The system soft limit for the maximum number of processes is low: maximum_processes.
A low value for the soft limit for the maximum number of processes might prevent the processing elements (PEs) of an instance from starting. A value of UNKNOWN indicates that the soft limit for the maximum number of processes cannot be determined.
Before you run the product, use the ulimit -a command to analyze your ulimit settings. Adjust the soft limit for the maximum number of processes according to your environment. For more information about the ulimit settings, see the Streams product documentation.