Outage on 25th April - the impact of a misconfigured redis server
On Tuesday evening, post the launch of the new home page, we had a second set of performance problems that impacted the entire tes.com site around 6pm for 40 minutes, and then subsequently during two periods at 9pm and 12am. The root cause turned out to be a misconfigured Redis caching server that was moved to in response to the issues on the 24th of April. During the post-mortem of the issues the day before we had agreed that a key action was to upgrade and improve the monitoring of the part of our platform that does the composition of the shared fragments (e.g.