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首先，我讀了這個this。Cassandra啓動問題
我無法獲得Cassandra並再次運行。 我使用Hector作爲我的客戶端連接到Cassandra 0.8.2的一個實例&加載我的模式。通過Hector，我使用2個不同的類來創建2個不同的列族 - 文章& TagsArticlesCF。
通過主類，我創建了一個名爲「公司章程」和「TagsArticlesCF」這樣的列族：
public static void main(String[] args) {
cluster = HFactory.getOrCreateCluster("test cluster", "xxx.xxx.xxx.xxx:9160");
newKeyspaceDef = HFactory.createKeyspaceDefinition(keyspaceName);
if((cluster.describeKeyspace(keyspaceName)) == null){
createSchema();
}
Keyspace ksp = HFactory.createKeyspace(keyspaceName, cluster);
Articles art = new Articles(cluster, newKeyspaceDef,ksp);
TagsArticlesCF tags = new TagsArticlesCF(cluster,newKeyspaceDef,ksp);
這裏是什麼我列族的樣子/他們是如何創造了一個例子：
public Articles(Cluster cluster, KeyspaceDefinition ksp, Keyspace ksp2) {
BasicColumnFamilyDefinition bcfDef = new BasicColumnFamilyDefinition();
bcfDef.setName("Articles");
bcfDef.setKeyspaceName("test3");
bcfDef.setDefaultValidationClass(ComparatorType.UTF8TYPE.getClassName());
bcfDef.setKeyValidationClass(ComparatorType.UTF8TYPE.getClassName());
bcfDef.setComparatorType(ComparatorType.UTF8TYPE);
ColumnFamilyDefinition cfDef = new ThriftCfDef(bcfDef);
BasicColumnDefinition columnDefinition = new BasicColumnDefinition();
columnDefinition.setName(StringSerializer.get().toByteBuffer("title"));
columnDefinition.setIndexType(ColumnIndexType.KEYS);
columnDefinition.setValidationClass(ComparatorType.UTF8TYPE.getClassName());
cfDef.addColumnDefinition(columnDefinition);
...
我想將一個完整的模式添加到卡桑德拉，這將支持我計劃在加載的數據上執行的查詢。我運行了幾次主要方法來將新的列族加載到數據庫中。在多次運行main方法並調整了一些東西（檢查列系列是否已經在KeyspaceDefinition中）之後，Cassandra的運行實例就停止了。
我很好奇使用赫克託/ java的幾件事情：
我計劃有不同的列（以支持不同的查詢），10家左右的列族。組織我的課程是否是最佳做法，以便我爲每個專欄家庭提供課程？
究竟是一個KeyspaceDefinition &一個Keyspace之間的區別是什麼？爲什麼區分呢？
我們試圖讓卡桑德拉&的新實例，這裏是我們碰上了。我想更好地瞭解發生了什麼事情的話，任何意見，並有助於避免這些類型的錯誤，將不勝感激：
[[email protected] bin]# ./cassandra -p cassandra.pid
[[email protected] bin]# INFO 10:52:36,437 Logging initialized
INFO 10:52:36,484 JVM vendor/version: Java HotSpot(TM) 64-Bit Server VM/1.6.0_25
INFO 10:52:36,485 Heap size: 1046937600/1046937600
INFO 10:52:36,490 JNA not found. Native methods will be disabled.
INFO 10:52:36,526 Loading settings from file:/opt/cassandra/apache-cassandra-0.8.2/conf/cassandra.yaml
[[email protected] bin]# INFO 10:52:36,872 DiskAccessMode 'auto' determined to be mmap, indexAccessMode is mmap
INFO 10:52:37,346 Global memtable threshold is enabled at 332MB
INFO 10:52:37,348 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:37,497 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:37,617 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:37,984 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:38,252 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:38,259 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:38,545 Opening /opt/cassandra/persist8/data/system/IndexInfo-g-73
INFO 10:52:38,661 Opening /opt/cassandra/persist8/data/system/Schema-g-169
INFO 10:52:38,685 Opening /opt/cassandra/persist8/data/system/Schema-g-170
INFO 10:52:38,730 Opening /opt/cassandra/persist8/data/system/Schema-g-171
INFO 10:52:38,751 Opening /opt/cassandra/persist8/data/system/Migrations-g-171
INFO 10:52:38,763 Opening /opt/cassandra/persist8/data/system/Migrations-g-170
INFO 10:52:38,776 Opening /opt/cassandra/persist8/data/system/Migrations-g-169
INFO 10:52:38,795 Opening /opt/cassandra/persist8/data/system/LocationInfo-g-2
INFO 10:52:38,827 Opening /opt/cassandra/persist8/data/system/LocationInfo-g-1
INFO 10:52:39,048 Loading schema version ec437ac0-d28a-11e0-0000-c4ffed3367ff
INFO 10:52:39,645 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:39,663 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
...（更多的相同）...
