tencent cloud

Environmental Dependencies

• HADOOP-COS and the corresponding cos_api-bundle.
• DataX version: DataX 3.0

Download and Installation

Downloading HADOOP-COS

Download HADOOP-COS and the corresponding cos_api-bundle on Github.

Downloading DataX package

Download DataX on Github.

Installing HADOOP-COS

After HADOOP-COS is downloaded, copy hadoop-cos-2.x.x-${version}.jar and cos_api-bundle-${version}.jar to the Datax decompression paths plugin/reader/hdfsreader/libs/ and plugin/writer/hdfswriter/libs/.

How to Use

DataX configuration

Modifying datax.py script

Open the bin/datax.py script in the DataX decompression directory, and modify the CLASS_PATH variable in the script as follows:

CLASS_PATH = ("%s/lib/*:%s/plugin/reader/hdfsreader/libs/*:%s/plugin/writer/hdfswriter/libs/*:.") % (DATAX_HOME, DATAX_HOME, DATAX_HOME)

Configuring hdfsreader and hdfswriter in JSON configuration file

A sample JSON file is as shown below:

{
"job": {
    "setting": {
        "speed": {
            "byte": 10485760
        },
        "errorLimit": {
            "record": 0,
            "percentage": 0.02
        }
    },
    "content": [{
        "reader": {
            "name": "hdfsreader",
            "parameter": {
                "path": "testfile",
                "defaultFS": "cosn://examplebucket-1250000000/",
                "column": ["*"],
                "fileType": "text",
                "encoding": "UTF-8",
                "hadoopConfig": {
                    "fs.cosn.impl": "org.apache.hadoop.fs.CosFileSystem",
                    "fs.cosn.userinfo.region": "ap-beijing",
                    "fs.cosn.tmp.dir": "/tmp/hadoop_cos",
                    "fs.cosn.userinfo.secretId": "COS_SECRETID",
                    "fs.cosn.userinfo.secretKey": "COS_SECRETKEY"
                },
                "fieldDelimiter": ","
            }
        },
        "writer": {
            "name": "hdfswriter",
            "parameter": {
                "path": "/user/hadoop/",
                "fileName": "testfile1",
                "defaultFS": "cosn://examplebucket-1250000000/",
                "column": [{
                        "name": "col",
                        "type": "string"
                    },
                    {
                        "name": "col1",
                        "type": "string"
                    },
                    {
                        "name": "col2",
                        "type": "string"
                    }
                ],
                "fileType": "text",
                "encoding": "UTF-8",
                "hadoopConfig": {
                    "fs.cosn.impl": "org.apache.hadoop.fs.CosFileSystem",
                    "fs.cosn.userinfo.region": "ap-beijing",
                    "fs.cosn.tmp.dir": "/tmp/hadoop_cos",
                    "fs.cosn.userinfo.secretId": "COS_SECRETID",
                    "fs.cosn.userinfo.secretKey": "COS_SECRETKEY"
                },
                "fieldDelimiter": ":",
                "writeMode": "append"
            }
        }
    }]
}
}

Notes:

• Configure hadoopConfig as required for cosn.
• Use defaultFS to specify the cosn path, e.g. cosn://examplebucket-1250000000/.
• In fs.cosn.userinfo.region, enter the region where your bucket resides, such as ap-beijing. For more information, see Regions and Access Endpoints.
• For COS_SECRETID and COS_SECRETKEY, use your own COS key information.

The other fields can be the same as those for hdfs.

Migrating data

Save the configuration file as hdfs_job.json in the job directory by running

bin/datax.py job/hdfs_job.json

The resulting output is as shown below:

2020-03-09 16:49:59.543 [job-0] INFO  JobContainer - 
       [total cpu info] => 
              averageCpu                     | maxDeltaCpu                    | minDeltaCpu                    
              -1.00%                         | -1.00%                         | -1.00%
                      
        [total gc info] => 
               NAME                 | totalGCCount       | maxDeltaGCCount    | minDeltaGCCount    | totalGCTime        | maxDeltaGCTime     | minDeltaGCTime     
               PS MarkSweep         | 1                  | 1                  | 1                  | 0.024s             | 0.024s             | 0.024s             
               PS Scavenge          | 1                  | 1                  | 1                  | 0.014s             | 0.014s             | 0.014s             
2020-03-09 16:49:59.543 [job-0] INFO  JobContainer - PerfTrace not enable!
2020-03-09 16:49:59.543 [job-0] INFO  StandAloneJobContainerCommunicator - Total 2 records, 33 bytes | Speed 3B/s, 0 records/s | Error 0 records, 0 bytes |  All Task WaitWriterTime 0.000s |  All Task WaitReaderTime 0.033s | Percentage 100.00%
2020-03-09 16:49:59.544 [job-0] INFO  JobContainer - 
Job start time                    : 2020-03-09 16:49:48
Job end time                    : 2020-03-09 16:49:48
Job duration                    :                 11s
Average job traffic                    :                3B/s
Recorded write speed                    :              0rec/s
Recorded read count                    :                   2
Read/Write failure count                    :                   0