running_maps counter in the metrics is not decremented when the tasks of a job is killed/failed. Below are the exact steps to reproduce the problem:
- Initially running_maps=0
- Submit a job with 5 maps. running_maps is set to 5
- Kill 2 attempts of a map task
- Fail 4 attempts of the same map task so that the job is finally marked killed.
- Once the job is marked killed, running_maps is set to 3 and not 0.