Thanks for the clarification, We are using newgaugemetric collector, which in turn convert data in to Prometheus gauge format. We need to use gauge to monitor metric value at some point. Counter won't works in our case.
Function which we are using to convert in Prometheus gauge format. prometheus.NewGauge(prometheus.GaugeOpts) Can you please put some light on custom collector or any example we can refer to or any exporter where someone used same custom collectors.?? That would be a great help for us. Thanks and regards On Sat, Jan 23, 2021, 7:04 PM Stuart Clark <[email protected]> wrote: > On 23/01/2021 13:15, akshay sharma wrote: > > Thanks for the clarification, > > > > It makes sense, but why we are deleting the data as soon as Prometheus > > scrapes becuase next time (at t15minutes) we can't register same > > metric ,as it is already registered at time t1. We are using > > Prometheus go client and that's the limitation. > > > > And if we delete data or unregistered at t15, and add new data or > > register again with new values then will loose data which was register > > by other go routines and which haven't processed yet. > > > > So how can we monitor dynamic metrics ?? > > Or how can we resolve above issue? > > > > Or can we do ,only set.value (for the metric was already register) > > instead of unregister and register again? Using goclient library.?? > > I'm not as directly familiar with the Go client library, but my > understanding is it operates very similarly with other ones such as the > Python one. > > Broadly there are two ways to use the client library. The first is for > direct instrumentation of an application. With this you create > counter/gauge/etc objects and then when something happens (e.g. > increment a counter on an event, add request time to a counter) you use > those objects to adjust the current metric state. Separately you have > the HTTP interface which allows Prometheus (or any other system which > can understand OpenMetrics or Prometheus exposition format) to fetch the > current metric state. > > The second mechanism, which sound like the one you actually want, is > commonly used for exporters where the metric information isn't created > via code running and adjusting objects directly, but instead by calling > an external service and converting the returned data or (as in your > case) querying a cache of such data. For that you would register a > custom collector which is called on every scrape. That collector is then > responsible for doing whatever is needed to obtain the information > (again for you just look at some local state data storage) and then > convert and return the data in the correct Prometheus format. The > difference between the two can be easily seen with a counter. For direct > instrumentation you would have an object that represents the counter and > then you would use the increment method to adjust its value based on the > events that are occurring (e.g. adding the timing of an action to a > counter). At no point does the main code know or care what the current > value of the counter is - that is purely for the HTTP interface to use. > For an exporter the custom collector instead creates an object during > the scrape process (rather than it being created on startup) and > directly sets the value (not using increments). > > Some Python code can be found here to explain that: > > https://godoc.org/github.com/prometheus/client_golang/prometheus#hdr-Custom_Collectors_and_constant_Metrics > > For Go the equivalent documentation seems to be here: > > https://godoc.org/github.com/prometheus/client_golang/prometheus#hdr-Custom_Collectors_and_constant_Metrics > > From what you describe I'm not sure if you are using the custom > collector method or are trying to use the mechanism designed for direct > instrumentation. > > -- You received this message because you are subscribed to the Google Groups "Prometheus Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/prometheus-users/CAOrgXNKY2jpZj2UXFNKm8hcrY5h6hJtzOdaUTegcz4UAsdM4vA%40mail.gmail.com.
