Use string type for node id when use toml format

[zyy17]

What type of enhancement is this?

Configuration

What does the enhancement do?

Background

I'm trying to allocate datanode a node id based on the hash of the node name, for example, 14695981039346656037, then I got an out-of-range error, although we did define node id as u64 type:

Error { inner: OutOfRange(Some("u64")) }

After some digging, I found out the reason is that the toml doesn't support u64. Actually, it supports i64 internally(toml-rs/toml#705). Any numbers that are bigger than i64::MAX will fail to parse.

Although u64 type is not a human-readable type for toml, it's helpful when we want to use some complicate node id allocation.

Advices

For the workaround, I think we can use string type for node id in toml format and parse it as u64 type. However, it would be a breaking change.

Implementation challenges

No response