On Wed, Oct 2, 2013 at 11:58 AM, John R Pierce pierce@hogranch.com wrote:
but, if you really want historical data going back months, I do think I'd look into something like cactii, which is built on RRDtool, which replaced the legacy mrtg. This will maintain a set of web pages with hourly/daily/weekly/monthly stats of as many parameters as you wish to track going back as far as you like.
For anyone who doesn't know about rrdtool, it is the 'round robin database' that holds time series data with long histories in a small file fixed-size by having a certain number of data points representing 'recent' times where it holds the full-resolution sample values (normally converted to a rate), and as the samples age they are averaged into larger timespan samples so you lose granularity to save space since you usually are more interested in the nearby times. And it includes tools to draw graphs out of the stored data. OpenNMS can either use the standard native-code rrdtool library or a pure-java reimplementation called jrobin.