# March 2, 2022 release notes¶

## OPAL¶

### Updated metrics functions¶

• rate() function and rate rollup method

The rate() function has been simplified, it now has the same behavior for both gauge and cumulativeCounter type metrics. If the next recorded value for a metric is less than the previous, we presume the metric was reset back to zero between observations. rate() now always returns a positive value.

The previous gauge behavior, where the rate could be negative, was very rarely used. This update simplifies the more common case, and also applies to the rate rollup method.

• deriv() function

If you need the original gauge type behavior, where a decreasing value results in a negative rate, use deriv() instead.