XML Over HTTP Writer Output Adapter

Introduction

The TIBCO StreamBaseĀ® XML-Over-HTTP Output Adapter is suitable for posting tuples to an HTTP server. Tuples are posted as HTTP POST transactions where a parameter named tuple is set to the URL-encoded version of the serialized input tuple as XML. The adapter does not support fields in the input tuple of type list or tuple.

Tuples can be buffered into single POST calls by setting the flushInterval parameter. The number of messages to post in any interval can be limited by specifying a Max Message Cache size. When using Max Message Cache, messages above the limit are not delivered.

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 options: This field provides a link to the Cluster Aware tab, where you configure the conditions under which this adapter starts.

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 Editor canvas, you can see the description by pressing Ctrl while the component's tooltip is displayed.

Adapter Properties Tab

The XML Over HTTP Writer adapter is configured with the properties shown in the following table. Properties are set in the Properties view, Adapter Settings tab.

Property Description Default
URL (string) The URL to HTTP post to. None
Flush Interval (optional string) How often to deliver messages to the specified URL, in milliseconds. If set to 0, messages are delivered immediately. See the next property for the case where this parameter is required. 0, write immediately
Max Message Cache (int) The maximum number of messages to queue each interval. If set to 0, unlimited messages are cached per interval. If this parameter is set, the Flush Interval parameter must also be set and its value must be greater than 0. 0, unlimited
Log Level Controls the level of verbosity the adapter uses to send notifications to the console. This setting can be higher than the containing application's log level. If set lower, the system log level will be used. Available values, in increasing order of verbosity, are: OFF, ERROR, WARN, INFO, DEBUG, TRACE. INFO

Cluster Aware Tab

Use the settings in this tab to allow this operator or adapter to start and stop based on conditions that occur at runtime in a cluster with more than one node. During initial development of the fragment that contains this operator or adapter, and for maximum compatibility with TIBCO Streaming releases before 10.5.0, leave the Cluster start policy control in its default setting, Start with module.

Cluster awareness is an advanced topic that requires an understanding of StreamBase Runtime architecture features, including clusters, quorums, availability zones, and partitions. See Cluster Awareness Tab Settings on the Using Cluster Awareness page for instructions on configuring this tab.

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.

Typechecking and Error Handling

URL must be a parseable URL.

If Max Message Cache is set, must be 0 or greater, and Flush Interval must be set and greater than 0.

The input stream cannot contain fields of type list or tuple

If specified and those conditions are not met, typechecking fails.

Suspend and Resume Behavior

On suspend, all cached messages are delivered.

On resumption, caching is restarted. The first message delivery occurs at resume time + Flush Interval.