[IOTDB-4566] If a DataNode is down, then remove other DataNode may failed

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: Core/Cluster
• Assignee: QiangShaowei
• Reporter: QiangShaowei
• Created: 30/Sep/22 07:55
• Updated: 30/Sep/22 08:13
• Resolved: 30/Sep/22 08:13

Description

In the current logic, if remove a DataNode X,  we will exec regions migrate on DataNode  Y or DataNode  Z,   (X, Y, Z has  same region replica) 

But before  move DataNode X, if DataNode Y or DataNode Z  is down,  maybe ConfigNode will  send regioin migrate task to the down node,  will cause remove DataNode X failed.

solution:  filter online DataNode to exec region migrate