INFO 10:52:40,463 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:41,390 Opening /opt/cassandra/persist8/data/test3/Articles-g-367
ERROR 10:52:41,392 Missing sstable component in /opt/cassandra/persist8/data/test3/Articles-g-367=[Index.db, Data.db]; skipped because of /opt/cassandra/persist8/data/test3/Articles-g-367-Index.db (No such file or directory)
INFO 10:52:41,863 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
INFO 10:52:41,865 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
...（更多同...）
INFO 10:52:41,892 Removing compacted SSTable files (see http://wiki.apache.org/cassandra/MemtableSSTable)
ERROR 10:52:41,898 Exception encountered during startup.
java.lang.RuntimeException: javax.management.InstanceAlreadyExistsException: org.apache.cassandra.db:type=ColumnFamilies,keyspace=test3,columnfamily=TagsArticlesCF
at org.apache.cassandra.db.ColumnFamilyStore.<init>(ColumnFamilyStore.java:315)
at org.apache.cassandra.db.ColumnFamilyStore.createColumnFamilyStore(ColumnFamilyStore.java:466)
at org.apache.cassandra.db.ColumnFamilyStore.createColumnFamilyStore(ColumnFamilyStore.java:436)
at org.apache.cassandra.db.Table.initCf(Table.java:369)
at org.apache.cassandra.db.Table.<init>(Table.java:306)
at org.apache.cassandra.db.Table.open(Table.java:111)
at org.apache.cassandra.service.AbstractCassandraDaemon.setup(AbstractCassandraDaemon.java:187)
at org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:341)
at org.apache.cassandra.thrift.CassandraDaemon.main(CassandraDaemon.java:80)
Caused by: javax.management.InstanceAlreadyExistsException: org.apache.cassandra.db:type=ColumnFamilies,keyspace=test3,columnfamily=TagsArticlesCF
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:453)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.internal_addObject(DefaultMBeanServerInterceptor.java:1484)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:963)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:917)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:312)
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:482)
at org.apache.cassandra.db.ColumnFamilyStore.<init>(ColumnFamilyStore.java:311)
... 8 more
Exception encountered during startup.
java.lang.RuntimeException: javax.management.InstanceAlreadyExistsException: org.apache.cassandra.db:type=ColumnFamilies,keyspace=test3,columnfamily=TagsArticlesCF
at org.apache.cassandra.db.ColumnFamilyStore.<init>(ColumnFamilyStore.java:315)
at org.apache.cassandra.db.ColumnFamilyStore.createColumnFamilyStore(ColumnFamilyStore.java:466)
at org.apache.cassandra.db.ColumnFamilyStore.createColumnFamilyStore(ColumnFamilyStore.java:436)
at org.apache.cassandra.db.Table.initCf(Table.java:369)
at org.apache.cassandra.db.Table.<init>(Table.java:306)
at org.apache.cassandra.db.Table.open(Table.java:111)
at org.apache.cassandra.service.AbstractCassandraDaemon.setup(AbstractCassandraDaemon.java:187)
at org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:341)
at org.apache.cassandra.thrift.CassandraDaemon.main(CassandraDaemon.java:80)
Caused by: javax.management.InstanceAlreadyExistsException: org.apache.cassandra.db:type=ColumnFamilies,keyspace=test3,columnfamily=TagsArticlesCF
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:453)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.internal_addObject(DefaultMBeanServerInterceptor.java:1484)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:963)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:917)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:312)
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:482)
at org.apache.cassandra.db.ColumnFamilyStore.<init>(ColumnFamilyStore.java:311)
... 8 more
[[email protected] bin]#
謝謝！
好的。我想出了KeyspaceDefinition和Keyspace之間的區別。從這裏（http://groups.google.com/group/hector-users/browse_thread/thread/405dbc1b03e97e05） – Henry
我得到的實例備份，但我不明白爲什麼我得到這個錯誤的第一位。這似乎是一個不穩定的情況。 – Henry