[HDFS-16547] [SBN read] Namenode in safe mode should not be transfered to observer state

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: namenode
• Labels: pull-request-available
• Target Version/s: 3.4.0
• Hadoop Flags: Reviewed
• Assignee: Tao Li
• Reporter: Tao Li
• Created: 19/Apr/22 11:25
• Updated: 16/Oct/24 18:29
• Resolved: 21/Nov/22 18:14

Description

Currently, when a Namenode is in safemode(under starting or enter safemode manually), we can transfer this Namenode to Observer by command. This Observer node may receive many requests and then throw a SafemodeException, this causes unnecessary failover on the client.

So Namenode in safe mode should not be transfer to observer state.

Issue Links

• relates to: HDFS-14201 Ability to disallow safemode NN to become active
• links to: GitHub Pull Request #4201