Help Center/ MapReduce Service/ Troubleshooting/ Using Hive/ Setting the Map/Reduce Memory on the Client
Updated on 2025-12-01 GMT+08:00
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Setting the Map/Reduce Memory on the Client

Symptom

How do I set Map and Reduce memory on the client?

Procedure

Before SQL statement execution, run the set command to set parameters of clients related to Map/Reduce.

The following parameters are related to Map and Reduce memory: 
set mapreduce.map.memory.mb=4096; //Memory required by each Map task
set mapreduce.map.java.opts=-Xmx3276M; //Maximum memory used by the JVM of each Map task
set mapreduce.reduce.memory.mb=4096; //Memory required by each Reduce task
set mapreduce.reduce.java.opts=-Xmx3276M; //Maximum memory used by the JVM of each Reduce task
set mapred.child.java.opts=-Xms1024M -Xmx3584M; //A global parameter used to set Map and Reduce in a unified manner

Parameter settings take effect for the current session only.

Parent topic: Using Hive