[IOTDB-5383] [confignode]start-confignode fail with NPE

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.1-SNAPSHOT
• Component/s: Core/Server
• Sprint: Catalyst-Backlog
• Assignee: Song Ziyang
• Reporter: changxue
• Created: 07/Jan/23 06:51
• Updated: 06/Jul/23 08:50
• Resolved: 21/Mar/23 06:59

Description

[confignode]start-confignode fail with NPE

reproduction:
1. config_node_ratis_snapshot_trigger_threshold=30 append in iotdb-common.properties
2. start 3C3D cluster

expect: start successfully

actual result:
2C3D start successfully but it failed with NPE when start the third confignode

show cluster
+------+----------+-------+---------------+------------+
|NodeID|  NodeType| Status|InternalAddress|InternalPort|
+------+----------+-------+---------------+------------+
|     0|ConfigNode|Running|   172.20.70.44|       10710|
|     2|ConfigNode|Running|   172.20.70.45|       10710|
|     1|  DataNode|Running|   172.20.70.44|       10730|
|     3|  DataNode|Running|   172.20.70.45|       10730|
|     5|  DataNode|Running|   172.20.70.46|       10730|
+------+----------+-------+---------------+------------+

2023-01-07 14:42:11,745 [grpc-default-executor-0] INFO  o.a.r.g.s.GrpcServerProtocolService$ServerRequestStreamObserver:143 - 8: Completed INSTALL_SNAPSHOT, lastRequest: 0->8#0-t1,chunk:ba310edb-b921-452d-8023-4ef2ad4f51f9,8 
2023-01-07 14:42:11,746 [8@group-000000000000-StateMachineUpdater] ERROR o.a.r.s.i.StateMachineUpdater:194 - 8@group-000000000000-StateMachineUpdater caught a Throwable. 
java.lang.NullPointerException: snapshot == null
	at java.util.Objects.requireNonNull(Objects.java:228)
	at org.apache.ratis.server.impl.StateMachineUpdater.reload(StateMachineUpdater.java:219)
	at org.apache.ratis.server.impl.StateMachineUpdater.run(StateMachineUpdater.java:179)
	at java.lang.Thread.run(Thread.java:748)

猜测与 config_node_ratis_snapshot_trigger_threshold 配置太小有关。第三个confignode启动不了，show timeseries root.** 也运行不了，即集群不可用。