我在单节点Cassandra设置中使用身份验证和授权，但我经常在Cassandra服务器日志中收到以下错误，
ERROR [SharedPool-Worker-71] 2018-06-01 10:40:36,661 ErrorMessage.java:338 - Unexpected exception during request
java.lang.RuntimeException: org.apache.cassandra.exceptions.ReadTimeoutException: Operation timed out - received only 1 responses.
at org.apache.cassandra.auth.CassandraRoleManager.getRole(CassandraRoleManager.java:489) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.CassandraRoleManager.getRoles(CassandraRoleManager.java:269) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.RolesCache.getRoles(RolesCache.java:66) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.Roles.hasSuperuserStatus(Roles.java:51) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.AuthenticatedUser.isSuper(AuthenticatedUser.java:71) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.CassandraAuthorizer.authorize(CassandraAuthorizer.java:76) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.PermissionsCache.getPermissions(PermissionsCache.java:68) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.AuthenticatedUser.getPermissions(AuthenticatedUser.java:104) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.ClientState.authorize(ClientState.java:412) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.ClientState.checkPermissionOnResourceChain(ClientState.java:345) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.ClientState.ensureHasPermission(ClientState.java:322) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.ClientState.hasAccess(ClientState.java:309) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.ClientState.hasColumnFamilyAccess(ClientState.java:293) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.cql3.statements.SelectStatement.checkAccess(SelectStatement.java:198) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:203) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.cql3.QueryProcessor.processPrepared(QueryProcessor.java:487) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.cql3.QueryProcessor.processPrepared(QueryProcessor.java:464) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.transport.messages.ExecuteMessage.execute(ExecuteMessage.java:130) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:507) [apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:401) [apache-cassandra-3.0.8.jar:3.0.8]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [netty-all-4.0.23.Final.jar:4.0.23.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) [netty-all-4.0.23.Final.jar:4.0.23.Final]
at io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32) [netty-all-4.0.23.Final.jar:4.0.23.Final]
at io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324) [netty-all-4.0.23.Final.jar:4.0.23.Final]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_91]
at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) [apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) [apache-cassandra-3.0.8.jar:3.0.8]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_91]
Caused by: org.apache.cassandra.exceptions.ReadTimeoutException: Operation timed out - received only 1 responses.
at org.apache.cassandra.service.ReadCallback.awaitResults(ReadCallback.java:132) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.ReadCallback.get(ReadCallback.java:137) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.AbstractReadExecutor.get(AbstractReadExecutor.java:145) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.StorageProxy$SinglePartitionReadLifecycle.awaitResultsAndRetryOnDigestMismatch(StorageProxy.java:1715) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.StorageProxy.fetchRows(StorageProxy.java:1664) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.StorageProxy.readRegular(StorageProxy.java:1605) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.service.StorageProxy.read(StorageProxy.java:1524) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.db.SinglePartitionReadCommand$Group.execute(SinglePartitionReadCommand.java:954) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.cql3.statements.SelectStatement.execute(SelectStatement.java:263) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.cql3.statements.SelectStatement.execute(SelectStatement.java:224) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.CassandraRoleManager.getRoleFromTable(CassandraRoleManager.java:497) ~[apache-cassandra-3.0.8.jar:3.0.8]
at org.apache.cassandra.auth.CassandraRoleManager.getRole(CassandraRoleManager.java:485) ~[apache-cassandra-3.0.8.jar:3.0.8]
... 27 common frames omitted
因此，考虑到这一点，我尝试启用一次Cassandra身份验证和授权检查并永久缓存，具体取决于在URL中观察到的以下设置，
authenticator: PasswordAuthenticator
authorizer: CassandraAuthorizer
role_manager: CassandraRoleManager
roles_validity_in_ms: 0
permissions_validity_in_ms: 0
但是我仍然经常在服务器日志中看到上述错误，是否还需要添加此混淆：credentials_validity_in_ms: 0
或者我错过了什么？
谢谢，
哈利
答案 0 :(得分：2)
此消息实际上是您的设置出现问题的信号 - 机器过载或类似的情况。
不是完全禁用这些设置（更改密码或chaning角色需要重新启动节点），我建议改为执行以下操作：
roles_validity_in_ms，permissions_validity_in_ms＆amp; credentials_validity_in_ms具有相当高的价值，例如月份; roles_update_interval_in_ms，credentials_update_interval_in_ms＆amp; permissions_update_interval_in_ms有一些价值，比如一分钟如果您拥有大量用户，那么调整permissions_cache_max_entries也是有意义的。表。