Hello everyone!   My cluster have 4 datanode. Each Datanode has 32G RAM. Recently, the Datanode has been reported Exception Out Of Memory.   I looed up some document, just mentioned namenode memory situations.   CDH Manager，Host memory usage chart display physical memory is full, but The role of resident memory less than 1G.   i don't know why it took so much of physical memory.  On the system currently has 12 million blocks     I have turn off all other services,just run the hdfs service. ... View more