[collectd] What is GaugeMax of tail plugin?

[Denis Melnikov]

Hi!

collectd-4.9.2_1

collectd.conf(5) says: "GaugeMax    Use the greatest number only."
My collectd.conf is:

<Plugin "tail">
  <File "/var/log/nginx-access.log">
    Instance "nginx"
    <Match>
      Regex " 200 resp=([0-9]+\\.[0-9]+)"
      DSType "GaugeMax"
      Type "response_time"
      Instance "max"
    </Match>
  </File>
</Plugin>

My RRD graph to see overall maximum is:

DEF:maxresp=tail-nginx/response_time-max.rrd:value:MAX \
VDEF:maxall=maxresp,MAXIMUM \
GPRINT:maxall:%.1lf

Now if I see for example 783.3 on my graph I believe I can see
" 200 resp=783.3" in the logfile. But I don't see it!
Instead, I find " 200 resp=1537.387".
`rrdtool fetch` lists as follows:

1284033470: 2.4634500000e+01
1284033480: 7.8328150000e+02
1284033490: 7.7944550000e+02
1284033500: 1.9102000000e+01

So '783.3' is what RRD stores. But I want to see 1537.387 - the actual
maximum.
Is it possible? Otherwise, what is a benefit of GaugeMax?

Sincerely,
Denis