SSH remote control question

I am pretty new to linux so forgive me for asking a basic question

I am using SSH to control 40 machines. What i am trying to do is remotely bash a shell script on each machine. I am using a for loop to bash every script, code as follows.

code in host machine runallworkers.sh:

...

i=1

for each $ip[] in ip[]   #just for example, i have saved all ips in a array ip[]
do
SSH -i aaa.rsa ubuntu@${ip[]} 'bash /home/ubuntu/program/runworker.sh'
echo "running worker in node $i"
let i++
done
...

code in each runworker.sh in each worker machine:

./worker.pl 7000 &
#worker.pl is a socket server program. it takes the parameter 7000 to run. it listens to port 7000

i can manually bash the runworker.sh file in each worker machine. So the worker.pl file should work fine. I can use the for loop to do other stuff on each node, so the loop should work fine too.
But the problem occurs when i run the script in the host machine, it stop responding after the first bashing, so the loop can not go on... the screen shows something like this:

ubuntu@1.1.1.1:~$ bash runallworkers.sh
running worker in node 1

please someone help me out...
Thanks in advance!!

The way you're starting your script has it wait for any child processes to return before it exits itself. You can circumvent that by running it as

nohup ./worker.pl 7000 &

.

Also, if you don't need a TTY attached to your process you can run ssh with the -T option, but that's optional.

for BASH or KSH you should also add disown after that.