Local Wrapper

The local wrapper is used for communication between two different virtual sensors in the same GSN instance.

Parameters:

• query This is a sql query sent to perform filtering at the source. This query can only contain one single table (no joins, self-joins, inner-selects) and basic filtering (no aggregation, group by, having, database specific key words. Notice that if you don't specify the TIMED field in your query (eg. select HEAP, NON_HEAP from memorymonitorvs) then the time assigned to the data will be the current time.
• name This an alternative to the query (query has a higher priority), if you only specify name without query, GSN generates select * from NAME as the value of the query parameter.
• start-time The system starts downloading the historical data. Once the historical items delivered, the data producer sends the real time data as they get produced.

 <source alias="source1" sampling-rate="1" storage-size="1">
   <address wrapper="local">
      <predicate key="query">select * from MemoryMonitorVS</predicate>
      <predicate key="start-time">2001-02-06T11:56:10.004+02:00</predicate>
   </address>
   <query>select *  from wrapper</query>
 </source>