polyglot conversion is asynchronous on http request. We want to measure polyglot time elapse on conversion. 

On Polyglot Restle, record the checkin timestamp in rabbitmq, the sender will receive the timestamp from the rabbitmq and calculate the diff between the checkin time and sending time.

the diff consists of the elapse of request sending to polyglot, request queueing time and input/output file(transferring time) and conversion time.