After watching the Zero Downtime Patching (ZDP) TechNet video, I wanted to share my thoughts about when that is helpful and when a simpler approach is needed. Ultimately we are given options and asked to balance cost with questions such as:
- What is the cost of outage/downtime?
- What is our SLA?
- What hours do users normally work?
- What is the cost of High Availability redundant farm topology?
- What is the support effort to maintain HA farms?
- What is the VM, licensing, and storage cost?
- Bottom line – Does the cost of outage exceed the cost of HA? Or vice versa?
What is ZDP?
- [TechNet] “Zero Down-Time patching doesn’t demand any server downtime while patching a SharePoint Server 2016 farm, but does require that your farm be set up in a Highly Available (HA) configuration (so that SharePoint roles are hosted on more than one server). That way, patching can be done in batches where certain of the redundant servers are taken out of load balancing, patched, replaced, and tested for soundness before the other servers follow through the same process. During Zero down-time patching, users can add and edit files and use search just as at any other time.”
What is MDP?
- I would define Minimal Downtime Patching as “Planning an acceptable window of brief downtime to apply system updates as quickly as possible.” This implies an SLA less than 99.99% and 365/24 hour availability. Choosing a time window for a brief outage is already done today by most support teams. A few hours outage might come at zero cost (if zero active users) and is often an attractive choice compared to the complexity of Highly Available (HA) farm design, implementation, and support. ZDP is a high cost endeavor, appropriate for scenarios with high cost of downtime. Absent that, we should consider lower cost options where brief downtime is acceptable with little impact. Compare two costs and choice what is best for your business.
|Zero Down Time|
|Minimal Down Time|
Overall, use the right tool for the job. There are good scenarios for both options. Even with ZDP used on large Production farms, we need other suitable options for lower environments like Dev and Test.
- TechNet – VIDEO demo of Zero Downtime Patching in SharePoint Server 2016
- Stefan Goßner – SharePoint Server 2016 Zero-Downtime Patching demystified
- Russ Maxwell – Why SharePoint 2013 Cumulative Update takes 5 hours to install?
MDP PowerShell Script