我们知道，Flume可以和许多的系统进行整合，包括了Hadoop、Spark、Kafka、Hbase等等；当然，强悍的Flume也是可以和Mysql进行整合，将分析好的日志存储到Mysql（当然，你也可以存放到pg、oracle等等关系型数据库）。

如果想及时了解Spark、Hadoop或者Hbase相关的文章，欢迎关注微信公共帐号：iteblog_hadoop

其实，Flume和Mysql进行整合开发的过程也是相当的简单的。代码如下：

package com.iteblog.flume;

/**
 * User: 过往记忆
 * Date: 14-9-4
 * Time: 下午13:16
 * bolg: 
 * 本文地址：/archives/1109
 * 过往记忆博客，专注于hadoop、hive、spark、shark、flume的技术博客，大量的干货
 * 过往记忆博客微信公共帐号：iteblog_hadoop
 */

import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import com.google.common.collect.Lists;
import org.apache.flume.*;
import org.apache.flume.conf.Configurable;
import org.apache.flume.sink.AbstractSink;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.List;

public class MysqlSink extends AbstractSink implements Configurable {

    private Logger LOG = LoggerFactory.getLogger(MysqlSink.class);
    private String hostname;
    private String port;
    private String databaseName;
    private String tableName;
    private String user;
    private String password;
    private PreparedStatement preparedStatement;
    private Connection conn;
    private int batchSize;

    public MysqlSink() {
        LOG.info("MysqlSink start...");
    }

    @Override
    public void configure(Context context) {
        hostname = context.getString("hostname");
        Preconditions.checkNotNull(hostname, "hostname must be set!!");
        port = context.getString("port");
        Preconditions.checkNotNull(port, "port must be set!!");
        databaseName = context.getString("databaseName");
        Preconditions.checkNotNull(databaseName, "databaseName must be set!!");
        tableName = context.getString("tableName");
        Preconditions.checkNotNull(tableName, "tableName must be set!!");
        user = context.getString("user");
        Preconditions.checkNotNull(user, "user must be set!!");
        password = context.getString("password");
        Preconditions.checkNotNull(password, "password must be set!!");
        batchSize = context.getInteger("batchSize", 100);
        Preconditions.checkNotNull(batchSize > 0, "batchSize must be a positive number!!");
    }

    @Override
    public void start() {
        super.start();
        try {
            //调用Class.forName()方法加载驱动程序
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

        String url = "jdbc:mysql://" + hostname + ":" + port + "/" + databaseName; 
        //调用DriverManager对象的getConnection()方法，获得一个Connection对象

        try {
            conn = DriverManager.getConnection(url, user, password);
            conn.setAutoCommit(false);
            //创建一个Statement对象
            preparedStatement = conn.prepareStatement("insert into " + tableName + 
                                               " (content) values (?)");

        } catch (SQLException e) {
            e.printStackTrace();
            System.exit(1);
        }

    }

    @Override
    public void stop() {
        super.stop();
        if (preparedStatement != null) {
            try {
                preparedStatement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public Status process() throws EventDeliveryException {
        Status result = Status.READY;
        Channel channel = getChannel();
        Transaction transaction = channel.getTransaction();
        Event event;
        String content;

        List<String> actions = Lists.newArrayList();
        transaction.begin();
        try {
            for (int i = 0; i < batchSize; i++) {
                event = channel.take();
                if (event != null) {
                    content = new String(event.getBody());
                    actions.add(content);
                } else {
                    result = Status.BACKOFF;
                    break;
                }
            }

            if (actions.size() > 0) {
                preparedStatement.clearBatch();
                for (String temp : actions) {
                    preparedStatement.setString(1, temp);
                    preparedStatement.addBatch();
                }
                preparedStatement.executeBatch();

                conn.commit();
            }
            transaction.commit();
        } catch (Throwable e) {
            try {
                transaction.rollback();
            } catch (Exception e2) {
                LOG.error("Exception in rollback. Rollback might not have been" +
                        "successful.", e2);
            }
            LOG.error("Failed to commit transaction." +
                    "Transaction rolled back.", e);
            Throwables.propagate(e);
        } finally {
            transaction.close();
        }

        return result;
    }
}

pom文件中的依赖：

<dependencies>
        <dependency>
            <groupId>org.apache.flume</groupId>
            <artifactId>flume-ng-core</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.flume</groupId>
            <artifactId>flume-ng-configuration</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.25</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <scope>test</scope>
        </dependency>
</dependencies>

运行程序时，先在Mysql中创建一个表

mysql> create table mysqltest(
    -> id int(11) NOT NULL AUTO_INCREMENT,
    -> content varchar(50000) NOT NULL,
    -> PRIMARY KEY (`id`)
    -> ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;  
Query OK, 0 rows affected, 1 warning (0.05 sec)

然后在flume中创建以下配置

# User: 过往记忆
# Date: 14-9-4
# Time: 下午13:16
# bolg: 
# 本文地址：/archives/1109
# 过往记忆博客，专注于hadoop、hive、spark、shark、flume的技术博客，大量的干货
# 过往记忆博客微信公共帐号：iteblog_hadoop

agent.sinks.mysqlSink.type = com.iteblog.flume.MysqlSink
agent.sinks.mysqlSink.hostname=localhost
agent.sinks.mysqlSink.port=3306
agent.sinks.mysqlSink.databaseName=ngmonitor
agent.sinks.mysqlSink.tableName=mysqltest
agent.sinks.mysqlSink.user=root
agent.sinks.mysqlSink.password=123456
agent.sinks.mysqlSink.channel = c1

用下面的命令就可以启动：

bin/flume-ng agent -c conf/ -f conf/mysql_test.conf  -n agent

再看下Mysql中的情况：

mysql> select count(*) from mysqltest;
+----------+
| count(*) |
+----------+
|    98300 | 
+----------+

　　好了，开发完成！上面的程序还可以改进，可以用Mybatis进行编写，将Flume处理逻辑和业务的处理逻辑分离开，这样下次只需要处理业务，Flume那块都不需要我们去考虑了，大大降低了编程的难度。具体怎么开发我就不说了，有需要请线下讨论。