This script performs broker failure tests with the following
setup in a single local machine:

1. A cluster of Kafka source brokers
2. A cluster of Kafka mirror brokers with embedded consumers in 
   point-to-point mode
3. An independent ConsoleConsumer in publish/subcribe mode to
   consume messages from the SOURCE brokers cluster
4. An independent ConsoleConsumer in publish/subcribe mode to
   consume messages from the MIRROR brokers cluster
5. A producer produces batches of messages to the SOURCE brokers
6. One of the Kafka SOURCE or MIRROR brokers in the cluster will
   be randomly terminated and waiting for the consumer to catch up.
7. Repeat Step 4 & 5 as many times as specified in the script

Expected results:
==================
There should not be any discrepancies by comparing the unique 
message checksums from the source ConsoleConsumer and the 
mirror ConsoleConsumer.

Notes:
==================
The number of Kafka SOURCE brokers can be increased as follows:
1. Update the value of $num_kafka_source_server in this script
2. Make sure that there are corresponding number of prop files:
   $base_dir/config/server_source{1..4}.properties

The number of Kafka MIRROR brokers can be increased as follows:
1. Update the value of $num_kafka_target_server in this script
2. Make sure that there are corresponding number of prop files:
   $base_dir/config/server_target{1..3}.properties

Quick Start:
==================
Execute this script as follows:
  <kafka home>/system_test/broker_failure $ bin/run-test.sh

In the event of failure, by default the brokers and zookeepers
remain running to make it easier to debug the issue - hit Ctrl-C
to shut them down.