Spark中的Spark Streaming可以用于实时流项目的开发,实时流项目的数据源除了可以来源于日志、文件、网络端口等,常常也有这种需求,那就是实时分析处理MySQL中的增量数据。
面对这种需求当然我们可以通过JDBC的方式定时查询Mysql,然后再对查询到的数据进行处理也能得到预期的结果,但是Mysql往往还有其他业务也在使用,这些业务往往比较重要,通过JDBC方式频繁查询会对Mysql造成大量无形的压力,甚至可能会影响正常业务的使用,在基本不影响其他Mysql正常使用的情况下完成对增量数据的处理,那就需要Canal了。
Canal [kə'næl] 是阿里巴巴开源的纯java开发的基于数据库binlog的增量订阅&消费组件。Canal的原理是模拟为一个Mysql slave的交互协议,伪装自己为MySQL slave,向Mysql Master发送dump协议,然后Mysql master接收到这个请求后将binary log推送给slave(也就是Canal),Canal解析binary log对象。
1.1 Canal 安装
Canal的server mode在1.1.x版本支持的有TPC、Kafka、RocketMQ。本次安装的canal版本为1.1.2,Canal版本最后在1.1.1之后。server端采用MQ模式,MQ选用Kafka。服务器系统为Centos7,其他环境为:jdk8、Scala 2.11、Mysql、Zookeeper、Kafka。
1.1.1 准备
安装Canal之前我们先把如下安装好
Mysql
a.如果没有Mysql: 详细的安装过程可参考我的另一篇博客[Centos7环境下离线安装mysql 5.7 mysql 8.0]
b.开启Mysql的binlog。修改/etc/my.cnf,在[mysqld]下添加如下配置,改完之后重启 Mysql/etc/init.d/mysql restart
[mysqld]#添加这一行就oklog-bin=mysql-bin#选择row模式binlog-format=ROW#配置mysql replaction需要定义,不能和canal的slaveId重复server_id=1
c. 创建一个Mysql用户并赋予相应权限,用于Canal使用
mysql> CREATE USER canal IDENTIFIED BY 'canal';mysql> GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%';mysql> GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%' ;mysql> FLUSH PRIVILEGES;
Zookeeper
因为安装Kafka时需要Zookeeper,例如ZK安装后地址为:cdh3:2181,cdh4:2181,cdh5:2181
Kafka
例如安装后的地址为:node1:9092,node2:9092,node3:9092 安装后创建一个Topic,例如创建一个 example
kafka-topics.sh --create --zookeeper cdh3:2181,cdh4:2181,cdh5:2181 --partitions 2 --replication-factor 1 --topic example
1.1.2 安装Canal
1.下载Canal
访问Canal的Release页 canal v1.1.2 wget https://github.com/alibaba/canal/releases/download/canal-1.1.2/canal.deployer-1.1.2.tar.gz
2.解压
注意 这里一定要先创建出一个目录,直接解压会覆盖文件 mkdir -p usr/local/canal mv canal.deployer-1.1.2.tar.gz usr/local/canal/ tar -zxvf canal.deployer-1.1.2.tar.gz
3.修改instance 配置文件
vim $CANAL_HOME/conf/example/instance.properties,修改如下项,其他默认即可
## mysql serverId , v1.0.26+ will autoGen , 不要和server_id重复canal.instance.mysql.slaveId=3# position info。Mysql的urlcanal.instance.master.address=node1:3306# table meta tsdb infocanal.instance.tsdb.enable=false# 这里配置前面在Mysql分配的用户名和密码canal.instance.dbUsername=canalcanal.instance.dbPassword=canalcanal.instance.connectionCharset=UTF-8# 配置需要检测的库名,可以不配置,这里只检测canal_test库canal.instance.defaultDatabaseName=canal_test# enable druid Decrypt database passwordcanal.instance.enableDruid=false# 配置过滤的正则表达式,监测canal_test库下的所有表canal.instance.filter.regex=canal_test\\..*# 配置MQ## 配置上在Kafka创建的那个Topic名字canal.mq.topic=example## 配置分区编号为1canal.mq.partition=1
4.修改canal.properties配置文件
vim $CANAL_HOME/conf/canal.properties,修改如下项,其他默认即可
# 这个是如果开启的是tcp模式,会占用这个11111端口,canal客户端通过这个端口获取数据canal.port = 11111# 可以配置为:tcp, kafka, RocketMQ,这里配置为kafkacanal.serverMode = kafka# 这里将这个注释掉,否则启动会有一个警告#canal.instance.tsdb.spring.xml = classpath:spring/tsdb/h2-tsdb.xml########################################################### MQ ###############################################################canal.mq.servers = node1:9092,node2:9092,node3:9092canal.mq.retries = 0canal.mq.batchSize = 16384canal.mq.maxRequestSize = 1048576canal.mq.lingerMs = 1canal.mq.bufferMemory = 33554432Canal的batch size, 默认50K, 由于kafka最大消息体限制请勿超过1M(900K以下)canal.mq.canalBatchSize = 50# Canal get数据的超时时间, 单位: 毫秒, 空为不限超时canal.mq.canalGetTimeout = 100# 是否为flat json格式对象canal.mq.flatMessage = truecanal.mq.compressionType = nonecanal.mq.acks = all# kafka消息投递是否使用事务#canal.mq.transaction = false
5.启动Canal
