Job Counters
Launched map tasks=3
Launched reduce tasks=45
Data-local map tasks=1
Rack-local map tasks=2
Total time spent by all maps in occupied slots (ms)=29338
Total time spent by all reduces in occupied slots (ms)=200225
Total time spent by all map tasks (ms)=29338
Total time spent by all reduce tasks (ms)=200225
Total vcore-seconds taken by all map tasks=29338
Total vcore-seconds taken by all reduce tasks=200225
Total megabyte-seconds taken by all map tasks=30042112
Total megabyte-seconds taken by all reduce tasks=205030400
what does "vcore-seconds" mean and what is the difference between "vcore-seconds " and "Total time spent"
There isn't a official documentation about this metrics, but if I understand fine (see here), vcore-seconds is the sum of seconds in which Hadoop allocate vcore for some task.
I think this metric show how much time spend your MapReduce application in Map and Reduce phases, without involved other tasks (Scheduled task, shuffle and sort intermediate keys, etc...)