mr读取mysql_MR总结(一)-Mapreduce原理解析

本文深入解析MapReduce框架,包括其基本原理、执行流程和编程模型。MapReduce利用普通计算机集群处理大规模数据,用户主要实现Mapper和Reducer。Mapper接收key/value对,转化为新的key/value对,Reducer对相同key的value进行聚合。MapReduce执行包括Driver初始化、InputData处理、Mapper与Reducer工作、Shuffle与Sort、Reducer执行和Output。MapReduce编程涉及Mapper、Reducer、Combiner和Distributed Cache等组件。

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本文主要内容: ★理解MapReduce基本原理 ★了解MapReduce应用的执行 ★理解MapReduce应用的设计 一、了解MapReduce MapReduce是一个框架,能够利用许多普通计算机对大规模的数据集进行高并发的、分布式的算法处理。 用户的任务是实现mapper与reducer,这两

本文主要内容:

★理解MapReduce基本原理

★了解MapReduce应用的执行

★理解MapReduce应用的设计

一、了解MapReduce

MapReduce是一个框架,能够利用许多普通计算机对大规模的数据集进行高并发的、分布式的算法处理。

用户的任务是实现mapper与reducer,这两个类会继承Hadoop提供的基础类来解决特殊的问题。就像图3-1中所示的,Mapper将key/value(k1,v1)键值对形式的数据作为输入,然后将他们转变为另一种key/value键值对形式。MapReduce框架对所有mapper输出的key/value进行排序,并将key值相同的所有value值合并(k2,{v2,v2,…})。这些kye/value结合后的会被传递到reducer模块,reducer会将他们转化为另一种key/value对(k3,v3)。

maper%E5%92%8Creducer.png

maper和reducer

核心组件:

Mapper与Reducer和MapReduce框架。

Mapper功能:

一个mapper与reducer一起组成一个Hadoop作业。Mapper是作业的强制性部分,可以产生0个或者更多个key/value(k2,v2)键值对。

Reducer功能:

Reducer是作业的可选择性部分,可以没有产出或者产出更多的key/value对(k3,v3)。

MapReduce功能:

调度、同步、容错

MapReduce框架的主要任务(根据用户提供的代码)是统筹所有任务的协调执行。

包括

1.选择合适的机器(节点)运行mapper、启动与监控mapper的执行

2.为reducer的执行选择合适的节点,对mapper的输出进行排序与拉去并且传送给reducer节点、?启动与监控reducer的执行。

3.Mapreduce框架负责调度和监控任务,再次执行失败的任务。

现在我们对MapReduce有了一些了解,下面让我们进一步看看MapReduce作业是如何执行的。

二、Mapreduce作业执行

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高层次的hadoop执行框架

下面介绍MapReduce执行管道线的主要组件。

★? Driver:这是主程序,用来初始化MapReduce job。它定义了job的个性化配置,并且标注了所有的组件(包括输入输出格式,mapper与reducer,使

