Xymon Mailing List Archive search

Default Graph SIze

list Ralph Mitchell
Fri, 23 Dec 2011 17:59:48 -0500
Message-Id: <CAAEjoCWPFiw7=8NtfzJf=user-3579bea204e6@xymon.invalid>

The one day graph *would* look fine, but I kinda like the 3-day.

The "blocky" look I'm seeing comes from RRD generating the graph using the
best datasource to fit the size you're asking for.  By default, the first
data store contains 576 points at 5 minute intervals, which covers 2 days.
 The second data store contains 576 point at 30 minute intervals, which is
12 days.  Each of the 30-minute data points is generated by averaging
together 6 of the 5-minute data points.  If you ask rrd to generate a 3 day
graph, there are not enough points in the first data store, so it uses the
second store and each point on the graph then covers more pixels.

It's the same effect as zooming in on a graph.  To fix it, I've resized the
existing RRDs to hold 864 data points, so there will be enough fine-grain
data to get a decent 3-day graph.

Ralph Mitchell


2011/12/23 James Wade <user-659655b2ea05@xymon.invalid>
Ralph,

I just changed TrendSeconds to 8640 (1 day)  and left the RRDWIDTH the
same. I get a one day graph which looks fine.

James

On Fri, Dec 23, 2011 at 9:38 AM, Ralph Mitchell <user-00a5e44c48c0@xymon.invalid>wrote:
On Thu, Dec 22, 2011 at 5:02 PM, Henrik Størner <user-ce4a2c883f75@xymon.invalid> wrote:
On 22-12-2011 22:56, James Wade wrote:
I'm doing a new installation of xymon. Everything is working great, but
I'm in the process of configuring and could use some assistance, so you
might see a few more posts from me.

Is there a way to have the graphs on each default to a different
setting? As an example, when looking at cpu, instead of a two day graph
have a one hour graph. Is there a global setting?
TRENDSECONDS in xymonserver.cfg. If you change this, then you'll
probably also want to change the RRDWIDTH setting, which defines the size
of the graph image.

On www.xymon.com, TRENDSECONDS is set to 259200 = 3 days, and RRDWIDTH
is set to 864; the reasoning being that with measurements every 5 minutes
there are 288 measurements per day, so 3 days = 864 measurements. Matching
the RRDWIDTH setting with this means that each measurement gets 1 pixel.
If I set  TRENDSECONDS & RRDWIDTH, I get blocky graphs, presumably due to
there not being sufficient data at the normal resolution.  To fix that, I
*think* I need to:

1) resize all the the rrd files with 'rrdtool resize' - wrote a script
for that
2) alter server/etc/rrddefinitions.cfg to set the defaults for new rrd -
done that

Did I miss anything?

Thanks,

Ralph Mitchell