我正在运行一个2节点（每个节点8个内核）的Cassandra 3.10集群，复制因子为1。随着时间的推移，我在我的Cassandra集群上已经拥有了大量的密钥空间。
我最近注意到，当我停止/启动时，返回的时间非常慢。我在system.log和debug.log中看到了数千条**“预准备语句重建”**堆栈跟踪，如下面的示例所示。看起来Cassandra正试图为已不存在的键空间准备语句，因为我之前已经删除了它们。
注意我没有任何应用程序/客户端等连接到cassandra时，它启动。我也手动清理了commitlog，保存的缓存沿着数据文件，为以前的下降键空间，这没有什么区别，在启动时。我看到相同的行为与我们没有数据和提交日志。
有人知道Cassandra在启动时从哪里获得这些信息和/或如何在保留现有密钥空间的同时解决这个问题吗？
预准备语句重新创建警告：

WARN  [main] 2017-07-07 14:44:14,362 QueryProcessor.java:159 - prepared statement recreation error: update metric_resource set attributes = ? where t_uid ='TUID1' and metric_name =? and resource_name=?
org.apache.cassandra.db.KeyspaceNotDefinedException: Keyspace test_keyspace_1 does not exist
        at org.apache.cassandra.thrift.ThriftValidation.validateKeyspace(ThriftValidation.java:85) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.thrift.ThriftValidation.validateColumnFamily(ThriftValidation.java:109) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.statements.ModificationStatement$Parsed.prepare(ModificationStatement.java:796) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.statements.ModificationStatement$Parsed.prepare(ModificationStatement.java:789) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.QueryProcessor.getStatement(QueryProcessor.java:557) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.QueryProcessor.prepare(QueryProcessor.java:412) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.QueryProcessor.preloadPreparedStatement(QueryProcessor.java:154) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:358) [apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:601) [apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:735) [apache-cassandra-3.10.jar:3.10]

与不存在的密钥空间相关的其他堆栈跟踪：

org.apache.cassandra.db.KeyspaceNotDefinedException: Keyspace test_keyspace1 does not exist
        at org.apache.cassandra.thrift.ThriftValidation.validateKeyspace(ThriftValidation.java:85) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.thrift.ThriftValidation.validateColumnFamily(ThriftValidation.java:109) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.statements.SelectStatement$RawStatement.prepare(SelectStatement.java:920) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.statements.SelectStatement$RawStatement.prepare(SelectStatement.java:915) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.QueryProcessor.getStatement(QueryProcessor.java:557) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.QueryProcessor.prepare(QueryProcessor.java:412) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.cql3.QueryProcessor.preloadPreparedStatement(QueryProcessor.java:154) ~[apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:358) [apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:601) [apache-cassandra-3.10.jar:3.10]
        at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:735) [apache-cassandra-3.10.jar:3.10]