Background processing and safe async modification of keys

[ccollie]

In my module, I have a new data type which is automatically updated (on rayon threads) on an interval triggered by valkey timers. The objects are groups of multiple, possibly dependent rules.

pub struct Group {
   pub name: String,
   pub rules: Vec<Rule>,
   pub interval: Duration,
   pub last_processed: Timestamp
}

The issue is that rules can be arbitrarily complex and take a non-trivial amount of time (hence rayon). I'm specifically concerned about queries/mutations overlapping rule processing. In my mind there are a few options

1. disallow mutation of the group structure entirely (allow only create and delete). Given the domain and prior art, this may be acceptable, but from an api ergonomics perspective I'd want to avoid it.
2. copy the group during rule processing and sync updates to the original afterwards.
3. rework the struct so that rules are disjoint with respect to borrowing/access (maybe in arena based storage)

Any ideas ?

[ccollie]

Also, what are the implications of this arrangement from a valkey internals perspective ?