执行ruby代码时出现Logstash错误（发生ruby异常：未定义浮点分配器）

试图在logstash中执行以下代码，但它一直引发异常

if [received_at] and [sent_at] {
    ruby {
      init => "require 'time'"
      code => "
        received_by_finacle = (Time.parse(event.get('received_at').to_f)*1000).round(2);
        sent_out_by_finacle = (Time.parse(event.get('sent_at').to_f)*1000).round(2);
        event.set('delta', (sent_out_by_finacle - received_by_finacle)).to_s;
        event.set('epoch_received_at_in_milliseconds', received_by_finacle);
        event.set('epoch_sent_at_in_milliseconds', sent_out_by_finacle);
        "
      add_tag => [ "calculated_time_difference" ]
    }
}  

返回的错误是

[2018-10-10T22:01:05,631][ERROR][logstash.filters.ruby ] Ruby exception occurred: allocator undefined for Float
[2018-10-10T22:01:05,640][ERROR][logstash.filters.ruby ] Ruby exception occurred: allocator undefined for Float

---

你知道为什么吗？

多亏了logstash社区的一位成员@Ganesh_Venkataraman，我才想出了解决办法。我不得不加上一个“救援零”（稍后会读更多）。 这是最终对我有用的代码

if [received_at] and [sent_at] {
    ruby {
        init => "require 'time'"
        code => "
            received_by_finacle   = (Time.parse(event.get('received_at')).to_f)*1000;
            sent_out_by_finacle   = (Time.parse(event.get('sent_at')).to_f)*1000;
            timetaken = (sent_out_by_finacle - received_by_finacle) rescue nil;
            event.set('time_delta',timetaken);
            event.set('epoch_received_at_in_milliseconds',received_by_finacle);
            event.set('epoch_sent_at_in_milliseconds',sent_out_by_finacle);
            "
            add_tag => [ "calculated_time_difference" ]
    }
} 

谢谢