[root@node ~]# start-dfs.sh Starting namenodes on [node] Last login: 二 7月 8 16:00:18 CST 2025 from 192.168.1.92 on pts/0 Starting datanodes Last login: 二 7月 8 16:00:38 CST 2025 on pts/0 Starting secondary namenodes [node] Last login: 二 7月 8 16:00:41 CST 2025 on pts/0 SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. [root@node ~]# start-yarn.sh Starting resourcemanager Last login: 二 7月 8 16:00:45 CST 2025 on pts/0 Starting nodemanagers Last login: 二 7月 8 16:00:51 CST 2025 on pts/0 [root@node ~]# mapred --daemon start historyserver [root@node ~]# jps 3541 ResourceManager 4007 Jps 2984 NameNode 3944 JobHistoryServer 3274 SecondaryNameNode [root@node ~]# mkdir -p /weblog [root@node ~]# cat > /weblog/access.log << EOF > 192.168.1.1,2023-06-01 10:30:22,/index.html > 192.168.1.2,2023-06-01 10:31:15,/product.html > 192.168.1.1,2023-06-01 10:32:45,/cart.html > 192.168.1.3,2023-06-01 11:45:30,/checkout.html > 192.168.1.4,2023-06-01 12:10:05,/index.html > 192.168.1.2,2023-06-01 14:20:18,/product.htm > EOF [root@node ~]# ls /weblog access.log [root@node ~]# hdfs dfs -mkdir -p /weblog/raw SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. [root@node ~]# hdfs dfs -put /weblog/access.log /weblog/raw/ SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. [root@node ~]# hdfs dfs -ls /weblog/raw SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Found 1 items -rw-r--r-- 3 root supergroup 269 2025-07-08 16:03 /weblog/raw/access.log [root@node ~]# cd /weblog [root@node weblog]# mkdir weblog-mapreduce [root@node weblog]# cd weblog-mapreduce [root@node weblog-mapreduce]# touch CleanMapper.java [root@node weblog-mapreduce]# vim CleanMapper.java import java.io.IOException; import org.apache.hadoop.io.*; import org.apache.hadoop.mapreduce.*; public class CleanMapper extends Mapper<LongWritable, Text, Text, NullWritable> { public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException { String line = value.toString(); String[] fields = line.split(","); if(fields.length == 3) { String ip = fields[0]; String time = fields[1]; String page = fields[2]; if(ip.matches("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}")) { String outputLine = ip + "," + time + "," + page; context.write(new Text(outputLine), NullWritable.get()); } } } } [root@node weblog-mapreduce]# touch CleanReducer.java [root@node weblog-mapreduce]# vim CleanReducer.java import java.io.IOException; import org.apache.hadoop.io.*; import org.apache.hadoop.mapreduce.*; public class CleanReducer extends Reducer<Text, NullWritable, Text, NullWritable> { public void reduce(Text key, Iterable<NullWritable> values, Context context) throws IOException, InterruptedException { context.write(key, NullWritable.get()); } } [root@node weblog-mapreduce]# touch LogCleanDriver.java [root@node weblog-mapreduce]# vim LogCleanDriver.java import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.*; import org.apache.hadoop.mapreduce.*; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; public class LogCleanDriver { public static void main(String[] args) throws Exception { Configuration conf = new Configuration(); Job job = Job.getInstance(conf, "Web Log Cleaner"); job.setJarByClass(LogCleanDriver.class); job.setMapperClass(CleanMapper.class); job.setReducerClass(CleanReducer.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(NullWritable.class); FileInputFormat.addInputPath(job, new Path(args[0])); FileOutputFormat.setOutputPath(job, new Path(args[1])); System.exit(job.waitForCompletion(true) ? 0 : 1); } } [root@node weblog-mapreduce]# ls /weblog/weblog-mapreduce CleanMapper.java CleanReducer.java LogCleanDriver.java [root@node weblog-mapreduce]# javac -classpath $(hadoop classpath) -d . *.java [root@node weblog-mapreduce]# ls /weblog/weblog-mapreduce CleanMapper.class CleanReducer.class LogCleanDriver.class CleanMapper.java CleanReducer.java LogCleanDriver.java [root@node weblog-mapreduce]# jar cf logclean.jar *.class [root@node weblog-mapreduce]# ls /weblog/weblog-mapreduce CleanMapper.class CleanReducer.class LogCleanDriver.class logclean.jar CleanMapper.java CleanReducer.java LogCleanDriver.java [root@node weblog-mapreduce]# hdfs dfs -ls /weblog/raw SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Found 1 items -rw-r--r-- 3 root supergroup 269 2025-07-08 16:03 /weblog/raw/access.log [root@node weblog-mapreduce]# hdfs dfs -ls /weblog/output SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. ls: `/weblog/output': No such file or directory [root@node weblog-mapreduce]# hadoop jar logclean.jar LogCleanDriver /weblog/raw /weblog/output SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. [root@node weblog-mapreduce]# [root@node weblog-mapreduce]# mapred job -status job_1751961655287_0001 SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Job: job_1751961655287_0001 Job File: hdfs://node:9000/tmp/hadoop-yarn/staging/history/done/2025/07/08/000000/job_1751961655287_0001_conf.xml Job Tracking URL : http://node:19888/jobhistory/job/job_1751961655287_0001 Uber job : false Number of maps: 1 Number of reduces: 1 map() completion: 1.0 reduce() completion: 1.0 Job state: SUCCEEDED retired: false reason for failure: Counters: 54 File System Counters FILE: Number of bytes read=287 FILE: Number of bytes written=552699 FILE: Number of read operations=0 FILE: Number of large read operations=0 FILE: Number of write operations=0 HDFS: Number of bytes read=372 HDFS: Number of bytes written=269 HDFS: Number of read operations=8 HDFS: Number of large read operations=0 HDFS: Number of write operations=2 HDFS: Number of bytes read erasure-coded=0 Job Counters Launched map tasks=1 Launched reduce tasks=1 Data-local map tasks=1 Total time spent by all maps in occupied slots (ms)=1848 Total time spent by all reduces in occupied slots (ms)=2016 Total time spent by all map tasks (ms)=1848 Total time spent by all reduce tasks (ms)=2016 Total vcore-milliseconds taken by all map tasks=1848 Total vcore-milliseconds taken by all reduce tasks=2016 Total megabyte-milliseconds taken by all map tasks=1892352 Total megabyte-milliseconds taken by all reduce tasks=2064384 Map-Reduce Framework Map input records=6 Map output records=6 Map output bytes=269 Map output materialized bytes=287 Input split bytes=103 Combine input records=0 Combine output records=0 Reduce input groups=6 Reduce shuffle bytes=287 Reduce input records=6 Reduce output records=6 Spilled Records=12 Shuffled Maps =1 Failed Shuffles=0 Merged Map outputs=1 GC time elapsed (ms)=95 CPU time spent (ms)=1050 Physical memory (bytes) snapshot=500764672 Virtual memory (bytes) snapshot=5614292992 Total committed heap usage (bytes)=379584512 Peak Map Physical memory (bytes)=293011456 Peak Map Virtual memory (bytes)=2803433472 Peak Reduce Physical memory (bytes)=207753216 Peak Reduce Virtual memory (bytes)=2810859520 Shuffle Errors BAD_ID=0 CONNECTION=0 IO_ERROR=0 WRONG_LENGTH=0 WRONG_MAP=0 WRONG_REDUCE=0 File Input Format Counters Bytes Read=269 File Output Format Counters Bytes Written=269 [root@node weblog-mapreduce]# hdfs dfs -ls /weblog/output SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Found 2 items -rw-r--r-- 3 root supergroup 0 2025-07-08 16:34 /weblog/output/_SUCCESS -rw-r--r-- 3 root supergroup 269 2025-07-08 16:34 /weblog/output/part-r-00000 [root@node weblog-mapreduce]# hdfs dfs -cat /weblog/output/part-r-00000 | head -5 SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. 192.168.1.1,2023-06-01 10:30:22,/index.html 192.168.1.1,2023-06-01 10:32:45,/cart.html 192.168.1.2,2023-06-01 10:31:15,/product.html 192.168.1.2,2023-06-01 14:20:18,/product.htm 192.168.1.3,2023-06-01 11:45:30,/checkout.html [root@node weblog-mapreduce]# hive SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Hive Session ID = 5199f37c-a381-428a-be1b-0a2afaab8583 Logging initialized using configuration in jar:file:/home/hive-3.1.3/lib/hive-common-3.1.3.jar!/hive-log4j2.properties Async: true 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. Hive Session ID = f38c99b3-ff7c-4f61-ae07-6b21d86d7160 hive> CREATE EXTERNAL TABLE weblog ( > ip STRING, > access_time TIMESTAMP, > page STRING > ) > ROW FORMAT DELIMITED > FIELDS TERMINATED BY ',' > LOCATION '/weblog/output'; OK Time taken: 1.274 seconds hive> select * from weblog; OK 192.168.1.1 2023-06-01 10:30:22 /index.html 192.168.1.1 2023-06-01 10:32:45 /cart.html 192.168.1.2 2023-06-01 10:31:15 /product.html 192.168.1.2 2023-06-01 14:20:18 /product.htm 192.168.1.3 2023-06-01 11:45:30 /checkout.html 192.168.1.4 2023-06-01 12:10:05 /index.html Time taken: 1.947 seconds, Fetched: 6 row(s) hive> select * from weblog limit 5; OK 192.168.1.1 2023-06-01 10:30:22 /index.html 192.168.1.1 2023-06-01 10:32:45 /cart.html 192.168.1.2 2023-06-01 10:31:15 /product.html 192.168.1.2 2023-06-01 14:20:18 /product.htm 192.168.1.3 2023-06-01 