使用Pyspark与HBase交互的最佳方法是什么?



我正在使用pyspark [spark2.3.1]和hbase1.2.1,我想知道使用pyspark访问HBase的最佳方法是什么?

我进行了一些初始级别的搜索级别,发现几乎没有使用SHC核心的选项:1.1.1.1-2.1-s_2.11.jar,这可以实现,但是无论我尝试寻找一些示例,在大多数地方,代码都以Scala编写,示例也基于Scala。我尝试在pyspark中实现基本代码:

from pyspark import SparkContext
from pyspark.sql import SQLContext
def main():
    sc = SparkContext()
    sqlc = SQLContext(sc)
    data_source_format = 'org.apache.spark.sql.execution.datasources.hbase'
    catalog = ''.join("""{
        "table":{"namespace":"default", "name":"firsttable"},
        "rowkey":"key",
        "columns":{
            "firstcol":{"cf":"rowkey", "col":"key", "type":"string"},
            "secondcol":{"cf":"d", "col":"colname", "type":"string"}
        }
    }""".split())
    df = sqlc.read.options(catalog=catalog).format(data_source_format).load()
    df.select("secondcol").show()
# entry point for PySpark application
if __name__ == '__main__':
    main()

并使用:

运行它
spark-submit  --master yarn-client --files /opt/hbase-1.1.2/conf/hbase-site.xml --packages com.hortonworks:shc-core:1.1.1-2.1-s_2.11  --jars /home/ubuntu/hbase-spark-2.0.0-alpha4.jar HbaseMain2.py

它正在让我返回空白输出:

+---------+
|secondcol|
+---------+
+---------+

我不确定我在做什么错?也不确定最好的方法是什么?

任何参考都将不胜感激。

问候

最后,使用 SHC ,我可以使用Pyspark代码连接到HBASE-1.2.1。以下是我的工作:

  • 我所有的Hadoop [Namenode,DataNode,NodeManager,ResourceManager]&HBASE [HMASTER,HREGIONSERVER,HQUORUMPER] Deamons在我的EC2实例上启动并运行。

  • 我将emp.csv文件放置在HDFS位置/test/emp.csv,带有数据:

key,empId,empName,empWeight
1,"E007","Bhupesh",115.10
2,"E008","Chauhan",110.23
3,"E009","Prithvi",90.0
4,"E0010","Raj",80.0
5,"E0011","Chauhan",100.0
  • i创建 readwritehbase.py 文件,具有以下代码[用于从HDF读取emp.csv文件的行,然后在HBase中首先创建tblemloyee,将数据推入tblem opplionee,然后再次读取读取来自同一表的某些数据并在控制台上显示它]:

    from pyspark.sql import SparkSession
    def main():
        spark = SparkSession.builder.master("yarn-client").appName("HelloSpark").getOrCreate()
        dataSourceFormat = "org.apache.spark.sql.execution.datasources.hbase"
        writeCatalog = ''.join("""{
                    "table":{"namespace":"default", "name":"tblEmployee", "tableCoder":"PrimitiveType"},
                    "rowkey":"key",
                    "columns":{
                      "key":{"cf":"rowkey", "col":"key", "type":"int"},
                      "empId":{"cf":"personal","col":"empId","type":"string"},
                      "empName":{"cf":"personal", "col":"empName", "type":"string"},
                      "empWeight":{"cf":"personal", "col":"empWeight", "type":"double"}
                    }
                  }""".split())
        writeDF = spark.read.format("csv").option("header", "true").option("inferSchema", "true").load("/test/emp.csv")
        print("csv file read", writeDF.show())
        writeDF.write.options(catalog=writeCatalog, newtable=5).format(dataSourceFormat).save()
        print("csv file written to HBase")
        readCatalog = ''.join("""{
                    "table":{"namespace":"default", "name":"tblEmployee"},
                    "rowkey":"key",
                    "columns":{
                      "key":{"cf":"rowkey", "col":"key", "type":"int"},
                      "empId":{"cf":"personal","col":"empId","type":"string"},
                      "empName":{"cf":"personal", "col":"empName", "type":"string"}
                    }
                  }""".split())
        print("going to read data from Hbase table")
        readDF = spark.read.options(catalog=readCatalog).format(dataSourceFormat).load()
        print("data read from HBase table")
        readDF.select("empId", "empName").show()
        readDF.show()
    # entry point for PySpark application
    if __name__ == '__main__':
        main()
    
  • 使用命令在VM控制台上运行此脚本:

    spark-submit --master yarn-client --packages com.hortonworks:shc-core:1.1.1-2.1-s_2.11 --repositories http://nexus-private.hortonworks.com/nexus/content/repositories/IN-QA/ readwriteHBase.py
    
  • 中间结果:阅读CSV文件后:

    +---+-----+-------+---------+
    |key|empId|empName|empWeight|
    +---+-----+-------+---------+
    |  1| E007|Bhupesh|    115.1|
    |  2| E008|Chauhan|   110.23|
    |  3| E009|Prithvi|     90.0|
    |  4|E0010|    Raj|     80.0|
    |  5|E0011|Chauhan|    100.0|
    +---+-----+-------+---------+
    
  • 最终输出:从HBase读取数据后:

    +-----+-------+
    |empId|empName|
    +-----+-------+
    | E007|Bhupesh|
    | E008|Chauhan|
    | E009|Prithvi|
    |E0010|    Raj|
    |E0011|Chauhan|
    +-----+-------+
    

Note :创建HBase表并将数据插入HBase表中时,它预计数字跨度应该大于3,因此我在将数据添加到HBase

时添加了options(catalog=writeCatalog, newtable=5)

相关内容

  • 没有找到相关文章

最新更新