To take advantage of the Advanced Server Analysis, the Web Performance Server Monitoring Agent must be installed on your server. The agent will collect performance data from your server while a load test is running.
Most configuration of the server monitoring agent is performed through the Web Performance Load Tester controller. Generally, once the server and controller have been started, an entry for the server will appear in the Servers View of Web Performance Load Tester.
The Server Monitor agent will collect extended metrics for Windows, Linux, and AIX servers with minimal configuration overhead.
To install the Server Monitoring Agent, first download a copy of the installer appropriate for the platform of the server from www.webperformance.com. The installer should then be run on each server that will be monitored during the test. On Windows platforms, a GUI will lead the user through the installation process. For Unix systems, the installer will run on the command line. For example:
chmod +x ServerAgent_Linux_4.2.bin
./ServerAgent_Linux_4.2.bin
Note: In the vast majority of cases the Server Monitor agent does not need any special permissions. On Linux, it does not need root. On Windows, it does not need to be an administrator. It is conceivable that some specific Linux or Windows security policy could prevent the server monitor from accessing the data it needs, however, we rarely if ever encounter such problems in the field. The server monitor agent will, by default, respond to any client who attempts to connect to the ports that it listens to (typically 1099 and an arbitrarily chosen high-numbered port).
The Server Agent can be installed silently by adding the argument "-i silent" to the command line. For example:
./ServerAgent_Linux_4.2.bin –i silent
This will install the server agent with default settings. Alternatively, the installation may be customized by creating a plain-text file named "installer.properties", located in the same directory as the downloaded installer. This file may contain the lines:
INSTALLER_UI=silent USER_INSTALL_DIR=~/Web_Performance_Server_Monitor_Agent USER_SHORTCUTS=~
If any of these lines are omitted, default settings will be used.
An older version of the agent software has already been installed on a server, then it may be upgraded by selecting the corresponding entry in the Servers View and using the "Upgrade" function.
As of version 4.2, it is no longer necessary to import any license onto the agent.
By default, a folder named "Web Performance Server Monitor Agent" will be created in the Start menu. Selecting the option "Server Monitor Agent" will launch a console application while the agent is accepting and/or communicating with Load Tester™. Simply type "quit" at the console to terminate the agent.
By default, a shortcut named "Server_Monitor_Agent" will be installed in the user's home folder. This shortcut will start the Server Monitoring Agent. For example:
root> ./Server_Monitor_Agent
The agent will then run as a console application while the it is accepting and/or communicating with Load Tester™. Simply type "quit" at the console to terminate the agent.
When the monitoring agent starts, it will identify itself on the network, allowing any running Load Tester™ controllers to automatically detect and configure the agent. Depending on your network configuration, the network broadcast may not be routed from the server to the controller. In this case, you will need to add the monitoring agent to the server list manually - using the Add... button in the Servers View. For more information, see the Basic Server Monitoring page - the procedures are similar.
Once the controller has been able to successfully connect to an agent, the agent may be managed through the Servers View.
The data collected by the monitoring agent is automatically integrated into the test results.
In the Load Test Report, select the Servers section for charts and tables detailing the server performance as well as a performance checklist.
In the Metrics View, use the drop-down controls to select the server and the metrics will be presented in the table.
This capability is available only on Linux at this time.
The agent is an interactive command-line application, but it can be made to run as a background process using 'screen'. For your convenience, a script has been created that will start the agent in the background in an automated way.
You can safely launch the agent from /etc/rc.local. To do this, simply add a line to /etc/rc.local as follows:
/home/[USER]/Web_Performance_Server_Monitor_Agent/Start_Server_Monitor_In_Background
Where [USER] is the appropriate login credential. It is also possible to pass this command, for example, as a parameter to ssh:
$ ssh [USER]@example.com './Web_Performance_Server_Monitor_Agent/Start_Server_Monitor_In_Background'
If you have launched the agent as described above, it will be running inside a screen session named WPASA. In general, you can search for screen sessions using:
$ screen -ls
and connect specifically to the agent using:
$ screen -Dr WPASA