SparkSql函数文档

spark sql也支持函数,但与通常的数据库函数有些区别,附上官方api文档,以作备忘: http://spark.apache.org/docs/latest/api/sql/index.html#acos

Maven如何正确导入本地包,保证在线上正常运行

方法一:直接通过命令导入本地包 mvn install:install-file -Dfile=your-artifact-1.0.jar \ [-DpomFile=your-pom.xml] \ [-Dsources=src.jar] \ [-Djavadoc=apidocs.jar] \ [-DgroupId=org.some.group] \ [-DartifactId=your-artifact] \ [-Dversion=1.0] \ [-Dpackaging=jar] \ [-Dclassifier=sources] \ [-DgeneratePom=true] \ [-DcreateChecksum=true] 方法二:通过plugin导入本地包 pom设置 <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-install-plugin</artifactId> <version>2.5.1</version> <executions> <execution> <id>install-jar-lib</id> <goals> <goal>install-file</goal>

为服务开启BBR加速

脚本: wget --no-check-certificate https://github.com/teddysun/across/raw/master/bbr.sh && chmod +x bbr.sh && ./bbr.sh 查看结果: sysctl net.ipv4.tcp_available_congestion_control

Scala运算符优先顺序

运算符的优先级由其第一个字符决定 以下列出的字符按优先级从高到低的顺序排列 (all letters) | ^ & < > = ! + - * / % (all other special characters)