数据仓库 Hive（内含大数据镜像下载）

文章目录

- 1. 特点
- 2. Hive 体系架构
- 3. 安装 Hive
- - 3.1 安装 MySQL
  - 3.2 安装 Hive
  - 3.3 配置 Hive
- 4. 实践
- - 4.1 函数
  - 4.2 Hive Shell

安装没成功：直接用现成的镜像
大数据Linux实验环境虚拟机镜像文件 http://dblab.xmu.edu.cn/blog/1645-2/
cloudera-quickstart-vm-集成了大数据平台的虚拟机镜像

1. 特点

查询语言与 SQL 接近
并行执行
使用 HDFS 存储
支持多种数据格式
不支持数据更新
不支持索引
执行延迟高（不适合在线数据查询）
可扩展性高
数据规模大

2. Hive 体系架构

3. 安装 Hive

先安装 hadoop：hadoop 多机全分布式安装步骤（虚拟机1master+2slave）

3.1 安装 MySQL

在 master 上安装

yum localinstall https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
或者
wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
rpm -ivh mysql57-community-release-el7-11.noarch.rpm

查看可选版本

yum repolist all | grep mysql

yum install -y mysql-community-server

启动 MySQL

[root@master opt]# systemctl start mysqld
[root@master opt]# systemctl status mysqld
● mysqld.service - MySQL ServerLoaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)Active: active (running) since 一 2021-03-29 06:25:16 CST; 22h agoDocs: man:mysqld(8)http://dev.mysql.com/doc/refman/en/using-systemd.htmlProcess: 49287 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)Process: 49266 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)Main PID: 49291 (mysqld)Tasks: 28CGroup: /system.slice/mysqld.service└─49291 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/my...3月 29 06:25:13 master systemd[1]: Starting MySQL Server...
3月 29 06:25:16 master systemd[1]: Started MySQL Server.

测试 MySQL

mysql -u root -p

enter 空密码，报错

报错参考https://blog.csdn.net/vv19910825/article/details/82979563
（操作：vim /etc/my.cnf, 添加 skip-grant-tables跳过密码 systemctl restart mysqld，下面改过密码了，在删除）

修改密码，注意满足密码强度

mysql> flush privileges; -> alter user 'root'@'localhost' identified by '!@#123qwe';-> flush privileges;

vim /etc/my.cnf, 删除 skip-grant-tables
systemctl restart mysqld

mysql -u root -p 使用新密码，再次登录

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

在 MySQL 中创建 Hive 所需用户和数据库，并授权

mysql> create user 'dnn' identified by '!@#123Qwe';
mysql> create database hive;
Query OK, 1 row affected (0.02 sec)
mysql> grant all privileges on hive.* to 'dnn'@'localhost' identified by '!@#123Qwe';
mysql> flush privileges;

hive 表创建成功

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hive               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

3.2 安装 Hive

下载地址： https://hive.apache.org/downloads.html

我下载的是 apache-hive-3.1.2-bin.tar.gz

tar -zxvf apache-hive-3.1.2-bin.tar.gz

- 赋权限给普通用户 dnn

[root@master opt]# chown -R dnn /opt/hive3.1.2/

复制 MySQL 的 JDBC 驱动包到 Hive 的 /lib 下

下载地址 https://dev.mysql.com/downloads/connector/j/

解压

tar -zxvf mysql-connector-java-5.1.49.tar.gz

移动

[dnn@master Downloads]$ mv mysql-connector-java-5.1.49/mysql-connector-java-5.1.49-bin.jar /opt/hive3.1.2/lib
[dnn@master Downloads]$ rm -rf mysql-connector-java-5.1.49

3.3 配置 Hive

配置 hive-env.sh

[dnn@master opt]$ cd /opt/hive3.1.2/conf/
[dnn@master conf]$ cp hive-env.sh.template  hive-env.sh
[dnn@master conf]$ vim hive-env.sh

第48行改为自己的路径 HADOOP_HOME=/opt/hadoop-3.3.0
第51行 export HIVE_CONF_DIR=/opt/hive3.1.2/conf
第54行 export HIVE_AUX_JARS_PATH=/opt/hive3.1.2/lib

