
Money trace plugin
  This is a remap plugin  that allows ATS to participate in a distributed
  tracing system based upon the Comcast "Money" distributed tracing
  and monitoring library.  The Comcast "Money" library has its roots in
  Google's Dapper and Twitters Zipkin systems.  A money trace header or
  session id, is attached to transaction and allows an operator with
  the appropriate logging systems in place, to determine where errors
  and/or latency may exit.

  Use of the library enables the tracing of a transaction through all
  systems that participate in handling the request. See the documentation
  on this open source library at https://github.com/Comcast/money/wiki.

  This plugin checks incoming requests for the "X-MoneyTrace" header.
  If the header is not present no further processing takes place.
  However if the header is present,  the plugin will check to to
  see if the request has been cached.  If so, the plugin will add the
  "X-Moneytrace" header from the incoming request to the cached response
  returned to the client as required by the money_trace protocol.
  If the request has not been cached, the plugin will extends the trace
  context by creating a new "X-MoneyTrace" header for inclusion in the
  outgoing request to a parent cache or origin server.  The extended
  header includes the 'trace-id' from the incoming request, the incoming
  span-id becomes the outgoing parent-id and the plugin generates a new
  random long span id for the outgoing request.  See the documentation
  at the link above for a complete description on the "X-MoneyTrace"
  header and how to use and extend it in a distributed tracing system.

  To configure and use this plugin, simply add it in the remap.config
  file where needed.  EXAMPLE:

  map http://vod.foobar.com http://origin.vod.foobar.com @plugin=money_trace.so


Plugin Author: John J. Rushford, jrushford@apache.org
