SSD Admission Control for Content Delivery Networks

Content delivery networks (CDNs) are utilized to deliver content with low latency. Solid State Drive (SSD) devices are a cost-effective option for intermediate tier caches in servers used in CDNs. However, excessive writes of content to SSD devices can degrade useful life of such devices. This disclosure describes admission control techniques to manage content in an SSD cache. In particular, a popularity metric for content items is determined based on an inter-arrival time. The popularity metric takes into account past admission history and is dynamically to account for variations in content popularity over different time periods. These techniques balance the SSD cache write rates to optimize the device life and cache performance.