The attributes of the address is removed when passing to the picker.

[MooooonStar]

I am using my own balancer.PickerBuilder in my program. I attach some info to the address with the func SetAddrInfo in weightedroundrobin.go and read it from Build(info PickerBuildInfo) balancer.Picker.

It works well in grpc-go@v1.34.0, but failed in grpc-go@v1.35.0.

I read the release note and find this strip attributes from addresses.

In the function

func (b *baseBalancer) regeneratePicker() {
	if b.state == connectivity.TransientFailure {
		b.picker = NewErrPicker(b.mergeErrors())
		return
	}
	readySCs := make(map[balancer.SubConn]SubConnInfo)

	// Filter out all ready SCs from full subConn map.
	for addr, sc := range b.subConns {
		if st, ok := b.scStates[sc]; ok && st == connectivity.Ready {
			readySCs[sc] = SubConnInfo{Address: addr}
		}
	}
	b.picker = b.pickerBuilder.Build(PickerBuildInfo{ReadySCs: readySCs})
}

It uses b.subConns to pass ready connections to the picker. But the key in b.subConns contains no attributes now. So I got

empty attributes and my program failed.

It is a feature or a bug? What should I do?

[menghanl]

There's a PR for this: #4253
Can you take a look and see if it solves the problem?

[MooooonStar]

oh, yes! I works. It seems that he got the same problem as me.