The query and analysis layer is used for different data management
and data analysis purposes. The data management service
component handles all of the generic data access to different data
sources in the data storage layer and triggers event actions under
pre-defined conditions. The data query component supports query
for data points by specifying their query properties such as data
stream name/id and a time range, as well as optionally providing
tags, block id and unit id. For each request the name or the id of the
data stream needs to be specified in order to locate the data.