Server Monitoring Tools and Commands

Commands to monitor the process.

===> Find Out The Top 10 Memory Consuming Process

ps -auxf | sort -nr -k 4 | head -10

===> Find Out top 10 CPU Consuming Process

 ps -auxf | sort -nr -k 3 | head -10

===> Max cpu resource usage

ps -eo pcpu,pid,user,args | sort -r -k1 | more

===> To get the long list of a process, if we have pid

 ps -efm –columns 2048 | grep

Iostat

The command iostat report Central Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network filesystems (NFS).

 ...MRTG(Multi Router Traffic Grapher)

  

MRTG (Multi Router Traffic Grapher) is an application that allows us to observe the traffic of a network.

Before Mrtg installation we have to install SNMP on the server.

#yum install net-snmp-utils net-snmp

And we start the server.

# chkconfig –level 345 snmpd

We can see that it is running in port 199.
# service snmpd start


# netstat -natv | grep ‘:199′

tcp 0 0 127.0.0.1:199 0.0.0.0:* LISTEN

Configuration

We run ‘snmpwalk’ which creates a “tree” of information for our network. If you see an output like this one you may proceed with the MRTG installation. Else you should make some configuration first.
# snmpwalk -v 1 -c public localhost IP-MIB::ipAdEntIfIndex

ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.127.0.0.1 = 1
ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.192.168.0.3 = 2

We keep a backup of snmpd.conf just in case anything goes wrong
# cp /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.original

# nano /etc/snmp/snmpd.conf

And do the follow changes:

* Replace following line

com2sec notConfigUser default public

with those

com2sec local localhost public
com2sec mynetwork 10.0.0.0/8 public

(where 10.0.0.0/8 we put what our network is)

* Replace following line

group notConfigGroup v1 notConfigUser
group notConfigGroup v2c notConfigUser

with those

group MyRWGroup v1 local
group MyRWGroup v2c local
group MyRWGroup usm local
group MyROGroup v1 mynetwork
group MyROGroup v2c mynetwork
group MyROGroup usm mynetwork

* find and replace following lines

view systemview included .1.3.6.1.2.1.1
view systemview included .1.3.6.1.2.1.25.1.1

with this

view all included .1 80

* find and replace following line

access notConfigGroup “” any noauth exact systemview none none

with those

access MyROGroup “” any noauth exact all none none
access MyRWGroup “” any noauth exact all all none

* and finally replace those lines

syslocation Unknown (edit /etc/snmp/snmpd.conf)
syscontact Root (configure /etc/snmp/snmp.local.conf)

with something like this

syslocation Linux, Fedora Core 6
syscontact Root root@localhost

We restart the server to take affect of the notices

# service snmpd restart

And we run again

# snmpwalk -v 1 -c public localhost IP-MIB::ipAdEntIfIndex

Now we should see something like that

IP-MIB::ipAdEntIfIndex.10.103.0.33 = INTEGER: 2
IP-MIB::ipAdEntIfIndex.127.0.0.1 = INTEGER: 1

(Where 10.103.0.33 is your ip address. )

MRTG Installation

# yum install mrtg
# mkdir /var/www/html/mrtg/
( in which our graphs and html pages will be kept)

And next run ‘cfgmaker’ for the configuration file to be created.

# cfgmaker –global “workdir: /var/www/mrtg” -ifref=ip –output /etc/mrtg/mrtg.cfg –global ‘options[_]: growright,bits’ public@localhost

With this command we tell MRTG to create a configuration file with the name ‘mrtg.cfg’ for the traffic of our computer (localhost). Instead of localhost you may put the address of any computer you may monitor as long as it runs SNMP.

Next we create our default index page

# indexmaker –output=/var/www/html/mrtg/index.html /etc/mrtg/mrtg.cfg

Apache configuration

MRTG creates a file ‘mrtg.cfg’ under /etc/httpd/conf.d we contains all the necessary for Apache. We change it to contain the ips we want to have access to our MRTG graphs.

Alias /mrtg /var/www/mrtg


Order deny,allow
Deny from all
Allow from 127.0.0.1 10.0.0.0/8

We run the following command

In case you get an error like this
# mrtg /etc/mrtg/mrtg.cfg

ERROR: Mrtg will most likely not work properly when the environment
variable LANG is set to UTF-8. Please run mrtg in an environment
where this is not the case. Try the following command to start:
env LANG=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg
 

You have to run the above command more than once till it runs without any error. This is normal.
# env LANG=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg

26-11-2010 17:28:53, Rateup WARNING: /usr/bin/rateup Can’t remove localhost_2.old updating log file

# env LANG=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg


Now you can access mrtg at

http://127.0.0.1/mrtg

Options Directive

Using this Options directive controls  we can set server features  for a particular directory.

Options  can be set to None, in which case none of the extra features are enabled.

All :

All options except for MultiViews. (Default Settings).

ExecCGI :

Execution of CGI scripts using mod_cgi is permitted.

FollowSymLinks :

The server will follow symbolic links in this directory.

Includes :

Server-side includes provided by mod_include are permitted.

Indexes :

If the directory does not contain any  DirectoryIndex (e.g., index.html) in that directory, then mod_autoindex will return a formatted listing of the directory.

MultiViews :

Content negotiated “MultiViews” are allowed using mod_negotiation.

You have to be very care full while using + and - symbols with Options

For example, without any + and - symbols:


Options Indexes FollowSymLinks


Options Includes

then only Includes will be set for the /home/sibu/test directory.

If the second Options directive uses the + and - symbols:


Options Indexes FollowSymLinks


Options +Includes -Indexes

then the options FollowSymLinks and Includes are set for the /home/kishore/test directory.

Kishore