You're managing critical applications. How can you prioritize system updates to minimize impact?

Risk assessment is a crucial step in managing system updates, especially for critical applications. It involves evaluating the potential impact and severity of each update to determine which updates should be prioritized. By analyzing factors such as the vulnerability of the system, potential security threats, and the likelihood of system disruption, risk assessment helps IT teams make informed decisions. This process ensures that the most urgent and high-risk issues are addressed first, minimizing the chances of system failure or downtime. Risk assessment also aids in identifying dependencies and compatibility concerns, which can prevent cascading issues across the system.

Prioritizing system updates for critical applications requires careful planning and risk management. This involves assessing update criticality, evaluating system impact, planning and scheduling updates, risk mitigation, and monitoring and communicating with stakeholders. This includes assessing security patches, stability and performance fixes, regulatory compliance requirements, dependencies, and user impact. Regular updates should be deployed in phases across different environments, and maintenance windows should be scheduled to minimize disruption. Regular real-time monitoring and stakeholder communication are essential for effective management.

It requires careful planning to avoid system disruptions 1. Perform the risk assessment to focus on security patches with critical vulnerabilities and simultaneously identify business critical applications and analyze the potential consequences of downtime or system failure 2. Create patch priority framework to categorize in the order of critical security updates, critical infrastructure updates and application specific updates 3. Conduct extensive testing and plan the deployment only during maintenance window 4. Perform rolling updates if possible and also consider the deployment in a balancing structure if the infrastructure supports 5. Monitor the environment and be ready with the contingency plan 6. Coordinate with application vendors

If you don't have a procedure and automation ready when the vulnerability drops, then you are half way behind. At this point you need to know what are you're service/patching windows and contingency procedures for delaying the patch. Risk assessment should include assessing the flaw on your architecture. You may *slightly* postpone a critical flaw in a service with strict access controls in a separated, non-NAT network. By "slightly" I mean hours instead of "now". And finally: costs of being hacked are magnitudes greater than costs of downtime.

Common criteria for prioritizing software projects include business value, customer satisfaction, technical feasibility, risk and uncertainty, and dependencies and synergies. Business value looks at how much revenue or profit the project might generate or protect.

Run tests in the staging environment to evaluate the update’s impact on performance, stability, and compatibility with other applications. Monitor system resource usage (CPU, memory, etc.) to ensure no degradation occurs. Also, test critical functions that users rely on to identify any potential breaks.

You have a staging environment? You have a staging environment, right? One that mirrors your hardware and software architecture? One that was not scrapped for being "too costly"? And by the time you read this your automation should already have installed the updates and monitoring should start receiving new data to compare with the previous one.

To ensure a seamless update deployment, I create a staging environment that replicates our production setup, allowing me to identify and address potential issues, such as compatibility problems and unforeseen bugs, before they impact our users.

If you need to schedule critical updates after regular working hours remember that you have less eyes to look on it and handle eventual problems. And you should have the capacity to update a part of your infrastructure during your near-peak hours so you can handle a rolling update or a single failure.

Yes Thank you for coming to my TED talk. But I'll emphasize the importance of a good monitoring platform properly configured. And the whole processes of monitoring and automation should be kept somewhat agile. Because unnecessary distractions and manual work should be minimized, like false alerts, event closures, changing clients' requirements, as they do impact teams workload.

Rolling back should be as easy as rolling in. All thanks to the configuration management you have implemented and tested. You have tested a roll back, have you? There are different strategies, and some can use your already present infrastructure, like backups, or VM infrastructure with CoW-cabable storage backend, Timeshift on Linux. You should be able to set a timer for a roll back, and if it breaches say "OK, we're unspooling backups/Reverting to previous VM's". Good VM infrastructure could be very useful in such scenario. If you can wind up an older version and have the newer aside version to research how the upgrade failed you could research the problem and keep the uptime at the same time.

This should be your starting point, not an afterthought. And I'm being dead serious here. You absolutely require a baseline to navigate the mentioned issues. And be mindful that the baseline will change with infrastructure changes, client/user requirements, etc.