[RATIS-577] NPE in LogAppender while creating a new request.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.3.0
• Fix Version/s: 0.4.0
• Component/s: server
• Labels: MiniOzoneChaosCluster
• Target Version/s: 0.4.0
• Assignee: Tsz-wo Sze
• Reporter: Mukul Kumar Singh
• Created: 30/May/19 09:54
• Updated: 13/Jun/19 20:45
• Resolved: 13/Jun/19 20:45

Description

Found the following NPE in the LogAppender while creating a new request.

2019-05-30 08:10:44,275 ERROR impl.LogAppender (LogAppender.java:run(90)) - org.apache.ratis.server.impl.LogAppender$AppenderDaemon@5e4b44cc unexpected exception
java.lang.NullPointerException
        at java.util.Objects.requireNonNull(Objects.java:203)
        at java.util.Optional.<init>(Optional.java:96)
        at java.util.Optional.of(Optional.java:108)
        at org.apache.ratis.server.impl.ServerProtoUtils.getStateMachineEntry(ServerProtoUtils.java:197)
        at org.apache.ratis.server.impl.ServerProtoUtils.getStateMachineData(ServerProtoUtils.java:205)
        at org.apache.ratis.server.impl.ServerProtoUtils.shouldReadStateMachineData(ServerProtoUtils.java:210)
        at org.apache.ratis.server.raftlog.segmented.SegmentedRaftLog.getEntryWithData(SegmentedRaftLog.java:206)
        at org.apache.ratis.server.impl.LogAppender.createRequest(LogAppender.java:209)
        at org.apache.ratis.grpc.server.GrpcLogAppender.appendLog(GrpcLogAppender.java:169)
        at org.apache.ratis.grpc.server.GrpcLogAppender.runAppenderImpl(GrpcLogAppender.java:113)
        at org.apache.ratis.server.impl.LogAppender$AppenderDaemon.run(LogAppender.java:80)
        at java.lang.Thread.run(Thread.java:748)