Using the Feed Simulation Editor

The Feed Simulation editor is StreamBase Studio's interface for creating new feed simulations or editing existing ones. See Running Feed Simulations to learn about running your feed simulations.

StreamBase 3.7 introduced a new version of the StreamBase Feed Simulator and a new file format for the feed simulation files. If you have feed simulations saved with StreamBase 3.5 or earlier, you can upgrade your simulation files to the 3.7 or later format. See Upgrading Legacy Feed Simulations.

Open the Feed Simulation editor by opening an existing feed simulation file or by creating a new feed simulation.

Open an existing feed simulation file as follows:

Create a new feed simulation in one of the following ways:

In the New StreamBase Feed Simulation dialog:

The Feed Simulation editor contains both graphical and source views of the same feed simulation. Notice that there are two tabs at the bottom of the editor. Use these tabs to switch between graphical and source presentations. The settings and values you enter on one tab are reflected on its partner tab after you save the changes.

The graphical presentation of the Feed Simulation editor contains the following sections:

Enter a brief description for the overall feed simulation in the top Simulation Description field. (You can document each stream in this simulation with the second description field at the bottom of the editor view.)

An example of the Simulation Description section:

Use the Simulation Streams section to add, edit, or remove input streams from the current feed simulation. For example:

A single feed simulation file can be defined to enqueue data to one or more input streams. The feed simulation definition for each stream can define properties unique to that stream.

You can use a feed simulation with more than one application, provided that the input stream names match in those applications.

The schema for an input stream in the application does not have to exactly match the schema defined in the feed simulation. For example, you might use a feed simulation to send a subset of data to a stream, using default values for the other fields in the schema.

Let's say a StreamBase application has two input streams: TradesIn and FuturesIn. In the Simulation Streams section, click Add to invoke the Add Simulation Stream dialog. In the following example, we have identified the name of the additional input stream in the application:

In this dialog, add a schema to the feed simulation using either of the following methods:

After clicking OK on this dialog and again on the Add Simulation Stream dialog, the updated Simulation Streams section might look like this:

Use the Generation Method section to specify how this feed simulation should generate or read data for the selected stream. Be sure to select the stream of interest in the Simulation Streams section before continuing with the Generation Method section.

There are four ways to generate or read data:

Select the Default option to specify that this feed simulation should generate a default load. This means the following when you run the feed simulation on a running StreamBase application:

When you select the Default generation method, the Timestamp from column, Tuple buffer, and Prefill Tuple buffer controls are greyed out.

In the Generation Method section, select the Data File option, then click Options. In the Data File Options dialog, specify the path to an existing data file that this feed simulation should use to populate the selected stream. You can also specify which fields in the application's input stream correspond to which columns in the data file.

For example:

The following table describes the data file options:

In the Generation Method section, select Custom. In this case, the Timestamp from column, Tuple buffer, and Prefill Tuple buffer controls are greyed out.

Click Customize Fields. In the Customize Fields dialog, choose values in the Generation Method column for each field in the schema. For example:

The table displays the names and types of the fields available in the selected input stream. The Generation Method column summarizes the way you customize each field. To specify a customized value, select the row and click into the Generation Method cell. Use the pull-down menu for that cell to select from a number of different options, then press Tab or click to move the cursor to the Data Type column. With the cursor moved, one or more data fields appear below the table. In those fields, specify the values relevant for the input stream field.

The choices in the dropdown list vary by the data type for each field, as described in the following sections.

In the Generation Method section, select the JDBC option, then click Options. In the JDBC Data Source Options dialog, specify the information required to connect to a JDBC-compliant database, and specify a SQL query that will generate a response from the database that will populate the selected input stream.

To use this option, you must obtain and install the JAR file or files that implement the JDBC driver for the target database from the database vendor. These JDBC JAR files must be installed in one of the following locations on the computer that will run the feed simulation:

The following table describes the JDBC Data Source options:

Use the Processing Options section to set the runtime behavior of the selected stream. Be sure to select the stream of interest in the Simulation Streams section before continuing with the Processing Options section.

The following table describes the feed simulation processing options:

Note that when you enter default values for these settings, the values do not appear in the generated feed simulation source file.

BA,51.25,"09/27/08 16:20:30",100.0
DEAR,25.43,"09/27/08 16:20:45",102.0
EPIC,142.85,"09/27/08 16:20:50",105.0
FUL,15.76,"09/27/08 16:21:00",105.5
GE,25.151,"09/27/08 16:21:05",106.0

Use the Description for StreamName field at the bottom of the Editor view to document the currently selected stream. (Use the Description field at the top of the view to document the feed simulation as a whole.)

For example:

On the upper tabs of the Feed Simulation Editor, StreamBase Studio displays an asterisk if the file has changed. You cannot toggle between a graphical or source presentation of the feed simulation until you save the file. All feed simulations have the .sbfs file extension, and are saved by default in the currently active Studio project.

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