This documentation is for WSO2 Complex Event Processor 4.0.0. View documentation for the latest release.
WSO2 Complex Event Processor is succeeded by WSO2 Stream Processor. To view the latest documentation for WSO2 SP, see WSO2 Stream Processor Documentation.

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Event Stream NameName of the event stream.
Event Stream VersionVersion of the event stream. (Default value is 1.0.0.)
Event Stream DescriptionDescription of the events stream. (This is optional.)
Event Stream Nick-NameNick-names of an event streams separated by commas. (This is optional.)
Stream Attributes

Stream Attributes attributes contains the data of the event. These are  Data is divided into three logical separations to give more usability and maintenance to the userthe following 3 logical categories for maintenance and usability. It is not mandatory required to to have attributes in for all three sections, but 3 categories, but there should be at least one section category with at least one attribute defined. Also The attribute names should be unique within each sectioncategory.

  • Meta Data: Contains the This refers to meta information of the events (e.g., timestamp, host, IP, etc.). (Referred to as They are received with the meta tag (i.e., in the meta_<attribute name> format).)
  • Correlation Data: Contains the correlation information of the events.  (Referred to as This refers to information that is used to correlate multiple events (e.g., correlation_id,temporal_id etc.). They are received with the correlation tag (i.e., in the correlation_<attribute name>. format).
  • Payload Data: Contains the actual data that the event intends to have.   (Referred Referred to as <attribute name>.)

It is recommended to have logistic separation but the internal system does not differentiate or give privilege based on above separations. Also please note if you edit and add another attribute to existing stream definition, other artifacts which are associated with the stream will be inactive. So that it is recommended to create a new stream definition with a version including the additional attribute.

For example consider following attributes which e.g., The following attributes exist in a single event.

  • event_timestamp
  • request_IP_address
  • correlation_Id
  • price
, symbol with there corresponding data types.

We can logically separate the above attributes as following.

  • Meta Data :- event_timestamp,
  • symbol

These attributes can be logically categorized as follows.

Meta Data
  • event_timestamp
  • request_IP_address
(These describes
These attributes provide information about the events
Correlation Data
  • correlation_Id
(These correlates events
This attribute correlates the event with other events from other streams, and
will be
it is useful when
you perform a
performing join operations on a stream
Payload Data
  • price
  • symbol
These are
actual information/details of the event)
information provided via the event.
  • Note that the internal system does not differentiate the attributes based on this categorization. However, it is recommended to categorize the attributes for the purpose of organizing them in a logical manner within the stream definition.
  • If you edit an attribute in an event stream or add a new attribute to it, other artifacts that are associated with the stream will be inactive. Therefore, it is recommended to redefine the stream with a new version including the additional/changed attribute.

Adding an event stream