我有一个三节点 Cassandra 集群，其节点位于 10.3.10.129、10.3.10.130 和 10.3.10.131。集群有一个预先存在的包含数据的键空间。opscenter-agents 已安装在所有三个节点上。尝试使用 OpsCenter 网页通过一个（或所有）节点添加预先存在的集群时，我收到一条错误消息：“创建集群时出错。添加集群时超时。请查看日志以获取有关问题的详细信息。”
如何避免这些超时？
日志显示已经实现了与三个节点的连接。opscenterd.log 中还有一条额外的警告消息：“WARN: ProcessingError while calling CreateClusterConfController: Timeout while adding cluster。有关问题的详细信息，请查看日志。”
Cassandra 版本是 2.0.6。DataStax OpsCenter 版本是 4.1.2。发行说明声称 4.1.2 修复了 Cassandra 2.0 的错误，所以看起来 OpsCenter 确实支持我正在使用的 Cassandra 版本。
2014-04-15 21:15:27+0000 [] INFO: Starting new cluster services for Layer8Demo
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Starting services for cluster Layer8Demo
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Loading event plugins
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Loading event plugin conf /etc/opscenter/event-plugins/posturl.conf
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Successfully loaded event plugin conf /etc/opscenter/event-plugins/posturl.conf
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Loading event plugin conf /etc/opscenter/event-plugins/email.conf
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Successfully loaded event plugin conf /etc/opscenter/event-plugins/email.conf
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Done loading event plugins
2014-04-15 21:15:27+0000 [] INFO: Metric caching enabled with 50 points and 1000 metrics cached
2014-04-15 21:15:27+0000 [] INFO: Starting PushService
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: Starting CassandraCluster service
2014-04-15 21:15:27+0000 [Layer8Demo] INFO: agent_config items: {'cassandra_log_location': '/var/log/cassandra/system.log', 'thrift_port': 9160, 'thrift_ssl_truststore': None, 'rollups300_ttl': 2419200, 'rollups86400_ttl': -1, 'jmx_port': 7199, 'metrics_ignored_solr_cores': '', 'api_port': '61621', 'metrics_enabled': 1, 'thrift_ssl_truststore_type': 'JKS', 'kerberos_use_ticket_cache': True, 'use_ssl': 0, 'kerberos_renew_tgt': True, 'rollups60_ttl': 604800, 'cassandra_install_location': '', 'rollups7200_ttl': 31536000, 'kerberos_debug': False, 'storage_keyspace': 'OpsCenter', 'ec2_metadata_api_host': '169.254.169.254', 'provisioning': 0, 'kerberos_use_keytab': True, 'metrics_ignored_column_families': '', 'thrift_ssl_truststore_password': None, 'metrics_ignored_keyspaces': 'system, system_traces, system_auth, dse_auth, OpsCenter'}
2014-04-15 21:15:27+0000 [] INFO: Stopping factory <opscenterd.ThriftService.NoReconnectCassandraClientFactory instance at 0x225af80>
2014-04-15 21:15:29+0000 [Layer8Demo] INFO: Enterprise functionality: False
2014-04-15 21:15:29+0000 [Layer8Demo] INFO: Snitch: org.apache.cassandra.locator.PropertyFileSnitch
2014-04-15 21:15:29+0000 [Layer8Demo] INFO: Partitioner: org.apache.cassandra.dht.Murmur3Partitioner
2014-04-15 21:15:29+0000 [Layer8Demo] INFO: Cluster Name: Layer8Demo
2014-04-15 21:15:31+0000 [Layer8Demo] INFO: Recognizing new node 10.3.10.130 ('4124999021280409113')
2014-04-15 21:15:31+0000 [Layer8Demo] INFO: Node 10.3.10.130 has multiple tokens (vnodes). Only one picked for display.
2014-04-15 21:15:31+0000 [Layer8Demo] INFO: Recognizing new node 10.3.10.129 ('1364620421069081446')
2014-04-15 21:15:31+0000 [Layer8Demo] INFO: Node 10.3.10.129 has multiple tokens (vnodes). Only one picked for display.
2014-04-15 21:15:31+0000 [Layer8Demo] INFO: Recognizing new node 10.3.10.131 ('6921776330201546034')
2014-04-15 21:15:31+0000 [Layer8Demo] INFO: Node 10.3.10.131 has multiple tokens (vnodes). Only one picked for display.
