Design and evaluation of an inter-core QUIC connection migration approach for intra-server load balancing

Abstract: With the emergence of novel cloud applications and their critical latency demand [1], Quick UDP Internet Connection (QUIC) [2] was proposed as a new transport protocol that is promising to reduce the connection establishment overhead while providing security properties similar to Transport Layer Security (TLS) [3]. However, without an efficient task scheduling mechanism, the high cost for encryption and decryption in QUIC can easily lead to load imbalance among multiple Central Processing Unit (CPU) cores and thus cause a high tail latency. In this paper, we proposed a QUIC connection inter-core migration scheme that can dynamically dispatch QUIC connections among CPU cores while keeping the service continuity. We emulated a scenario where the traffic load on two CPU cores is not even and tried to migrate connections from an overloaded CPU to another idle one. The results showed that the load imbalance can be reduced and both of the two CPU cores can be efficiently utilized. Moreover, the throughput can be improved by around 15% with a set of proper parameters thanks to the inter-core connection migration scheme. It was also revealed that the overhead introduced by the connection inter-core migration mechanism is relatively low when applying the migration to a large connection.