$CANAL_HOME/bin/startup.sh
6.验证
查看日志:启动后会在logs下生成两个日志文件:logs/canal/canal.log、logs/example/example.log,查看这两个日志,保证没有报错日志。
如果是在虚拟机安装,最好给2个核数以上。
确保登陆的系统的hostname可以ping通。
在Mysql数据库中进行增删改查的操作,然后查看Kafka的topic为example的数据:
kafka-console-consumer.sh --bootstrap-server node1:9092,node2:9092,node3:9092 --from-beginning --topic example
7.关闭Canal
不用的时候一定要通过这个命令关闭,如果是用kill或者关机,当再次启动依然会提示要先执行stop.sh脚本后才能再启动。
$CANAL_HOME/bin/stop.sh
1.2 Canal客户端代码
如果我们不使用Kafka作为Canal客户端,我们也可以用代码编写自己的Canal客户端,然后在代码中指定我们的数据去向。此时只需要将canal.properties配置文件中的canal.serverMode值改为tcp。编写我们的客户端代码。在Maven项目的pom中引入:
<dependency><groupId>com.alibaba.otter</groupId><artifactId>canal.client</artifactId><version>1.1.2</version></dependency>
编写代码:
/*** Canal客户端。* 注意:canal服务端只会连接一个客户端,当启用多个客户端时,其他客户端是就无法获取到数据。所以启动一个实例即可* @see <a href="https://github.com/alibaba/canal/wiki/ClientExample">官方文档:ClientSample代码</a>*/public class SimpleCanalClientExample {public static void main(String args[]) {*** 创建链接* SocketAddress: 如果提交到canal服务端所在的服务器上运行这里可以改为 new InetSocketAddress(AddressUtils.getHostIp(), 11111)* destination 通服务端canal.properties中的canal.destinations = example配置对应* username:* password:*/CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("node1", 11111),"example", "", "");int batchSize = 1000;int emptyCount = 0;try {connector.connect();connector.subscribe(".*\\..*");connector.rollback();int totalEmptyCount = 120;while (emptyCount < totalEmptyCount) {Message message = connector.getWithoutAck(batchSize); 获取指定数量的数据long batchId = message.getId();int size = message.getEntries().size();if (batchId == -1 || size == 0) {emptyCount++;System.out.println("empty count : " + emptyCount);try {Thread.sleep(1000);} catch (InterruptedException e) {}} else {emptyCount = 0;System.out.printf("message[batchId=%s,size=%s] \n", batchId, size);printEntry(message.getEntries());}connector.ack(batchId); 提交确认connector.rollback(batchId); 处理失败, 回滚数据}System.out.println("empty too many times, exit");} finally {connector.disconnect();}}private static void printEntry(List<Entry> entrys) {for (Entry entry : entrys) {if (entry.getEntryType() == EntryType.TRANSACTIONBEGIN || entry.getEntryType() == EntryType.TRANSACTIONEND) {continue;}RowChange rowChage = null;try {rowChage = RowChange.parseFrom(entry.getStoreValue());} catch (Exception e) {throw new RuntimeException("ERROR ## parser of eromanga-event has an error , data:" + entry.toString(),e);}EventType eventType = rowChage.getEventType();System.out.println(String.format("================> binlog[%s:%s] , name[%s,%s] , eventType : %s",entry.getHeader().getLogfileName(), entry.getHeader().getLogfileOffset(),entry.getHeader().getSchemaName(), entry.getHeader().getTableName(),eventType));*** 如果只对某些库的数据操作,可以加如下判断:* if("库名".equals(entry.getHeader().getSchemaName())){* TODO option* }** 如果只对某些表的数据变动操作,可以加如下判断:* if("表名".equals(entry.getHeader().getTableName())){* todo option* }**/for (RowData rowData : rowChage.getRowDatasList()) {if (eventType == EventType.DELETE) {printColumn(rowData.getBeforeColumnsList());} else if (eventType == EventType.INSERT) {printColumn(rowData.getAfterColumnsList());} else {System.out.println("-------> before");printColumn(rowData.getBeforeColumnsList());System.out.println("-------> after");printColumn(rowData.getAfterColumnsList());}}}}private static void printColumn(List<Column> columns) {for (Column column : columns) {System.out.println(column.getName() + " : " + column.getValue() + " update=" + column.getUpdated());}}}
