flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (FLINK-3311) Add a connector for streaming data into Cassandra
Date Tue, 05 Apr 2016 15:39:25 GMT

    [ https://issues.apache.org/jira/browse/FLINK-3311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15226480#comment-15226480
] 

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

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

    https://github.com/apache/flink/pull/1771#discussion_r58561402
  
    --- Diff: flink-streaming-connectors/flink-connector-cassandra/src/main/java/org/apache/flink/streaming/connectors/cassandra/CassandraTupleWriteAheadSink.java
---
    @@ -0,0 +1,136 @@
    +/**
    + * 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.BoundStatement;
    +import com.datastax.driver.core.Cluster;
    +import com.datastax.driver.core.PreparedStatement;
    +import com.datastax.driver.core.ResultSet;
    +import com.datastax.driver.core.ResultSetFuture;
    +import com.datastax.driver.core.Session;
    +import com.google.common.util.concurrent.FutureCallback;
    +import com.google.common.util.concurrent.Futures;
    +import org.apache.flink.api.common.typeutils.TypeSerializer;
    +import org.apache.flink.api.java.ClosureCleaner;
    +import org.apache.flink.api.java.tuple.Tuple;
    +import org.apache.flink.api.java.typeutils.runtime.TupleSerializer;
    +import org.apache.flink.streaming.runtime.operators.CheckpointCommitter;
    +import org.apache.flink.streaming.runtime.operators.GenericAtLeastOnceSink;
    +
    +import java.util.concurrent.atomic.AtomicInteger;
    +
    +/**
    + * Sink that emits its input elements into a Cassandra database. This sink stores incoming
records within a 
    + * {@link org.apache.flink.runtime.state.AbstractStateBackend}, and only commits them
to cassandra
    + * if a checkpoint is completed.
    + *
    + * @param <IN> Type of the elements emitted by this sink
    + */
    +public class CassandraTupleWriteAheadSink<IN extends Tuple> extends GenericAtLeastOnceSink<IN>
{
    +	protected transient Cluster cluster;
    +	protected transient Session session;
    +
    +	private final String insertQuery;
    +	private transient PreparedStatement preparedStatement;
    +
    +	private transient Throwable exception = null;
    +	private transient FutureCallback<ResultSet> callback;
    +
    +	private ClusterBuilder builder;
    +
    +	private int updatesSent = 0;
    +	private AtomicInteger updatesConfirmed = new AtomicInteger(0);
    +
    +	private transient Object[] fields;
    +
    +	protected CassandraTupleWriteAheadSink(String insertQuery, TypeSerializer<IN>
serializer, ClusterBuilder builder, String jobID, CheckpointCommitter committer) throws Exception
{
    +		super(committer, serializer, jobID);
    +		this.insertQuery = insertQuery;
    +		this.builder = builder;
    +		ClosureCleaner.clean(builder, true);
    +	}
    +
    +	public void open() throws Exception {
    +		super.open();
    +		if (!getRuntimeContext().isCheckpointingEnabled()) {
    +			throw new IllegalStateException("The write-ahead log requires checkpointing to be
enabled.");
    +		}
    +		this.callback = new FutureCallback<ResultSet>() {
    +			@Override
    +			public void onSuccess(ResultSet resultSet) {
    +				updatesConfirmed.incrementAndGet();
    +			}
    +
    +			@Override
    +			public void onFailure(Throwable throwable) {
    +				exception = throwable;
    --- End diff --
    
    Error logging here as well


> 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)



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message