Cassandra startup issue - cassandra

Question

First, I read this this.
I cannot get Cassandra up and running again.
I am using Hector as my client to connect to an instance of Cassandra 0.8.2 & load my schema. Through Hector, I am using 2 different classes to create 2 different column families - Articles & TagsArticlesCF.
Through the main class, I create a column families named "Articles" and "TagsArticlesCF" like this:
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);
Here is an example of what my column families look like/ how they are created:
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);
...
I am trying to add a full schema into Cassandra that will support queries that I plan to execute on the loaded data. I ran the main method a few times to load the new column families into the database. After running the main method several times and adjusting a few things (checking if the column family was already in the KeyspaceDefinition), the running instance of Cassandra went down.
I am curious about a few things using Hector/java:
I plan to have 10 or so column families with different columns (to support different queries). Is it best practice to organize my classes so that I have a class for each column family?
What exactly is the difference between a KeyspaceDefinition & a Keyspace? Why is the distinction made?
We tried to get a new instance of Cassandra & here is what we ran into. I am trying to better understand what's going on so, any comments and help to avoid these types of errors would be greatly appreciated:
[root#appscluster1 bin]# ./cassandra -p cassandra.pid
[root#appscluster1 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
[root#appscluster1 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)
... (more of same)...
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)
... (more of same) ...
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
[root#appscluster1 bin]#
Thanks!

Answer 1

How are you sending the Keyspace definition to the cluster?
Take a look at the methods following test case:
https://github.com/rantav/hector/blob/master/core/src/test/java/me/prettyprint/cassandra/service/CassandraClusterTest.java#L115-189
If a keyspace and or column family already exist, you should be able to catch an IllegalArgumentException.