本地运行上述代码,我们修改Mysql数据中的数据,可在控制台中看到数据的改变:
empty count : 20empty count : 21empty count : 22================> binlog[mysql-bin.000009:1510] , name[canal_test,customer] , eventType : INSERTid : 4 update=truename : spark update=trueempty count : 1empty count : 2empty count : 3
通过上一步我们已经能够获取到 canal_test 库的变化数据,并且已经可将将变化的数据实时推送到Kafka中,Kafka中接收到的数据是一条Json格式的数据,我们需要对 INSERT 和 UPDATE 类型的数据处理,并且只处理状态为1的数据,然后需要计算 mor_rate 的变化,并判断 mor_rate 的风险等级,0-75%为G1等级,75%-80%为R1等级,80%-100%为R2等级。最后将处理的结果保存到DB,可以保存到Redis、Mysql、MongoDB,或者推送到Kafka都可以。这里是将结果数据保存到了Mysql。
2.1 在Mysql中创建如下两张表
-- 在canal_test库下创建表CREATE TABLE `policy_cred` (p_num varchar(22) NOT NULL,policy_status varchar(2) DEFAULT NULL COMMENT '状态:0、1',mor_rate decimal(20,4) DEFAULT NULL,load_time datetime DEFAULT NULL,PRIMARY KEY (`p_num`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;-- 在real_result库下创建表CREATE TABLE `real_risk` (p_num varchar(22) NOT NULL,risk_rank varchar(8) DEFAULT NULL COMMENT '等级:G1、R1、R2',mor_rate decimal(20,4) ,ch_mor_rate decimal(20,4),load_time datetime DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8;
2.2 Spark代码开发
2.2.1 在resources下new一个项目的配置文件my.properties
## spark# spark://cdh3:7077spark.master=local[2]spark.app.name=m_policy_credit_appspark.streaming.durations.sec=10spark.checkout.dir=src/main/resources/checkpoint## Kafkabootstrap.servers=node1:9092,node2:9092,node3:9092group.id=m_policy_credit_gid# latest, earliest, noneauto.offset.reset=latestenable.auto.commit=falsekafka.topic.name=example## Mysqlmysql.jdbc.driver=com.mysql.jdbc.Drivermysql.db.url=jdbc:mysql://node1:3306/real_resultmysql.user=rootmysql.password=123456mysql.connection.pool.size=102.2.2 在pom.xml文件中引入如下依赖
<properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><maven.compiler.source>1.8</maven.compiler.source><maven.compiler.target>1.8</maven.compiler.target><scala.version>2.11.8</scala.version><spark.version>2.4.0</spark.version><canal.client.version>1.1.2</canal.client.version></properties><dependencies><dependency><groupId>com.alibaba.otter</groupId><artifactId>canal.client</artifactId><version>${canal.client.version}</version><exclusions><exclusion><groupId>io.netty</groupId><artifactId>netty-all</artifactId></exclusion></exclusions></dependency><dependency><groupId>org.scala-lang</groupId><artifactId>scala-library</artifactId><version>${scala.version}</version></dependency><!-- Spark --><!-- spark-core --><dependency><groupId>org.apache.spark</groupId><artifactId>spark-core_2.11</artifactId><version>${spark.version}</version></dependency><!-- spark-streaming --><dependency><groupId>org.apache.spark</groupId><artifactId>spark-streaming_2.11</artifactId><version>${spark.version}</version></dependency><!-- spark-streaming-kafka --><dependency><groupId>org.apache.spark</groupId><artifactId>spark-streaming-kafka-0-10_2.11</artifactId><version>${spark.version}</version></dependency><!-- spark-sql --><dependency><groupId>org.apache.spark</groupId><artifactId>spark-sql_2.11</artifactId><version>${spark.version}</version></dependency><dependency><groupId>org.apache.hadoop</groupId><artifactId>hadoop-client</artifactId><version>2.6.1</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.51</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency></dependencies>
