hello
When I start the elasticsearch 6.6.0，everything is ok，but after 10 minutes passed，elasticsearch throw the java.nio.file.NoSuchFileException: /home/wsn/es6.6/es_data/node_2/data/nodes/0/node.lock and most of shareds had lost，
but I found the file named 【node.lock】 in this path（/home/wsn/es6.6/es_data/node_2/data/nodes/0）
how to solve this problem
part of exception info is as follow:
[2019-04-01T17:14:22,307][WARN ][o.e.e.NodeEnvironment ] [10.10.2.130_node2] lock assertion failed
java.nio.file.NoSuchFileException: /home/wsn/es6.6/es_data/node_2/data/nodes/0/node.lock
at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86) ~[?:?]
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102) ~[?:?]
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107) ~[?:?]
at sun.nio.fs.UnixFileAttributeViews$Basic.readAttributes(UnixFileAttributeViews.java:55) ~[?:?]
at sun.nio.fs.UnixFileSystemProvider.readAttributes(UnixFileSystemProvider.java:144) ~[?:?]
at sun.nio.fs.LinuxFileSystemProvider.readAttributes(LinuxFileSystemProvider.java:99) ~[?:?]
at java.nio.file.Files.readAttributes(Files.java:1737) ~[?:1.8.0_181]
at org.apache.lucene.store.NativeFSLockFactory$NativeFSLock.ensureValid(NativeFSLockFactory.java:189) ~[lucene-core-7.6.0.jar:7.6.0 719cde97f84640faa1e3525690d262946571245f - nknize - 2018-12-07 14:44:20]
at org.elasticsearch.env.NodeEnvironment.assertEnvIsLocked(NodeEnvironment.java:999) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.env.NodeEnvironment.availableShardPaths(NodeEnvironment.java:817) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.gateway.TransportNodesListGatewayStartedShards.nodeOperation(TransportNodesListGatewayStartedShards.java:120) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.gateway.TransportNodesListGatewayStartedShards.nodeOperation(TransportNodesListGatewayStartedShards.java:61) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.action.support.nodes.TransportNodesAction.nodeOperation(TransportNodesAction.java:138) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.action.support.nodes.TransportNodesAction$NodeTransportHandler.messageReceived(TransportNodesAction.java:259) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.action.support.nodes.TransportNodesAction$NodeTransportHandler.messageReceived(TransportNodesAction.java:255) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.transport.SecurityServerTransportInterceptor$ProfileSecuredRequestHandler$1.doRun(SecurityServerTransportInterceptor.java:250) ~[?:?]
at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.common.util.concurrent.EsExecutors$1.execute(EsExecutors.java:140) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.transport.SecurityServerTransportInterceptor$ProfileSecuredRequestHandler.lambda$messageReceived$0(SecurityServerTransportInterceptor.java:299) ~[?:?]
at org.elasticsearch.action.ActionListener$1.onResponse(ActionListener.java:60) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.transport.ServerTransportFilter$NodeProfile.lambda$inbound$2(ServerTransportFilter.java:155) ~[?:?]
at org.elasticsearch.xpack.security.authz.AuthorizationUtils$AsyncAuthorizer.maybeRun(AuthorizationUtils.java:177) ~[?:?]
at org.elasticsearch.xpack.security.authz.AuthorizationUtils$AsyncAuthorizer.setRunAsRoles(AuthorizationUtils.java:171) ~[?:?]
at org.elasticsearch.xpack.security.authz.AuthorizationUtils$AsyncAuthorizer.authorize(AuthorizationUtils.java:153) ~[?:?]
at org.elasticsearch.xpack.security.transport.ServerTransportFilter$NodeProfile.lambda$inbound$3(ServerTransportFilter.java:157) ~[?:?]
at org.elasticsearch.action.ActionListener$1.onResponse(ActionListener.java:60) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lambda$authenticateAsync$2(AuthenticationService.java:177) ~[x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lambda$lookForExistingAuthentication$4(AuthenticationService.java:210) ~[x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.lookForExistingAuthentication(AuthenticationService.java:221) [x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.authenticateAsync(AuthenticationService.java:175) [x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.authc.AuthenticationService$Authenticator.access$000(AuthenticationService.java:134) [x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.authc.AuthenticationService.authenticate(AuthenticationService.java:104) [x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.transport.ServerTransportFilter$NodeProfile.inbound(ServerTransportFilter.java:131) [x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.xpack.security.transport.SecurityServerTransportInterceptor$ProfileSecuredRequestHandler.messageReceived(SecurityServerTransportInterceptor.java:306) [x-pack-security-6.6.0.jar:6.6.0]
at org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:66) [elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.transport.TcpTransport$RequestHandler.doRun(TcpTransport.java:1288) [elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:759) [elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) [elasticsearch-6.6.0.jar:6.6.0]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_181]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_181]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]
[2019-04-01T17:14:22,312][WARN ][o.e.g.MetaStateService ] [10.10.2.130_node2] [[device_info/mOSboYwlQOGUbI8AsNRu6g]]: failed to write index state
java.lang.IllegalStateException: environment is not locked
at org.elasticsearch.env.NodeEnvironment.assertEnvIsLocked(NodeEnvironment.java:1002) ~[elasticsearch-6.6.0.jar:6.6.0]
at org.elasticsearch.env.NodeEnvironment.indexPaths(NodeEnvironment.java:798) ~[elasticsearch-6.6.0.jar:6.6.0]
thanks