WebSocket Client Read Adapter

Introduction

TIBCO StreamBase® Read Adapter for WebSocket Client allows StreamBase applications to read data from a server. It is powered by an embedded Jetty client. While multiple WebSocket Client Read input adapters can be used to connect to different URIs, multiple connections to the same URI are not supported. If an instance of a WebSocket Client Read input adapter connects to multiple URIs, a new Jetty connection object is created for each unique URI address.

Adapter Properties

This section describes the properties you can set for this adapter, using the various tabs of the Properties view in StreamBase Studio.

General Tab

Name: Use this required field to specify or change the name of this instance of this component, which must be unique in the current EventFlow module. The name must contain only alphabetic characters, numbers, and underscores, and no hyphens or other special characters. The first character must be alphabetic or an underscore.

Adapter: A read-only field that shows the formal name of the adapter.

Class name: Shows the fully qualified class name that implements the functionality of this adapter. If you need to reference this class name elsewhere in your application, you can right-click this field and select Copy from the context menu to place the full class name in the system clipboard.

Start with application: If this field is set to Yes (default) or to a module parameter that evaluates to true, this instance of this adapter starts as part of the JVM engine that runs this EventFlow module. If this field is set to No or to a module parameter that evaluates to false, the adapter instance is loaded with the engine, but does not start until you send an sbadmin resume command, or until you start the component with StreamBase Manager.

Enable Error Output Port: Select this check box to add an Error Port to this component. In the EventFlow canvas, the Error Port shows as a red output port, always the last port for the component. See Using Error Ports to learn about Error Ports.

Description: Optionally enter text to briefly describe the component's purpose and function. In the EventFlow canvas, you can see the description by pressing Ctrl while the component's tooltip is displayed.

Adapter Properties Tab

Property Type Description
Default URI string This required field will set the URI that the adapter will automatically connect to if the Connect At Startup check box is selected or if the incoming tuple's URI field is null.
Connect Timeout (MS) string The time in milliseconds before a connect command times out.
Write Timeout (MS) string The time in milliseconds before a write command times out. Note that this value only affects the WebSocket Client Write output adapter.
Idle Timeout (MS) string The time in milliseconds before a web socket times out from idle behavior.
Connect at Startup check box When enabled, the adapter will attempt to connect to the default URI when the Studio session starts. Note that if this box is unchecked then it is required that the control port is enabled.
Enable Control Port check box When enabled, the adapter will allow incoming tuples to control the actions of this adapter. Note that if Connect At Startup is unchecked then it is required that the control port is enabled.
Enable Status Port check box When enabled, the adapter will send out informational data on the status port about various states of the adapter.
Log Level INFO Controls the level of verbosity the adapter uses to issue informational traces to the console. This setting is independent of the containing application's overall log level. Available values, in increasing order of verbosity, are: OFF, ERROR, WARN, INFO, DEBUG, TRACE.

Concurrency Tab

Use the Concurrency tab to specify parallel regions for this instance of this component, or multiplicity options, or both. The Concurrency tab settings are described in Concurrency Options, and dispatch styles are described in Dispatch Styles.

Caution

Concurrency settings are not suitable for every application, and using these settings requires a thorough analysis of your application. For details, see Execution Order and Concurrency, which includes important guidelines for using the concurrency options.

Control Port

Description

Use the control port is used to send action commands to the adapter. Tuples enqueued on this port cause the adapter to connect or disconnect from a URI.

Control Port Schema

  • Command, string, the command to send to the adapter.

    The values are:

    • Connect — Tells the adapter to connect to the URI specified in the input tuple.

    • Disconnect — Tells the adapter to disconnect from the URI specified in the input tuple (if a connection to that URI already exists).

  • URI, string. The URI to connect to.

Status Port

Description

The status port is used to send status information tuples downstream to inform the user of changes.

Status Port Schema

  • Type, string. The type of status information emitted on this port

  • Action, string.

    • Error — An error has occurred

    • Command — A command status information is being reported such as a connect or a disconnect to a URI.

    • Connected — A web socket connection has been made.

    • Disconnected — A web socket connection has been terminated.

  • Object, string. This value may be null. If it is not null, it contains a value relevant to the status message.

  • Message, string. This is a formatted human readable message that explains the status message.

  • Time, timestamp. The time at which the status message was sent.