tree f6fabaf873d482a901aec9b8f40f08fa9177802b
parent b92bafb0d5db05612326b2134749ba0791a17c16
author Jake Biesinger <jake.biesinger@gmail.com> 1385638557 -0800
committer Jake Biesinger <jake.biesinger@gmail.com> 1385638557 -0800

add support for Hadoop Counters via job.setCounterAggregatorClass

The PregelixJob.setCounterAggregatorClass sets up a (user-specified)
global aggregator and an iterationComplete hook to save Counter values.

The user-specified Counter-based aggregator (must extend
HadoopCountersAggregator) is saved to HDFS in each iteration and should
be restart/snapshot-aware.

The usage for setting up counters is to make a call to
job.setCounterAggregatorClass.  After job completion, the Counters may
be retrieved from HDFS using BspUtils.getCounters(job).

Note that there is currently only one spot for iterationComplete hooks
and this behavior occupies it.