Update 27th November 2017 05:30 GMT
All maintenance work is complete and was successful. No further maintenance is scheduled at this time.
- There will be no interruption to Kobas EPoS service.
- Maintenance window is 4am to 7am on Monday 27th November 2017.
- No significant interruption of service is anticipated; this is notice of increased risk of interruption of Kobas Cloud service during the maintenance window.
- Status updates will be clearly communicated on our Twitter feed during this maintenance.
As mentioned in my Autumn Report, we plan to increase Kobas Cloud resilience and capacity ahead of the elevated trade and reporting demand anticipated during the Christmas period. We have already made some infrastructure improvements that carried no service interruption risk, but there remain some more substantial changes that we will implement early on the morning of Monday 27th November 2017.
Why do this on a Monday?
Early on a Monday morning is statistically the time when Kobas Cloud is in least demand. As many Kobas venues trade exceptionally late on a Saturday evening, some until 6am Sunday morning, and others open for Sunday breakfast, Kobas Cloud doesn’t see much respite at that time. With the exception of Sundays preceding a bank holiday Monday, no Kobas venues are open especially late on Sundays, so we find that Kobas Cloud is much quieter early on a Monday morning.
What are the technical details of these works?
Kobas Cloud is hosted on Amazon Web Services (AWS). In order to increase capacity, we both increase web server and database server resource. The nature of our service makes it easy to increase web server resource, which has already been completed.
On Monday 27th November we plan to double the capacity of each of our database servers. Kobas client accounts are grouped together onto various database shards, and each of these will in turn be upgraded. We will be migrating from MariaDB 10.1.19 to 10.1.26, we will be ensuring all databases have a standby instance in a secondary availability zone, and as all databases will have their capacity doubled, the most powerful machines will now have 16 vCPUs and 64 GB RAM at their disposal.
This upgrade process takes around 15 minutes for each database server, during which time any unavailability is anticipated to be minimised to just a few seconds. While this means that any one Kobas client should not expect any significant interruption of availability, it should be acknowledged that these kind of infrastructure changes do inherently increase the risk of service interruption, hence we are issuing this notice in accordance with our SLA.