A Monotonic Counter (uint64) is used to measure the rate at which an event is occurring, when the source data is a monotonically increasing number. A minimum of two samples must be sent, in order to calculate a delta value and report it to the backend as a rate-per-second. A variety of networking metrics may be reported monotonically, and this metric type provides a convenient means of recording these values, at the expense of a slower time-to-first metric.

Call Set() when an event occurs:

```cpp

include

int main() { auto config = Config(WriterConfig(WriterTypes::UDP)); auto r = Registry(config);

// Option 1: Directly create a Monotonic Counter uint64_t
auto interfaceBytes = r.CreateMonotonicCounterUint("iface.bytes");
interfaceBytes.Set(10);

// Option 2: Create a Monotonic Counter uint64_t from a MeterID
auto interfaceBytesMeter = r.CreateNewId("iface.bytes");
r.CreateMonotonicCounterUint(interfaceBytesMeter).Set(10);

} ```