Continually maintaining high availability (HA) when running business-critical data is challenging, to say the least. But maintaining HA with Microsoft SQL Server in a Linux environment poses even more challenges, generating a need for a simpler approach to maintenance without jeopardising the safety and performance of an organisation. Let us talk about the challenges, then I’ll venture on to discuss the simpler approach of using SANless clusters to protect SQL in the cloud.
Challenge one – cost
Choices for IT departments are limited, particularly when it comes to cost. You would need to pay more for the SQL Server Enterprise Edition, for example, undermining the cost-effective strategy of an open-source OS on commodity hardware.
Challenge two – Complexity
Complex ‘do it yourself’ HA Linux configurations can be tedious work. Open-source software such as Pacemaker and Corosync, or SUSE Linux Enterprise High Availability Extension is suitable when providing HA across all applications. However, all require a bespoke configuration for the software to function as desired. For example, we would need to create and run commands, test scripts when minor changes have been made for each of these applications, possibly resulting in the software being unsupported. Running commands to help protect data from being corrupted by concurrent access can be a pain. For a cluster service to run efficiently, you may need to set some constraints which means building more usage commands. So – a little laborious.
Creating the cluster on a node
The HA solution
There is more than one HA solution. But let’s focus on the host-based solution where a storage-agnostic cluster is created across Linux server instances. Now, that already spells less expense, as local storage is used rather than SAN. Linux server instances can operate across both the LAN and WAN in private, public and hybrid clouds with the aid of SIOS protection suite for Linux.
The clustering software can be used to support Linux (as well as Windows) environments where it oversees the complete application stack, managing application failover, and synchronizing storage. It enables complete configuration flexibility and provides a simple, cost-efficient practical HA and DR solution. Noteworthy is the fact that most software solutions offer a modern, practical and coherent user-friendly interface to make any configuration a walk in the park.
The software allows both failovers and failbacks to occur automatically with the aided control of a browser-based system. Maintenance can be carried out with the provision of HA for the application and its data simultaneously, the solution is certainly worth considering for SQL Server.