  Distributed caching systems (e.g., Memcached) are widely used by service
providers to satisfy accesses by millions of concurrent clients. Given their
large-scale, modern distributed systems rely on a middleware layer to manage
caching nodes, to make applications easier to develop, and to apply load
balancing and replication strategies. In this work, we performed a
dependability evaluation of three popular middleware platforms, namely
Twemproxy by Twitter, Mcrouter by Facebook, and Dynomite by Netflix, to assess
availability and performance under faults, including failures of Memcached
nodes and congestion due to unbalanced workloads and network link bandwidth
bottlenecks. We point out the different availability and performance trade-offs
achieved by the three platforms, and scenarios in which few faulty components
cause cascading failures of the whole distributed system.
