digraph G {
   orientation=L;
   node [shape = diamond];
   {rank = same; 3 4}
   {rank = same; 5 6}
   {rank = same; 7 8}

   1 -> 2 [label = postgres];
   1 -> 3 [label = redis];
   2 -> 4 [label = HA];
   3 -> 5 [label = "key-value store"];
   5 -> 6 [label = "Performance comparison"];
   6 -> 7 [label = "Live data check"];
   7 -> 8 [label = "Support provider avail."];
   
}