Source
A source is a start point of a flow and defines how data is acquired from an external data source. A flow may have multiple sources.
Each source specifies:
an input adapter (reader) for collection of real-time data from external sources such as database tables or log files (for more detailed information, see Sources)
properties required by the selected reader, such as a host name, directory path, authentication credentials, and so on
with some readers, a parser that defines what to do with the data from the source (for example, DSVParser to parse delimited files, or FreeFormTextParser to parse using regex)
an output stream to pass the data to other flow components
Here is the TQL code for one of the sources in the MultiLogApp sample application:
CREATE SOURCE Log4JSource USING FileReader (
directory:'Samples/MultiLogApp/appData',
wildcard:'log4jLog.xml',
positionByEOF:false
)
PARSE USING XMLParser(
rootnode:'/log4j:event',
columnlist:'log4j:event/@timestamp,
log4j:event/@level,
log4j:event/log4j:message,
log4j:event/log4j:throwable,
log4j:event/log4j:locationInfo/@class,
log4j:event/log4j:locationInfo/@method,
log4j:event/log4j:locationInfo/@file,
log4j:event/log4j:locationInfo/@line'
)
OUTPUT TO RawXMLStream;Log4JSource uses the FileReader adapter to read …/Striim/Samples/MultiLogApp/appData/log4jLog.xml, parses it with XMLParser, and outputs the data to RawXMLStream. In the UI, the same source looks like this:
Note: The other examples in the Concepts Guide appear in their TQL form only, but they all have UI counterparts similar to the above.