Loop Sample

About This Sample

This sample application takes input from a provided feed simulation. It splits incoming trades into smaller trades of qty = split_size and, if necessary, adds an additional trade for the remainder of qty/split_size. The filter operator is a required part of creating a conditional loop.

Arcs usually take their schemas from upstream operators. But the arc that creates the loop in loop.sbapp requires an explicit schema. As a best practice, when possible, re-use the named schema from the incoming stream (in this case, InputStream) for the looping arc's schema.

Importing This Sample into StreamBase Studio

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

  • From the top menu, select FileLoad StreamBase Sample.

  • Type loop to narrow the list of options.

  • Select the loop sample from Applications category.

  • Click OK.

StreamBase Studio creates a project for the sample.

Running This Sample in StreamBase Studio

To run this sample:

  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 named application file 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. Open the Feed Simulations tab.

  6. Select the loop-feedsim.sbfs feed simulation file and click Run.

  7. Observe the tuples emitted from the SmallTradesOut stream.

  8. 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.


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:


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