This blog post provides an explanation of Viewpoint portlet date/time stamp behavior. The rationale for the blog post is that often new customers conclude that their portlets are not working correctly as the time stamp does not match the current time or rewind time. So let's do a quick review on the intent of the portlet time stamp.
The time stamp is located in the portlet header of portlets that display information focused on points in time. This is why portlets that work off durations of time (like Query Spotlight or the trending portlets Capacity Heatmap and Metrics Graph) don't display a time stamp. An example of the time stamp is circled below in the System Health portlet.
The time stamp conveys a subtle piece of information about the data that is being displayed in the portlet. To review, data in Viewpoint is pulled from Teradata systems through a series of data collectors enabled and configured in the Admin - Teradata Systems setup menu. Each data collector has a default (but configurable) collection rate for how often it collects the associated information. The Teradata Viewpoint Configuration Guide provides a list of data collectors with an excellent explanation of what data is being collected in what manner, and identification of what portlets leverage that information.
The information being displayed in Viewpoint is dependent on when the data is collected by a particular data collector, and also the behavior of a particular portlet. The intent of the time stamp is to notify users about the CURRENCY of the data being displayed, not a reflection of the current time or rewind time. Here are a few examples for better understanding this behavior.
The first and most common example is where a portlet shows a time stamp related to the associated data collection. With the Query Monitor portlet it relates to the chosen "rewind" time although the portlet has the same behavior in real time. The Query Monitor portlet depends on the Sessions data collector, which by default collects information based on the Teradata session sampling rate (every 30 seconds). So it is considered normal operation (considering the 30 second data collection) that the time displayed in Query Monitor may be up to a minute different from current or "rewind" time as shown below, because the last data collection was in the prior minute.
If one would leverage the rewind forward by seconds option, the next data collection would be encountered at some point in that minute and realign with the actual rewind time as shown below (9:29:18 versus prior 9:29:15).
The second example is with the Productivity portlet which displays information based on 15-minute intervals. So this example is more about the behavior of the portlet than the associated data collection shown above. As this portlet works off 15-minute intervals, one will only see the time stamp reflecting minute intervals of 00, 15, 30, or 45 past the hour. This justifies the discrepancy shown below where the System Health portlet is displaying a time closer to real time than the Productivity portlet.
In conclusion, the Viewpoint portlet time stamp is not intended to match real time or rewind time. Its intent is to indicate that the data being displayed is relevant to the time stamp of the portlet. This time stamp behavior helps to highlight the currency of the data within that portlet. This avoids comparison confusion when using multiple portlets for analysis that may have different points of collection. Hope that helps and thanks for reading.
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