November 2021
Intermediate to advanced
340 pages
10h 46m
Chinese
Content preview from Spark快速大数据分析（第2版）
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Spark
应用的优化与调优
｜
155
图 7-1：Spark 3.0 UI 的 Environment 标签页
要想用编程方式设置或修改已有配置，首先要检查该配置项是否允许修改。
spark.conf.
isModifiable("<config_name>")
会返回
true
或
false
。所有可修改的配置项都可以用
API
设置为新的值。
// Scala代码
scala>
spark.conf.get("spark.sql.shuffle.partitions")
res26:
String
= 200
scala>
spark.conf.set("spark.sql.shuffle.partitions", 5)
scala>
spark.conf.get("spark.sql.shuffle.partitions")
res28:
String
= 5
# Python代码
>>>
spark.conf.get("spark.sql.shuffle.partitions")
'200'
>>>
spark.conf.set("spark.sql.shuffle.partitions", 5)
>>>
spark.conf.get("spark.sql.shuffle.partitions")
'5'
所有设置
Spark
配置属性的方式间存在优先级关系，高优先级的配置可以覆盖低优先级的
配置。
Spark
首先会读取
spark-defaults.conf
中定义的值和标志
，然后读取调用
spark-submit ...
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