I don’t really understand why you think that you’d need to have separate RRD 
files for the ‘daily’ graphs and the ‘monthly’ one.

 

Why not have a single RRD, with two RRAs – one with 1cdp=1pdp (that you use for 
your daily graph) and one with a higher granularity – maybe 1cdp=1hour=4pdp – 
that extends for 62 days (to allow a graph of the last and current calendar 
months).  When you generate your graph, simply use the start and end params to 
specify that you’re making a daily or monthly graph, and the correct RRA should 
be used.  This is how MRTG, Cacti and similar use RRDTool.

 

As you add new data to the RRD, RRDtool will take care of the summarisation and 
expiry of data.  If you want to archive daily data for longer, then simply 
extend the first RRA as far as required.

 

Steve

 

Steve Shipway

[email protected]

 

From: [email protected] 
[mailto:[email protected]] On Behalf 
Of Steven Sim
Sent: Wednesday, 11 June 2014 3:53 a.m.
To: Simon Hobson
Cc: [email protected]
Subject: Re: [rrd-users] If input is already in text format and I craft a perl 
script to parse the text format and update rrd database, what should the step 
and heartbeat be?

 

Simon;

 

What if a single data file has data metrics for a single day ... I can easily 
generate the RRD and Graphs based on this single file single day. (much thanks 
to Steve Shipway valuable pointers)

 

But at the end of the month, my management would want to review the trend for 
the ENTIRE month.

 

What would be an elegant practice for the above?

 

to accumulate data from each day onto a single RRD file?

Warmest Regards
Steven Sim

 

On Tue, Jun 10, 2014 at 4:18 PM, Simon Hobson <[email protected]> wrote:

Steve Shipway <[email protected]> wrote:

> If your metrics are all coming in the same file, for the same point in time, 
> and all being pushed into the RRD at the same time, then it makes sense to 
> have a single RRD to hold them as in your example.  You would usually use a 
> separate RRD if the data came separately, potentially for different times.  
> Then separate RRD would make sense as you may get one sample but not another, 
> or they were sampled at differing times.

To add to that, also consider how things may change over time. Eg, suppose you 
are logging disk/filesystem utilisation - both in terms of data transferred, 
and space used/available.

It would make sense to collate all the quantities from one filesystem into a 
single RRD - so perhaps an RRD with bytes written, bytes read, % space used, 
$inodes used. But, a machine will almost certainly have multiple filesystems, 
and more importantly the number may change - so it would make sense to have one 
RRD/filesystem. Of course, there may well be more than one filesystem on a disk 
- so you might want to collect stats for the physical disk (probably just bytes 
read/written) into one RRD, and have a separate RRD for each physical disk (or 
array) since the number of physical disks/arrays may change (eg if you add a 
disk because you've run out of space).

There isn't really a right and wrong. It's perfectly OK to have lots of small 
RRDs with a single DS each. It's also perfectly OK to have fewer RRDs with many 
DSs each. It's a matter of balancing your requirements with the ability to 
manage the RRDs - and of course, as mentioned above, the requirement to update 
all DSs in a single RRD at the same time.

I tend to use a mixture.
At one extreme I have an RRD for our UPS stats with many parameters logged, and 
another with 508 DSs (data in and out for all 254 usable addresses in our /24 
subnet) - in both cases, data is collected and graphed with custom scripts, and 
all the data is collected in a single operation.
At the other extreme, I have a whole bunch of RRDs with just 2 DSs (data in and 
out) - one per port for a bunch of switches (the data is collected and graphed 
with Cacti), and the data for each port is collected separately (it's the way 
Cacti works).

_______________________________________________
rrd-users mailing list
[email protected]
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

 

Attachment: smime.p7s
Description: S/MIME cryptographic signature

_______________________________________________
rrd-users mailing list
[email protected]
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

Reply via email to