[ 
https://issues.apache.org/jira/browse/FLINK-3311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15231954#comment-15231954
 ] 

ASF GitHub Bot commented on FLINK-3311:
---------------------------------------

Github user zentol commented on a diff in the pull request:

    https://github.com/apache/flink/pull/1771#discussion_r59004103
  
    --- Diff: 
flink-streaming-connectors/flink-connector-cassandra/src/main/java/org/apache/flink/streaming/connectors/cassandra/CassandraCommitter.java
 ---
    @@ -0,0 +1,126 @@
    +/**
    + * 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
    + * <p/>
    + * http://www.apache.org/licenses/LICENSE-2.0
    + * <p/>
    + * 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.
    + */
    +package org.apache.flink.streaming.connectors.cassandra;
    +
    +import com.datastax.driver.core.Cluster;
    +import com.datastax.driver.core.PreparedStatement;
    +import com.datastax.driver.core.Session;
    +import org.apache.flink.api.java.ClosureCleaner;
    +import org.apache.flink.streaming.runtime.operators.CheckpointCommitter;
    +
    +/**
    + * CheckpointCommitter that saves information about completed checkpoints 
within a separate table in a cassandra
    + * database.
    + * <p/>
    + * Entries are in the form |operator_id | subtask_id | 
last_completed_checkpoint|
    + */
    +public class CassandraCommitter extends CheckpointCommitter {
    +   private ClusterBuilder builder;
    +   private transient Cluster cluster;
    +   private transient Session session;
    +
    +   private static final String KEYSPACE = "flink_auxiliary";
    +   private String TABLE = "checkpoints_";
    +
    +   private transient PreparedStatement deleteStatement;
    +   private transient PreparedStatement updateStatement;
    +   private transient PreparedStatement selectStatement;
    +
    +   public CassandraCommitter(ClusterBuilder builder) {
    +           this.builder = builder;
    +           ClosureCleaner.clean(builder, true);
    +   }
    +
    +   /**
    +    * Internally used to set the job ID after instantiation.
    +    *
    +    * @param id
    +    * @throws Exception
    +    */
    +   public void setJobId(String id) throws Exception {
    +           super.setJobId(id);
    +           TABLE += id;
    +   }
    +
    +   /**
    +    * Generates the necessary tables to store information.
    +    *
    +    * @return
    +    * @throws Exception
    +    */
    +   @Override
    +   public void createResource() throws Exception {
    +           cluster = builder.getCluster();
    +           session = cluster.connect();
    +
    +           session.execute(String.format("CREATE KEYSPACE IF NOT EXISTS %s 
with replication={'class':'SimpleStrategy', 'replication_factor':3};", 
KEYSPACE));
    +           session.execute(String.format("CREATE TABLE IF NOT EXISTS %s.%s 
(sink_id text, sub_id int, checkpoint_id bigint, PRIMARY KEY (sink_id, 
sub_id));", KEYSPACE, TABLE));
    --- End diff --
    
    fixed


> Add a connector for streaming data into Cassandra
> -------------------------------------------------
>
>                 Key: FLINK-3311
>                 URL: https://issues.apache.org/jira/browse/FLINK-3311
>             Project: Flink
>          Issue Type: New Feature
>          Components: Streaming Connectors
>            Reporter: Robert Metzger
>            Assignee: Andrea Sella
>
> We had users in the past asking for a Flink+Cassandra integration.
> It seems that there is a well-developed java client for connecting into 
> Cassandra: https://github.com/datastax/java-driver (ASL 2.0)
> There are also tutorials out there on how to start a local cassandra instance 
> (for the tests): 
> http://prettyprint.me/prettyprint.me/2010/02/14/running-cassandra-as-an-embedded-service/index.html
> For the data types, I think we should support TupleX types, and map standard 
> java types to the respective cassandra types.
> In addition, it seems that there is a object mapper from datastax to store 
> POJOs in Cassandra (there are annotations for defining the primary key and 
> types)



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