字符串转换为float<1>

zjtest7-frontend:/usr/local/logstash-2.3.4/config# cat g01.conf
input {stdin{}}
 filter {
    grok {
     match => {
     "message" =>"\s+(?<request_time>\d+(?:\.\d+)?)\s+"
     }
   }
     mutate {
                        convert => [ "request_time", "float"]
               }
 }
output {
      stdout {
               codec => rubydebug{}
                }
}

zjtest7-frontend:/usr/local/logstash-2.3.4/config# ../bin/logstash -f g01.conf
Settings: Default pipeline workers: 1
Pipeline main started
begin 123.456 end
{
         "message" => "begin 123.456 end",
        "@version" => "1",
      "@timestamp" => "2016-09-11T05:31:32.576Z",
            "host" => "0.0.0.0",
    "request_time" => "123.456"
}

此时  "request_time" => "123.456" 输出的是字符串

zjtest7-frontend:/usr/local/logstash-2.3.4/config# cat g01.conf
input {stdin{}}
 filter {
    grok {
     match => {
     "message" =>"\s+(?<request_time>\d+(?:\.\d+)?)\s+"
     }
   }
       mutate {
                        convert => [ "request_time", "float"]
               }
 }
output {
      stdout {
               codec => rubydebug{}
                } 

zjtest7-frontend:/usr/local/logstash-2.3.4/config# ../bin/logstash -f g01.conf
Settings: Default pipeline workers: 1
Pipeline main started
begin 123.456 end
{
         "message" => "begin 123.456 end",
        "@version" => "1",
      "@timestamp" => "2016-09-11T05:34:13.040Z",
            "host" => "0.0.0.0",
    "request_time" => 123.456
}

把字符串转换为	float型