The request... use SQL to determine if the DDM/DRDA server was active, and if not, start it.

ddm server.sql

--
-- Subject: The request... use SQL to determine if the DDM/DRDA server was active, and if not, start it.
-- Author: Scott Forstie  
-- Date  : June, 2022
-- Features Used : This Gist uses QSYS2.ACTIVE_JOB_INFO, BOOLEAN, QSYS2.QCMDEXC scalar function, CTE, case expression
--
--
-- Is the DDM/DRDA listener active? (If at IBM i 7.4 or earlier)
--
select count(*) as DDM_DRDA_Listener_Active
  from table (
      qsys2.active_job_info(SUBSYSTEM_LIST_FILTER => 'QSYSWRK', JOB_NAME_FILTER => 'QRWTLSTN')
    );
stop;

--
-- Is the DDM/DRDA listener active? (If at IBM i 7.5 or later)
--
select boolean(count(*)) as DDM_DRDA_Listener_Active
  from table (
      qsys2.active_job_info(SUBSYSTEM_LIST_FILTER => 'QSYSWRK', JOB_NAME_FILTER => 'QRWTLSTN')
    );
stop;

--
-- Restart the *DDM TCPSVR as needed (If at IBM i 7.4 or later)
--
with ddmsvr (started) as (
    select count(*) as DDM_DRDA_Listener_Active
      from table (
          qsys2.active_job_info(SUBSYSTEM_LIST_FILTER => 'QSYSWRK', JOB_NAME_FILTER => 'QRWTLSTN')
        )
  )
  select
    case started
      when 0 then qsys2.qcmdexc('QSYS/STRTCPSVR SERVER(*DDM)')
      else 1
    end
    from ddmsvr;
stop;
     
--
-- Restart the *DDM TCPSVR as needed (If at IBM i 7.5 or later)
--
with ddmsvr (started) as (
    select boolean(count(*)) as DDM_DRDA_Listener_Active
      from table (
          qsys2.active_job_info(SUBSYSTEM_LIST_FILTER => 'QSYSWRK', JOB_NAME_FILTER => 'QRWTLSTN')
        )
  )
  select
    case started
      when false then qsys2.qcmdexc('QSYS/STRTCPSVR SERVER(*DDM)')
      else 1
    end
    from ddmsvr;
     
stop;

--
-- Is the DDM/DRDA server active?
--
select subsystem, count(*) as QRWTSRVR_Jobs
  from table (
      qsys2.active_job_info(JOB_NAME_FILTER => 'QRWTSRVR')
    )
  group by subsystem;
stop;