Data collectors and data servers

MainView for Linux — Servers uses data servers and data collector programs to collect data and store data from various sources to be displayed by views. Specifically, the MainView for Linux — Servers data collectors obtain data from Linux systems and automatically makes the information available to be selected and monitored from the BMC AMI Ops console.

MainView for Linux — Servers collects and displays heartbeat data and requested data. MainView for Linux — Servers always collects data from the monitored Linux system in background mode. For efficiency and response time purposes, heartbeat data is stored in the PAS. Because the SYLOVRZR view displays heartbeat data, the response time when viewing the SYLOVRZR view should be faster than the response time of other real-time views.

When you are viewing other real-time views, the request is sent to the data server that is running on the monitored Linux system. The data server then returns the last sampled value. At this time, demand sampling will start and continue until the view is deactivated and the demand mode sampling duration has expired. The data collector continues sampling data in background sampling mode. This design lets data be collected at lower sampling intervals (low system overhead) when a view is not active. However, data is collected more often when a specific real-time view is activated.

Heartbeat data

Heartbeat data is used for a quick understanding of how your monitored Linux images are running—a “snapshot” of your key system statistics. The Data Server on each monitored Linux image obtains the heartbeat data and sends it to the MainView for Linux — Servers PAS. Key system statistics are collected automatically at specified intervals.

The heartbeat interval is specified by using Monitor Rule parameters. To change these parameters, see Using rules and images. Heartbeat data is available on the SYLOVRZR view. For more information about the SYLOVRZR view, see Using views.

Real-time data

Real-time data is data that you request MainView for Linux — Servers to retrieve and display. Real-time data offers two modes: Background Sampling mode and Demand Sampling mode.

MainView for Linux — Servers is always collecting data in Background Sampling mode. When you invoke a real-time view, Demand Sampling begins automatically. Real-time data is not limited to key system statistics (as heartbeat data is) and can be as new as 10 seconds; however, real-time data is more costly in CPU overhead and network traffic.

The sampling intervals are specified for the Demand Sampling mode and the Background Sampling mode by using the Monitor Rules parameters. To change the sampling intervals, see Rule-parameters

Historical data

MainView for Linux — Servers allows you to effectively re-create the operating environment as it existed during a particular time period in the past. This feature, called the historical data or interval data feature, stores information about your operating environment at the end of each historical data interval, so that you can compare your current system to what it was doing yesterday, last week, or last month—all on the same screen. You can use this information to determine whether current behavior is an anomaly or part of a trend. The default interval is set to 15 minutes. This value is located in BBPARM(MMLTIR00).

At the end of every Background Sampling interval, the data server obtains the data sample from the data collector (either one of the supported VM performance monitors or the BMC z/VM Monitor Reader for z/VM data or BMC Performance Assurance Data Collector for Linux data) and sends it to the PAS. The Background Sampling Interval is set through Monitor Rules and the default is one minute. To change the sampling intervals, see Linux rule parameters.

For information about using historical data, see Displaying historical data, or type HELP TIME on any BMC AMI Ops command line. BMC AMI Ops Infrastructure also describes how to use the TIME command in detail.