RRDtool is a database designed for storing and displaying time-series data such as network bandwidth, temperatures, or stock prices. It uses approximations and controlled memory loss to store data efficiently while allowing for quick setup and use with included graphics capabilities. The document discusses various performance improvements that can be made to RRDtool such as disk striping, tmpfs storage, optimizing buffer cache usage through fadvise and madvise calls, and implementing an RRD cache daemon to batch updates. New features in recent versions include improved graphics, integration with other databases, predictive functions, and remote graphing through the cache daemon.

1. RRDtool - how to make it sit up and beg?
Tobias Oetiker
OETIKER+PARTNER AG
GoOpen 09

2. about rrdtool
a database with controlled memory loss
data is only an approximation of reality
quick setup and use
graphics included

3. designed for speed

4. diy performance improvements
rrd is disk bound
striping
nvram
tmpfs and copy

5. scientific approach
Dave Plonka, LISA’07
vm optimization kills rrd
fix read-ahead with fadvise random
batch updates of a single rrd
running 320k RRD updates every 5 Minutes

6. buffer cache is king
empirical evidence shows cache helps
no-cache: double the work
worse: writes gets blocked by read

7. active buffer cache management with fadvise
fadvise and madvise
RANDOM - no read ahead
DONTNEED - drop synced data from cache
highly implementation dependent
linux >= 2.6.18 gets it right
keep only the hot blocks

8. features of RRDtool 1.3
active buffer cache management with fadvise and madvise
memory mapped io (bernhard fischer)
holt winters with moving baseline (evan miller)
cairo and pango for graphics
pdf, svg, eps output
inline text formatting
anti-aliasing controllable

9. rrd cache daemon
multiple updates to the same rrd are the fastest
cache daemon batches updates
journal replay for crash case
remote updates (no auth)

10. features of RRDtool 1.4
beta out now
rrd cache daemon (florian forster and kevin brintnall)
libdbi integration for instant db access (martin sperl)
graph prediction functions (martin sperl)
graph legend placement (melchior rabe)
inline text formatting

11. features of RRDtool 1.5
portable data format
remote graphing through rrd cache daemon
authentication for rrdcached
...

12. ?

13. Tobi Oetiker <tobi@oetiker.ch>

14. Graph Critic - HTTP Cache Traffic
graph by Charles Glass

15. Graph Critic - RTT of MPLS VPN endpoints
graph by Bruno Ciscato

16. Graph Critic - System Information
graph by kmindi

17. Graph Critic - Energy Mix
graph by Lutz Schulze

18. Graph Critic - Thermostat Indoor / Outdoor
graph by Andres Brownworth