[RATIS-522] NPE on client in LogService from verification

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: LogService
• Assignee: Unassigned
• Reporter: Josh Elser
• Created: 10/Apr/19 18:59
• Updated: 10/Apr/19 18:59

Description

2019-04-09 18:32:17,016 ERROR server.LogStateMachine (VerificationTool.java:waitForCompletion(85)) - Got exception
java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.io.IOException: java.io.IOException: java.lang.NullPointerException
    at java.util.concurrent.FutureTask.report(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:192)
    at org.apache.ratis.logservice.tool.VerificationTool.waitForCompletion(VerificationTool.java:79)
    at org.apache.ratis.logservice.tool.VerificationTool.main(VerificationTool.java:72)
Caused by: java.lang.RuntimeException: java.io.IOException: java.io.IOException: java.lang.NullPointerException
    at org.apache.ratis.logservice.tool.VerificationTool$BulkReader.run(VerificationTool.java:155)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: java.io.IOException: java.lang.NullPointerException
    at org.apache.ratis.logservice.impl.LogReaderImpl.readNext(LogReaderImpl.java:98)
    at org.apache.ratis.logservice.tool.VerificationTool$BulkReader.run(VerificationTool.java:142)
... 5 more
Caused by: java.io.IOException: java.lang.NullPointerException
    at org.apache.ratis.logservice.impl.LogReaderImpl.readNext(LogReaderImpl.java:86)
... 6 more

Saw this in the verification step of the VerificationTool. Seems like there is a situation where we don't get an Exception thrown back from the Ratis server.

      ReadLogReplyProto proto = ReadLogReplyProto.parseFrom(reply.getMessage().getContent());
      if (proto.hasException()) {
        LogServiceException e = proto.getException();
        throw new IOException(e.getErrorMsg());
      }

LogReaderImpl.java:86 is on the above new IOException creation, seeming to indicate that the LogServiceException is null.