Server Monitoring

Following are few commands used for the Linux server load monitoring and maintenance

Commands:

top: - used for the viewing current process going on the server. You will get a dynamic table of running process as a output .The table content following columns.
For example using more option with the top command you can get a better output
For example: -

top c PID    USER      Page Ranking  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND

PID: - process id
User: - owner of that process
We omit the Page Ranking  NI  VIRT  RES  SHR
%CPU: - CPU usage of the process
%MEM   : - memory usage of the proces                                                                                            TIME+   :-    the process is running form.
COMMAND: - the actual command

You can kill or renice the process  is causing high load on the using the kill command

Format:-
1. Kill -9 PID

-9 is special Kill signal, which will kill the process.

2. Killall process name

killall -9 lighttpd

Another command to view process going on the server,

ps aufx

Usage :-

ps aufx | grep processname

example :-

ps aufx | grep nobody

ps -aux | grep ftp >> used for checking ftp action taken by user like uploading /downloading files

Log files :-
tail -f /usr/local/apache/logs/access_log  :-
tail -f /usr/local/apache/logs/error_log :- site access error logs
tail -f /var/log/exim_mainlog :- mail logs.

usr/local/apache/logs :: access log, error log, if configured php logs, domain logs(domlogs),module logs, httpd pid

tail -f /usr/local/apache/logs/access_log fro httpd



/var/log/

    * /var/log/message: Genreal message and system releated stuff

    * /var/log/auth.log: Authenication logs

    * /var/log/kern.log: Kernel logs

    * /var/log/cron.log: Crond logs

    * /var/log/maillog: Mail logs

    * /var/log/qmail/ : Qmail log directory (more files inside this directory)

    * /var/log/httpd/: Apache access and error logs directory

    * /var/log/lighttpd: Lighttpd access and error logs directory

    * /var/log/boot.log : System boot log

    * /var/log/mysqld.log: MySQL database server log file

    * /var/log/secure: Authentication log

    * /var/log/utmp or /var/log/wtmp : Login records file

    * /var/log/yum.log: Yum log files





For spamming issue or high mail queue you can check the logs 



tail -f /var/log/exim_mainlog | grep sendmail, public_html, tmp



MYSQL:-



mysqladmin processlist :- shows current mysql database usage



watch mysqladmin processlist :- dynamic usage of mysql process .



Service restart commands- /scripts/restartsrv_servicename

restartsrv_entropychat*

restartsrv_exim*

 restartsrv_eximstats*

 restartsrv_ftpserver*

 restartsrv_httpd*

 restartsrv_imap*

restartsrv_inetd*

 restartsrv_interchange*

 restartsrv_ipaliases*

 restartsrv_melange*

 restartsrv_mysql*

 restartsrv_named*

 restartsrv_nsd*

 restartsrv_postgres*

 restartsrv_postgresql*

restartsrv_proftpd*

restartsrv_pureftpd*

 restartsrv_rsyslogd*

restartsrv_spamd*

 restartsrv_sshd*

 restartsrv_syslogd*

restartsrv_tailwatchd*

 restartsrv_tomcat*

 restartsrv_xinetd*