11:45:30 /checkout.html Time taken: 0.148 seconds, Fetched: 5 row(s) hive> hive> CREATE TABLE page_visits AS > SELECT > page, > COUNT(*) AS visits > FROM weblog > GROUP BY page > ORDER BY visits DESC; Query ID = root_20250708183002_ec44d1b4-af24-403c-bb67-380dfb6961c3 Total jobs = 2 Launching Job 1 out of 2 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> Starting Job = job_1751961655287_0002, Tracking URL = http://node:8088/proxy/application_1751961655287_0002/ Kill Command = /home/hadoop/hadoop3.3/bin/mapred job -kill job_1751961655287_0002 Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 1 2025-07-08 18:30:12,692 Stage-1 map = 0%, reduce = 0% 2025-07-08 18:30:16,978 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 1.8 sec 2025-07-08 18:30:23,184 Stage-1 map = 100%, reduce = 100%, Cumulative CPU 3.66 sec MapReduce Total cumulative CPU time: 3 seconds 660 msec Ended Job = job_1751961655287_0002 Launching Job 2 out of 2 Number of reduce tasks determined at compile time: 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> Starting Job = job_1751961655287_0003, Tracking URL = http://node:8088/proxy/application_1751961655287_0003/ Kill Command = /home/hadoop/hadoop3.3/bin/mapred job -kill job_1751961655287_0003 Hadoop job information for Stage-2: number of mappers: 1; number of reducers: 1 2025-07-08 18:30:35,969 Stage-2 map = 0%, reduce = 0% 2025-07-08 18:30:41,155 Stage-2 map = 100%, reduce = 0%, Cumulative CPU 1.23 sec 2025-07-08 18:30:46,313 Stage-2 map = 100%, reduce = 100%, Cumulative CPU 2.95 sec MapReduce Total cumulative CPU time: 2 seconds 950 msec Ended Job = job_1751961655287_0003 Moving data to directory hdfs://node:9000/hive/warehouse/page_visits MapReduce Jobs Launched: Stage-Stage-1: Map: 1 Reduce: 1 Cumulative CPU: 3.66 sec HDFS Read: 12379 HDFS Write: 251 SUCCESS Stage-Stage-2: Map: 1 Reduce: 1 Cumulative CPU: 2.95 sec HDFS Read: 7308 HDFS Write: 150 SUCCESS Total MapReduce CPU Time Spent: 6 seconds 610 msec OK Time taken: 46.853 seconds hive> hive> describe page_visits; OK page string visits bigint Time taken: 0.214 seconds, Fetched: 2 row(s) hive> CREATE TABLE ip_visits AS > SELECT > ip, > COUNT(*) AS visits > FROM weblog > GROUP BY ip > ORDER BY visits DESC; Query ID = root_20250708183554_da402d08-af34-46f9-a33a-3f66ddd1a580 Total jobs = 2 Launching Job 1 out of 2 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> Starting Job = job_1751961655287_0004, Tracking URL = http://node:8088/proxy/application_1751961655287_0004/ Kill Command = /home/hadoop/hadoop3.3/bin/mapred job -kill job_1751961655287_0004 Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 1 2025-07-08 18:36:04,037 Stage-1 map = 0%, reduce = 0% 2025-07-08 18:36:09,250 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 1.57 sec 2025-07-08 18:36:14,393 Stage-1 map = 100%, reduce = 100%, Cumulative CPU 3.3 sec MapReduce Total cumulative CPU time: 3 seconds 300 msec Ended Job = job_1751961655287_0004 Launching Job 2 out of 2 Number of reduce tasks determined at compile time: 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> Starting Job = job_1751961655287_0005, Tracking URL = http://node:8088/proxy/application_1751961655287_0005/ Kill Command = /home/hadoop/hadoop3.3/bin/mapred job -kill job_1751961655287_0005 Hadoop job information for Stage-2: number of mappers: 1; number of reducers: 1 2025-07-08 18:36:27,073 Stage-2 map = 0%, reduce = 0% 2025-07-08 18:36:31,215 Stage-2 map = 100%, reduce = 0%, Cumulative CPU 1.25 sec 2025-07-08 18:36:36,853 Stage-2 map = 100%, reduce = 100%, Cumulative CPU 3.27 sec MapReduce Total cumulative CPU time: 3 seconds 270 msec Ended Job = job_1751961655287_0005 Moving data to directory hdfs://node:9000/hive/warehouse/ip_visits MapReduce Jobs Launched: Stage-Stage-1: Map: 1 Reduce: 1 Cumulative CPU: 3.3 sec HDFS Read: 12445 HDFS Write: 216 SUCCESS Stage-Stage-2: Map: 1 Reduce: 1 Cumulative CPU: 3.27 sec HDFS Read: 7261 HDFS Write: 129 SUCCESS Total MapReduce CPU Time Spent: 6 seconds 570 msec OK Time taken: 44.523 seconds hive> [root@node weblog-mapreduce]# hive> [root@node weblog-mapreduce]# describe ip_visite; bash: describe: command not found... [root@node weblog-mapreduce]# hive SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Hive Session ID = 57dafc2a-afe2-41a4-8159-00f8d44b5add Logging initialized using configuration in jar:file:/home/hive-3.1.3/lib/hive-common-3.1.3.jar!