什麼是RockMq:

    Apache RocketMQ™ is an open source distributed messaging and streaming data platform.

為什麼會有RocketMq：

    Based on our research, with increased queues and virtual topics in use, ActiveMQ IO module reaches a bottleneck. We tried our best to solve this problem through throttling, circuit breaker or degradation, but it did not work well. So we begin to focus on the popular messaging solution Kafka at that time. Unfortunately, Kafka can not meet our requirements especially in terms of low latency and high reliability, see here for details.

     In this context, we decided to invent a new messaging engine to handle a broader set of use cases, ranging from traditional pub/sub scenarios to high volume real-time zero-loss tolerance transaction system. 

對比圖

連結：http://rocketmq.apache.org/docs/motivation/

   英語很重要，但讓我看懂官網文件的，首當其衝的是技術