March 2021
Intermediate to advanced
265 pages
6h 50m
Chinese
Content preview from Presto实战
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生产环境部署
｜
67
例如以下日志级别文件：
io.prestosql=INFO
io.prestosql.plugin.postgresql=DEBUG
第一行将
io.prestosql
包内的所有类（包括嵌套包，如
io.prestosql.spi.connector
和
io.prestosql.plugin.hive
）的最低日志级别设置为
INFO
。由于默认的日志级别就是
INFO
，
因此这个例子的第一行设定不会改变任何包的日志级别。将默认级别的设定放在文件中只
是为了让配置更加明显。然而，第二行设定将
PostgreSQL
连接器的日志配置覆盖为
DEBUG
级别。
一共有四个日志级别，按照详细程度从高到低排列依次是
DEBUG
、
INFO
、
WARN
和
ERROR
。本
书在讨论
Presto
故障排除等主题时，可能会参考日志设置。
在设置日志级别时，使用
DEBUG
级别可能会输出特别多的内容。请只在实际
需要排除故障的特定低级别包上设置
DEBUG
级别，以免产生大量的日志信
息，从而对系统性能产生负面影响。
启动
Presto
后，除非你在
etc/node.properties
文件中指定了其他位置，否则将在安装目录下
的
var/log
目录中看到多种日志文件。
launcher.log
此文件由启动器（参见
5.6
节）创建
，它与服务器的标准输出（
stdout
）流和标准错误
（
stderr
）流相连，包含服务器初始化时产生的一些日志信息，以及
JVM
产生的错误和
诊断信息。
server.log
这是
Presto
主要的日志文件
。如果服务器初始化失败 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.