"timing($name, $time, $sample_rate = 1)"¶

Log timing information. Time is assumed to be in milliseconds (ms).

    Net::Statsd::timing('some.timer', 500);

"increment($counter, $sample_rate=1)"¶

"increment(\@counter, $sample_rate=1)"¶

Increments one or more stats counters

    # +1 on 'some.int'
    Net::Statsd::increment('some.int');
    # 0.5 = 50% sampling
    Net::Statsd::increment('some.int', 0.5);

To increment more than one counter at a time, you can pass an array reference:

    Net::Statsd::increment(['grue.dinners', 'room.lamps'], 1);

You can also use "inc()" instead of "increment()" to type less.

"decrement($counter, $sample_rate=1)"¶

Same as increment, but decrements. Yay.

    Net::Statsd::decrement('some.int')

You can also use "dec()" instead of "decrement()" to type less.

"update_stats($stats, $delta=1, $sample_rate=1)"¶

Updates one or more stats counters by arbitrary amounts

    Net::Statsd::update_stats('some.int', 10)

equivalent to:

    Net::Statsd::update_stats('some.int', 10, 1)

A sampling rate less than 1 means only update the stats every x number of times (0.1 = 10% of the times).

"gauge($name, $value)"¶

Log arbitrary values, as a temperature, or server load.

    Net::Statsd::gauge('core.temperature', 55);

Statsd interprets gauge values with "+" or "-" sign as increment/decrement. Therefore, to explicitly set a gauge to a negative number it has to be set to zero first.

However, if either the zero or the actual negative value is lost in UDP transport to statsd server because of e.g. network congestion or packet loss, your gauge will become skewed.

To ensure network problems will not skew your data, "Net::Statsd::gauge()" supports packing multiple values in single UDP packet sent to statsd:

    Net::Statsd::gauge(
        'core.temperature' => 55,
        'freezer.temperature' => -18
    );

Make sure you don't supply too many values, or you might risk exceeding the MTU of the network interface and cause the resulting UDP packet to be dropped.

In general, a safe limit should be 512 bytes. Related to the example above, "core.temperature" of 55 will be likely packed as a string:

    core.temperature:55|g

which is 21 characters, plus a newline used as delimiter (22). Using this example, you can pack at least 20 distinct gauge values without problems. That will result in a UDP message of 440 bytes (22 times 20), which is well below the safe threshold of 512.

In reality, if the communication happens on a local interface, or over a 10G link, you are allowed much more than that.

"send(\%data, $sample_rate = 1)"¶

Squirt the metrics over UDP.

    Net::Statsd::send({ 'some.int' => 1 });

"_sample_data(\%data, $sample_rate = 1)"¶

This method is used internally, it's not part of the public interface.

Takes care of transforming a hash of metrics data into a sampled hash of metrics data, according to the given $sample_rate.

If "$sample_rate == 1", then sampled data is exactly the incoming data.

If "$sample_rate = 0.2", then every metric value will be marked with the given sample rate, so the Statsd server will automatically scale it. For example, with a sample rate of 0.2, the metric values will be multiplied by 5.