Using a connection URL of
one would expect initial connection attempts to go on for at least 13 seconds (13 reconnect attempts with 1000ms delay between attempts) but in fact the error "No uris available to connect to" returned in less than a second. Changing useExponentialBackOff to true delays a failure report to about 41 seconds, which is 10ms * 2^12, which is what you'd expect with 12 reconnect attempts (13 connect attempts) starting with the default 10ms delay and doubling with every attempt, since 2^0+2^1+2^2+...2^n-1 is approx 2^n. (I guess maxReconnectAttempts should be called maxConnectAttempts, but I'm not opening a bug about that.) Changing maxReconnectAttempts to 12 causes the delay to be about 20 seconds, half of what it is for 13, so that checks out.
Altogether this points to the initialReconnectDelay parameter being ignored on initial connection attempts. It is supposed to work per http://activemq.apache.org/discovery-transport-reference.html