Unlocking Near-Zero Downtime Patch Management With High Availability Clustering
Patch management is a familiar and challenging responsibility for most IT teams. Operating system (OS) and application vendors issue monthly or quarterly updates that often include vital improvements to cybersecurity that need to be applied as soon as possible. IT then scrambles to test and apply them with as little disruption to business operations as possible. However, the challenge of testing and applying patches quickly and with minimal downtime is even more significant in mission-critical applications and databases. This article will discuss the ways that many organizations are meeting this challenge by using high availability (HA) clustering to test patches and updates more easily and to apply them in production environments with near-zero application downtime.
The Patch Testing Dilemma
The well-established IT best practice is to extensively test any changes, patches, or updates to OS and critical applications in quality assurance (QA) environments before deploying them. Given the complexity of today’s IT infrastructure and the myriad combinations of software versions and configurations in use, there is no other way to know how a change or update will affect the existing systems. However, testing takes time, and QA resources (both human and lab) may be limited, requiring IT to delay applying the patches in production by days or even weeks. For these reasons, they may feel pressured to test less thoroughly than they should.
The Growing Threat of Zero-Day Exploits
The pressure to rush patches into production is further exacerbated by cyberattacks focusing on zero-day vulnerabilities. Attackers rapidly scan for known vulnerabilities following patch announcements, often launching attacks within hours. Delayed patching – even for testing – heightens the risk of breaches. According to the Ponemon Institute, 57% of data breaches stem from unpatched vulnerabilities. IT is also under pressure from regulations, such as NIST 800-53, HIPAA Security Rule and PCI DSS 4.0, which mandate timely patching. However, incidents like the recent CrowdStrike update failure highlight the potential consequences of rushed patches and inadequate testing.
Challenges of Planned Downtime in Patch Management
Applying patches often requires planned downtime, during which IT teams take systems offline to install updates and restart applications. In sectors such as manufacturing (ERP systems), healthcare (electronic health record (EHR) management), emergency response (computer-aided dispatch) and aviation (VMS, access control, ticketing, baggage handling), even brief downtime (planned or unplanned) is extremely costly. Gartner estimates that the average cost of IT downtime is $5,600 per minute, underscoring the importance of minimizing service disruptions. The solution lies in the use of advanced HA clustering solutions that enable IT to test patches and apply them with near-zero downtime.
How it Works: Seamless Patching and Failover Protection
High availability clustering involves running an application on one server node, called the primary node and pairing it with a secondary server node in a clustered environment configuration. Clustering software monitors the application to ensure it is operational. While there are several clustering software options, the more advanced clustering software monitors the entire environment, including the application, storage, network connections and OS. If the software detects a failure, it automatically moves operations to the secondary node, where it continues without disruption to the business. Enterprise-class HA software enables IT to plug in application and cloud-specific modules that ensure failover procedures in complex database environments adhere to vendor-specific (e.g., SAP, Oracle, SQL Server, AWS, Azure, GCP) best practices and ensure stability.
In the context of patch management, this configuration enables IT teams to conduct a “rolling upgrade” as follows:
- Apply patches to the secondary node while the primary node remains operational.
- Test the update on the secondary node before switching application operations.
- If the patch testing reveals issues, IT can revert operations instantly and continue operations on the primary node until the issue is resolved.
- If the update is successful, IT can move the operation of the application to the secondary node and patch the primary node.
This approach mitigates the risk of patch failures, accelerates update deployment and eliminates the need for system-wide downtime.
Conclusion
With increasing cybersecurity risks and rising uptime expectations, integrating HA software into patch management strategies is essential. By leveraging high availability clustering, organizations can execute timely security patches while maintaining business continuity, minimizing downtime and ensuring regulatory compliance. Incorporating clustering solutions into IT operations strengthens overall resilience, mitigates risks associated with patch failures and safeguards mission-critical applications against evolving cyberthreats.
