In this article, we will learn how to add a SQL database to an existing Alwayson availability group. Alwayson availability group is high availability and disaster recovery solution of Microsoft SQL Server. The database must meet the following prerequisites to be a part of an availability group.
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In this article, we will learn about the high availability features recently introduced in Azure Database for PostgreSQL.
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This article discusses useful considerations for SQL Server Disaster Recovery.
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This article explores the configuration of Windows failover clusters, storage controllers, and quorum configurations for SQL Server Always On Availability Groups.
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In this series for SQL Server Always On Availability Groups, we are covering end to end configurations for SQL Server 2019 on Windows Server 2016. In the article, A comprehensive guide to SQL Server Always On Availability Groups on Windows Server 2016, we configured three virtual machines with their networking configurations.
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In this article, we will configure a SQL Server Always On Availability Group on the Windows Server 2016. We use SQL Server 2019 for configuration.
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In this article, we will review how to set up multi-subnet Always On Availability groups using AWS EC2 instances and AWS FSx as file share witness.
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SQL Server Always On is a high-availability and disaster recovery solution. We can use multiple secondary replicas for configuring database backups, redirect read requests to offload primary instance load.
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In this article, I am going to explain how we can deploy the MySQL InnoDB cluster. InnoDB Cluster is a high availability solution provided by MySQL that has single and multi-master capabilities and failover detection.
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In this article, I am going to explain how we can use the SQL Server Express edition for the SQL witness server of the database mirroring setup. Database mirroring is a cost-effective and easy to configure high availability solution. Unfortunately, this feature has been deprecated, but still, some organizations use database mirroring as a high availability solution.
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This article gives an overview of Windows Failover Cluster Quorum modes that is necessary for SQL Server Always on Availability Groups.
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This article gives an overview of the Max Worker Threads for the SQL Server Always On Availability Group databases.
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In this article, we will review how to set up auto-failover groups in Azure SQL Server and how failover group is different from active geo-replication in Azure. Auto-failover group is an Azure SQL database feature that replicates one or a group of databases to the secondary Azure SQL server in the cross-region. We cannot have a secondary server in the same region. This feature is used to failover all the databases in the failover group in case of disaster and the failover is automatic.
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In this article, we will review how to set up Geo-Replication on Azure SQL databases. Geo-Replication is an Azure SQL database feature that allows you to create a readable secondary database in the same region or cross-region. We can failover to the secondary database in case of an outage for a long time on the primary database server. We can also use this feature to migrate a database from one server to another server in the same or cross region with minimal downtime. Geo-replication uses the Always-on feature to replicate committed transactions to the secondary database asynchronously.
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SQL Server Always On Availability Groups provides HADR solutions for the SQL databases. Here HA refers to high availability and DR refers to disaster recovery. The priority of this feature is to keep the database highly available and then provide Disaster recovery. Due to this reason, if the secondary replica goes down in a synchronous data commit mode, SQL Server changes commit mode to Asynchronous so that users can continue run the transactions and a secondary replica can be in sync later once it bought up. SQL Listener also points to the primary replica and continues redirects connection to the primary replica.
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In this article, we will review how to setup SQL replication with publisher database in Always On availability groups so that replication continuous to sync even after failover to the secondary server in the availability group.
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SQL Server Always On Availability Groups feature provides high availability (HA) and disaster recovery solutions. We can add multiple databases in a single Always on Availability Group on SQL Server Enterprise edition. Before we add a database in the AG group, we need to use the following checklist.
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In my previous article, Data synchronization in SQL Server Always On Availability Groups, we explored the internal data synchronization for both Asynchronous and Synchronous data commit mode. In the following image, on the secondary replica, we can see two important processes.
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In SQL Server Always On Availability Groups, we can add a database into an existing availability group using different methods. We get the following option in the Initial Data Synchronization wizard in SSMS.
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In this article, we will explore configuring Read Scale Availability Group that does not require a failover clustering configuration. It helps to scale read-only connections to the secondary replica in a cluster less configuration.
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SQL Server Statistics are an essential part of query performance in SQL Server. They help the query optimizer to prepare a query plan using the distribution of values in participating rows. If we do not have updated statistics, it might lead to resource intensive query execution plan. For example, for a large table having a billion records, SQL may choose to have an index scan instead of an index seek.
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This article on SQL Server Always On Listeners includes an overview and various connection configurations for specifying MultiSubnetFailover including SSMS, ODBC, ADO.NET, as well as MultiSubnetFailover limitations and how to connect to all IP addresses via RegisterAllProvidersIP.
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In a high OLTP environment, we may observe strain on CPU and IO due to frequent backups. It might include further complexity due to backup compressions. SQL Server Always On Availability groups provides the capability to perform database backups from the secondary replicas. This article explores Log backups in SQL Server Always On Availability Group.
In my previous article Data Synchronization in SQL Server Always On Availability Group, we described a scenario where if a secondary replica goes down in synchronous data commit mode, SQL Server Always on Availability group changes to asynchronous data commit mode. It ensures that users can get their transaction commit irrespective of waiting for a secondary replica to come online.
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This article describes the data synchronization process on SQL Server Always On Availability Groups in both Synchronous, and Asynchronous data commit mode.
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