2014-04-15 21:15:42+0000 [Layer8Demo] INFO: Keyspaces: {'xs': CassandraKeyspace(name=xs, column_families=[], tables=[u'threat_morph', u'con_hit', u'session_event', u'threat_undo_morph', u'ip_alert', u'session_alert', u'url_table', u'session_event_morph', u'threat', u'con_hit_morph', u'session_end_morph'], attributes={'strategy_options': {'DC1': '2'}, 'replica_placement_strategy': 'org.apache.cassandra.locator.NetworkTopologyStrategy'}), 'system': CassandraKeyspace(name=system, column_families=['IndexInfo', 'NodeIdInfo', 'schema_keyspaces', 'hints'], tables=[u'peers', u'range_xfers', u'schema_keyspaces', u'schema_columns', u'IndexInfo', u'schema_triggers', u'sstable_activity', u'peer_events', u'paxos', u'batchlog', u'NodeIdInfo', u'compaction_history', u'compactions_in_progress', u'schema_columnfamilies', u'local', u'hints'], attributes={'strategy_options': {}, 'replica_placement_strategy': 'org.apache.cassandra.locator.LocalStrategy'}), 'OpsCenter': CassandraKeyspace(name=OpsCenter, column_families=['events_timeline', 'settings', 'rollups60', 'rollups86400', 'pdps', 'rollups7200', 'events', 'rollups300'], tables=[u'events_timeline', u'settings', u'rollups60', u'rollups86400', u'pdps', u'rollups7200', u'events', u'rollups300'], attributes={'strategy_options': {'replication_factor': '2'}, 'replica_placement_strategy': 'org.apache.cassandra.locator.SimpleStrategy'}), 'system_traces': CassandraKeyspace(name=system_traces, column_families=[], tables=[u'events', u'sessions'], attributes={'strategy_options': {'replication_factor': '2'}, 'replica_placement_strategy': 'org.apache.cassandra.locator.SimpleStrategy'})}
2014-04-15 21:15:47+0000 [] WARN: ProcessingError while calling CreateClusterConfController: Timeout while adding cluster. Please check the log for details on the problem.
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Initializing event storage.
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Persisting config to Cassandra for agent on 10.3.10.130
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Attempting to load all persisted alert rules
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Done initializing event storage.
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Done loading persisted scheduled job descriptions
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Done loading persisted alert rules
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Persisting config to Cassandra for agent on 10.3.10.131
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Persisting config to Cassandra for agent on 10.3.10.129
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: OpsCenter starting up.
2014-04-15 21:17:06+0000 [Layer8Demo] INFO: Stopping repair service
datastax-agent 的启动日志确认已建立连接。
INFO [main] 2014-04-15 20:41:06,116 Loading conf files: /var/lib/datastax-agent/conf/address.yaml
INFO [main] 2014-04-15 20:41:06,188 Java vendor/version: Java HotSpot(TM) 64-Bit Server VM/1.7.0_51
INFO [main] 2014-04-15 20:41:06,265 Default config values: {:rollups300_ttl 2419200, :settings_cf "settings", :my_channel_prefix "/agent", :poll_period 60, :kerberos_hostname nil, :storage_dc nil, :thrift_conn_timeout 10000, :thrift_max_frame_size 15728640, :rollups60_ttl 604800, :stomp_port 61620, :shorttime_interval 10, :longtime_interval 300, :private-conf-props ["initial_token" "listen_address" "broadcast_address" "rpc_address"], :thrift_port 9160, :async_retry_timeout 5, :agent-conf-group "global-cluster-agent-group", :jmx_host "127.0.0.1", :ec2_metadata_api_host "169.254.169.254", :metrics_enabled 1, :async_queue_size 5000, :autodiscovery_interval 120, :rollups7200_ttl 31536000, :autodiscovery_enabled true, :thrift_ssl_truststore nil, :rollup_snapshot_period 300, :is_package true, :monitor_command "/usr/share/datastax-agent/bin/datastax_agent_monitor", INFO [main] 2014-04-15 20:41:06,116 Loading conf files: /var/lib/datastax-agent/conf/address.yaml
INFO [main] 2014-04-15 20:41:06,188 Java vendor/version: Java HotSpot(TM) 64-Bit Server VM/1.7.0_51
INFO [main] 2014-04-15 20:41:06,265 Default config values: {:rollups300_ttl 2419200, :settings_cf "settings", :my_channel_prefix "/agent", :poll_period 60, :kerberos_hostname nil, :storage_dc nil, :thrift_conn_timeout 100 :thrift_socket_timeout 5000, :cassandra_log_location "/var/log/cassandra/system.log", :jmx_port 7199, :jmx_metrics_threadpool_size 4, :use_ssl 0, :rollups86400_ttl -1, :nodedetails_threadpool_size 3, :api_port 61621, :kerberos_service nil, :kerberos_client_principal nil, :jmx_thread_pool_size 5, :production 1, :runs_sudo 1, :stomp_interface "10.1.3.33", :storage_keyspace "OpsCenter", :rollup_snapshot_threshold 300, :thrift_ssl_truststore_type "JKS", :realtime_interval 5}
INFO [main] 2014-04-15 20:41:06,266 Waiting for the config from OpsCenter
INFO [main] 2014-04-15 20:41:06,268 Attempting to determine Cassandra's broadcast address through JMX
INFO [main] 2014-04-15 20:41:06,269 Starting Stomp
INFO [Initialization] 2014-04-15 20:41:06,270 New JMX connection (127.0.0.1:7199)
INFO [main] 2014-04-15 20:41:06,274 SSL communication is disabled
INFO [main] 2014-04-15 20:41:06,274 Creating stomp connection to 10.1.3.33:61620
INFO [StompConnection receiver] 2014-04-15 20:41:06,288 Reconnecting in 0s.
INFO [main] 2014-04-15 20:41:06,323 Starting Jetty server: {:port 61621, :host nil, :ssl? false, :join? false}
INFO [StompConnection receiver] 2014-04-15 20:41:06,605 Connected to 10.1.3.33:61620