This problem concerns a client behavioral when it faces a network issue connection to a new added server. In my case it's https://issues.redhat.com/browse/ISPN-12828 , so i can consistently reproduce this problem.

for the firs failed connection attempt, server ends up in failedServers and once it's in this Set, all attempts to connect to it would be redirected to other servers

INFO org.infinispan.HOTROD [] - ISPN004014: New server added(127.0.0.1/<unresolved>:11272), adding to the pool.
DEBUG org.infinispan.client.hotrod.impl.transport.netty.ChannelFactory [] - Creating new channel pool for 127.0.0.1/<unresolved>:11272
TRACE org.infinispan.client.hotrod.impl.transport.netty.ChannelFactory [] - Connection attempt failed, we now have 1 servers with no established connections: [127.0.0.1/<unresolved>:11272]
WARN org.infinispan.HOTROD [] - ISPN004015: Failed adding new server 127.0.0.1/<unresolved>:11272

io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: /127.0.0.1:11272
Caused by: java.net.ConnectException: finishConnect(..) failed: Connection refused

TRACE org.infinispan.client.hotrod.impl.transport.netty.ChannelFactory [] - Server 127.0.0.1/<unresolved>:11272 is suspected, trying another for PutOperation

followed by endless repetitions of the "is suspected" log above