配置 hive-default.xml，直接复制模板

cp hive-default.xml.template hive-default.xml

配置 vim hive-site.xml

<configuration><property><name>javax.jdo.option.ConnectionURL</name><value>jdbc:mysql://localhost:3306/hive?createDatabaseIfNotExist=true</value><description>JDBC connect string for a JDBC metastore.
ql.jdbc.Driver     To use SSL to encrypt/authenticate the connection, provide database-specific SSL flag in the connection URL.For example, jdbc:postgresql://myhost/db?ssl=true for postgres database.</description></property><property><name>javax.jdo.option.ConnectionDriverName</name><value>com.mysql.cj.jdbc.Driver</value><description>Driver class name for a JDBC metastore,com.mysql.jdbc.Driver is depricated</description></property><property><name>javax.jdo.option.ConnectionUserName</name><value>dnn</value><description>Username to use against metastore database</description></property><property><name>javax.jdo.option.ConnectionPassword</name><value>!@#123Qwe</value><description>password to use against metastore database</description></property>
</configuration>

初始化 Hive Metastore
在 hive 的 bin 目录下 ./schematool -initSchema -dbType mysql

配置环境变量

vim ~/.bashrc

添加

export HIVE_HOME=/opt/hive3.1.2
export PATH=${HIVE_HOME}/bin:$PATH

使之生效

source ~/.bashrc

4. 实践

启动 hadoop 命令：

start-dfs.sh
start-yarn.sh
mr-jobhistory-daemon.sh start historyserver
# 第三条可以用下面的命令，上面的显示过期了，以后弃用
mapred --daemon start historyserver

4.1 函数

显示函数 show functions;

hive> show functions;
OK
!
!=
$sum0
%
(省略。。。)

显示函数帮助信息：describe function upper（函数名）;

hive> > describe function upper;
OK
upper(str) - Returns str with all characters changed to uppercase
Time taken: 0.007 seconds, Fetched: 1 row(s)

自定义函数，重写 UDF 中的 evaluate()

package michael_package;import org.apache.hadoop.hive.ql.exec.UDF;public class Sub extends UDF{public Integer evaluate(Integer a, Integer b) {if(a==null || b==null)return null;return a-b;}public Double evaluate(Double a, Double b) {if(a==null || b==null)return null;return a-b;}public Integer evaluate(Integer a, Integer[] b) {if(a==null || b==null)return null;int ans = a;for(int i = 0; i < b.length; ++i) {if(b[i] != null)ans -= b[i];}return ans;}
}

表生成自定义函数 UDTF
聚集自定义函数 UDAF

4.2 Hive Shell

create table，show tables，describe 表name

hive> create table student(> id string,> name string,> sex string,> age tinyint,> dept string)> row format delimited fields terminated by '\t';
OK
Time taken: 0.464 seconds
hive> show tables;
OK
student
Time taken: 0.085 seconds, Fetched: 1 row(s)
hive> describe student;
OK
id                  	string              	                    
name                	string              	                    
sex                 	string              	                    
age                 	tinyint             	                    
dept                	string              	                    
Time taken: 0.069 seconds, Fetched: 5 row(s)

编写个数据文件

hadoop@dblab-VirtualBox:/usr/local/eclipse$ vim /home/hadoop/workspace/student.txt
hadoop@dblab-VirtualBox:/usr/local/eclipse$ cat /home/hadoop/workspace/student.txt
1	michael	male	18	bigdata
2	ming	male	19	AI
3	lili	female	18	math
4	huahua	female	20	AI

加载数据到表格

hive> load data local inpath '/home/hadoop/workspace/student.txt' into table student;
Loading data to table default.student
OK
Time taken: 1.158 seconds

select 操作表

hive> select * from student;
OK
1	michael	male	18	bigdata
2	ming	male	19	AI
3	lili	female	18	math
4	huahua	female	20	AI
Time taken: 0.789 seconds, Fetched: 4 row(s)

hive> select * from student where sex='male';
OK
1	michael	male	18	bigdata
2	ming	male	19	AI
Time taken: 1.565 seconds, Fetched: 2 row(s)

