Spark使用OSS Select加速数据查询 _云知道

本文介绍如何配置Spark使用OSS Select加速数据查询，以及使用OSS Select查询数据的优势。
背景信息本文所有操作基于 Apache Impala(CDH6) 处理OSS数据搭建的CDH6集群及配置。
说明文中所有${}的内容为环境变量，请根据您实际的环境修改。
步骤一：配置Spark支持读写OSS由于Spark默认没有将OSS的支持包放到它的CLASSPATH里面，所以我们需要配置Spark支持读写OSS 。您需要在所有的CDH节点执行以下操作：

进入到${CDH_HOME}/lib/spark目录，执行如下命令：

[root@cdh-master spark]# cd jars/
[root@cdh-master jars]# ln -s ../../../jars/hadoop-aliyun-3.0.0-cdh6.0.1.jar hadoop-aliyun.jar
[root@cdh-master jars]# ln -s ../../../jars/aliyun-sdk-oss-2.8.3.jar aliyun-sdk-oss-2.8.3.jar
[root@cdh-master jars]# ln -s ../../../jars/jdom-1.1.jar jdom-1.1.jar
进入到${CDH_HOME}/lib/spark目录，运行一个查询。

[root@cdh-master spark]# ./bin/spark-shell
WARNING: User-defined SPARK_HOME (/opt/cloudera/parcels/CDH-6.0.1-1.cdh6.0.1.p0.590678/lib/spark) overrides detected (/opt/cloudera/parcels/CDH/lib/spark).
WARNING: Running spark-class from user-defined location.
Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel).
Spark context Web UI available at http://x.x.x.x:4040
Spark context available as 'sc' (master = yarn, app id = application_1540878848110_0004).
Spark session available as'spark'.
Welcome to
______
/ __/_____ _____/ /__
_ / _ / _ `/ __/'_/
/___/ .__/_,_/_/ /_/_version 2.2.0-cdh6.0.1
/_/

Using Scala version 2.11.8 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_152)
Type in expressions to have them evaluated.
Type :help for more information.

scala> val myfile = sc.textFile("oss://{your-bucket-name}/50/store_sales")
myfile: org.apache.spark.rdd.RDD[String] = oss://{your-bucket-name}/50/store_sales MapPartitionsRDD[1] at textFile at <console>:24

scala> myfile.count()
res0: Long = 144004764

scala> myfile.map(line => line.split('|')).filter(_(0).toInt >= 2451262).take(3)
res15: Array[Array[String]] = Array(Array(2451262, 71079, 20359, 154660, 284233, 6206, 150579, 46, 512, 2160001, 84, 6.94, 11.38, 9.33, 681.83, 783.72, 582.96, 955.92, 5.09, 681.83, 101.89, 106.98, -481.07), Array(2451262, 71079, 26863, 154660, 284233, 6206, 150579, 46, 345, 2160001, 12, 67.82, 115.29, 25.36, 0.00, 304.32, 813.84, 1383.48, 21.30, 0.00, 304.32, 325.62, -509.52), Array(2451262, 71079, 55852, 154660, 284233, 6206, 150579, 46, 243, 2160001, 74, 32.41, 34.67, 1.38, 0.00, 102.12, 2398.34, 2565.58, 4.08, 0.00, 102.12, 106.20, -2296.22))

scala> myfile.map(line => line.split('|')).filter(_(0) >= "2451262").saveAsTextFile("oss://{your-bucket-name}/spark-oss-test.1")可正常执行查询，则部署生效。