/hive-log4j2.properties Async: true Hive Session ID = f866eae4-4cb4-4403-b7a2-7a52701c5a74 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. hive> describe ip_visite; FAILED: SemanticException [Error 10001]: Table not found ip_visite hive> describe ip_visits; OK ip string visits bigint Time taken: 0.464 seconds, Fetched: 2 row(s) hive> SELECT * FROM page_visits; OK /index.html 2 /product.html 1 /product.htm 1 /checkout.html 1 /cart.html 1 Time taken: 2.095 seconds, Fetched: 5 row(s) hive> SELECT * FROM ip_visits; OK 192.168.1.2 2 192.168.1.1 2 192.168.1.4 1 192.168.1.3 1 Time taken: 0.176 seconds, Fetched: 4 row(s) hive> hive> [root@node weblog-mapreduce]# [root@node weblog-mapreduce]# mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 48 Server version: 8.0.42 MySQL Community Server - GPL Copyright (c) 2000, 2025, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> CREATE DATABASE IF NOT EXISTS weblog_db; Query OK, 1 row affected (0.06 sec) mysql> USE weblog_db; Database changed mysql> CREATE TABLE IF NOT EXISTS page_visits ( -> page VARCHAR(255), -> visits BIGINT -> ) ENGINE=InnoDB DEFAULT CHARSET=utf8; Query OK, 0 rows affected, 1 warning (0.05 sec) mysql> SHOW TABLES; +---------------------+ | Tables_in_weblog_db | +---------------------+ | page_visits | +---------------------+ 1 row in set (0.00 sec) mysql> DESCRIBE page_visits; +--------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+--------------+------+-----+---------+-------+ | page | varchar(255) | YES | | NULL | | | visits | bigint | YES | | NULL | | +--------+--------------+------+-----+---------+-------+ 2 rows in set (0.00 sec) mysql> CREATE TABLE IF NOT EXISTS ip_visits ( -> ip VARCHAR(15), -> visits BIGINT -> ) ENGINE=InnoDB DEFAULT CHARSET=utf8; Query OK, 0 rows affected, 1 warning (0.02 sec) mysql> SHOW TABLES; +---------------------+ | Tables_in_weblog_db | +---------------------+ | ip_visits | | page_visits | +---------------------+ 2 rows in set (0.01 sec) mysql> DESC ip_visits; +--------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------+------+-----+---------+-------+ | ip | varchar(15) | YES | | NULL | | | visits | bigint | YES | | NULL | | +--------+-------------+------+-----+---------+-------+ 2 rows in set (0.00 sec) mysql> ^C mysql> [root@node weblog-mapreduce]# hive SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Hive Session ID = f34e6971-71ae-4aa5-aa22-895061f33bdf Logging initialized using configuration in jar:file:/home/hive-3.1.3/lib/hive-common-3.1.3.jar!/hive-log4j2.properties Async: true 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. Hive Session ID = f7a06e76-e117-4fbb-9ee8-09fdfd002104 hive> DESCRIBE FORMATTED page_visits; OK # col_name data_type comment page string visits bigint # Detailed Table Information Database: default OwnerType: USER Owner: root CreateTime: Tue Jul 08 18:30:47 CST 2025 LastAccessTime: UNKNOWN Retention: 0 Location: hdfs://node:9000/hive/warehouse/page_visits Table Type: MANAGED_TABLE Table Parameters: COLUMN_STATS_ACCURATE {\"BASIC_STATS\":\"true\"} bucketing_version 2 numFiles 1 numRows 5 rawDataSize 70 totalSize 75 transient_lastDdlTime 1751970648 # Storage Information SerDe Library: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe InputFormat: org.apache.hadoop.mapred.TextInputFormat OutputFormat: org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat Compressed: No Num Buckets: -1 Bucket Columns: [] Sort Columns: [] Storage Desc Params: serialization.format 1 Time taken: 1.043 seconds, Fetched: 32 row(s) hive> 到这里就不会了 6.2.2sqoop导出格式 6.2.3导出page_visits表 6.2.4导出到ip_visits表 6.3验证导出数据 6.3.1登录MySQL 6.3.2执行查询
最新发布
07-09
[root@node ~]# mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 8 Server version: 8.0.42 MySQL Community Server - GPL Copyright (c) 2000, 2025, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> CREATE DATABASE weblog_db; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'CREATE DATABASE weblog_db' at line 1 mysql> CREATE DATABASE weblog_db; ERROR 1007 (HY000): Can't create database 'weblog_db'; database exists mysql> USE weblog_db; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> DROP DATABASE IF EXISTS weblog_db; Query OK, 2 rows affected (0.02 sec) mysql> CREATE DATABASE weblog_db; Query OK, 1 row affected (0.01 sec) mysql> USE weblog_db; Database changed mysql> CREATE TABLE page_visits ( -> page VARCHAR(255) , -> visits BIGINT -> ); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'TABLE page_visits ( page VARCHAR(255) , visits BIGINT )' at line 1 mysql> CREATE TABLE page_visits ( -> page VARCHAR(255), -> visits BIGINT -> ); Query OK, 0 rows affected (0.02 sec) mysql> SHOW TABLES; +---------------------+ | Tables_in_weblog_db | +---------------------+ | page_visits | +---------------------+ 1 row in set (0.00 sec) mysql> ^C mysql> q -> quit -> exit -> ^C mysql> ^C mysql> ^C mysql> ^DBye [root@node ~]# hive SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Hive Session ID = 7bb79582-cc2b-49b6-abc7-020dcdc46542 Logging initialized using configuration in jar:file:/home/hive-3.1.3/lib/hive-common-3.1.3.jar!/hive-log4j2.properties Async: true 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. Hive Session ID = 15d9da52-e18e-40b2-a80f-e76eda81df4c hive> DESCRIBE FORMATTED page_visits; OK # col_name data_type comment page string visits bigint # Detailed Table Information Database: default OwnerType: USER Owner: root CreateTime: Tue Jul 08 01:43:42 CST 2025 LastAccessTime: UNKNOWN Retention: 0 Location: hdfs://node:9000/hive/warehouse/page_visits Table Type: MANAGED_TABLE Table Parameters: COLUMN_STATS_ACCURATE {\"BASIC_STATS\":\"true\"} bucketing_version 2 numFiles 1 numRows 4 rawDataSize 56 totalSize 60 transient_lastDdlTime 1751910222 # Storage Information SerDe Library: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe InputFormat: org.apache.hadoop.mapred.TextInputFormat OutputFormat: org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat Compressed: No Num Buckets: -1 Bucket Columns: [] Sort Columns: [] Storage Desc Params: serialization.format 1 Time taken: 0.785 seconds, Fetched: 32 row(s) hive> [root@node ~]# [root@node ~]# sqoop export \ > --connect jdbc:mysql://localhost/weblog_db \ > --username root \ > --password Aa@123456 \ > --table page_visits \ > --export-dir hdfs://node:9000/hive/warehouse/page_visits \ > --input-fields-terminated-by '\001' \ > --num-mappers 1 Warning: /home/sqoop-1.4.7/../hcatalog does not exist! HCatalog jobs will fail. Please set $HCAT_HOME to the root of your HCatalog installation. Warning: /home/sqoop-1.4.7/../accumulo does not exist! Accumulo imports will fail. Please set $ACCUMULO_HOME to the root of your Accumulo installation. 2025-07-08 15:28:12,550 INFO sqoop.Sqoop: Running Sqoop version: 1.4.7 2025-07-08 15:28:12,587 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead. 2025-07-08 15:28:12,704 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset. 2025-07-08 15:28:12,708 INFO tool.CodeGenTool: Beginning code generation Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary. 2025-07-08 15:28:13,225 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `page_visits` AS t LIMIT 1 2025-07-08 15:28:13,266 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `page_visits` AS t LIMIT 1 2025-07-08 15:28:13,280 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/hadoop/hadoop3.3 Note: /tmp/sqoop-root/compile/363869e21c2078b9742685122c43a3cc/page_visits.java uses or overrides a deprecated API. Note: Recompile with -Xlint:deprecation for details. 2025-07-08 15:28:16,377 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-root/compile/363869e21c2078b9742685122c43a3cc/page_visits.jar 2025-07-08 15:28:16,391 INFO mapreduce.ExportJobBase: Beginning export of page_visits 2025-07-08 15:28:16,391 INFO Configuration.deprecation: mapred.job.tracker is deprecated. Instead, use mapreduce.jobtracker.address 2025-07-08 15:28:16,484 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar 2025-07-08 15:28:17,339 INFO Configuration.deprecation: mapred.reduce.tasks.speculative.execution is deprecated. Instead, use mapreduce.reduce.speculative 2025-07-08 15:28:17,342 INFO Configuration.deprecation: mapred.map.tasks.speculative.execution is deprecated. Instead, use mapreduce.map.speculative 2025-07-08 15:28:17,343 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps 2025-07-08 15:28:17,555 INFO client.DefaultNoHARMFailoverProxyProvider: Connecting to ResourceManager at node/192.168.196.122:8032 2025-07-08 15:28:17,782 INFO mapreduce.JobResourceUploader: Disabling Erasure Coding for path: /tmp/hadoop-yarn/staging/root/.staging/job_1751959003014_0001 2025-07-08 15:28:26,026 INFO input.FileInputFormat: Total input files to process : 1 2025-07-08 15:28:26,029 INFO input.FileInputFormat: Total input files to process : 1 2025-07-08 15:28:26,495 INFO mapreduce.JobSubmitter: number of splits:1 2025-07-08 15:28:26,528 INFO Configuration.deprecation: mapred.map.tasks.speculative.execution is deprecated. Instead, use mapreduce.map.speculative 2025-07-08 15:28:26,619 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1751959003014_0001 2025-07-08 15:28:26,620 INFO mapreduce.JobSubmitter: Executing with tokens: [] 2025-07-08 15:28:26,805 INFO conf.Configuration: resource-types.xml not found 2025-07-08 15:28:26,805 INFO resource.ResourceUtils: Unable to find 'resource-types.xml'. 