Pause between tasks or jobs?

[xeon Mailinglist]

I am looking for a way to pause a chained job or a chained task. I want to
do this because I want to validate the output of each map or reduce phase,
or between each job execution. Is it possible to pause the execution of
chained jobs or chained mappers or reducers in MapReduce V2. I was looking
for the ChainedMapper and ChainedReducer, but I haven't found anything that
could allow me to pause the execution.