Glances: installing and tuning default thresholds on RedHat ES6
Glances is a free (under LGPL license) tool, written by Nicolas HENNION (aka Nicolargo) in Python and using libstatgrab to monitor your system.
I like the concept and it’s very easy to install and to handle.
I used to work a lot with top and sar on linux but now if I have the opportunity to install Glances, I do it.
Conceptually Glances is more like nmon on AIX, or glance on HP-UX (quite the same name, what a coincidence?).
Installation:
Download Glances (1.3.7 on this post) :
Compile glance (you will need gcc) :
# tar ztf glances-1.3.7.tar.gz # cd glances-1.3.7/ # ./configure # make # make install
Then install libstatgrab and pystatgrab librairies.
# rpm -Uvh libstatgrab-0.15-1.el6.rf.x86_64.rpm # rpm -Uvh pystatgrab-0.5-9.el6.x86_64.rpm
You will not found the 2 rpm on RH ES6 CDs but you can find them on rpm.pbone.net for instance.
Don’t try to install pystatgrab from the sources: it won’t work as it uses pkg-config and pkg-config is not able to locate the libs on RedHat (don’t now why?).
Run Glances:
# glances.py
From the screenshot one can see that the server’s main statistics are available on one screen:
Cpu, load, Memory, Network, Disk I/O, Disk space, and process
For the monitoring part you have colors for current thresholds overflow and an history of the last 3 to 10 warning and critical alerts.
For more information see the man page or Nicolargo’s web site (in French):
If you want to change the default limits, you will have to edit glances.py
# locate glances.py /usr/local/bin/glances.py # vi /usr/local/bin/glances.py
Find glancesLimits class :
class glancesLimits(): """ Manage the limit OK,CAREFUL,WARNING,CRITICAL for each stats """ # The limit list is stored in an hash table: # limits_list[STAT] = [ CAREFUL , WARNING , CRITICAL ] # Exemple: # limits_list['STD'] = [ 50, 70 , 90 ] __limits_list = { # CAREFUL WARNING CRITICAL 'STD': [50, 70, 90], 'LOAD': [0.7, 1.0, 5.0] }
And modify the default limits, for instance:
__limits_list = { # CAREFUL WARNING CRITICAL 'STD': [40, 50, 70], 'LOAD': [0.2, 0.5, 1.0]
Now you can see that while cpu% user if still lower than 90, the color is now red, meaning CRITICAL and the process who were in CAREFUL state before (<70) are now in WARNING state. Same comment on the load.