Apologies if this has already been discussed. I was getting 'Netty connect'[1] error every time I started a topology with more than 1 worker. I'm using Storm 0.9.5. Because of this issue I was forced to run 1 worker with multiple spout/bolt threads.
I had default kernel settings in my servers, which I think were too low for the amount of connection/data thrown out to them. I was able to see high number of Tcp receive queue full and tcp failed accepts with netstat -s command. Now after I tweaked few linux kernel network parameters [2], my topologies with 4 works each have been running without a single error since last few days. This seems to have solved the reconnect issues I was having. Let me know if you have questions. [1] 2015-09-17T21:59:58.790+0000 b.s.m.n.Client [ERROR] connection attempt 103 to Netty-Client-storm-host-name/1.2.3.4:6710 failed: java.lang.RuntimeException: Returned channel was actually not established [2] net.ipv4.tcp_window_scaling = 1 net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_slow_start_after_idle = 0