The failure of an intermediary that serves thousands of sites from its own edge servers, leaving services unreachable although their own infrastructure is intact.
A content delivery network places servers at the edge of the network so that a site's pages, images and scripts are served to visitors from a nearby point, which speeds up loading, absorbs traffic spikes and filters denial of service attacks. The trade-off is interposition: the visitor no longer speaks to the origin server but to the intermediary, so a failure at the intermediary makes the service unreachable while the insured's own infrastructure is intact and its own backups are of no use. The market is highly concentrated, with a handful of operators serving a substantial share of global traffic, which makes each one an accumulation point insureds are often unaware of, since the relationship may sit with an agency rather than with them. Recorded incidents show near-instant propagation, a configuration change rolling out within minutes to every point of presence, without the gradual deployment that would allow it to be halted. For underwriting, the decisive point is that contingent business interruption cover responds only where the wording names this kind of supplier, which many pre-2021 texts do not.
On 8 June 2021, a configuration change by a single customer triggered a latent software fault at the operator Fastly and took many major websites offline for roughly an hour, including those of several governments and international news organizations.
CDN outage, panne CDN, content delivery network, réseau de diffusion de contenu