MYSQL backend (MYSQL VM1) which is replicated to a backup vm (MYSQL VM2). The ...
joebegborg07's user avatar
1 vote
0 answers
97 views

SQL Server 2016 HA Options for thousand databases

Currently we have a 4 node Active\Active\Active\Active Windows\SQL Server 2008r2(ENT Edition) cluster that we need to upgrade to Win2012r2\SQL Server 2016. We have over a thousand databases, and ...
user3585655's user avatar
1 vote
0 answers
269 views

AlwaysOn Availability Group and workgroup servers

Has anyone had any luck setting up AGs with servers in a workgroup, neither server in a domain (no domain even exists for this client). I've added DNS suffix to both servers, like recommended. I have ...
Jason B.'s user avatar
  • 642
1 vote
0 answers
129 views

Losing records during transitioning to a failover cluster

Recently we had an outage in our primary SQL Server cluster and traffic was directed to the fail-over cluster. This process has taken a few seconds. The funny thing is that application logs show we ...
Mori's user avatar
  • 163
1 vote
0 answers
322 views

Quorum Questions For An FCI And AlwaysOn in a WSFC

I was reading the white paper on FCI + AlwaysOn as well as several other resources on quorum voting differences in Windows Server 2008 and 2014 and had 3 questions. 1- Will giving a node in the ...
Ali Razeghi - AWS's user avatar
1 vote
1 answer
39 views

Setting up HA and a synced up reporting box all together using SQL Server 2014 Standard Edition

Scenario: We are going to upgrade our third party application. Also we are going to upgrade our DBMS from SQL Server 2008 R2 to SQL Server 2014 Standard edition. We also wanted to have a high ...
sachin-SQLServernewbiee's user avatar
1 vote
0 answers
60 views

Synchronization report for uncontained objects across each of the replicas in HAG

I have seen How to transfer logins and passwords between instances of SQL Server , Synchronize Availability Group Logins and Jobs and SQL Server 2012 Availability Group Add-in to synchronize ...
amit_g's user avatar
  • 111
1 vote
0 answers
41 views

Replicating data from SQL Server 2014 to SQL Server 2005 - temporary solution

I will be installing a new SQL Server 2014 database system, which is based on our current SQL Server 2005 database system. The new system will be on a completely new infrastructure when we go live, ...
Joe's user avatar
  • 41
1 vote
0 answers
441 views

IP from a different subnet is registered even after node and resource were removed

We run two SQL server at primary site in AlwaysOn High Availability Group on subnet 10.10.0.0/24 A third SQL server is running on secondary site in a different subnet 10.10.1.0/24 We have had third ...
clunkyorange's user avatar