org.apache.tez.runtime.api

Interface Output

All Known Subinterfaces:

LogicalOutput

All Known Implementing Classes:

AbstractLogicalOutput

@InterfaceAudience.Public
public interface Output

Represents an Output through which a TezProcessor writes information to an edge.

This interface has methods which can be used by a Processor to control execution of this Output and write data to it. Users are expected to derive from AbstractLogicalOutput

Method Summary

Modifier and Type	Method and Description
Writer	getWriter() Gets an instance of the Writer in an Output
void	start() Start any processing that the Output may need to perform.

Method Detail

start

void start()
    throws Exception

Start any processing that the Output may need to perform. It is the responsibility of the Processor to start Outputs. This typically acts as a signal to Outputs to start any Processing that they may required. This method may be invoked by the framework under certain circumstances, and as such requires the implementation to be non-blocking. Outputs must be written to handle multiple start invocations - typically honoring only the first one.

Throws:

Exception

getWriter

Writer getWriter()
          throws Exception

Gets an instance of the Writer in an Output

Returns:

Gets an instance of the Writer in an Output

Throws:

Exception - if an error occurs