I'm working with Cassandra-0.8.2. I am working with the most recent version of Hector & My java version is 1.6.0_26
I'm very new to Cassandra & Hector.
What I'm trying to do: 1. connect to an up & running instance of cassandra on a different server. I know it's running b/c I can ssh through my terminal into the server running this Cassandra instance and run the CLI with full functionality. 2. then I want to connect to a keyspace & create a column family and then add a value to that column family through Hector.
I think my problem is that this running instance of Cassandra on this server might not be configured to get commands that are not local. I think my next step will be to add a local instance of Cassandra on the cpu I'm working on and try to do this locally. What do you think?
Here's my Java code:
import me.prettyprint.cassandra.serializers.StringSerializer;
import me.prettyprint.cassandra.service.CassandraHostConfigurator;
import me.prettyprint.hector.api.Cluster;
import me.prettyprint.hector.api.Keyspace;
import me.prettyprint.hector.api.ddl.ColumnFamilyDefinition;
import me.prettyprint.hector.api.ddl.ComparatorType;
import me.prettyprint.hector.api.factory.HFactory;
import me.prettyprint.hector.api.mutation.Mutator;
public class MySample {
public static void main(String[] args) {
Cluster cluster = HFactory.getOrCreateCluster("Test Cluster", "xxx.xxx.x.41:9160");
Keyspace keyspace = HFactory.createKeyspace("apples", cluster);
ColumnFamilyDefinition cf = HFactory.createColumnFamilyDefinition("apples","ColumnFamily2",ComparatorType.UTF8TYPE);
StringSerializer stringSerializer = StringSerializer.get();
Mutator<String> mutator = HFactory.createMutator(keyspace, stringSerializer);
mutator.insert("jsmith", "Standard1", HFactory.createStringColumn("first", "John"));
}
}
My ERROR is:
16:22:19,852 INFO CassandraHostRetryService:37 - Downed Host Retry service started with queue size -1 and retry delay 10s
16:22:20,136 INFO JmxMonitor:54 - Registering JMX me.prettyprint.cassandra.service_Test Cluster:ServiceType=hector,MonitorType=hector
Exception in thread "main" me.prettyprint.hector.api.exceptions.HInvalidRequestException: InvalidRequestException(why:Keyspace apples does not exist)
at me.prettyprint.cassandra.connection.HThriftClient.getCassandra(HThriftClient.java:70)
at me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:226)
at me.prettyprint.cassandra.service.KeyspaceServiceImpl.operateWithFailover(KeyspaceServiceImpl.java:131)
at me.prettyprint.cassandra.service.KeyspaceServiceImpl.batchMutate(KeyspaceServiceImpl.java:102)
at me.prettyprint.cassandra.service.KeyspaceServiceImpl.batchMutate(KeyspaceServiceImpl.java:108)
at me.prettyprint.cassandra.model.MutatorImpl$3.doInKeyspace(MutatorImpl.java:222)
at me.prettyprint.cassandra.model.MutatorImpl$3.doInKeyspace(MutatorImpl.java:219)
at me.prettyprint.cassandra.model.KeyspaceOperationCallback.doInKeyspaceAndMeasure(KeyspaceOperationCallback.java:20)
at me.prettyprint.cassandra.model.ExecutingKeyspace.doExecute(ExecutingKeyspace.java:85)
at me.prettyprint.cassandra.model.MutatorImpl.execute(MutatorImpl.java:219)
at me.prettyprint.cassandra.model.MutatorImpl.insert(MutatorImpl.java:59)
at org.cassandra.examples.MySample.main(MySample.java:25)
Caused by: InvalidRequestException(why:Keyspace apples does not exist)
at org.apache.cassandra.thrift.Cassandra$set_keyspace_result.read(Cassandra.java:5302)
at org.apache.cassandra.thrift.Cassandra$Client.recv_set_keyspace(Cassandra.java:481)
at org.apache.cassandra.thrift.Cassandra$Client.set_keyspace(Cassandra.java:456)
at me.prettyprint.cassandra.connection.HThriftClient.getCassandra(HThriftClient.java:68)
... 11 more
Thank you in advance for your help.
Bonding is the process of giving LP tokens or an accepted currency to the protocol in exchange for HEC at a discounted price. (more HEC for less money). There are two types of bonds: 4,4 and 1,1. 4,4 bonds are paid in sHEC, which means your HEC is automatically staked from the second you buy the bond.
Hector DAO operates using two key concepts: staking and bonding. Staking is depositing your money in a staking contract (like a pool) and earning interest that is automatically compounded. Bonding is buying the native token HEC from the protocol directly in exchange for discounted HEC.
The way the Hector DAO cryptocurrency works is through liquidity, which is provided by the cryptos that back it. If the price of those falls below one HEC, then the protocol behind HEC buys back HEC tokens and then burns them, thus raising the price of Hector DAO until it is above what is backing it.
The exception you are getting is,
why:Keyspace apples does not exist
In your code, this line does not actually create the keyspace,
Keyspace keyspace = HFactory.createKeyspace("apples", cluster);
As described here, this is the code you need to define your keyspace,
ColumnFamilyDefinition cfDef = HFactory.createColumnFamilyDefinition("MyKeyspace", "ColumnFamilyName", ComparatorType.BYTESTYPE);
KeyspaceDefinition newKeyspace = HFactory.createKeyspaceDefinition("MyKeyspace", ThriftKsDef.DEF_STRATEGY_CLASS, replicationFactor, Arrays.asList(cfDef));
// Add the schema to the cluster.
// "true" as the second param means that Hector will block until all nodes see the change.
cluster.addKeyspace(newKeyspace, true);
We also have a getting started guide up on the wiki as well which might be of some help.
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