Marco’s presentation at RIPE about unpredictable Internet clouds

At the RIPE meeting in October 2019, our colleague Marco Chiesa presented some of our findings from the study on the effects of recent traffic engineering trends in public Internet. The details are in the RIPE blog post. An excerpt of our findings is shown below.

TCP RTT latency measured between two Amazon VMs deployed in Oregon and Virginia. The black dotted vertical lines highlight moments when RTT latency changed and indicate potential TE activity (such as path changes).

Our upcoming CoNEXT 2019 paper “RSS++: load and state-aware receive side scaling”

While the current literature typically focuses on load-balancing among multiple servers, in our upcoming CoNEXT 2019 paper, we demonstrate the importance of load-balancing within a single machine (potentially with hundreds of CPU cores). In this context, we propose a new load-balancing technique (RSS++) that dynamically modifies the receive side scaling (RSS) indirection table to spread the load across the CPU cores in a more optimal way. RSS++ incurs up to 14x lower 95th percentile tail latency and orders of magnitude fewer packet drops compared to RSS under high CPU utilization. RSS++ allows higher CPU utilization and dynamic scaling of the number of allocated CPU cores to accommodate the input load, while avoiding the typical 25% over-provisioning. RSS++ has been implemented for both (i) DPDK and (ii) the Linux kernel. Additionally, we implement a new state migration technique, which facilitates sharding and reduces contention between CPU cores accessing per-flow data. RSS++ keeps the flow-state by groups that can be migrated at once, leading to a 20% higher efficiency than a state of the art shared flow table.

This is joint work with Tom Barbette, Georgios P. Katsikas, Gerald Q. Maguire Jr., and Dejan Kostic