The Delay operator postpones sending data along a stream for a specified amount of time.
Example uses might include:
- An application that needs to load a set of trading parameters prior to receiving market data.
- Traders may want to build up a trading metric (like the beta of a portfolio) by analyzing market data over a specified interval before initiating their trading strategies.
The sample application includes a DelayFiveSeconds operator, to demonstrate delaying the stream by a constant amount of time, and a DelayVariable operator, to demonstrate delaying by a variable amount of time.
Both are instances of the DelayOperator component found in the Project Operators drawer of the Palette view. In the Operator Properties tab of the Properties view, specify the delay period as a StreamBase expression that resolves to an interval timestamp. In the case of DelayVariable, the expression is a field name in the incoming stream. In the case of DelayFiveSeconds, the delay expression is seconds(5).
Usage Notes:
- Data passed to the operator leaves in the same order it came out, as it operates much like a First-In-First-Out queue.
- The data passed to the operator is not altered except for the fact that the output tuple is delayed by the specified amount of time.
Version History
1.2: Fixed application pauses that may occur under rare circumstances when using this operator. 1.1: Fixed a deadlock bug.