Custom Graphing Troubleshooting

[Vernon Everett]

OK, here it is again, for your reading pleasure. :-)
Cut and pasted from my sent items - you may have to read the original thread
to appreciate the context, but the process is sound for any graph
The original thread is here
http://www.hswn.dk/hobbiton/2010/06/msg00068.html

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Hi

When in doubt, take it from the top.
1. Make sure data is coming through. (You have an icon, so it probably is)
2. Check that USERS:227 really is on its own line in the html display. (Use
view source in your browser) Anything else on that line will cause problems,
and your data will not go into the rrd file.
3. Check that an appropriate rrd file is being created.
4. Check that there is data in the rrd file. rrdtool dump <rrdfile.rrd> |
grep name (Should see "<name> USERS </name>")
5. Check there is data too. rrdtool dump <rrdfile.rrd> | grep "/row>" | grep
-v "NaN" (You should see values between <v> and </v>

If all of the above are good, then you are getting data, and storing it.
This means your issue is in the graphing. (See below)
If they are failing, check as follows
1a. Make sure your test is running correctly and sending data properly.
(troubleshooting guides available in many places)
2a. Modify your data output to ensure the data:value is really on its own
line. NOTHING may share the line. Even if it looks alone in the display, it
may have HTML formatting stuff before or after. This will cause it to break.
3a. Make sure the appropriate entries exist in hobbitserver.cfg. (looks OK
in your case) If in doubt use NCV_testname="*:GAUGE" It's a hack, but valid,
and adds anything it thinks is a value to the rrd file. Once you know what
the entry looks like in the rrdfile (see step 4 above) you can refine the
NCV entry, delete the rrdfile and let it start over. Remember, a restart is
required after making changes to hobbitserver.cfg
4a. Make sure the rrd helper apps are running on your server. Check
~/server/etc/hobbitlaunch.cfg to make sure nothing related to rrd is
disabled. If in doubt, do a restart. Log files may also help here.
5a. Check the log files. Normally /var/log/xymon/rrd*.log Lots of grep
required to make it look sane.

As mentioned, if all of the above is good, then we probably have a graphing
problem.
Looking at your graph definition, we need to check the following.
6. [graphname] must match the test name as seen on the main page and must be
unique. (You are getting empty graphs, so this is probably correct)
7. TITLE and YAXIS is free-form text, they can be anything, but no special
characters please.
8. DEF is a vital line, and you need to get it right.
    DEF:AnyName=rrdfile.rrd:
column_name:AVERAGE
    This is defining an internal "variable" called AnyName to be the value
of the column_name in rrdfile.rrd
    column_name must match the name you get from doing rrdtool dump
rrdfile.rrd (Step 4 above) Getting this bit wrong is common.
9. AREA defines the graph type, data and colour.
AREA:AnyName#00CC00:Description
    AREA could be LINE1, LINE2, it merely defines your graph type. (As long
as it's valid, it should be good)
    AnyName has to correspond to the "variable" you defined in the DEF line.
(See 8 above) Get it wrong, no graph.
    #00CC00 is an HTML colour definition See here for a partial list of
valid values. http://html-color-codes.com/
    Description is what will appear next to the colour legend just below the
graph. (It's also free-form, but no special characters)
10. COMMENT is also free-form, but no special characters. (Comment it out
for troubleshooting)
11. The GPRINT lines are simply defining your min, max, cur and average
values below the graph. For troubleshooting, you can comment them out.
(Process of elimination)

Be patient. Because you are using averages, it needs data to average. So it
needs at least 2 values. If you have bad timing, it could take as long as 10
minutes to collect 2 values.

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