Server Monitoring Tools

The term of Server Monitoring describe as an application that consistently monitor server performance and resources usage to ensure that your company’s SLA are met. System administrator will be alert when ever server monitoring tool detect symptoms that indicate server resources usage are over limit.

There many commercial products for server monitoring in the market with advanced functionality and there is some product are free although the functionality are limited to only basic monitoring. For this article I would like to introduce you with server monitoring program which already pre-installed on Unix system. It monitors server performance and resources usage and provide a report regularly depending on your setting.

System Activity Report (SAR)

System Activity Report is bundled with sysstat package – a collection of linux performance monitoring tools which include sar, sadf, mpstat, iostat, nfsiostat, cifsiostat, pidstat and sa. By interpreting the reports provided by above monitoring tools, you can identify system bottlenecks and suggest some possible solutions on performance problems.

Example report produce as per below screen shot.

Setup sysstat package.

First step is to check if your server already installed with sysstat package.

Output below show server are already installed with sysstat package

If it return empty, it’s mean you doesn’t have sysstat package installed in your server. To setup by run command below:

Output:

Configuration

By default retention period for SAR logs will remain in server for 7 days and will be removed when retention period exceed. Therefore if you wish to increase retention period please edit below file and change value for HISTORY accordingly. Strongly recommended to increase log retention period to 30 days.

# vi /etc/sysconfig/sysstat

In order for SAR to capture server performance data, cronjob sysstat will execute script sa1 every 10 minutes to gather all resources usage and stored into file sa<day> located at /var/log/sa/. Later the second script sa2 will be executed at 23:53pm everyday to interpreted data collected by sa1 and stored into file sar<day> at same location.

If you wish to gather server performance data more often example like 2 minute, edit file below.

# vi /etc/cron.d/sysstat

Change to 2 minute

Once done, start sysstat service.

Output:

Congratulation, SAR program are successful installed in your server. In few days you will get your daily report on server performance at location /var/log/sa/.

For next article, I will brief more detail on how we can manage to convert above boring text report format into more beautiful graph report format.