elasticsearch 不明原因挂掉

[2020-07-07T15:34:20,098][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [] fatal error in thread [elasticsearch[fmHtTt2][bulk][T#1]], exiting
java.lang.AssertionError: Unexpected AlreadyClosedException
        at org.elasticsearch.index.engine.InternalEngine.failOnTragicEvent(InternalEngine.java:983) ~[elasticsearch-5.1.1.jar:5.1.1]
        at org.elasticsearch.index.engine.InternalEngine.maybeFailEngine(InternalEngine.java:997) ~[elasticsearch-5.1.1.jar:5.1.1]
        at org.elasticsearch.index.engine.InternalEngine.index(InternalEngine.java:414) ~[elasticsearch-5.1.1.jar:5.1.1]
        at org.elasticsearch.index.shard.IndexShard.index(IndexShard.java:556) ~[elasticsearch-5.1.1.jar:5.1.1]
 
 
[ERROR][o.e.i.e.InternalEngine$EngineMergeScheduler] [fmHtTt2] [email][0] failed to merge
org.apache.lucene.store.AlreadyClosedException: refusing to delete any files: this IndexWriter hit an unrecoverable exception
 
 
[ERROR][i.n.u.c.D.rejectedExecution] Failed to submit a listener notification task. Event loop shut down?
java.util.concurrent.RejectedExecutionException: event executor terminated
 
][ERROR][o.e.b.Bootstrap          ] Exception
java.lang.IllegalStateException: Failed to created node environment
 
 
主要报错综上，原因不明