| 1 | [[PageOutline]] |
| 2 | |
| 3 | ◢ <[wiki:III110813/Lab3 實作三]> | <[wiki:III110813 回課程大綱]> ▲ | <[wiki:III110813/Lab5 實作五]> ◣ |
| 4 | |
| 5 | = 實作五 Lab 5 = |
| 6 | |
| 7 | {{{ |
| 8 | #!html |
| 9 | <div style="text-align: center;"><big style="font-weight: bold;"><big>在單機模式執行 MapReduce 基本運算<br/>Running MapReduce in local mode by Examples</big></big></div> |
| 10 | }}} |
| 11 | |
| 12 | == MapReduce 範例一『字數統計(WordCount)』 == |
| 13 | |
| 14 | * STEP 1 : 練習 MapReduce 丟 Job 指令: 『__'''hadoop jar <local jar file> <class name> <parameters>'''__』 |
| 15 | {{{ |
| 16 | Jazz@human ~ |
| 17 | $ cd /opt/hadoop/ |
| 18 | |
| 19 | Jazz@human /opt/hadoop |
| 20 | $ hadoop jar hadoop-*-examples.jar wordcount input output |
| 21 | 11/10/21 14:08:58 INFO input.FileInputFormat: Total input paths to process : 12 |
| 22 | 11/10/21 14:09:00 INFO mapred.JobClient: Running job: job_201110211130_0001 |
| 23 | 11/10/21 14:09:01 INFO mapred.JobClient: map 0% reduce 0% |
| 24 | 11/10/21 14:09:31 INFO mapred.JobClient: map 16% reduce 0% |
| 25 | 11/10/21 14:10:29 INFO mapred.JobClient: map 100% reduce 27% |
| 26 | 11/10/21 14:10:33 INFO mapred.JobClient: map 100% reduce 100% |
| 27 | 11/10/21 14:10:35 INFO mapred.JobClient: Job complete: job_201110211130_0001 |
| 28 | 11/10/21 14:10:35 INFO mapred.JobClient: Counters: 17 |
| 29 | 11/10/21 14:10:35 INFO mapred.JobClient: Job Counters |
| 30 | 11/10/21 14:10:35 INFO mapred.JobClient: Launched reduce tasks=1 |
| 31 | 11/10/21 14:10:35 INFO mapred.JobClient: Launched map tasks=12 |
| 32 | 11/10/21 14:10:35 INFO mapred.JobClient: Data-local map tasks=12 |
| 33 | 11/10/21 14:10:35 INFO mapred.JobClient: FileSystemCounters |
| 34 | 11/10/21 14:10:35 INFO mapred.JobClient: FILE_BYTES_READ=16578 |
| 35 | 11/10/21 14:10:35 INFO mapred.JobClient: HDFS_BYTES_READ=18312 |
| 36 | 11/10/21 14:10:35 INFO mapred.JobClient: FILE_BYTES_WRITTEN=32636 |
| 37 | 11/10/21 14:10:35 INFO mapred.JobClient: HDFS_BYTES_WRITTEN=10922 |
| 38 | 11/10/21 14:10:35 INFO mapred.JobClient: Map-Reduce Framework |
| 39 | 11/10/21 14:10:35 INFO mapred.JobClient: Reduce input groups=592 |
| 40 | 11/10/21 14:10:35 INFO mapred.JobClient: Combine output records=750 |
| 41 | 11/10/21 14:10:35 INFO mapred.JobClient: Map input records=553 |
| 42 | 11/10/21 14:10:35 INFO mapred.JobClient: Reduce shuffle bytes=15674 |
| 43 | 11/10/21 14:10:35 INFO mapred.JobClient: Reduce output records=592 |
| 44 | 11/10/21 14:10:35 INFO mapred.JobClient: Spilled Records=1500 |
| 45 | 11/10/21 14:10:35 INFO mapred.JobClient: Map output bytes=24438 |
| 46 | 11/10/21 14:10:35 INFO mapred.JobClient: Combine input records=1755 |
| 47 | 11/10/21 14:10:35 INFO mapred.JobClient: Map output records=1755 |
| 48 | 11/10/21 14:10:35 INFO mapred.JobClient: Reduce input records=750 |
| 49 | }}} |
| 50 | * [[BR]][[Image(Hadoop4Win:hadoop4win_14.jpg,width=600)]] |
| 51 | |
| 52 | * STEP 2 : 練習從 http://localhost:50030 查看目前 MapReduce Job 的運作情形 |
| 53 | * [[BR]][[Image(Hadoop4Win:hadoop4win_15.jpg,width=600)]] |
| 54 | |
| 55 | * STEP 3 : 使用 HDFS 指令: 『__'''hadoop fs -get <HDFS file/dir> <local file/dir>'''__』,並了解輸出檔案檔名均為 part-r-*****,且執行參數會紀錄於 <HOSTNAME>_<TIME>_job_<JOBID>_0001_conf.xml,不妨可以觀察 xml 內容與 hadoop config 檔的參數關聯。 |
| 56 | {{{ |
| 57 | Jazz@human /opt/hadoop |
| 58 | $ hadoop fs -get output my_output |
| 59 | |
| 60 | Jazz@human /opt/hadoop |
| 61 | $ ls -alR my_output |
| 62 | my_output: |
| 63 | total 12 |
| 64 | drwxr-xr-x+ 3 Jazz None 0 Oct 21 14:12 . |
| 65 | drwxr-xr-x+ 15 Jazz None 0 Oct 21 14:12 .. |
| 66 | drwxr-xr-x+ 3 Jazz None 0 Oct 21 14:12 _logs |
| 67 | -rwxr-xr-x 1 Jazz None 10922 Oct 21 14:12 part-r-00000 |
| 68 | |
| 69 | my_output/_logs: |
| 70 | total 0 |
| 71 | drwxr-xr-x+ 3 Jazz None 0 Oct 21 14:12 . |
| 72 | drwxr-xr-x+ 3 Jazz None 0 Oct 21 14:12 .. |
| 73 | drwxr-xr-x+ 2 Jazz None 0 Oct 21 14:12 history |
| 74 | |
| 75 | my_output/_logs/history: |
| 76 | total 48 |
| 77 | drwxr-xr-x+ 2 Jazz None 0 Oct 21 14:12 . |
| 78 | drwxr-xr-x+ 3 Jazz None 0 Oct 21 14:12 .. |
| 79 | -rwxr-xr-x 1 Jazz None 26004 Oct 21 14:12 localhost_1319167815125_job_201110211130_0001_Jazz_word+count |
| 80 | -rwxr-xr-x 1 Jazz None 16984 Oct 21 14:12 localhost_1319167815125_job_201110211130_0001_conf.xml |
| 81 | }}} |
| 82 | * [[BR]][[Image(Hadoop4Win:hadoop4win_22.jpg,width=600)]] |