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Parent Topic: Getting Started with Configuring the Server
Systems with many devices or with devices that perform frequent acquisitions can quickly require a significant amount of disk space to store data. NI InsightCM Server provides features for automatically discarding some data events after configurable conditions are met. This automatic process, called aging, is useful for conserving space on disk while maintaining a desirable collection of data.
NI InsightCM Server applies the aging process to one periodic data event that results from a time, delta EU, or force trigger at a time. However, for streams, which consist of multiple data events, the aging process discards an entire set of stream data events at a time. NI InsightCM Server maintains separate aging strategies for stream and periodic data, as the following table describes.
|Note NI InsightCM Server ignores periodic data events triggered by an alarm transition and never deletes them due to aging.|
|Data Type||Where to Configure|
|Periodic||navigation menu »Options, then select Periodic Aging Strategy|
|Streaming||navigation menu »Options, then select Streaming Aging Strategy|
Periodic data events can contain a data set and a trend point, whereas stream data events contain only a trend point. After the daily aging process runs, NI InsightCM Server reduces trend point only data events to one point per hour. If a data event contains a data set and a trend point, NI InsightCM Server counts that as the trend point for that hour and deletes all other trend points.
In addition to allowing you to permanently retain all data events, NI InsightCM Server provides a calendar-based strategy to determine when and how much data it discards. The calendar-based aging strategy follows a time-based schedule to discard data events or sets of stream data after a configurable number of days. You can optionally configure the strategy to discard all but the data sets collected at a specific time. For example, consider a strategy that, after two days elapse, deletes all periodic data events but those collected at 12:00pm. This is useful because it allows you to retain some data to trend over an extended period of time. You can also choose to retain data events that have alarms or comments associated with them and exclude data events from a particular operating state.
|Note The aging process runs every fifteen minutes, so NI InsightCM Server might not discard data immediately after the aging condition is met.|
The following table compares how two different aging strategies operate on data. In these examples, assume Day 1 begins with zero data events.
|Strategy||Day 1||Day 2||Day 3|
|Calendar-based—Retain from the past two days||3||0||3||3||0||6||4||All three from Day 1||7|
|Calendar-based—Retain from the past two days,
and then permanently retain the data event collected at 12:00pm every day
All collected on Day 1
except the one collected at 12:00pm
In this example, the calendar-based strategy in the last row can be useful because, although you might want to allow access to all acquired data during the recent past, the same amount of data might less useful in the long term. For example, consider equipment that experiences a failure. You might want to review data from every single acquisition that occurred during a few days prior to the failure. However, data from twenty days prior to the failure might be less useful. Instead, you might want to view data from only one acquisition per day during that extended time period.
You can identify data that NI InsightCM Server exempts from aging if the Trend viewer shows data points from times that defy aging rules. For example, if NI InsightCM Server is configured to delete all periodic data three days after collecting it, but the Trend viewer displays a value that is five days old, the data might be exempt from aging.
In some cases, you might want to ensure data from a specific acquisition remains available for viewing regardless of aging strategies. For example, if you observe an anomaly or value of interest, you might want to ensure you and others can view the data for a longer period of time than the aging strategy allows. You can ensure NI InsightCM Server retains data in one of two ways:
|Note Refer to Preserving Data for Future Viewing for more information about retaining data.|