[cricket-users] Graphing the Delta

[Tory M Blue]

W0w seems like it's been some time since I've had to ask a question.

I'm looking to trend/graph the delta. I will have an ever increasing
counter that I would like to grab the delta and graph that. (for
trending).

So I really want to be able to subtract the current result from the
previous result and having a hard time working that out. What am I
missing?

Thanks
Tory

[Chris Adams]

Post by Tory M Blue
W0w seems like it's been some time since I've had to ask a question.
I'm looking to trend/graph the delta. I will have an ever increasing
counter that I would like to grab the delta and graph that. (for
trending).
So I really want to be able to subtract the current result from the
previous result and having a hard time working that out. What am I
missing?

That's the way the interface counters work, so you can look at those for
examples. You want to use DERIVE or COUNTER as your rrd-ds-type; note
that this is set at RRD creation time, so simply changing the Cricket
config later won't help. You'll have to re-create (or at least dump,
edit, and restore) your RRDs.

See "man rrdcreate" for a little bit of discussion about DERIVE vs.
COUNTER.

[Tory M Blue]

Chris responded>

Post by Chris Adams
That's the way the interface counters work, so you can look at those for
examples.  You want to use DERIVE or COUNTER as your rrd-ds-type; note
that this is set at RRD creation time, so simply changing the Cricket
config later won't help.  You'll have to re-create (or at least dump,
edit, and restore) your RRDs.
See "man rrdcreate" for a little bit of discussion about DERIVE vs.
COUNTER.

Thanks guys,

Ya I rebooted and figured out that my question was flawed (brain
reboot, not system). I'm running a query on a DB and getting a
response with say, how many rows , I than run that same query an hour
later and would like to know how much it's changed.

Using DERIVE and COUNTERS my numbers in the graphs are like 6 1 2 when
the actual results of the query were;

Retrieved data for rows (): 281392,20695,88650

And the numbers previous were

Retrieved data for rows (): 281016,20654,88501

So I'm unclear where cricket/rrd is grabbing the results of 6,1,2 ( as
seen in the graph), when the differential is quite a bit more.

I thought maybe it was in my scaling or use of integer in precision,
but that doesn't seem like the case. In all honesty would be nice to
follow this with getting the difference from the day previous at the
same check time. But right now something is not right, not using
scaling, not using units, but something is giving me the wrong results

Thanks again

Tory

[Chris Adams]

Post by Tory M Blue
Ya I rebooted and figured out that my question was flawed (brain
reboot, not system). I'm running a query on a DB and getting a
response with say, how many rows , I than run that same query an hour
later and would like to know how much it's changed.
Using DERIVE and COUNTERS my numbers in the graphs are like 6 1 2 when
the actual results of the query were;
Retrieved data for rows (): 281392,20695,88650
And the numbers previous were
Retrieved data for rows (): 281016,20654,88501

(281392 - 281016) / 60 = 6.27 (6) per minute
(20695 - 20654) / 60 = 0.68 (1) per minute
(88650 - 88501) / 60 = 2.48 (2) per minute

Post by Tory M Blue
So I'm unclear where cricket/rrd is grabbing the results of 6,1,2 ( as
seen in the graph), when the differential is quite a bit more.

What are you expecting your graph to look like?

[Tory M Blue]

Post by Chris Adams
(281392 - 281016) / 60 = 6.27 (6) per minute
(20695 - 20654) / 60 = 0.68 (1) per minute
(88650 - 88501) / 60 = 2.48 (2) per minute

Post by Tory M Blue
So I'm unclear where cricket/rrd is grabbing the results of 6,1,2 ( as
seen in the graph), when the differential is quite a bit more.

What are you expecting your graph to look like?

Your a smart one :) Thanks.. I don't really care about the per minute,
I need to know how many rows have been added in the hour. And really
thanks, I had no idea. but that makes perfect sense now.

What I would like it to look like? I would like it to show me how many
rows were added in the last hour. I guess with what you told me here,
I could multiple the results by 60 (that just seems silly). It's
dawning on me that I'm missing a large bit of
information/understanding of what rrd/cricket is doing here

thanks Chris

Tory

[Richman, Marc]

Is there a reason you are not using the DERIVE datasource type?

-----Original Message-----
From: Tory M Blue [mailto:***@gmail.com]
Sent: Tuesday, August 18, 2009 1:40 PM
To: cricket-***@lists.sourceforge.net
Subject: [cricket-users] Graphing the Delta

W0w seems like it's been some time since I've had to ask a question.

I'm looking to trend/graph the delta. I will have an ever increasing
counter that I would like to grab the delta and graph that. (for
trending).

So I really want to be able to subtract the current result from the
previous result and having a hard time working that out. What am I
missing?

Thanks
Tory