Average duration handling for warnIfLonger job attribute

Current Situation

• If the job property warnIfLonger is specified as a percentage and a job has never run successfully, the average duration calculation may be performed every 2 seconds instead of just once and, in the worst case, never complete.

Desired Behaiviour

• The calculation of the average job duration should be performed only once.

Test Instruction

• Stop JOC-Cockpit.
• Remove the serialized monitoring entries in the database if they exist:
  • DELETE FROM JOC_VARIABLES WHERE NAME='monitor';
• Start JOC-Cockpit.
• Configure a new workflow with a "long" running error job (use e.g. ping -n 10 localhost) and the job property warnIfLonger e.g. 10%.
  • Note: using a new job is very important because the job with warnIfLonger should not have any entries in the History.
• Start the workflow execution.
• Stop JOC-Cockpit after the worflow execution.
• Check the serialized monitoring entries in the database:
  • SELECT * FROM JOC_VARIABLES WHERE NAME='monitor';
    • The query should return 0 rows.
      • This means that the warnIfLonger calculations have been completed.