2.2.3 在scala源码目录下的包下编写配置文件的工具类
package yore.sparkimport java.util.Properties/*** Properties的工具类** Created by yore on 2018-06-29 14:05*/object PropertiesUtil {private val properties: Properties = new Properties**** 获取配置文件Properties对象** @author yore* @return java.util.Properties*/def getProperties() :Properties = {if(properties.isEmpty){读取源码中resource文件夹下的my.properties配置文件val reader = getClass.getResourceAsStream("/my.properties")properties.load(reader)}properties}**** 获取配置文件中key对应的字符串值** @author yore* @return java.util.Properties*/def getPropString(key : String) : String = {getProperties().getProperty(key)}**** 获取配置文件中key对应的整数值** @author yore*/def getPropInt(key : String) : Int = {getProperties().getProperty(key).toInt}**** 获取配置文件中key对应的布尔值** @return java.util.Properties*/def getPropBoolean(key : String) : Boolean = {getProperties().getProperty(key).toBoolean}}
2.2.4 在scala源码目录下的包下编写数据库操作的工具类
package yore.sparkimport java.sql.{Connection, DriverManager, PreparedStatement, ResultSet, SQLException}import java.util.concurrent.LinkedBlockingDequeimport scala.collection.mutable.ListBuffer/**** Created by yore on 2018/11/14 20:34*/object JDBCWrapper {private var jdbcInstance : JDBCWrapper = _def getInstance() : JDBCWrapper = {synchronized{if(jdbcInstance == null){jdbcInstance = new JDBCWrapper()}}jdbcInstance}}class JDBCWrapper {连接池的大小val POOL_SIZE : Int = PropertiesUtil.getPropInt("mysql.connection.pool.size")val dbConnectionPool = new LinkedBlockingDeque[Connection](POOL_SIZE)tryClass.forName(PropertiesUtil.getPropString("mysql.jdbc.driver"))catch {case e: ClassNotFoundException => e.printStackTrace()}for(i <- 0 until POOL_SIZE){try{val conn = DriverManager.getConnection(PropertiesUtil.getPropString("mysql.db.url"),PropertiesUtil.getPropString("mysql.user"),PropertiesUtil.getPropString("mysql.password"));dbConnectionPool.put(conn)}catch {case e : Exception => e.printStackTrace()}}def getConnection(): Connection = synchronized{while (0 == dbConnectionPool.size()){try{Thread.sleep(20)}catch {case e : InterruptedException => e.printStackTrace()}}dbConnectionPool.poll()}*** 批量插入** @param sqlText sql语句字符* @param paramsList 参数列表* @return Array[Int]*/def doBatch(sqlText: String, paramsList: ListBuffer[ParamsList]): Array[Int] = {val conn: Connection = getConnection()var ps: PreparedStatement = nullvar result: Array[Int] = nulltry{conn.setAutoCommit(false)ps = conn.prepareStatement(sqlText)for (paramters <- paramsList) {paramters.params_Type match {case "real_risk" => {println("$$$\treal_risk\t" + paramsList)p_num, risk_rank, mor_rate, ch_mor_rate, load_timeps.setObject(1, paramters.p_num)ps.setObject(2, paramters.risk_rank)ps.setObject(3, paramters.mor_rate)ps.setObject(4, paramters.ch_mor_rate)ps.setObject(5, paramters.load_time)}}ps.addBatch()}result = ps.executeBatchconn.commit()} catch {case e: Exception => e.printStackTrace()} finally {if (ps != null) try {ps.close()} catch {case e: SQLException => e.printStackTrace()}if (conn != null) try {dbConnectionPool.put(conn)} catch {case e: InterruptedException => e.printStackTrace()}}result}}
2.2.5 在scala源码目录下的包下编写Spark程序代码
