This chapter describes how to monitor machine-load information. The Network Load Balancer (NLB) displays information about the nodes in the NQE cluster. This information is used for load balancing, display of machine load data, and display of request status in the cluster. For more information about cluster-wide request status, see “Using the NQE GUI Status Window” in Chapter 10.
To access machine-load information, click on the Load button of the NQE GUI interface. The window provides the following:
Continually updated status that allows easy comparison of the workload of servers
Visual indication that a host is not providing new data
Pop-up windows that provide information on a server
You can customize the display by editing the .Xdefaults file or using the Chart Editor option on the Options menu of the NQE GUI Load window (see “Configuring NQE Load Window Elements” in Chapter 9, or the nqe(1) man page).
You can view data from the main window, by individual host, and through a miniature summary display.
Figure 15-1 shows the default Load window:
 | Note: You can change the settings of the mouse buttons (see “Configuring NQE Load Window Elements” in Chapter 9). The settings described in this manual are the default settings. |
The Load window is composed of the menu bar, the NQE load display, and the server name display area. Each of these segments is described as follows:
Menu bar. The menu bar is located at the top of the Load window and displays buttons that open Load menus. To open a menu window, place the pointer on the menu name and press the left mouse button.
File menu. The File menu contains the Exit option, which closes all of the windows associated with the NQE load display and terminates the program.
The Options menu contains the Host Selection option, which provides selections for hosts that you want displayed, and the Chart Editor option, which creates new charts, changes the configuration of an existing chart, and adds or removes a chart from the Load window.
View menu. The View menu contains the Chart Formulae option, which displays the formula used to calculate each of the charts.
Help menu. The Help menu lets you view the nqe(1) man page or view information about how to access this manual.
NQE load display. The NQE load display provides continually updated machine load data for participating machines in the cluster. Each of the charts in the display has a title, a scale, and one button per host.
Server name display area. The server name display area displays the name of the server.
The system load application uses the NLB database information supplied by the ccollect program. The ccollect program relies on the sar(1) command to retrieve system performance data. If you are running UNICOS/mk, the sar(1) command will not provide system performance data for memory or swapping usage statistics. Therefore, the NQE Load window for memory demand will display a fixed value of 96% memory demand for the UNICOS/mk platforms.
If you choose Host Selection under the Options menu, a pop-up filter lets you select which hosts are displayed. Figure 15-2 shows this filter:
If you choose Chart Editor under the Options menu, a pop-up window lets you select editing options to create a new chart, change the configuration of an existing chart, and add or remove a chart from the Load window. Figure 15-3 shows the Chart Editor window.
If you choose Edit Chart in the Chart Editor window, a pop-up window lets you select options to change the configuration of an existing chart. Figure 15-4 shows the Edit Chart window.
If you choose Chart Formulae under the View menu, you will see the formulae used that result in the charts displayed on the main window. Figure 15-5 shows this display:
You can view data about a specific host as shown in Figure 15-6. You also can view the same data that is provided on the Load window (memory demand, percentage of system CPU in use, idle CPU, and total I/O per second) grouped by host rather than by type of data (as shown in Figure 15-7).
To display information about a specific host, place the pointer over the button that has the name of the host on the Load window and click the left mouse button. You will receive a display like the one shown in Figure 15-6. When the NLB receives new data, this display is updated.
To cancel this window, click on the Dismiss button at the bottom of the window or click the left mouse button over the host name in the Load window.
To display a window of data that is grouped by host rather than by type of data, position the pointer over the host name on the Load window and click the middle mouse button. As you select additional hosts, the window will expand and include a display for each host you select. Figure 15-7 shows the load summary displayed for four hosts that were selected individually:
To execute an rlogin command for a host, position the pointer over the host name and click on the left mouse button.
To cancel a host summary display, as shown in Figure 15-7, click the middle mouse button over the host name in the Load window. Repeat this action for each host summary you want to cancel.