How to 'createTimer' and 'Timer.cancel' when item change state?

[rlkoshak (Rich Koshak)]

Good Tutorial On Persistence (RRD4J and JDBC-MYSQL)?

The most complete documentation for persistence is the wiki. Persistence rrd4j MySQL The big trick with rrd4j and charts is you must save updates every minute (it’s complicated and has to do with how rrd4j works) or else charts will be blank. Also, rrd4j can only save numerical data so String Items cannot be saved there.