How do we know whether we running Datastage jobs on SMP or MPP System:

Look in the Configuration file if the "fastname" has the same value for all given nodes then you are running on SMP.
If there are different "fastname's" then its MPP.
For Server jobs it won't matter if it is SMP or MPP because Server jobs execute only on the machine where Datastage installed.
See below in Bold.
Ex :
main_program: APT configuration file: /ibmiscode/Configurations/ETL/apt_config_max
{ 
  node "DEV1" { 
    fastname "DEV1" 
    pools "" 
    resource disk "/is_resource1/isent" {pools ""} 
    resource scratchdisk "/scratch1/sent" {pools ""} 
  } 


  node "local2" { 
    fastname "DEV1" 
    pools "" 
    resource disk "/is_resource2/isent" {pools ""} 
    resource scratchdisk "/scratch2/sent" {pools ""} 
  } 


  node "local3" { 
    fastname "DEV1" 
    pools "" 
    resource disk "/is_resource3/isent" {pools ""} 
    resource scratchdisk "/scratch3/sent" {pools ""} 
  } 


  node "local4" { 
    fastname "DEV1" 
    pools "" 
    resource disk "/is_resource4/isent" {pools ""} 
    resource scratchdisk "/scratch4/sent" {pools ""} 
  } 
}