unable to find log file

when I insert into or query dgraph,it would occur this exception:Unable to find log file. Please retry. I guess it‘s becuase to when insert data the posting list lost,but I don’t have any ways to solve it.(I use java client insert data)

insert exception:
2018-09-12 19:20:42,750 ERROR DgraphDataHandlerList:183 - UNKNOWN: Unable to find log file. Please retry
io.grpc.StatusRuntimeException: UNKNOWN: Unable to find log file. Please retry
at io.grpc.Status.asRuntimeException(Status.java:526)
at io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onClose(ClientCalls.java:419)
at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:41)
at io.grpc.internal.CensusStatsModule$StatsClientInterceptor$1$1.onClose(CensusStatsModule.java:684)
at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:41)
at io.grpc.internal.CensusTracingModule$TracingClientInterceptor$1$1.onClose(CensusTracingModule.java:391)
at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:475)
at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:63)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:557)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$600(ClientCallImpl.java:478)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:590)
at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

query exception:
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87%E7%BC%96%E8%BE%91_20180917104423

A post was merged into an existing topic: Error in recording data times, unable to find log file