package yore.sparkimport com.alibaba.fastjson.{JSON, JSONArray, JSONObject}import org.apache.kafka.common.serialization.StringDeserializerimport org.apache.log4j.{Level, Logger}import org.apache.spark.SparkConfimport org.apache.spark.streaming.kafka010.ConsumerStrategies.Subscribeimport org.apache.spark.streaming.kafka010.KafkaUtilsimport org.apache.spark.streaming.kafka010.LocationStrategies.PreferConsistentimport org.apache.spark.streaming.{Seconds, StreamingContext}import scala.collection.mutable.ListBuffer/**** Created by yore on 2019/3/16 15:11*/object M_PolicyCreditApp {def main(args: Array[String]): Unit = {设置日志的输出级别Logger.getLogger("org").setLevel(Level.ERROR)val conf = new SparkConf().setMaster(PropertiesUtil.getPropString("spark.master")).setAppName(PropertiesUtil.getPropString("spark.app.name"))// !!必须设置,否则Kafka数据会报无法序列化的错误.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer")//如果环境中已经配置HADOOP_HOME则可以不用设置hadoop.home.dirSystem.setProperty("hadoop.home.dir", "/Users/yoreyuan/soft/hadoop-2.9.2")val ssc = new StreamingContext(conf, Seconds(PropertiesUtil.getPropInt("spark.streaming.durations.sec").toLong))ssc.sparkContext.setLogLevel("ERROR")ssc.checkpoint(PropertiesUtil.getPropString("spark.checkout.dir"))val kafkaParams = Map[String, Object]("bootstrap.servers" -> PropertiesUtil.getPropString("bootstrap.servers"),"key.deserializer" -> classOf[StringDeserializer],"value.deserializer" -> classOf[StringDeserializer],"group.id" -> PropertiesUtil.getPropString("group.id"),"auto.offset.reset" -> PropertiesUtil.getPropString("auto.offset.reset"),"enable.auto.commit" -> (PropertiesUtil.getPropBoolean("enable.auto.commit"): java.lang.Boolean))val topics = Array(PropertiesUtil.getPropString("kafka.topic.name"))val kafkaStreaming = KafkaUtils.createDirectStream[String, String](ssc,PreferConsistent,Subscribe[String, String](topics, kafkaParams))kafkaStreaming.map[JSONObject](line => { // str转成JSONObjectprintln("$$$\t" + line.value())JSON.parseObject(line.value)}).filter(jsonObj =>{ // 过滤掉非 INSERT和UPDATE的数据if(null == jsonObj || !"canal_test".equals(jsonObj.getString("database")) ){false}else{val chType = jsonObj.getString("type")if("INSERT".equals(chType) || "UPDATE".equals(chType)){true}else{false}}}).flatMap[(JSONObject, JSONObject)](jsonObj => { // 将改变前和改变后的数据转成Tuplevar oldJsonArr: JSONArray = jsonObj.getJSONArray("old")val dataJsonArr: JSONArray = jsonObj.getJSONArray("data")if("INSERT".equals(jsonObj.getString("type"))){oldJsonArr = new JSONArray()val oldJsonObj2 = new JSONObject()oldJsonObj2.put("mor_rate", "0")oldJsonArr.add(oldJsonObj2)}val result = ListBuffer[(JSONObject, JSONObject)]()for(i <- 0 until oldJsonArr.size ) {val jsonTuple = (oldJsonArr.getJSONObject(i), dataJsonArr.getJSONObject(i))result += jsonTuple}result}).filter(t => { // 过滤状态不为1的数据,和mor_rate没有改变的数据val policyStatus = t._2.getString("policy_status")if(null != policyStatus && "1".equals(policyStatus) && null!= t._1.getString("mor_rate")){true}else{false}}).map(t => {val p_num = t._2.getString("p_num")val nowMorRate = t._2.getString("mor_rate").toDoubleval chMorRate = nowMorRate - t._1.getDouble("mor_rate")val riskRank = gainRiskRank(nowMorRate)// p_num, risk_rank, mor_rate, ch_mor_rate, load_time(p_num, riskRank, nowMorRate, chMorRate, new java.util.Date)}).foreachRDD(rdd => {rdd.foreachPartition(p => {val paramsList = ListBuffer[ParamsList]()val jdbcWrapper = JDBCWrapper.getInstance()while (p.hasNext){val record = p.next()val paramsListTmp = new ParamsListparamsListTmp.p_num = record._1paramsListTmp.risk_rank = record._2paramsListTmp.mor_rate = record._3paramsListTmp.ch_mor_rate = record._4paramsListTmp.load_time = record._5paramsListTmp.params_Type = "real_risk"paramsList += paramsListTmp}/*** VALUES(p_num, risk_rank, mor_rate, ch_mor_rate, load_time)*/val insertNum = jdbcWrapper.doBatch("INSERT INTO real_risk VALUES(?,?,?,?,?)", paramsList)println("INSERT TABLE real_risk: " + insertNum.mkString(", "))})})ssc.start()ssc.awaitTermination()}def gainRiskRank(rate: Double): String = {var result = ""if(rate>=0.75 && rate<0.8){result = "R1"}else if(rate >=0.80 && rate<=1){result = "R2"}else{result = "G1"}result}}/*** 结果表对应的参数实体对象*/class ParamsList extends Serializable{var p_num: String = _var risk_rank: String = _var mor_rate: Double = _var ch_mor_rate: Double = _var load_time:java.util.Date = _var params_Type : String = _override def toString = s"ParamsList($p_num, $risk_rank, $mor_rate, $ch_mor_rate, $load_time)"}3.测试
启动ZK、Kafka、Canal。在canal_test库下的policy_cred表中插入或者修改数据,然后查看real_result库下的real_risk表中结果。
更新一条数据时Kafka接收到的json数据如下(这是canal投送到Kafka中的数据格式,包含原始数据、修改后的数据、库名、表名等信息):
{"data": [{"p_num": "1","policy_status": "1","mor_rate": "0.8800","load_time": "2019-03-17 12:54:57"}],"database": "canal_test","es": 1552698141000,"id": 10,"isDdl": false,"mysqlType": {"p_num": "varchar(22)","policy_status": "varchar(2)","mor_rate": "decimal(20,4)","load_time": "datetime"},"old": [{"mor_rate": "0.5500"}],"sql": "","sqlType": {"p_num": 12,"policy_status": 12,"mor_rate": 3,"load_time": 93},"table": "policy_cred","ts": 1552698141621,"type": "UPDATE"}
查看Mysql中的结果表:

在开发Spark代码是有时项目可能会引入大量的依赖包,依赖包之间可能就会发生冲突,比如发生如下错误:
Exception in thread "main" java.lang.NoSuchMethodError: io.netty.buffer.PooledByteBufAllocator.<init>(ZIIIIIIIZ)Vat org.apache.spark.network.util.NettyUtils.createPooledByteBufAllocator(NettyUtils.java:120)at org.apache.spark.network.client.TransportClientFactory.<init>(TransportClientFactory.java:106)at org.apache.spark.network.TransportContext.createClientFactory(TransportContext.java:99)at org.apache.spark.rpc.netty.NettyRpcEnv.<init>(NettyRpcEnv.scala:71)at org.apache.spark.rpc.netty.NettyRpcEnvFactory.create(NettyRpcEnv.scala:461)at org.apache.spark.rpc.RpcEnv$.create(RpcEnv.scala:57)at org.apache.spark.SparkEnv$.create(SparkEnv.scala:249)at org.apache.spark.SparkEnv$.createDriverEnv(SparkEnv.scala:175)at org.apache.spark.SparkContext.createSparkEnv(SparkContext.scala:257)at org.apache.spark.SparkContext.<init>(SparkContext.scala:424)at org.apache.spark.streaming.StreamingContext$.createNewSparkContext(StreamingContext.scala:838)at org.apache.spark.streaming.StreamingContext.<init>(StreamingContext.scala:85)at yore.spark.M_PolicyCreditApp$.main(M_PolicyCreditApp.scala:33)at yore.spark.M_PolicyCreditApp.main(M_PolicyCreditApp.scala)
我们可以在项目的根目录下的命令窗口中输人:mvn dependency:tree -Dverbose> dependency.log
然后可以在项目根目录下生产一个dependency.log文件,查看这个文件,在文件中搜索 io.netty 关键字,找到其所在的依赖包:

然就在canal.client将io.netty排除掉:
<dependency><groupId>com.alibaba.otter</groupId><artifactId>canal.client</artifactId><version>${canal.client.version}</version><exclusions><exclusion><groupId>io.netty</groupId><artifactId>netty-all</artifactId></exclusion></exclusions></dependency>作者:YoreYuan
来源:https://blog.csdn.net/github_39577257/article/details/88661052
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