In SQL Server Always On Availability Groups, maintaining data consistency during failovers is necessary for high availability and reliability. However, certain aspects of database behavior, such as the generation of values by IDENTITY columns and SEQUENCE objects, can lead to unexpected gaps or jumps after a failover or server restart. This can affect the continuity of sequential values, which is often important in business applications. In this post, we’ll look into how SQL Server handles IDENTITY columns and SEQUENCE objects in an Always On environment, explain the role of caching, and offer strategies to manage or prevent gaps in your sequences during failovers.
Category: Availability Groups
Ensuring Smooth SSRS Subscriptions in an Always On Availability Group
SQL Server Reporting Services (SSRS) is a powerful tool for managing and delivering reports in an enterprise environment. When configuring SSRS within a SQL Server Always On Availability Group, it’s essential to take specific steps to ensure that SSRS subscriptions continue to function properly during failovers. This blog outlines the key actions required to maintain seamless SSRS operations in such a setup.
Enhancing Availability with SQL Server AlwaysOn Database-Level Health Detection
AlwaysOn Database-Level Health Detection is an optional configuration that enhances the resilience of availability group databases. It monitors database transactions and, if an issue is detected, can automatically trigger a failover to another replica. This proactive measure helps maintain application availability even in the event of hardware or I/O failures.
Integrating SSISDB with SQL Server Always On Availability Groups: A Step-by-Step Guide
Incorporating SQL Server Integration Services (SSIS) with Always On Availability Groups (AGs) is not just a routine task but a necessary one to ensure the robustness of your data integration workflows. While SSISDB plays a central role in managing SSIS projects, it doesn’t inherently align with the high availability features provided by AGs. This guide aims to bridge that gap, offering a detailed and practical approach to integrating SSISDB with Always On Availability Groups, tailored to the unique demands of this database.
Enhancing Data Integrity: Automatic Page Repair with SQL Server Always On Availability Groups
SQL Server Always On Availability Groups are designed to provide a high-availability and disaster recovery solution that keeps your databases running smoothly even in the face of hardware failures and data corruption. One of the key features supporting this capability is Automatic Page Repair. This feature works behind the scenes to automatically fix corrupted pages in a database, thereby minimizing downtime and preserving data integrity. In this post, we will explore the mechanisms, benefits, and limitations of Automatic Page Repair, highlighting its role in enhancing SQL Server reliability.
Understanding Quorum Loss in a Windows Failover Cluster with SQL Server Always On Availability Groups
This article provides an in-depth exploration of quorum loss in Windows Failover Clusters and its impact on SQL Server Always On Availability Groups. It explains how nodes communicate using heartbeat packets, the process of handling failed heartbeats, and the rejoining of nodes to the cluster. The post also outlines various quorum voting configurations and their implications for cluster stability and data integrity. Additionally, it discusses the importance of maintaining quorum for high availability and disaster recovery in SQL Server environments.
Creating SQL Server AGs on Linux: Part 3 – Pacemaker Resources and Constraints
Welcome to the third part of our series on setting up SQL Server availability groups on Linux. In the previous post, we focused on enabling High Availability Disaster Recovery (HADR) on SQL Server and setting up the availability group. This post will guide you through configuring Pacemaker resources and constraints to manage the availability group effectively.
Creating SQL Server AGs on Linux: Part 2 – Enabling HADR on SQL Server
This is part of a series on setting up SQL Server availability groups on Linux. It details how to enable High Availability Disaster Recovery (HADR) on SQL Server, including creating master keys, certificates, and availability groups. Clear instructions are provided for configuring SQL Server and Pacemaker to ensure data redundancy and high availability. Follow these steps to enhance the reliability of your SQL Server instances on Ubuntu 20.04.
Creating SQL Server AGs on Linux: Part 1 – Installing and Configuring Pacemaker
This post is the first part of a series on setting up SQL Server availability groups on Linux. It covers the installation and configuration of Pacemaker on Ubuntu 20.04, creating the Pacemaker cluster, and configuring essential cluster properties. Designed for SQL Server DBAs with limited Linux experience, this guide lays the foundation for a robust high availability environment.
SQL Server AG Readonly Secondaries and their Associated Overhead
In SQL Server Always On Availability Groups, configuring read-access for one or more secondary replicas introduces additional overhead to the primary databases. This overhead, specifically a 14-byte addition to modified, inserted, or deleted data rows, is essential for the row versioning feature that ensures data consistency across replicas. Row versioning allows secondary replicas to perform read operations without being affected by ongoing changes on the primary replica, ensuring a consistent view of the data. Understanding this overhead and its impact on storage and performance is crucial for optimizing SQL Server environments.