exometer_statsd reports everything as gauge

[ludwikbukowski]

Even though statsd provides protocol for histograms, timers, sets and counters.
And seems that there exists code for that [1], but most likely is not used.
When I used dbg to trace UDP formats sent, everything is sent as gauge (its from elixir shell but it doesnt matter):

(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"counters">>,".",<<"lookups">>,".","value"],
 ":","1","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"counters">>,".",<<"lookups">>,".",
  "ms_since_reset"],
 ":","5002","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"histograms">>,".",
  <<"ecto_exec_query_time">>,".","mean"],
 ":","10072","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"histograms">>,".",
  <<"ecto_exec_query_time">>,".","min"],
 ":","10072","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"histograms">>,".",
  <<"ecto_exec_query_time">>,".","max"],
 ":","10072","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"histograms">>,".",
  <<"ecto_exec_query_time">>,".","median"],
 ":","10072","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"histograms">>,".",
  <<"ecto_exec_query_time">>,".","90"],
 ":","10072","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"histograms">>,".",
  <<"ecto_exec_query_time">>,".","95"],
 ":","10072","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"histograms">>,".",
  <<"ecto_exec_query_time">>,".","99"],
 ":","10072","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"spirals">>,".",<<"ecto_query_count">>,".",
  "count"],
 ":","1","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok
(<0.597.0>) call gen_udp:send(#Port<0.37825>,{127,0,0,1},8125,[[<<"empex">>,".",<<"dev">>,".",<<"spirals">>,".",<<"ecto_query_count">>,".",
  "one"],
 ":","1","|","g"])
(<0.597.0>) returned from gen_udp:send/4 -> ok

[EDIT]
As I look closer to the implementation, there is an undocumented option type_map which seems to define the mapping for the statsd

[1] https://github.com/Feuerlabs/exometer/blob/master/src/exometer_report_statsd.erl#L119

[ludwikbukowski]

However, seems that there is not simple and generic way to define type_map for e.g histograms when we don't know exactly the name of the metric.
Its because exometer creates the histograms on his own and only after that sends the values.
I mean that the function Reporter:report/5 will be called for each histogram's value type (99, mean, median etc).