How to start managed servers in parallel?

Question

Hello everyone,
I am developing a wlst script that would start all managed servers on a particular machine (machine_name should be provided) from the admin server side. The script works fine. However, since there were some domains that have 25+ managed servers for a single machine, it takes some time to start all of them in sequence. Is there a way to trigger a start command for each of the managed servers that I need to start just like what the node manager does when i start them through admin console? Something like triggering parallel processes running on background. Here is my code snippet:
                #It focuses only on all managed servers defined within the listen address provided
                if (server_listenaddress == managed_server) and (server_name != admin_name):
                        if (execute_command == "start"):
                                print 'About to start',server_name,'on',server_listenaddress,'...'
                                print
                                try:
                                        start(server_name)
                                        print
                                        state(server_name,'Server')
                                        print
                                        nmDisconnect()
                                except WLSTException:
                                        print 'Server instance',server_name,'could not be started. Skipping this server..'
                                        print
                                        state(server_name,'Server')
                        else:
                                print 'About to stop',server_name,'on',server_listenaddress,'...'
                                print
                                try:
                                        shutdown(server_name,force='true')
                                        print
                                        state(server_name,'Server')
                                        print
                                except WLSTException:
                                        print 'Server instance',server_name,'could not be stopped. Skipping this server..'
                                        print
                                        state(server_name,'Server')
                elif (server_name == admin_name):
                        #It skips to restart the admin server since this script it only to restart managed servers.
                        print 'Server',server_name,'is the admin server. Skipping...'
                        print
                else:
                        print 'Managed server',server_name,'is not configured with',managed_server,'listen address. Skipping this server..'
Thanks in advance for all your help!!
regards,
Rustan

Answer 1

Works perfectly, thanks!!!
In summary, I just modified this line:
start(server_name)
and changed it to:
start(server_name, block='false')
In Admin Console, it is set to false but in WLST, it is defaulted to true so we need to explicitly set it to false.
"Oracle Fusion Middleware Oracle WebLogic Scripting Tool, block is always set to true."