2025-07-08 15:28:27,226 INFO impl.YarnClientImpl: Submitted application application_1751959003014_0001 2025-07-08 15:28:27,264 INFO mapreduce.Job: The url to track the job: http://node:8088/proxy/application_1751959003014_0001/ 2025-07-08 15:28:27,264 INFO mapreduce.Job: Running job: job_1751959003014_0001 2025-07-08 15:28:34,334 INFO mapreduce.Job: Job job_1751959003014_0001 running in uber mode : false 2025-07-08 15:28:34,335 INFO mapreduce.Job: map 0% reduce 0% 2025-07-08 15:28:38,374 INFO mapreduce.Job: map 100% reduce 0% 2025-07-08 15:28:38,381 INFO mapreduce.Job: Job job_1751959003014_0001 failed with state FAILED due to: Task failed task_1751959003014_0001_m_000000 Job failed as tasks failed. failedMaps:1 failedReduces:0 killedMaps:0 killedReduces: 0 2025-07-08 15:28:38,448 INFO mapreduce.Job: Counters: 8 Job Counters Failed map tasks=1 Launched map tasks=1 Data-local map tasks=1 Total time spent by all maps in occupied slots (ms)=2061 Total time spent by all reduces in occupied slots (ms)=0 Total time spent by all map tasks (ms)=2061 Total vcore-milliseconds taken by all map tasks=2061 Total megabyte-milliseconds taken by all map tasks=2110464 2025-07-08 15:28:38,456 WARN mapreduce.Counters: Group FileSystemCounters is deprecated. Use org.apache.hadoop.mapreduce.FileSystemCounter instead 2025-07-08 15:28:38,457 INFO mapreduce.ExportJobBase: Transferred 0 bytes in 21.1033 seconds (0 bytes/sec) 2025-07-08 15:28:38,462 WARN mapreduce.Counters: Group org.apache.hadoop.mapred.Task$Counter is deprecated. Use org.apache.hadoop.mapreduce.TaskCounter instead 2025-07-08 15:28:38,462 INFO mapreduce.ExportJobBase: Exported 0 records. 2025-07-08 15:28:38,462 ERROR mapreduce.ExportJobBase: Export job failed! 2025-07-08 15:28:38,463 ERROR tool.ExportTool: Error during export: Export job failed! at org.apache.sqoop.mapreduce.ExportJobBase.runExport(ExportJobBase.java:445) at org.apache.sqoop.manager.SqlManager.exportTable(SqlManager.java:931) at org.apache.sqoop.tool.ExportTool.exportTable(ExportTool.java:80) at org.apache.sqoop.tool.ExportTool.run(ExportTool.java:99) at org.apache.sqoop.Sqoop.run(Sqoop.java:147) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:81) at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:183) at org.apache.sqoop.Sqoop.runTool(Sqoop.java:234) at org.apache.sqoop.Sqoop.runTool(Sqoop.java:243) at org.apache.sqoop.Sqoop.main(Sqoop.java:252) [root@node ~]# sqoop export \ > --connect jdbc:mysql://localhost/weblog_db \ > --username root \ > --password Aa@123456 \ > --table page_visits \ > --export-dir hdfs://node:9000/hive/warehouse/page_visits \ > --input-fields-terminated-by ',' \ > --num-mappers 1 Warning: /home/sqoop-1.4.7/../hcatalog does not exist! HCatalog jobs will fail. Please set $HCAT_HOME to the root of your HCatalog installation. Warning: /home/sqoop-1.4.7/../accumulo does not exist! Accumulo imports will fail. Please set $ACCUMULO_HOME to the root of your Accumulo installation. 2025-07-08 15:30:31,174 INFO sqoop.Sqoop: Running Sqoop version: 1.4.7 2025-07-08 15:30:31,218 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead. 2025-07-08 15:30:31,333 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset. 2025-07-08 15:30:31,336 INFO tool.CodeGenTool: Beginning code generation Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary. 2025-07-08 15:30:31,771 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `page_visits` AS t LIMIT 1 2025-07-08 15:30:31,814 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `page_visits` AS t LIMIT 1 2025-07-08 15:30:31,821 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/hadoop/hadoop3.3 Note: /tmp/sqoop-root/compile/ab00e36d1f5084a0f7d522b4e9a975e5/page_visits.java uses or overrides a deprecated API. Note: Recompile with -Xlint:deprecation for details. 