/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.concurrent.TimeUnit;
import com.google.common.util.concurrent.Uninterruptibles;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.cql3.QueryProcessor;
import org.apache.cassandra.cql3.UntypedResultSet;
import org.apache.cassandra.db.ConsistencyLevel;
import org.apache.cassandra.exceptions.RequestExecutionException;
import org.apache.cassandra.exceptions.RequestValidationException;
import org.apache.cassandra.service.*;
public class ClientOnlyExample
{
private static final Logger logger = LoggerFactory.getLogger(ClientOnlyExample.class);
private static final String KEYSPACE = "keyspace1";
private static final String COLUMN_FAMILY = "standard1";
private static void startClient() throws Exception
{
StorageService.instance.initClient();
}
private static void testWriting() throws Exception
{
// do some writing.
for (int i = 0; i < 100; i++)
{
QueryProcessor.process(String.format("INSERT INTO %s.%s (id, name, value) VALUES ( 'key%d', 'colb', 'value%d')",
KEYSPACE,
COLUMN_FAMILY,
i,
i),
ConsistencyLevel.QUORUM);
System.out.println("wrote key" + i);
}
System.out.println("Done writing.");
}
private static void testReading() throws Exception
{
// do some queries.
for (int i = 0; i < 100; i++)
{
String query = String.format("SELECT id, name, value FROM %s.%s WHERE id = 'key%d'",
KEYSPACE,
COLUMN_FAMILY,
i);
UntypedResultSet.Row row = QueryProcessor.process(query, ConsistencyLevel.QUORUM).one();
System.out.println(String.format("ID: %s, Name: %s, Value: %s", row.getString("id"), row.getString("name"), row.getString("value")));
}
}
/**
* First, bring one or more nodes up. Then run ClientOnlyExample with these VM arguments:
* <p/>
* -Xmx1G
* -Dcassandra.config=/Users/gary/cassandra/conf/cassandra.yaml (optional, will first look for cassandra.yaml on classpath)
* <p/>
* Pass "write" or "read" into the program to exercise the various methods.
* <p/>
* Caveats:
* <p/>
* 1. Much of cassandra is not reentrant. That is, you can't spin a client up, down, then back up in the same jvm.
* 2. Because of the above, you still need to force-quit the process. StorageService.stopClient() doesn't (can't)
* spin everything down.
*/
public static void main(String args[]) throws Exception
{
startClient();
setupKeyspace();
testWriting();
logger.info("Writing is done. Sleeping, then will try to read.");
Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
testReading();
// no need to do this:
// StorageService.instance().decommission();
// do this instead:
StorageService.instance.stopClient();
System.exit(0); // the only way to really stop the process.
}
private static void setupKeyspace() throws RequestExecutionException, RequestValidationException, InterruptedException
{
QueryProcessor.process("CREATE KEYSPACE IF NOT EXISTS " + KEYSPACE + " WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'}",
ConsistencyLevel.ANY);
QueryProcessor.process("CREATE TABLE IF NOT EXISTS " + KEYSPACE + "." + COLUMN_FAMILY + " (id ascii PRIMARY KEY, name ascii, value ascii )",
ConsistencyLevel.ANY);
TimeUnit.MILLISECONDS.sleep(1000);
}
}