TIBCO Rendezvous External Adapter

The StreamBase External Adapter for TIBCO Rendezvous performs the conversion between Rendezvous messages and StreamBase tuples, supporting data flow in both directions. When converting data from a tuple to a Rendezvous message, the fields in a StreamBase schema become the fields in a Rendezvous message. When converting data from a Rendezvous message, only the fields in the message that have matching name and data type will be copied into the fields in a tuple.

The following table describes the supported conversions from Rendezvous to StreamBase.

The following Rendezvous datatypes are unsupported (and ignored) because there are no matching StreamBase data types.

A Rendezvous message can contain another Rendezvous message; Rendezvous messages can be nested. The StreamBase Adapter for TIBCO Rendezvous looks for nested Rendezvous messages, extracts the values of the contained fields, and writes them onto a tuple. The TIBCO Rendezvous adapter takes a Rendezvous message with nested messages and flattens it out onto a tuple.

The TIBCO Rendezvous adapter maps a field in a Rendezvous message to a field on a StreamBase schema by matching their names. Nested messages work similarly. Given an incoming Rendezvous message that holds a nested message, the TIBCO Rendezvous adapter looks at each field in the nested message and tries to map it to a field on the tuple by name.

One consideration complicates this process: given nested messages, more than one message might have a field with the same name. For example, consider a tibrv message with three fields: a string field named stringField1, a string field named stringField2, and a message field named messageField1. The nested message messageField1 may also have a string field named stringField1, which results in a naming conflict.

The StreamBase TIBCO Rendezvous adapter deals with this by qualifying the name of the fields in a nested message with the name of the message that contains them. An underscore is placed between the name of the nested message and the name of its field.

In the above example, the top level message had three fields. The StreamBase TIBCO Rendezvous adapter will look for fields on the schema named stringField1 and stringField2. Since messageField1 has a type of TibrvMsg, the TIBCO Rendezvous adapter tries to map its contained field using the name messageField1_stringField1. That is, the name of a nested field consists of the name of its containing message, followed by an underscore, followed by its name.

The following table describes the supported conversions from StreamBase to Rendezvous.

The StreamBase Adapter supports the following Rendezvous subject to StreamBase stream mappings:

The following XML elements show how to configure these mappings in the adapter configuration file:

<!-- Single Rendezvous subject to single StreamBase stream mapping -->
<rv-to-sb src-subject="SIAC.HPQ.N" dest-stream="hpq_stock"/>

<!-- Multiple Rendezvous subjects to single StreamBase stream mapping -->
<rv-to-sb src-subject="SIAC.IBM.N" dest-stream="siac_stocks"/>
<rv-to-sb src-subject="SIAC.T.N" dest-stream="siac_stocks"/>
<rv-to-sb src-subject="SIAC.GE.N" dest-stream="siac_stocks"/>

<!-- Rendezvous wildcarded subject to single StreamBase stream mapping -->
<rv-to-sb src-subject="IDN.*.N" dest-stream="idn_stocks"/>

<!-- Single StreamBase stream to single Rendezvous message mapping -->
<sb-to-rv src-stream="AlertsIDN" dest-subject="alert_watch"/>

<!-- Using the subject found in tuple for publishing Rendezvous messages -->
<sb-to-rv src-stream="LowVolumeIDN" dest-subject=""/>

When a wildcarded Rendezvous subject is mapped to a stream, the subject of each Rendezvous message is carried in a tuple field. By default this tuple field is named RV_subject. Its name may be changed by setting the subject-field-name attribute of the rv-endpoint element in the adapter configuration file. For example:

<rv-endpoint daemon="127.0.0.1:7500" network="127.0.0.1" service="7500" batch="false" 
    convert-numeric-id-to-name="true" subject-field-name="tibco_subject" 
    field-name-and-id="false"/>

The subject carried in a tuple will be used when publishing messages to the Rendezvous bus from a StreamBase output stream if the destination subject (dest-subject) attribute of the sb-to-rv element is missing or set to empty string.

By default, data in Rendezvous message fields are copied into the StreamBase tuple fields that have matching field names and data types. Some message fields may only have field identifiers, but no field names. Set the convert-numeric-id-to-name attribute of the rv-endpoint element to true to convert message fields that only have field identifiers. For example:

<rv-endpoint daemon="127.0.0.1:7500" network="127.0.0.1" service="7500" batch="false" 
    convert-numeric-id-to-name="true" subject-field-name="tibco_subject" 
    field-name-and-id="true"/>

When converting a Rendezvous message to a StreamBase tuple, a tuple field that does not have a matching message field will be set to null. When converting a StreamBase tuple into a Rendezvous message, tuple fields whose values are null will be ignored.

When you run the sb-tibrv command, the adapter reads a required configuration file and connects to StreamBase Server (sbd) and the Rendezvous Daemon (rvd) accordingly.

The external adapter kits installs three sample applications to help you understand the Rendezvous-to-StreamBase (and vice versa) interaction. These samples are installed in streambase-install-dir\sample\adapter\external\tibrv.

The sample appears in StreamBase Studio's Load StreamBase Sample dialog only after you install the TIBCO Rendezvous External Adapter kit.

The first sample includes the following files:

This sample assumes that you downloaded and installed Rendezvous on a supported machine where StreamBase is also installed. For information about downloading an evaluation copy of Rendezvous, see the TIBCO web site.

<?xml version="1.0"?>
<rv-adapter-configuration>
 <rv-endpoint daemon="127.0.0.1:7500" network="localhost" service="rendezvous" batch="false"/>
 <sb-endpoint uri="sb://localhost:10000" max_to_buffer="200" buffer_timer="10" />
 <rv-to-sb src-subject="tickers.nyse" dest-stream="stocks_nyse"/>
 <sb-to-rv src-stream="alerts_nyse" dest-subject="alert_watch"/>
</rv-adapter-configuration>