An INT-based Load Balancing Mechanism for Cloud Datacenters

In this work, we propose Closer, a scalable congestion-aware load balancer for cloud datacenters. Closer complies with the evaluation of technology including the deployment of regular Clos topologies, overlays for network virtualization, and virtual machine (VM) clusters. Leveraging In-band Network Telemetry (INT) to obtain precise link load information, we design a simple but efficient algorithm that implements weighted ECMP at the edge of fabric, which enables Closer to proactively map the flows to the appropriate path and avoid the excessive congestion of a single link. Closer decouples the system into centralized route calculation and distributed route decision to guarantee its efficiency and stability in large-scale networks. In tested experiments, Closer achieves 2–7 times better flow completion time (FCT) than existing alternatives at 70% network load. (paper)