探讨：根据“Hadoop3.2.4+Hive3.1.2+sqoop1.4.7安装部署“一文后hive insert数据存在的问题研究

1.根据“Hadoop3.2.4+Hive3.1.2+sqoop1.4.7安装部署”一文中提到的mapred-site.xml配置，使用hive时，insert插入数据会报错。若将node02和03中mapred-site修改如下，则正常运行。

<configuration>
   <property>
        <name>yarn.resourcemanager.ha.enabled</name>
        <value>true</value>
    </property>
    <property>
        <name>yarn.resourcemanager.cluster-id</name>
        <value>yrc</value>
    </property>
    <property>
        <name>yarn.resourcemanager.ha.rm-ids</name>
        <value>rm1,rm2</value>
    </property>
    <property>
        <name>yarn.resourcemanager.hostname.rm1</name>
        <value>node01</value>
    </property>
    <property>
        <name>yarn.resourcemanager.hostname.rm2</name>
        <value>node02</value>
    </property>
    <property>
        <name>yarn.resourcemanager.zk-address</name>
        <value>node01:2181,node02:2181,nod03:2181</value>
    </property>
    <property>
        <name>yarn.resourcemanager.recovery.enabled</name>
        <value>true</value>
    </property>
    <property>
        <name>yarn.resourcemanager.ha.automatic-failover.enabled</name>
        <value>true</value>
    </property>
    <property>
        <name>yarn.resourcemanager.store.class</name>
        <value>org.apache.hadoop.yarn.server.resourcemanager.recovery.ZKRMStateStore</value>
    </property>
    <property>
        <name>yarn.nodemanager.aux-services</name>
        <value>mapreduce_shuffle</value>
    </property>
    <property>
        <name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
        <value>org.apache.hadoop.mapred.ShuffleHandler</value>
    </property>     
    <property>
        <name>yarn.resourcemanager.webapp.address.rm1</name>
        <value>node01:8088</value>
    </property>
    <property>
        <name>yarn.resourcemanager.webapp.address.rm2</name>
        <value>node02:8088</value>
    </property>
    <property>
        <name>yarn.nodemanager.resource.memory-mb</name>
        <value>4096</value>
    </property>
</configuration>

不难看出，这样的mapred-site配置与yarn-site一样，为什么？

2.若三台节点mapred-site配置如下 ：

<configuration>
    <property>
        <name>mapreduce.framework.name</name>
        <value>yarn</value>
    </property>
    <property>
        <name>yarn.app.mapreduce.am.env</name>
        <value>HADOOP_MAPRED_HOME=/export/servers/hadoop-3.2.4</value>
    </property>
    <property>
        <name>mapreduce.map.env</name>
        <value>HADOOP_MAPRED_HOME=/export/servers/hadoop-3.2.4</value>
    </property>
    <property>
        <name>mapreduce.reduce.env</name>
        <value>HADOOP_MAPRED_HOME=/export/servers/hadoop-3.2.4</value>
    </property>
</configuration>

则hive配置如下，insert插入数据正常不报错。

（1）node02节点上hive-site.xml如下：

<configuration>
    <property>
        <name>hive.metastore.warehouse.dir</name>
        <value>/user/hive_local/warehouse</value>
    </property>
    <property>
        <name>javax.jdo.option.ConnectionDriverName</name>
        <value>com.mysql.jdbc.Driver</value>
    </property>
    <property>
        <name>javax.jdo.option.ConnectionURL</name>
        <value>jdbc:mysql://localhost:3306/hive?createDatabaseIfNotExist=true&amp;useSSL=false</value>
    </property>
    <property>
        <name>javax.jdo.option.ConnectionUserName</name>
        <value>root</value>
    </property>
    <property>
        <name>javax.jdo.option.ConnectionPassword</name>
        <value>Itcast@2022</value>
    </property>
</configuration>

（2）node03节点上hive-site.xml如下：

<configuration>
    <property>
        <name>hive.metastore.warehouse.dir</name>
        <value>/user/hive_local/warehouse</value>
    </property>
    <property>
        <name>hive.metastore.local</name>
        <value>false</value>
    </property>
    <property>
        <name>hive.metastore.uris</name>
        <value>thrift://node02:9083</value>
    </property>
</configuration>