Hi ayubalfresco,
Since the Alfresco nodes are clustered the caches are replicated between them. I guess what you can do is put a load balancer in front of the Alfresco nodes and point both of them to the same Solr instance. So when Solr makes a query to track Alfresco it will hit the load balancer and will go to the available node.
When there's an update in the either of the nodes, they will update the Solr indexes.
Now, the problem is that there's a single point of failure with the indexes, if Solr goes down then the search in Alfresco won't work.
This is a problem Alfresco needs to solve and many people is struggling with.