Rushabh S Shah created HDFS-12278: ------------------------------------- Summary: LeaseManager#removeLease operation is inefficient in 2.8. Key: HDFS-12278 URL: https://issues.apache.org/jira/browse/HDFS-12278 Project: Hadoop HDFS Issue Type: Bug Components: namenode Affects Versions: 2.8.0 Reporter: Rushabh S Shah Assignee: Rushabh S Shah Priority: Blocker
After HDFS-6757, removeLease became expensive. HDFS-6757 changed the {{sortedLeases}} object from TreeSet to PriorityQueue. Previously the {{remove(Object)}} operation from {{sortedLeases}} was {{O(log n)}} but after the change it became {{O( n)}} since it has to find the object first. Recently we had an incident in one of our production cluster just hours after we upgraded from 2.7 to 2.8 The {{sortledLeases}} object had approximately 100,000 items within it. While removing the lease, it will acquire the LeaseManager lock and that will slow down the lookup of lease also. HDFS-6757 is a good improvement which replaced the path by inode id. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org