Hadoop is generally used for cold data processing. For real-time data, if you have to use it, you can use it in different ways.

Method 1: Use the hbase database on hadoop, thinking that hbase has no Map/Reduce, so the operation is at the millisecond level.

Method 2: Business data is divided into real-time data and cold data according to procedures. Real-time data is stored in relational database and cold data is stored in hadoop. For example, the data of the last month is stored in a relational database in order to respond to business processing in real time. Save the data a month ago in hadoop for historical data query, statistical analysis, data mining, etc.