When programs are trying to connect to an EMS server using an FT URL through the EMS client API, the connection will get established for the first available active server in that FT URL. As the client API cannot make a connection to a standby server, if the first server in the URL is in the standby state then the program cannot establish a connection and will move on to try the second server in that FT URL. If the second server is running and active, the program will get connected. But in the case of programs connecting through the admin API, even if the first server is in the standby state, the connection will get established, as the admin API can connect to a standby server. It will not move on to check for the next server as would a normal user.
 
If we assume that "tcp://serverA:portA,tcp://serverB:portB" is the FT URL, the client API will try establishing a connection with serverA. If serverA is an active server, the connection will get established. If not, the client will try establishing a connection to serverB. The connection will succeed if serverB is running and is active. But in the case of the admin API, even if serverA is in the standby state, the connection will get established.