[computerfan494]

In the above description of optimistic locking, it is assumed that it is impossible to issue the same token to multiple clients. Nodes can agree that a given token has also never been issued before just like a monotonically increasing value. The nice property about non-monitonically-increasing tokens is that nodes may generate them without coordinating if you can make other assumptions about that system. A good example is when nodes use an ID they were assigned beforehand as part of the token generation, guaranteeing that the leasing tokens they mint will not conflict with other nodes' as long as node IDs are not reused.

[bootsmann]

I have a hard time wrapping my head around what you are proposing here. Say client A requests data, they get the token a-abc. Then client B requests data, they get the token b-cde. Client A commits their write, does the storage reject it because they already issued another token (the one from client B) or does it accept it?

[computerfan494]

My understanding of what the OP was discussing is an optimistic locking system where the nodes only accept commits if the last issued token matches the token included in the commit. While agreeing on the last token requested requires coordination, unlike monotonically increasing tokens you could have well-behaved clients generate token content themselves without coordination. That may or may not be useful as a property.

[bootsmann]

Got it, thank you for clarifying this.