Heartbeat Aggregate Sample

About This Guide

The HeartbeatAggregate.sbapp sample uses a Heartbeat operator to output the number of stock quotes received every five seconds. The actual counting is done by an Aggregate operator, but it depends on the Heartbeat to trigger output during periods when no quotes are received.

Importing This Sample into StreamBase Studio

In StreamBase Studio, import this sample with the following steps:

  • From the top menu, click FileLoad StreamBase Sample.

  • Type operator to narrow the list of options.

  • Select Operator sample group from the Data Constructs and Operators category.

  • Click OK.

StreamBase Studio creates a single project for the operator samples.

Running HeartbeatAggregate.sbapp in StreamBase Studio

  1. In the Project Explorer, open the sample you just loaded.

  2. Open the src/main/eventflow folder.

  3. Open the package folder (most samples contain a single package folder. Open the top-level package folder if your sample contains more than one folder).

  4. Open the HeartbeatAggregate.sbapp application and click the Run button. This opens the SB Test/Debug perspective and starts the application.

    If you see red marks, wait a moment for the project in Studio to load its features.

    If red marks do not resolve themselves in a moment, select the project and right-click MavenUpdate Project from the context menu.

  5. In the Application Output view, select the TicCounts stream. No output is displayed at this point, but the Output View is prepared to receive output. This view will eventually show the output of the application.

  6. In the Manual Input view, select the InputTics input stream

  7. Enter IBM for symbol, and 83.17 for price.

  8. Click Send Data. Within five seconds, look for a tuple on the TicCounts output stream, stating that one quote was received in the last five seconds.

  9. Click Send Data three times in rapid succession. Within five seconds, look for a tuple on the TicCounts output stream, stating that three quotes were received in the last five seconds.

  10. Wait five seconds and look for a tuple on the TicCounts output stream, stating that zero quotes were received in the last five seconds.

  11. When done, press F9 or click the Stop Running Application button.

Sample Location

When you load the sample into StreamBase Studio, Studio copies the sample project's files to your Studio workspace, which is normally part of your home directory, with full access rights.

Important

Load this sample in StreamBase Studio, and thereafter use the Studio workspace copy of the sample to run and test it, even when running from the command prompt.

Using the workspace copy of the sample avoids permission problems. The default workspace location for this sample is:

studio-workspace/sample_operator

See Default Installation Directories for the default location of studio-workspace on your system.