Description:
Discussed since 1.3 so there may be an old bug report from a long time ago.
MEM records data for graphs at a certain resolution. As more servers or metrics are added logically the space requirements increase. While recent data is very important it is important for DBAs and sysadmins to look at trends going back in time up to perhaps 1 year or longer.
Other monitoring or graphical systems collect this data but store longer period information at a lower resolution, rolling up the shorter high resolution details as needed. This has the advantage of giving you a good idea of the information and at the same time reducing storage space (but also time to retrieve the information) significantly.
How to repeat:
Not checked in MEM 3 as I don't have enough data but MEM 2.3 has shown considerable delay in rendering long term graphs as the resolution of stored data is high. Disk space constraints have also made it impossible to collect data for as long as would be desirable.
Suggested fix:
Consider applying some sort of rollup + collection at lower resolution for the data that's being collected to allow me to see further back and reduce I/O and performance issue when dealing with long time periods.
For other software which does this look at:
- cacti
- graphite
- RRD tool
Maintaining the storage of the metrics in a database is fine if needed, even if the tools above do this differently.
