Java Can'；不要启动卡桑德拉

我正在尝试运行cqlsh连接到cassandra，并收到以下错误消息

a） 运行cqlsh时出错：

Connection error: ('Unable to connect to any servers', {'127.0.0.1:9042': error(61, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})

b） 运行cassandra后出现错误消息：

Exception (java.lang.ExceptionInInitializerError) encountered during startup: null
java.lang.ExceptionInInitializerError
    at org.apache.cassandra.db.SystemKeyspace.checkHealth(SystemKeyspace.java:709)
    at org.apache.cassandra.service.StartupChecks$9.execute(StartupChecks.java:351)
    at org.apache.cassandra.service.StartupChecks.verify(StartupChecks.java:109)
    at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:188)
    at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:607)
    at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:717)
Caused by: java.lang.IllegalArgumentException: Bad configuration; unable to start server: At least one DataFileDirectory must be specified
    at org.apache.cassandra.config.DatabaseDescriptor.createAllDirectories(DatabaseDescriptor.java:846)
    at org.apache.cassandra.db.Keyspace.<clinit>(Keyspace.java:66)
    ... 6 more
ERROR 00:27:05 Exception encountered during startup
java.lang.ExceptionInInitializerError: null
    at org.apache.cassandra.db.SystemKeyspace.checkHealth(SystemKeyspace.java:709) ~[apache-cassandra-2.2.17.jar:2.2.17]
    at org.apache.cassandra.service.StartupChecks$9.execute(StartupChecks.java:351) ~[apache-cassandra-2.2.17.jar:2.2.17]
    at org.apache.cassandra.service.StartupChecks.verify(StartupChecks.java:109) ~[apache-cassandra-2.2.17.jar:2.2.17]
    at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:188) [apache-cassandra-2.2.17.jar:2.2.17]
    at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:607) [apache-cassandra-2.2.17.jar:2.2.17]
    at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:717) [apache-cassandra-2.2.17.jar:2.2.17]
Caused by: java.lang.IllegalArgumentException: Bad configuration; unable to start server: At least one DataFileDirectory must be specified
    at org.apache.cassandra.config.DatabaseDescriptor.createAllDirectories(DatabaseDescriptor.java:846) ~[apache-cassandra-2.2.17.jar:2.2.17]
    at org.apache.cassandra.db.Keyspace.<clinit>(Keyspace.java:66) ~[apache-cassandra-2.2.17.jar:2.2.17]
    ... 6 common frames omitted

有人能在这个问题上提供帮助吗？

此错误是从中引发的-这意味着您没有Cassandra需要存储数据的配置选项

数据文件目录

，并且看起来好像没有设置

$Cassandra\u HOME

打开

cassandra.yaml

文件，取消注释

data\u file\u目录

配置选项和下一行，并指向cassandra可以在其中写入数据的目录，而不是默认的

/var/lib/cassandra/data

。您很可能还需要指定其他参数，例如，

commitlog\u目录

，

hints\u目录

，以及

saved\u缓存目录

Name          Status  User   Plist
cassandra@2.2 error    /Users/john/Library/LaunchAgents/homebrew.mxcl.cassandra@2.2.plist
rabbitmq      stopped        
redis         started  /Users/john/Library/LaunchAgents/homebrew.mxcl.redis.plist
tomcat@7      stopped