Statsd should expose "separator" configuration

[kri5]

When using templates using statsd, it seems that it uses a graphite parser, which is good because it reuses existing code.

The main issue here is that e619493 introduces a change in the way it is working, as it uses a "." separator, instead of a "_" previously.

The best would be to provide a way of specifying a separator in the statsd configuration.

Looking at the tests i don't know how they are still passing.

I have no good idea on how to implement that.

[sparrc]

Can you be more specific? What is not expected? Give some input/output examples

[kri5]

@sparrc Considering the documentation of the module, it's expected to have something like that

templates = [
"cpu.* measurement.measurement.region",
"mem.* measurement.measurement.host"
]
which would result in the following transformation:

cpu.load.us-west:100|g
=> cpu_load,region=us-west 100

mem.cached.localhost:256|g
=> mem_cached,host=localhost 256

But it result in having dotted measurement like

mem.cached.localhost:256|g
=> mem.cached,host=localhost 256

[sparrc]

@kri5 What version are you running and can you show me your config? that should not happen if the convert_names = true option is set

[kri5]

@sparrc i do not use convert_names, as that is not what i want to do here

it seems caused because the graphite template parser is called with a '.' separator https://github.com/influxdata/telegraf/blob/master/plugins/inputs/statsd/statsd.go#L434

Before e619493 the parser was called with '_'

convert_names implies that my dashes '-' would transform to '__' and that's not the behaviour i expect.

[sparrc]

okay, that option was added because some users actually want to keep the dot-separated metrics. So I think this issue is basically about separating out two options in the config:

1. convert . -> _
2. convert - -> __

[kri5]

@sparrc i was more thinking about adding a separator config that would be passed to the graphite parser, to be consistent with the statsd and graphite template documentation, instead of simply passing ".".

[sparrc]

that's a good idea too, and actually should be fairly simple

[jwerak]

@sparrc I have for example metric system.io.r_s -> my metric separator is .
What should be my config to keep it this way?

[jwerak]

ok, I can see the problem is in ouput plugin -

https://github.com/influxdata/telegraf/blob/master/plugins/outputs/datadog/datadog.go#L74 - this is really weird default behavior...

[sparrc]

can you open a separate issue for that?

[jwerak]

done #1024