Chapter 4 - DSpace at Waseda University

27
Chapter 3
The most widely used system monitoring tool is Nagios [66], which is the for network
monitoring. Nagios is able to monitoring host and network. The internet service is possible
the remote control for the local server monitoring. For example, the system monitor can
execute Nagios by using network and manage monitoring reports as connecting to central
management server.
There is another system monitoring tool, which is mostly used in Linux, order top. Order
top is to print out the condition of the process, CPU and memory, and operating time and
average loading number. There are two orders – ntop and htop.
Ntop [67] is a free network monitoring software. Ntop displays network usage information
in a similar fashion to the top command output. The current version of ntop features both
command line and web-based user interfaces, and is available on both UNIX and Win32
platforms. Ntop focuses on:
• Traffic measurement,
• Traffic monitoring,
• Network optimization and planning, and
• Detection of network security violations.
Htop [68] is similar to the top command with few additional features. The main difference is
that you can use a mouse to interact with the htop command output. Figure 3.3 shows htop,
an interactive process viewer for Linux. It is a text-mode application (for console or X
terminals).