1. UTF-8编码，无BOM格式，否则容易乱码
2. 经过压缩的JSON——单行文件
3. 带有line terminators——否则会导致不出发logstash的event
通过配置output为：
output { stdout { codec => json }
输出：
{"name":"lll","sex":"xxx","age":123,"@version":"1","@timestamp":"2016-03-07T15:51:04.211Z","path":"/home/data/test.json","host":"virtual-machine"}
可以发现，输出的内容也满足以上3个特点。
通过配置output为：
output { stdout { codec => rubydebug #codec => json }
输出：
Logstash startup completed
{
"name" => "lll",
"sex" => "xxx",
"age" => 123,
"@version" => "1",
"@timestamp" => "2016-03-07T15:51:43.005Z",
"path" => "/home/data/test.json",
"host" => "virtual-machine"
}
可以发现，输出的格式为ruby JSON。
原文：http://www.cnblogs.com/licongyu/p/5252505.html