I defined a docker template with image name 'kkm' and label 'docker-slave'.
I created two jenkins jobs (docker-test1 & docker-test2) to run on docker-slave.
When I run 'build now' simultaneously on both jobs sometimes the jobs will
execute in parallel sometimes only one job will run while the other waits.

See the attached jenkins logs. What is the expected behavior? These should run in parallel.