1 | Thrift API for HDFS |
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2 | ================== |
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3 | |
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4 | Introduction: |
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5 | ============ |
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6 | |
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7 | The Hadoop Distributed File System is written in Java. An application |
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8 | that wants to store/fetch data to/from HDFS can use the Java API |
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9 | This means that applications that are not written in Java cannot |
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10 | access HDFS in an elegant manner. |
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11 | |
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12 | Thrift is a software framework for scalable cross-language services |
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13 | development. It combines a powerful software stack with a code generation |
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14 | engine to build services that work efficiently and seamlessly |
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15 | between C++, Java, Python, PHP, and Ruby. |
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16 | |
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17 | This project exposes HDFS APIs using the Thrift software stack. This |
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18 | allows applciations written in a myriad of languages to access |
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19 | HDFS elegantly. |
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20 | |
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21 | |
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22 | The Application Programming Interface (API) |
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23 | =========================================== |
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24 | The HDFS API that is exposed through Thrift can be found in if/hadoopfs.thrift. |
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25 | |
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26 | Compilation |
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27 | =========== |
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28 | The compilation process creates a server org.apache.hadoop.thriftfs.HadooopThriftServer |
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29 | that implements the Thrift interface defined in if/hadoopfs.thrift. |
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30 | |
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31 | Th thrift compiler is used to generate API stubs in python, php, ruby, |
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32 | cocoa, etc. The generated code is checked into the directories gen-*. |
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33 | The generated java API is checked into lib/hadoopthriftapi.jar. |
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34 | |
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35 | There is a sample python script hdfs.py in the scripts directory. This python |
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36 | script, when invoked, creates a HadoopThriftServer in the background, and then |
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37 | communicates wth HDFS using the API. This script is for demonstration purposes |
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38 | only. |
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39 | |
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