So.. we’re left with no real explanation to why OT is better than CRDT other than a 5s video showing a poorly managed text node update that moves the cursor. I feel tricked.
> In OT, every user action is broken down into one or more operations. These operations are transmitted between clients along with their baseline reference; if two users perform actions at the same time, incoming operations must be transformed to include the local operations that have happened since that baseline. They are then applied locally and form the new baseline.
> This constant transformation of operations turned out to have too many edge cases where clients were found to not produce the same baseline (the "wrong" papers above). When that happens, the clients will never converge on the same result and break the fundamental assumption of collaboration.
And that’s exactly right. It’s fairly easy to have an OT system that is very vulnerable, because clients can cheaply generate change sets that are extremely computationally expensive on the server side. I’ve seen a system where a single mobile phone could, in a few seconds, lock up the synchronisation server for days.
As for the last question, I think the later posts will get to that.
In complex models it is symptomatic of a larger issue with complexity in CRDTs; the post was already quite long and I didn't want to repeat any more of the research I'd linked to.
The post is a good introduction to OT and CRDT, but is very light on actual trade-offs and seems to end with a gut-feeling conclusion, when the title promised “trade-offs between”.
I was driving at CRDT not being capable enough for arbitrary HTML structures, and giving a quick summary of what was an extended multi-week research process.