Importing Miscellaneous Data

This module reports on several variables that are not collectled as part of collectl's core metrics, partly because some of them don't exactly fit into collectl's main stats, but some users still find useful. There are also a few instructive techniques used in this simple module that are worth calling out:

use of its own routine grepProc() to find a specific entry in /proc and return either the first instance or the count of instances, noting that using the real grep has far too much overhead due to the grep process start-up and tear-down
support for a different monitoring interval yet still displays, exports and logs the data every cycle
ability to pass additional parameters with values, in this case the interval
use of getExec() for running another process to get the number of logged in users, noting this is slower than getProc() and the command being used is slow enough that a different monitoring interval is needed to avoid excess overhead.

The following example shows one importing both hello.ph and misc.ph while displaying cpu data and running all at the same interval:

[root@cag-dl585-02 collectl]# collectl -sc --import hello:misc
#<--------CPU--------><-Hello-><------CMU Extras----->
#cpu sys inter  ctxsw   Total   UTim  MHz MT Huge Log
   0   0  1034    149     140     94 2197  1    0   4
   0   0  1010    138     230     94 2197  1    0   4

In this example we're just doing the 2 imports, setting the misc monitoring interval to 2 and exporting the data with lexpr. As you can see, the hello data is reported every interval but the misc data only every other one:

[root@cag-dl585-02 collectl]# collectl --import hello:misc,i=2 --export lexpr
sample.time 1239625280.001
hwtotals.val 140
misc.uptime 93
misc.cpuMHz 2197
misc.mounts 1
misc.logins 4
sample.time 1239625281.001
hwtotals.val 230
sample.time 1239625282.002
hwtotals.val 319
misc.uptime 93
misc.cpuMHz 2197
misc.mounts 1
misc.logins 4
sample.time 1239625283.002
hwtotals.val 410
sample.time 1239625284.002
hwtotals.val 500
misc.uptime 93
misc.cpuMHz 2197
misc.mounts 1
misc.logins 4
sample.time 1239625285.002
hwtotals.val 590

updated Feb 21, 2011