The BBC’s weekend of technical issues on the BBC iPlayer and BBC Online was caused by a combination of increased load on its database and the failure of part of its caching layer.
The problems, which the BBC says have now been fixed, meant viewers were unable to access content across the BBC iPlayer and BBC iPlayer Radio, while video playback on other parts of bbc.co.uk were also affected.
In a blog post Richard Cooper, the BBC’s controller of distribution, explained the system of 58 application servers and 10 database servers had been hit by an increased load at around 9.30 on Saturday morning (July 19). As additional requests for metadata were made, the application servers began to fail.
As the work to restore the servers continued the emergency homepage was used for long periods.
“Performance of the system remained sufficiently poor that in the end we decided to do some significant remedial work on Saturday afternoon, which ran on until the evening. During that period, BBC iPlayer was effectively not useable,” said Cooper, stressing that with 3 billion requests a year such instances are incredibly rare.