KafkaOffsetMonitor监控工具2017年1月发布的版本

Functional changes: Graphs could sometimes be difficult to read because you would see non-whole numbers on the y-axis legend, when facts being drawn are always whole numbers. Set y-axis to draw only whole numbers in the legend to make the graph easier to interpret. Respect command-line arg kafkaOffsetForceFromStart, starting consumer offset listener clients from the beginning of the log by implementin a ConsumerRebalanceListener. Stability improvements: Created function tryParseOffsetMessage to attempt to parse a kafka offset message retrieved from the internal committed offset topic: Handles messages of other types and questionable correctness. Added 100% unit-test coverage for this new function. Add robustness to the log-end-offset getter thread: No longer shutting down the application on error. Instead, closing and destroying the client and re-creating it. Sleeping on error before re-creating client and continuing to process Deal with thread-safety issues on shared memory between threads that retrieve data from Kafka. Stopped polluting consumer groups in zookeeper by not creating a unique consumer group name for the consumer-offset and log-end-offset listener at each client instantiation. Improved createNewAdminClient code, simplifying the error paths and property calling close on error. Re-factored some of the error handling paths, simplifying them. Closing all kafka clients on error so connections do not leak.