Load balancing algorithm

[Dewangga Bachrul Alam]

Hello!

I got curios with load balancing algorithm, I got scenarios like this.

I have 3 galera cluster, each cluster have 3 node and it was solved with
stream module.

Cluster1:
Node1-Cluster1: 192.168.11.1
Node2-Cluster1: 192.168.11.2
Node3-Cluster1: 192.168.11.3

Cluster2:
Node1-Cluster2: 192.168.12.1
Node2-Cluster2: 192.168.12.2
Node3-Cluster2: 192.168.12.3

Cluster3:
Node1-Cluster3: 192.168.13.1
Node2-Cluster3: 192.168.13.2
Node3-Cluster3: 192.168.13.3

Cluster4:
Node1-Cluster1: 192.168.11.1
Node1-Cluster4: 192.168.14.1

But, I want to build another cluster and wont sync with galera cluster.
Is there any alternative instead of roundrobind, least_connected and
ip_hash?

I want the algorithm is connect to backend at the sametime, looks like:

upstream Cluster4{
	server 192.168.11.1:3306 max_fails=0;
	server 192.168.14.1:3306 max_fails=0;
}

Since it's not synced, the query to upstream "Cluster4" should be not
round robin or asynchronous to backend, it should be simultaneously.

Is it possible? If yes, which method should be picked up?