TCP Protective Load Balancing "PLB" Support Heading To Linux

Picked up this week in the "net-next" code ahead of the Linux 6.2 merge window in December is support for TCP Protective Load Balancing (PLB).

TCP Protective Load Balancing hooks into the Linux kernel's DataCenter TCP (DCTCP) code as part of congestion control. The Protective Load Balancing provides host-based load balancing across switch links by making use of Explicit Congestion Notification (ECN) and other congestion data from the transport layer to randomly change the path of the connection facing congestion. Currently this Linux TCP PLB implementation only works for IPv6 traffic and is disabled by default.

The TCP PLB support with the pending Linux patches can be enabled using the tcp_plb_enabled sysctl knob.

The Linux kernel TCP PLB implementation was merged to net-next on Friday with the work being carried out by Google's Mubashir Adnan Qureshi in cooperation as well with other Google engineers. Barring any issues coming up with this off-by-default feature, the code will then be merged come Linux 6.2.