Near Real Time (NRT) data

When you use the Data Access API or develop reports to run on demand, be mindful of whether you are requesting data through Near Real Time (NRT). Any request for current day data might include NRT data, which is obtained from the DataChannel, and merged with information retrieved from the database. The reporting queries are most optimized for database extraction rather than the DataChannel polling.

Avoid creating reports or Data Access requests that frequently retrieve large amounts of NRT data, as NRT data causes a significant performance burden on the system and result in delayed response time. Examples of such reports and requests include:

  • Resource Summary tables that include and sort on NRT statistics. The NRT statistics are lastValue, lastTime and BurstViolation.
  • Group Time Series charts with the NRT feature enabled.
  • Data Access requests by using the DVRSTProperty API for lastValue, lastTime, or BurstViolation statistics.
  • Data Access requests by using the DVTSProperty API for a large set of resources.

NRT polling is triggered when the preceding reports and requests include the current day in the specified time period. NRT polling can be handled for small sets of resources and metrics on an occasional basis when it is critical to view the most recently collected information.