I’ve downloaded and installed the Percona Linux template. I noticed the values for tx-drop had values of ‘m’ and ‘u’ and don’t quite understand why I’m getting values of micro and milli.
I was expecting reading to simply be the number of packet dropped at that point of time but it doesn’t appear so.
So I’m interpreting it as follows:
A defined time period divided by the number of dropped packets. eg. 12.5m would mean 80 packets dropped within a second. 150u would mean 6666.67 packets dropped within a second (1/150u)
Is this interpretation of the reading correct? Thanks.
TX-drop is constantly increasing counter (derive in Cacti).
So the daily graph (5 min avg) should reflect a rate of change in packets dropped/sec within 5 min. interval.
The current value on the graph (for derive) is calculated as (prev_value - cur_value) / 300.
If you see 12.5m, it should translate to X / 300 = 12.5m. Therefore, X = 300 * 12.5/1000 = 3.75 packets dropped within the last 5 min.
Accordingly, 150u == 0.045 packets.
Of course, it shouldn’t be decimal but may be you were looking to weekly or monthly graph where interval is not 300?
Capture “drop” number at the full 5-min. time, i.e. at XX:X5:00. Wait 5 min. and get the new “drop” number.
Calculate the change as (prev_value - cur_value) / 300 and compare with what is shown on the daily graph.