Load Balancing and Stateful Services

DNS may rotate records, but any DNS SRV algorithm will always pick the
entry with the lowest priority value, regardless of order. 
Thus, as long
as server42 is the only one with priority 0, order has no bearing on
behavior. The initial request sees
dynamicsoft.com:

prio weight
0    100 s1.dynamicsoft.com
0    100 s2.dynamicsoft.com
...
0    100 s42.dynamicsoft.com

Thus, first selection is randomized across all servers, with equal
probability. Assume s42 gets picked for the first request. The
Record-Route inserts server42.dynamicsoft.com, which resolves to

prio weight
0    0 s42.dynamicsoft.com
1    0 s1.dynamicsoft.com
1    0 s2.dynamicsoft.com

Thus, unless s42 is busted, the others will never be visited, 
regardless
of the order that DNS happens to arrange things.
