6. ⼀一、问题现象
• What is the problems?
1、thousands of threads lead to too much Context
Switching degrades performance
2、too much memory consumption lead to GC
stop the world
7. ⼆二、调查过程
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• One instance of Filesystem has one DFSClient
• One DFSClient has one thread of LeaseChecker
DFSClient
FileSystem
LeaseChecker
DFSClient
NameNode
Renew Lease
Thread