A collection of metrics to be monitored.

The result of reading a set of metrics.

create () is a fresh registry. This is mostly useful for testing.

The default registry.

Read the current value of each metric.

register t metric collector adds metric to the set of metrics being collected. It will call collector () to collect the values each time collect is called.

register_lwt t metric collector is the same as register t metrics collector but collector returns Sample_set.t LabelSetMap.t Lwt.t.

register_pre_collect t fn arranges for fn () to be called at the start of each collection. This is useful if one expensive call provides information about multiple metrics.

register_pre_collect t fn same as register_pre_collect but fn returns unit Lwt.t.