SimpleBenchmark:
1.a Do not rely on manual num.records / bytes collection on atomic integers.
1.b Rely on config files for num.threads, bootstrap.servers, etc.
1.c Add parameters for key skewness and value size.
1.d Refactor the tests for loading phase, adding tumbling-windowed count.
1.e For consumer / consumeproduce, collect metrics on consumer instead.
1.f Force stop the test after 3 minutes, this is based on empirical numbers of 10M records.
Other tests: use config for kafka bootstrap servers.
streams_simple_benchmark.py: only use scale 1 for system test, remove yahoo from benchmark tests.
Note that the JMX based metrics is more accurate than the manually collected metrics.
Reviewers: John Roesler <john@confluent.io>, Bill Bejeck <bill@confluent.io>, Matthias J. Sax <matthias@confluent.io>