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He Xiaoqiao commented on HDFS-14497: ------------------------------------ [~jojochuang],Thanks for your reviews and helps, I would like to update new patches If we need to backport to other branches. > Write lock held by metasave impact following RPC processing > ----------------------------------------------------------- > > Key: HDFS-14497 > URL: https://issues.apache.org/jira/browse/HDFS-14497 > Project: Hadoop HDFS > Issue Type: Improvement > Components: namenode > Reporter: He Xiaoqiao > Assignee: He Xiaoqiao > Priority: Major > Fix For: 3.3.0 > > Attachments: HDFS-14497.001.patch > > > NameNode meta save hold global write lock currently, so following RPC r/w > request or inner-thread of NameNode could be paused if they try to acquire > global read/write lock and have to wait before metasave release it. > I propose to change write lock to read lock and let some read request could > be process normally. I think it could not change informations which meta save > try to get if we try to open read request. > Actually, we need ensure that there are only one thread to execute metaSave, > otherwise, output streams could meet exception especially both streams hold > the same file handle or some other same output stream. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org