HiveQL 将命令转换为 MapReduce 操作

hive> select sex, count(*) from student group by sex;
WARNING: Hive-on-MR is deprecated in Hive 2 and may not be available in the future versions. Consider using a different execution engine (i.e. spark, tez) or using Hive 1.X releases.
Query ID = hadoop_20210331231151_0e76f173-ac54-46e0-8886-f018f8a7f480
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks not specified. Estimated from input data size: 1
In order to change the average load for a reducer (in bytes):set hive.exec.reducers.bytes.per.reducer=<number>
In order to limit the maximum number of reducers:set hive.exec.reducers.max=<number>
In order to set a constant number of reducers:set mapreduce.job.reduces=<number>
Job running in-process (local Hadoop)
2021-03-31 23:11:52,943 Stage-1 map = 100%,  reduce = 100%
Ended Job = job_local236806530_0001
MapReduce Jobs Launched: 
Stage-Stage-1:  HDFS Read: 352 HDFS Write: 0 SUCCESS
Total MapReduce CPU Time Spent: 0 msec
OK
female	2
male	2
Time taken: 1.55 seconds, Fetched: 2 row(s)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hive               |
| mysql              |
| performance_schema |
| spark              |
| sys                |
+--------------------+
6 rows in set (0.00 sec)mysql> use hive;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -ADatabase changed
mysql> show tables;
+---------------------------+
| Tables_in_hive            |
+---------------------------+
| AUX_TABLE                 |
| BUCKETING_COLS            |
| CDS                       |
| COLUMNS_V2                |
| COMPACTION_QUEUE          |
| COMPLETED_COMPACTIONS     |
| COMPLETED_TXN_COMPONENTS  |
| DATABASE_PARAMS           |
| DBS                       |
| DB_PRIVS                  |
| DELEGATION_TOKENS         |
| FUNCS                     |
| FUNC_RU                   |
| GLOBAL_PRIVS              |
| HIVE_LOCKS                |
| IDXS                      |
| INDEX_PARAMS              |
| KEY_CONSTRAINTS           |
| MASTER_KEYS               |
| NEXT_COMPACTION_QUEUE_ID  |
| NEXT_LOCK_ID              |
| NEXT_TXN_ID               |
| NOTIFICATION_LOG          |
| NOTIFICATION_SEQUENCE     |
| NUCLEUS_TABLES            |
| PARTITIONS                |
| PARTITION_EVENTS          |
| PARTITION_KEYS            |
| PARTITION_KEY_VALS        |
| PARTITION_PARAMS          |
| PART_COL_PRIVS            |
| PART_COL_STATS            |
| PART_PRIVS                |
| ROLES                     |
| ROLE_MAP                  |
| SDS                       |
| SD_PARAMS                 |
| SEQUENCE_TABLE            |
| SERDES                    |
| SERDE_PARAMS              |
| SKEWED_COL_NAMES          |
| SKEWED_COL_VALUE_LOC_MAP  |
| SKEWED_STRING_LIST        |
| SKEWED_STRING_LIST_VALUES |
| SKEWED_VALUES             |
| SORT_COLS                 |
| TABLE_PARAMS              |
| TAB_COL_STATS             |
| TBLS                      |
| TBL_COL_PRIVS             |
| TBL_PRIVS                 |
| TXNS                      |
| TXN_COMPONENTS            |
| TYPES                     |
| TYPE_FIELDS               |
| VERSION                   |
| WRITE_SET                 |
+---------------------------+
57 rows in set (0.00 sec)

非交互式，加载查询脚本

hadoop@dblab-VirtualBox:~/workspace$ vim script.q
hadoop@dblab-VirtualBox:~/workspace$ cat script.q 
select * from student;hadoop@dblab-VirtualBox:~/workspace$ hive -f script.q 
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/usr/local/hive/lib/log4j-slf4j-impl-2.4.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/usr/local/hadoop/share/hadoop/common/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.apache.logging.slf4j.Log4jLoggerFactory]Logging initialized using configuration in jar:file:/usr/local/hive/lib/hive-common-2.1.0.jar!/hive-log4j2.properties Async: true
Wed Mar 31 23:36:09 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 31 23:36:09 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 31 23:36:09 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 31 23:36:09 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 31 23:36:10 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 31 23:36:10 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 31 23:36:10 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 31 23:36:10 CST 2021 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
OK
1	michael	male	18	bigdata
2	ming	male	19	AI
3	lili	female	18	math
4	huahua	female	20	AI
Time taken: 1.376 seconds, Fetched: 4 row(s)