Cheshire Cat Computing

Hi,

I'm receving an error when using trend.cig. Debug reports the following.

un Aug 6 15:17:17 2006: Starting trending function
Sun Aug 6 15:17:17 2006: ds0,ds1: 400 rows every 7200 from Tue Jul 4 08:00:00 2006
Sun Aug 6 15:17:17 2006: Weighted average for 0 is: 7661.78717922585 = 145573.364576396 / 18.9999227557642, 242 valid samples
Sun Aug 6 15:17:17 2006: Delta=0, Deviation=6684.94157261305 : deltadelta=76.6178717922585, limit 0.00233819188819148
Sun Aug 6 15:17:17 2006: up->7327.54645156641, down->6696.14505434554
Sun Aug 6 15:17:17 2006: Delta=0, Deviation=6684.94157261305 : deltadelta=38.3089358961293, limit 0.00233819188819148
Sun Aug 6 15:17:17 2006: up->6931.55029003483, down->6604.47577160885
Sun Aug 6 15:17:17 2006: Delta set to -38.3089358961293
Sun Aug 6 15:17:17 2006: Weighted average for 1 is: 1427.10348082205 = 27114.8559001011 / 18.9999227557642, 242 valid samples
Sun Aug 6 15:17:17 2006: Delta=0, Deviation=740.423343784695 : deltadelta=14.2710348082205, limit 0.000435517419684463
Sun Aug 6 15:17:17 2006: up->911.929209901674, down->763.17688596129
Sun Aug 6 15:17:17 2006: Delta=0, Deviation=740.423343784695 : deltadelta=7.13551740411025, limit 0.000435517419684463
Sun Aug 6 15:17:17 2006: up->806.36267123407, down->725.005376019092
Sun Aug 6 15:17:17 2006: Delta set to -7.13551740411025
Sun Aug 6 15:17:17 2006: Didn't make the working rrd file
Sun Aug 6 15:17:17 2006: Complete
Sun Aug 6 15:24:49 2006: Starting trending function
Sun Aug 6 15:24:49 2006: ds0,ds1: 400 rows every 7200 from Tue Jul 4 08:00:00 2006
Sun Aug 6 15:24:49 2006: Weighted average for 0 is: 7661.78717922585 = 145573.364576396 / 18.9999227557642, 242 valid samples
Sun Aug 6 15:24:49 2006: Delta=0, Deviation=6684.94157261305 : deltadelta=76.6178717922585, limit 0.00233819188819148
Sun Aug 6 15:24:49 2006: up->7327.54645156641, down->6696.14505434554
Sun Aug 6 15:24:49 2006: Delta=0, Deviation=6684.94157261305 : deltadelta=38.3089358961293, limit 0.00233819188819148
Sun Aug 6 15:24:49 2006: up->6931.55029003483, down->6604.47577160885
Sun Aug 6 15:24:49 2006: Delta set to -38.3089358961293
Sun Aug 6 15:24:49 2006: Weighted average for 1 is: 1427.10348082205 = 27114.8559001011 / 18.9999227557642, 242 valid samples
Sun Aug 6 15:24:49 2006: Delta=0, Deviation=740.423343784695 : deltadelta=14.2710348082205, limit 0.000435517419684463
Sun Aug 6 15:24:49 2006: up->911.929209901674, down->763.17688596129
Sun Aug 6 15:24:49 2006: Delta=0, Deviation=740.423343784695 : deltadelta=7.13551740411025, limit 0.000435517419684463
Sun Aug 6 15:24:49 2006: up->806.36267123407, down->725.005376019092
Sun Aug 6 15:24:49 2006: Delta set to -7.13551740411025
Sun Aug 6 15:24:49 2006: Didn't make the working rrd file
Sun Aug 6 15:24:49 2006: Complete

I was orginally thinking it might be a problem with permissions but that doesn't seem to be the case.

I'm running this on FreeBSD 6.0 stable, trend.cgi v0.6, routers2 v2.16

$TMPPATH & $RRDTOOL are correct. The only other change I have made to trend.cgi is $conffile which is pointing at my routers2.conf file.

Any help you can provide would be appreciated.

thanks

OK, the problem is that it cannot create the temporary RRD file. It can read the existing data, but is not creating the temporary file used to make the graph.

The way it is done is that the data is read, the trending calculations done, then RRDs is called to create a new file and write the data into it.

(The older versions used a temporary .xml file and loaded it in, but the new version is pure RRD)

The message you get is when the do_trending has not created the .rrd file. The strange thing is that you should get an RRDCreate error message in the log in this case explaining WHY there is no file.

The tempoary file lives in $TMPPATH called trend.99999999.rrd for some big number. There *is* a race condition if two people ask for trending at exactly the same second although this is very unlikely.

Check to make sure that $TMPPATH is definitely writeable by the web server process (sometimes SELINUX can cause odd errors?). Also, check your RRDTool version and make sure you dont have multiple different versions installed, as this *might* do something odd like allow reading to work but break writing.

Is it in any way possible that something else might be 'cleaning' the $TMPPATH and deleting the file? The script doesnt check for the success of the update functions, so its possible it was deleted by something else just after its creation - although thats only a few seconds window.

Finally, what version of trend.cgi are you using? Current version is 1.3, I think you have 1.1 (at least 1.2 is needed for RRDTool v1.2.x)

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11

(sigh) it helps if I have the correct version. I had grabbed trend.cgi from the site instead of the routers2 compressed file. Now that I have corrected that all is good.

Thanks for the reply.

Pete

Great to hear it now works. I'll try to keep the one on the site up to date (although I think it mentions that the most recent version is always in the routers2 package)

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11

Yeah, I have seen that mentioned. I just didn't think about it this time around. Thanks again.