Re:Datacenter RPCs can be general and fast
by ignoramous on Monday March 18, 2019 @09:35AM
(#19420854)
(not an expert, just someone keeping abreast with development in the networking world)
There are inherent problems with relying on the OS in an elastic environment. Kernel's TCP/IP stack could be made to expose very specific APIs to help with NetworkFunctionVirtualization (NFV) and Software-defined Networking (SDN), but the advantages are not clear:
1. Vendors to rely on Kernel devs to do the their biding for their NFV/SDN deployments, and wrestle with various other priorities Kernel might already have.
2. Build/deploy the updated Kernel fleet wide, with those changes (which now include other Kernel changes vendor may or may not want).
3. Cater to strict Kernel community guidelines and expect to be driven by the established processes governed by designated gatekeepers, costing vendors time and speed to market.
With a userspace solution, esp since it allows vendors to be performant by simply interfacing with NICs, the vendors have a measure of control on their own destiny:
1. Deploy at will, at pace.
2. Ability to do custom packet/flow (virtualization), on-the-fly (SDN) even, without requiring any assistance from any other part of the system not in their control.
3. Reduce external factors that might influence their timelines or priorities.
The generic problem, however, with the Kernel's TCP/IP stack needing improvement is orthogonal to this. That effort will have little to no bearing on the direction the Networking industry is moving, imo.
There are inherent problems with relying on the OS in an elastic environment. Kernel's TCP/IP stack could be made to expose very specific APIs to help with NetworkFunctionVirtualization (NFV) and Software-defined Networking (SDN), but the advantages are not clear:
1. Vendors to rely on Kernel devs to do the their biding for their NFV/SDN deployments, and wrestle with various other priorities Kernel might already have.
2. Build/deploy the updated Kernel fleet wide, with those changes (which now include other Kernel changes vendor may or may not want).
3. Cater to strict Kernel community guidelines and expect to be driven by the established processes governed by designated gatekeepers, costing vendors time and speed to market.
With a userspace solution, esp since it allows vendors to be performant by simply interfacing with NICs, the vendors have a measure of control on their own destiny:
1. Deploy at will, at pace.
2. Ability to do custom packet/flow (virtualization), on-the-fly (SDN) even, without requiring any assistance from any other part of the system not in their control.
3. Reduce external factors that might influence their timelines or priorities.
The generic problem, however, with the Kernel's TCP/IP stack needing improvement is orthogonal to this. That effort will have little to no bearing on the direction the Networking industry is moving, imo.
---
Google Maglev (network load balancer): https://ai.google/research/pubs/pub44824
Dropbox MagicPocket (bypassing OS' VirtualFileSystem for storage at scale): https://blogs.dropbox.com/tech/2016/05/inside-the-magic-pock...
Facebook Haystack (an example of problems working with VFS at scale and a solution to it): https://code.fb.com/core-data/needle-in-a-haystack-efficient...
NFV: https://www.electronics-notes.com/articles/connectivity/nfv-...
VNF: https://www.electronics-notes.com/articles/connectivity/nfv-...