Katran

Katran is a term with more than one notable use. In Turkish, katran refers to tar or pitch, a viscous substance historically used for waterproofing wood, sealing boats, and road surfacing. In contemporary Turkish, it remains a common noun and appears in everyday language as well as in historical references to traditional materials.

Katran is also the name of an open-source software project developed by Meta (Facebook) that implements a high-performance load balancer and packet-processing framework for data centers. Designed to handle very high traffic volumes with low latency, Katran operates as a kernel-bypass datapath using user-space packet processing. It provides L4 load balancing and can distribute traffic across a pool of backend servers, using flow-based hashing to steer packets. The project emphasizes scalability, observability, and ease of deployment in large-scale Meta networks and has been released to the open-source community with documentation and example configurations.