Replication factor determination ignores inactive hosts

[rprevot]

Hi,

When using Token Aware load balancing, the replication factor is checked during startup.

This validation is done by the HostSelectionWithFallback class (initWithHosts and calculateReplicationFactor methods):

public void initWithHosts(Map<Host, HostConnectionPool<CL>> hPools) {
       List<HostToken> allHostTokens = tokenSupplier.getTokens(hPools.keySet());
       // ....
       if (localSelector.isTokenAware() && localRack != null) {
              replicationFactor.set(calculateReplicationFactor(allHostTokens));
       }
       // ...
}

Unfortunately, the given collection "hPools" contains only up hosts. So if one host is unavailable during startup, Dyno throws an exception even for symmetric configuration.