[smokeping-users] Re: RRDtool database settings

[Leos Bitto]

Hi Tobi,

Tobias Oetiker wrote:
> Hi Leo,
> 
> Today Leos Bitto wrote:
> 
> 
>>Hello everybody,
>>
>>I have succesfully set up SmokePing 2.0rc5 with RRDtool 1.2.11, and
>>sudddenly I found that the resolution of my gathered data (I run FPing
>>every 60 seconds) is lower when viewing older data. I think that I found
>>what is causing this: it's the parameter "AVERAGE  0.5   1  1008" in the
>>configuration file. If I understand it correctly, it means that the data
>>with my desired resolution (1 minute) are kept only for the 1008 last
>>occurences (meaning less than 17 hours). Older data are available only
>>with resolution 12 minutes (covered by "AVERAGE  0.5  12  4320"), and I
>>guess that even older data (older that 12*4320 minutes) would be
>>available with resolution 144 minutes (covered by "AVERAGE  0.5 144
>>720"). Here are my questions:
> 
> 
> ... la suiss 12 points
> 

I don't understand whether 12 points is enough, but as I don't see any 
objections, I think that I got it all right.

> 
> 
>>1) Are there any limitations when choosing those RRDtool database
>>parameters? Currently I am aware of the disk space requirements only.
> 
> 
> there is the long int limit an RRA can not have more than 2^32 rows (or columns)
> 

That's cool, I can easily live with this. I was afraid about some more 
restrictive rules - like that some number would need to be multiplier of 
some other number, etc.

> 
>>2) How can those RRDtool database parameters be configured differently
>>for different hosts (when using the FPing probe)?
> 
> 
> currently this setting is global, you would have to run separate
> smokeping instances ...
> 

I knew about the ability to run multiple instances (I already did this, 
but for other reasons), I just hoped that this could be done with one 
instance only. Now I guess that with careful configuration I could use 
multiple instances of the daemon only, point them to the same datadir, 
and share one cgi script (which would need another configuration file, 
basically a union of all the daemons' configuration) to generate one web 
page. However, having those parameters overridable at the host level 
would definitely be a nice feature for some future version of SmokePing.

> 
>>3) What needs to be done to keep the data which I have already gathered
>>when I decide to change those RRDtool database parameters?
> 
> 
> you can use rrdtool resize to change existing rrd files
> 

That seems easy. I could have found this myself, but I am using RRDtool 
since a week ago only (after I found and started using SmokePing), so 
please be patient with my basic questions.

Thanks a lot for your quick and accurate information, and thanks even 
more for such a nice piece of software!


Leos

--
Unsubscribe mailto:smokeping-users-request at list.ee.ethz.ch?subject=unsubscribe
Help        mailto:smokeping-users-request at list.ee.ethz.ch?subject=help
Archive     http://lists.ee.ethz.ch/smokeping-users
WebAdmin    http://lists.ee.ethz.ch/lsg2.cgi