文件输入不适用于logstash

当我使用stdin作为输入流时,我得到了正确的输出.但每当我使用该文件作为输入时,输出会在以下消息后冻结.

"Using milestone 2 input plugin 'file'. This plugin should be stable but if you see strange behavior, please let us know."

这是我的配置文件.

input {
  file {
    path => ["c:/users/a/b/c/logstash-1.4.1/bin/logs/logfile.log"]
    start_position => beginning
  }
}

filter {
    grok {
                patterns_dir => "./patterns"
                break_on_match => "false"
                match => ["message", "%{MY_DATE:my_date}"]
        }
    grok {
                patterns_dir => "./patterns"
                break_on_match => "false"
                match => ["message", "%{DATE:date}"]
        }
    grok {
                patterns_dir => "./patterns"
                break_on_match => "false"
                match => ["message", "%{TIME:time}"]
        }
    grok {
                patterns_dir => "./patterns"
                break_on_match => "false"
                match => ["message", "%{LOG_LEVEL:log_level}"]
        }
    grok {
                patterns_dir => "./patterns"
                break_on_match => "false"
                match => ["message", "%{SERVER:server}"]
        }
    grok {
                patterns_dir => "./patterns"
                break_on_match => "false"
                match => ["message", "%{CLASS_NAME:class_name}"]
        }

}

output {
  stdout { codec => rubydebug }
  elasticsearch { host => localhost }
 }

我的文件路径格式是否错误？