seastar::metrics Namespace Reference

Detailed Description

metrics creation and registration

the metrics namespace holds the relevant method and classes to generate metrics.

The metrics layer support registering metrics, that later will be exported via different API protocols.

To be able to support multiple protocols the following simplifications where made:

1. The id of the metrics is based on the collectd id
2. A metric could be a single value either a reference or a function

To add metrics definition to class A do the following:

• Add a metrics_group memeber to A
• Add a a set_metrics() method that would be called in the constructor.

In A header file

#include "core/metrics_registration.hh"
class A {
  metric_groups _metrics
 
  void setup_metrics();
 
};

In A source file:

include "core/metrics.hh"
 
void A::setup_metrics() {
  namespace sm = seastar::metrics;
  _metrics = sm::create_metric_group();
  _metrics->add_group("cache", {sm::make_gauge("bytes", "used", [this] { return _region.occupancy().used_space(); })});
}

Classes
class	description
	Human-readable description of a metric/group. More...
class	double_registration
struct	histogram
	Histogram data type. More...
struct	histogram_bucket
	Histogram bucket type. More...
class	label
	Class that creates label instances. More...
class	label_instance
	Label a metrics. More...
class	metric_definition
class	metric_group
	hold a single metric group Initialization is done in the constructor or with a call to add_group More...
class	metric_group_definition
class	metric_groups
	holds the metric definition. More...

Typedefs
using	metric_type_def = sstring
using	metric_name_type = sstring
using	instance_id_type = sstring
using	group_name_type = sstring

Functions
template<typename T >
impl::metric_definition_impl	make_gauge (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={})
	Gauge are a general purpose metric. More...
template<typename T >
impl::metric_definition_impl	make_gauge (metric_name_type name, description d, T &&val)
	Gauge are a general purpose metric. More...
template<typename T >
impl::metric_definition_impl	make_gauge (metric_name_type name, description d, std::vector< label_instance > labels, T &&val)
	Gauge are a general purpose metric. More...
template<typename T >
impl::metric_definition_impl	make_derive (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={})
	Derive are used when a rate is more interesting than the value. More...
template<typename T >
impl::metric_definition_impl	make_derive (metric_name_type name, description d, T &&val)
	Derive are used when a rate is more interesting than the value. More...
template<typename T >
impl::metric_definition_impl	make_derive (metric_name_type name, description d, std::vector< label_instance > labels, T &&val)
	Derive are used when a rate is more interesting than the value. More...
template<typename T >
impl::metric_definition_impl	make_counter (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={})
	create a counter metric More...
template<typename T >
impl::metric_definition_impl	make_absolute (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={})
	create an absolute metric. More...
template<typename T >
impl::metric_definition_impl	make_histogram (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={})
	create a histogram metric. More...
template<typename T >
impl::metric_definition_impl	make_histogram (metric_name_type name, description d, std::vector< label_instance > labels, T &&val)
	create a histogram metric. More...
template<typename T >
impl::metric_definition_impl	make_histogram (metric_name_type name, description d, T &&val)
	create a histogram metric. More...
template<typename T >
impl::metric_definition_impl	make_total_bytes (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={}, instance_id_type instance=impl::shard())
	create a total_bytes metric. More...
template<typename T >
impl::metric_definition_impl	make_current_bytes (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={}, instance_id_type instance=impl::shard())
	create a current_bytes metric. More...
template<typename T >
impl::metric_definition_impl	make_queue_length (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={}, instance_id_type instance=impl::shard())
	create a queue_length metric. More...
template<typename T >
impl::metric_definition_impl	make_total_operations (metric_name_type name, T &&val, description d=description(), std::vector< label_instance > labels={}, instance_id_type instance=impl::shard())
	create a total operation metric. More...
future	configure (const boost::program_options::variables_map &opts)
	set the metrics configuration
boost::program_options::options_description	get_options_description ()
	get the metrics configuration desciprtion

Variables
const bool	metric_disabled
label	shard_label

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Class Documentation

seastar::metrics::histogram_bucket

struct seastar::metrics::histogram_bucket

Class Members
uint64_t	count
double	upper_bound

Typedef Documentation

group_name_type

using seastar::metrics::group_name_type = typedef sstring

A group of logically related metrics