Page locked

This page is currently locked for editing by another user. You have to wait until this user finishes editing or the lock expires.

Currently locked by: 216.73.216.114,10.1.100.245
Lock expires at: 2025/06/25 18:34 (7 min)

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.

===== Tom's RRd Notes =====

This is an informal collection of notes to help me understand an RRD database.



==== Creation ====
The RRD database is created with the following syntax:

   rrdtool create target.rrd \
         --start 1023654125 \
         --step 300 \
         DS:mem:GAUGE:600:0:671744 \
         RRA:AVERAGE:0.5:12:24 \
         RRA:AVERAGE:0.5:288:31

In this example, **target.rrd** is the name of the database.\\
The **start time** in epoch seconds is given by --start 1023654125\\
The step is the time frequency in seconds. --step 300\\
**DS** is a keyword meaning DataSource followed by the variable name, in this case "mem".\\
**GAUGE** is the type of data which can be COUNTER, DERIVE, ABSOLUTE, GAUGE.Use GAUGE to store the data itself.\\
Next is the **heartbeat**, set to 600 here. If the database doesn't get an update every 300 seconds, in the next 300 second update it will store an UNKNOWN for the missed reading.\\