Database Administrators Stack Exchange
Database Administrators Stack Exchange

Questions tagged [hadr]

HA/DR refers to High Availability / Disaster Recovery, which is typically a suite of technologies provided by a database engine vendor with the aim of increasing availability of data stored in the database, and providing a fast method of return-to-service after a disaster.

DB2® High Availability Disaster Recovery (HADR) uses database logs to replicate data from the primary database to the standby database. Non-logged operations are allowed on the primary database, but not replicated to the standby database. If you want non-logged operations, such as updates to the history file, to be reflected in the standby database, you must take extra steps to cause this to happen.

Microsoft SQL Server 2012 HA/DR is referred to as AlwaysOn. 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. Optionally, secondary databases can be made available for read-only access and/or some backup operations.

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Are "Always On Failover Cluster Instances" and "SQL Server Failover Clustering" the same thing?

I'm reading documentations of SQL Server. On this page at https://learn.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/windows-server-failover-clustering-wsfc-with-sql-server, it says: Both Always On Availability Groups and Always On…
Just a learner
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Removing Databases in Recovery Pending Status after AG group was removed

I have removed a High Availability Group, disabled the option in sql configuration manager and restarted and I have also removed the Failover cluster components from windows and restarted. Unfortunately the databases are marked as Recovery Pending…
DamagedGoods
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Always On Primary Replica On Prem, Secondary Replica On Azure

We want to create an Always On Availability group where the primary replica will be On-premises and the secondary replica will be on an Azure VM. I have researched and I know it's possible to do this, but in all the examples I find, they always have…
Victor Barajas
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IBM DB2 v9.7 HADR TSA failure on the standby server

I have an environment here where I have 2 servers running DB2. One is the primary and the other one is standby. They replicate with HADR and failover is made automatically by TSA. What's the default behaviour when the standby host fails ? Because…
Pierre-Alain TORET
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Does SQL Server route connections to a secondary replica which has commit mode as synchronous in case of an AG with multiple secondary nodes?

If I have an AG with 4 different nodes as below: Primary Node Secondary Node 1 - Asynchronous Commit - Read Only Yes Secondary Node 2 - Synchronous Commit - Read Only No Secondary Node 3 - Synchronous Commit - Read Only Yes In this case, if a…
karun_r
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SQL Server Management Studio with Multi subnet HADR cluster

We are starting to deploy Multi-Subnet HADR AlwaysOn clusters for our environment. Using MultiSubnetFailover=True in application connection strings works. However, SSMS connections require manual paste of this connection parameter into the…
Jeremy Dearduff
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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.replica_server_name =…
youcantryreachingme
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Making Production database as Publisher and Distributor for Snasphot Replication

In our environment we are using Log Shipping as DR. Our primary database is a clustered instance. My requirement is to set up a snapshot replication for reporting purposes. My plan is as follows: Make the production database as the distributor and…
SQL_NoExpert
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Log Shipping or Always on as DR for SQL Failover CLuster

Which is easier to maintain as Disaster Recovery on a remote site for a 2-node SQL Server Cluster Log Shipping Single Instance of Always on Availability Group Instance. Any suggestion will be highly appreciated.
SQL_NoExpert
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A question about multisite Always On design

Your advice on Always On design please... Imagine a scenario where you have 2 datacentres in different countries. You want to be able to run at full capacity in either datacentre. in each datacentre you wish to offload backup and read-only queries…
Dave Allonby
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SQL Availability Group restore database to standalone server

Running: SQL Server 2012, Windows Server 2008 R2 I want to test a backup by restoring onto an isolated server. The backup was taken from an Availability Group (HADR) configuration, but the target server does not have the clustering/HADR…
Josh
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How to Start DB2 10.5 HADR on the Standby Database

I am trying to set up HADR to run on my DB2 10.5 DB2 servers. I believe I have followed the steps correctly, but I'm getting the following error: [db2insh1@rslvm20 OneView]$ db2 restore database onevwhad DB20000I The RESTORE DATABASE command…
Westy
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Azure SQL failover Group testing

If I set up a failover Group for an Azure SQL Database (not a Managed Instance or SQL Server on VM), is it possible to do a test failover, so there is a copy of the Azure SQL Database available for testing, whilst a copy of the production SQL…
AlexP012
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SQL Server Always On Availability Group on Multi-Subnet Cluster

We are building a multi-subnet, always-on availability group. I initially requested the below IPs. For Failover Cluster 192.168.1.129 192.168.2.129 For Listener 192.168.1.130 192.168.2.130 My network team provided the IPs below. For Failover…
SQL_NoExpert
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Release Database Transaction Log File Freespace In SQL Server 2016

Good afternoon, We have 4 node SQL Server configure in HA/DR. Periodically, we purge the old data to free up the space. Recently, after the SQL Job to purge the data was executed, we notice an increase of Freespace in the transaction log file size.…
rushabh138
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