There is also https://en.wikipedia.org/wiki/Rendezvous_hashing <https://en.wikipedia.org/wiki/Rendezvous_hashing>
> On 15 Jan 2021, at 21.18, Mikkel Fahnøe Jørgensen <[email protected]> wrote: > > I would be hesitant to introduce a situation where a load balancer is forced > to use memory, especially memory it doesn’t fully control. It may be fine as > a choice, but not the only choice. > > Aside from potential attacks, there is also the hardware cost/complexity. > SHA256 and AES is pretty standard in almost anything, but lots of RAM is a > cost driver. > > It is really hard to estimate crypto vs lookup overhead, but it is far from a > given that lookup will be faster once the tables grow large. > > Less coordination is a good thing though. I’m afraid that without out of band > payload to coordinate, there will have to be a choice between configuration > and state. > > Mikkel > >> On 15 Jan 2021, at 21.04, Martin Duke <[email protected] >> <mailto:[email protected]>> wrote: >> >> To muddy this discussion a little further, after a little more thinking I >> believe there's a way to generalize this approach to all three of the >> original algorithms, encrypted or unencrypted, so there is never a need to >> manually allocate server IDs. >> >> Again, the main tradeoff here is simpler configuration vs. more complexity >> and state at the load balancer. >> >> As a document organization matter, rather than have six different algorithms >> I would prefer to specify three with a separate section describing the two >> separate ways to allocate a server ID. >> >> But it is not too late to yell "stop" at this multiplicity of options if >> people feel the tradeoffs are clear-cut in one way or the other. >> >> On Mon, Jan 11, 2021 at 6:50 PM Martin Duke <[email protected] >> <mailto:[email protected]>> wrote: >> Yes. Do you have an alternate suggestion? >> >> On Mon, Jan 11, 2021 at 5:54 PM Christian Huitema <[email protected] >> <mailto:[email protected]>> wrote: >> >> >> On 1/11/2021 5:22 PM, Martin Duke wrote: >>> Perhaps I should make some edits for clarity! >>> >>> On Mon, Jan 11, 2021, 16:52 Christian Huitema <[email protected] >>> <mailto:[email protected]>> wrote: >>> I am looking at the text of section 4.2, and I am not sure how I would >>> implement that. What should be the value of the config rotation bits in CID >>> created by the server? >>> >>> Any config includes the corresponding CR bits, and when generating the CID >>> it would use those bits. >>> >>> The confusing part is that, for this algorithm, a usable SID has to be >>> extracted from any CID, hence all the weird stuff about CIDs with undefined >>> configs. >>> >>> Aside from that, it's like PCID: any server-generated CID uses the CR bits >>> in the config, optional length encoding, SID, server-use octets. >>> >>> >>> Should the 6 other bits in the first octet be set to a CID Len or to a >>> random value? >>> >>> It depends on the rest of the config, as with the other algorithms. >>> >>> Issss the timer set when the server ID is first added to the table, or is >>> the timer reset each time a packet is received with that CID? In the latter >>> case, is it reset when any packet is received, or only when a "first >>> initial" packet is received? >>> >>> When any packet is received with that SID (not CID), the expiration is >>> refreshed. >> OK. So we can have the following: >> >> 1) Server learns of Server-ID = X. >> >> 2) Server creates new CID with that server ID, uses it to complete handshake. >> >> 3) Client maintains a long running connection with that CID. >> >> 4) Server keeps receiving messages with CID pointing to server-ID = X >> >> 5) server-ID=X never expires. >> >> Is that by design? >> >> -- Christian Huitema >> >> >> >
