Using GNUPlot for Great Justice!
This post was originally written on 2012–10–31 on itbrokeand.ifixit.com by James Pearson. It’s being migrated to a new home on iFixit Engineering.
We here at iFixit are big fans of Graphite, but sometimes I want to plot data that hasn’t made its way into Graphite yet. For instance, today I wanted to see how our CSRF failures have changed over time.
Since we log every failure, we can pull out instances pretty easily with grep:
[$]> grep CSRF php_debug.log | head -n 5
Oct 1 01:16:39 10.250.0.0 php: ◼|>>> [0.0.0.0] Unknown user, invalid CSRF. Found: klFWI Expected: TdWnO Array
Oct 1 01:16:39 10.250.0.0 php: ◼|>>> [0.0.0.0] Unknown user, invalid CSRF. Found: klFWI Expected: TdWnO Array
Oct 1 01:16:40 10.250.0.0 php: ◼|>>> [0.0.0.0] Unknown user, invalid CSRF. Found: b1B35 Expected: 5PDl2 Array
Oct 1 01:16:40 10.250.0.0 php: ◼|>>> [0.0.0.0] Unknown user, invalid CSRF. Found: b1B35 Expected: 5PDl2 Array
Oct 1 01:16:42 10.250.0.0 php: ◼|>>> [0.0.0.0] Unknown user, invalid CSRF. Found: MTXff Expected: CQgPQ Array[$]> grep CSRF php_debug.log > csrf_failures.log
Grouping and counting these entries by date is easy with awkand sort:
[$]> awk '{print $1, $2}' csrf_failures.log | uniq -c
148275 Oct 1
120430 Oct 2
91808 Oct 3
85287 Oct 4
82859 Oct 5
81987 Oct 6
87585 Oct 7
88378 Oct 8
87490 Oct 9
82574 Oct 10
77563 Oct 11
80779 Oct 12
88841 Oct 13
91723 Oct 14
97711 Oct 15
92099 Oct 16
89417 Oct 17
69037 Oct 18
3683 Oct 19
4958 Oct 20
4308 Oct 21
6540 Oct 22
5514 Oct 23
3561 Oct 24
4818 Oct 25
22023 Oct 26
3915 Oct 27
4487 Oct 28
4657 Oct 29
4833 Oct 30
1804 Oct 31By the way, if you’re still scared of awk, go read Why you should learn just a little Awk — it gives you the basics you need to do really useful things without requiring you to learn all the intricacies of the tool.
Now, that’s an interesting set of data, but it’s a bit hard to visualize. Gnuplot is the standard solution for this problem, but its syntax is… a bit difficult to wrangle. Thankfully, Christian Wolf created eplot, a tool that takes stdin and munges it to be gnuplot-consumable. For terminal use, you’ll want to apply this patch:
--- eplot.orig 2012-10-12 17:07:35.000000000 -0700
+++ eplot 2012-10-12 17:09:06.000000000 -0700
@@ -377,6 +377,7 @@
# ---- print the options
com="echo '\n"+getStyleString+@oc["MiscOptions"]
com=com+"set multiplot;\n" if doMultiPlot
+ com=com+"set terminal dumb;\n"
com=com+"plot "+@oc["Range"]+comString+"\n'| gnuplot -persist"
printAndRun(com)
# ---- convert to PDFNow, run our previous command through eplot and... tada!
[$]> awk '{print $1, $2}' csrf_failures.log | uniq -c | eplot
160000 ++---------+----------+-----------+----------+----------+---------++
* + + "/tmp/eplot20121031-4728-zc5s8k-0" ****** +
140000 +* ++
|* |
| * |
120000 ++* ++
| * |
100000 ++ * ++
| * ****** |
| ***** ******** **** * |
80000 ++ *** ****** * ++
| * |
60000 ++ * ++
| * |
| * |
40000 ++ * ++
| * |
20000 ++ * * ++
| * * * |
+ + + + *********** ** +* ********+
0 ++---------+----------+-----------+-----*----+-----**---+-*-------+*
0 5 10 15 20 25 30
