环境：Spark 1.6, kafka 0.8
Failed to send producer request with correlation id java.io.IOException: Connection reset by peer kafka.common.FailedToSendMessageException: Failed to send messages after 3 tries.
由于使用spark读取和写入到kafka中，出现以上问题，一直以为是参数性能调整问题，调整不同的参数。
在producer端
producerConf.put(“retry.backoff.ms”, “8000”);
producerConf.put(“message.send.max.retries”, “10”);
producerConf.put(“topic.metadata.refresh.interval.ms”, “0”);
producerConf.put(“fetch.message.max.bytes”, “5252880”)
producerConf.put(“request.required.acks”, “0”)
在broker端 server.properties
message.max.bytes=5252880
replica.fetch.max.bytes=5252880
request.timeout.ms=600000
都无法解决些问题，后来才了解到producer默认的写入的方式是同步，因此问题就是在这一个参数上
producerConf.put(“producer.type”, “async”)
