Storage Developer Conference

With PMEM boasting a much higher density and DRAM-like performance, applying it to in-memory caching such as memcached seems like an obvious thing to try. Nonetheless, there are questions when it comes to new technology. Would it work for our use cases, in our environment? How much effort does it take to find out if it works? How do we capture the most value with reasonable investment of resource? How can we continue to find a path forward as we make discoveries? At Twitter, we took an iterative approach to explore cache on PMEM. With significant early help from Intel, we started with simple tests in memory mode in a lab environment, and moved on to app_direct mode with modifications to Pelikan (pelikan.io), a modular open-source cache backend developed by Twitter. With positive results from the lab runs, we moved the evaluation to platforms that more closely represent Twitter’s production environment, and uncovered interesting differences. With better understanding of how Twitter’s cache workload behaves on