2025-07-08 15:30:33,116 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-root/compile/ab00e36d1f5084a0f7d522b4e9a975e5/page_visits.jar 2025-07-08 15:30:33,129 INFO mapreduce.ExportJobBase: Beginning export of page_visits 2025-07-08 15:30:33,129 INFO Configuration.deprecation: mapred.job.tracker is deprecated. Instead, use mapreduce.jobtracker.address 2025-07-08 15:30:33,212 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar 2025-07-08 15:30:33,877 INFO Configuration.deprecation: mapred.reduce.tasks.speculative.execution is deprecated. Instead, use mapreduce.reduce.speculative 2025-07-08 15:30:33,880 INFO Configuration.deprecation: mapred.map.tasks.speculative.execution is deprecated. Instead, use mapreduce.map.speculative 2025-07-08 15:30:33,880 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps 2025-07-08 15:30:34,097 INFO client.DefaultNoHARMFailoverProxyProvider: Connecting to ResourceManager at node/192.168.196.122:8032 2025-07-08 15:30:34,310 INFO mapreduce.JobResourceUploader: Disabling Erasure Coding for path: /tmp/hadoop-yarn/staging/root/.staging/job_1751959003014_0002 2025-07-08 15:30:39,127 INFO input.FileInputFormat: Total input files to process : 1 2025-07-08 15:30:39,131 INFO input.FileInputFormat: Total input files to process : 1 2025-07-08 15:30:39,995 INFO mapreduce.JobSubmitter: number of splits:1 2025-07-08 15:30:40,022 INFO Configuration.deprecation: mapred.map.tasks.speculative.execution is deprecated. Instead, use mapreduce.map.speculative 2025-07-08 15:30:40,532 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1751959003014_0002 2025-07-08 15:30:40,532 INFO mapreduce.JobSubmitter: Executing with tokens: [] 2025-07-08 15:30:40,689 INFO conf.Configuration: resource-types.xml not found 2025-07-08 15:30:40,689 INFO resource.ResourceUtils: Unable to find 'resource-types.xml'. 2025-07-08 15:30:40,746 INFO impl.YarnClientImpl: Submitted application application_1751959003014_0002 2025-07-08 15:30:40,783 INFO mapreduce.Job: The url to track the job: http://node:8088/proxy/application_1751959003014_0002/ 2025-07-08 15:30:40,784 INFO mapreduce.Job: Running job: job_1751959003014_0002 2025-07-08 15:30:46,847 INFO mapreduce.Job: Job job_1751959003014_0002 running in uber mode : false 2025-07-08 15:30:46,848 INFO mapreduce.Job: map 0% reduce 0% 2025-07-08 15:30:50,893 INFO mapreduce.Job: map 100% reduce 0% 2025-07-08 15:30:51,905 INFO mapreduce.Job: Job job_1751959003014_0002 failed with state FAILED due to: Task failed task_1751959003014_0002_m_000000 Job failed as tasks failed. failedMaps:1 failedReduces:0 killedMaps:0 killedReduces: 0 2025-07-08 15:30:51,973 INFO mapreduce.Job: Counters: 8 Job Counters Failed map tasks=1 Launched map tasks=1 Data-local map tasks=1 Total time spent by all maps in occupied slots (ms)=2058 Total time spent by all reduces in occupied slots (ms)=0 Total time spent by all map tasks (ms)=2058 Total vcore-milliseconds taken by all map tasks=2058 Total megabyte-milliseconds taken by all map tasks=2107392 2025-07-08 15:30:51,979 WARN mapreduce.Counters: Group FileSystemCounters is deprecated. Use org.apache.hadoop.mapreduce.FileSystemCounter instead 2025-07-08 15:30:51,980 INFO mapreduce.ExportJobBase: Transferred 0 bytes in 18.0828 seconds (0 bytes/sec) 2025-07-08 15:30:51,983 WARN mapreduce.Counters: Group org.apache.hadoop.mapred.Task$Counter is deprecated. Use org.apache.hadoop.mapreduce.TaskCounter instead 2025-07-08 15:30:51,983 INFO mapreduce.ExportJobBase: Exported 0 records. 2025-07-08 15:30:51,983 ERROR mapreduce.ExportJobBase: Export job failed! 2025-07-08 15:30:51,984 ERROR tool.ExportTool: Error during export: Export job failed! at org.apache.sqoop.mapreduce.ExportJobBase.runExport(ExportJobBase.java:445) at org.apache.sqoop.manager.SqlManager.exportTable(SqlManager.java:931) at org.apache.sqoop.tool.ExportTool.exportTable(ExportTool.java:80) at org.apache.sqoop.tool.ExportTool.run(ExportTool.java:99) at org.apache.sqoop.Sqoop.run(Sqoop.java:147) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:81) at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:183) at org.apache.sqoop.Sqoop.runTool(Sqoop.java:234) at org.apache.sqoop.Sqoop.runTool(Sqoop.java:243) at org.apache.sqoop.Sqoop.main(Sqoop.java:252) [root@node ~]# 6.2 Sqoop导出数据 6.2.1从Hive将数据导出到MySQL 6.2.2sqoop导出格式 6.2.3导出page_visits表 6.2.4导出到ip_visits表 6.3验证导出数据 6.3.1登录MySQL 6.3.2执行查询
07-09
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