3. Configuration¶
3.1. Configuring Routing Service¶
This document describes how to configure Routing Service. For installation instructions or to walk through some simple examples, please see the appropriate section.
When you start Routing Service, you can specify a configuration file in XML format. In that file, you can set properties that control the behavior of the service. This chapter describes how to write a configuration file.
3.2. Terms to Know¶
Before learning how to configure Routing Service, you should become familiar with a few key terms and concepts:
- A RoutingService entity refers to an execution of Routing Service.
- A DomainRoute defines a two-way mapping between two data domains (DDS, MQTT, AMQP, etc.).
- A Session defines a safe, threaded context for Routes. A Route can be processed by a single thread a time. If the session defines a thread pool, Routes can be processed concurrently.
- A Route defines a mapping between input streams and output streams belonging to any of the data domains defined in a DomainRoute. For example, in a Route between DDS and MQTT, the input streams will be DDS topics and the output streams will be MQTT subscriptions.
- An AutoRoute defines a set of potential Routes that can be instantiated based on deny/allow filters on the stream name and registered type name.
- A Transformation is a pluggable component that changes data from an input stream to an output stream.
- An Adapter is a pluggable component that allows Routing Service to consume and produce data for different data domains. By default, Routing Service is distributed with a builtin DDS adapter.
3.3. How to Load the XML Configuration¶
Routing Service loads its XML configuration from multiple locations. This section presents the various sources of configuration files, listed in load order.
[working directory]/USER_ROUTING_SERVICE.xml
This file is loaded automatically if it exists.[NDDSHOME]/resource/xml/RTI_ROUTING_SERVICE.xml
This file is loaded automatically if it exists.- File specified using the command-line parameter
-cfgFile
.
Note
[working directory]
indicates the path to the current working
directory from which you run Routing Service.
The tag [NDDSHOME]
indicates the path to your Connext DDS installation.
You may use a combination of the above sources and load multiple configuration files.
Here is an example configuration file. You will learn the meaning of each line as you read the rest of this section.
<?xml version="1.0"?>
<dds>
<routing_service name="TopicBridgeExample" group_name="MyGroup">
<domain_route name="DomainRoute">
<participant name="domain0">
<domain_id>0</domain_id>
</participant>
<participant name="domain1">
<domain_id>1</domain_id>
</participant>
<session name="Session">
<topic_route name="SquaresToCircles">
<input participant="domain0">
<registered_type_name>
ShapeType
</registered_type_name>
<topic_name>Square</topic_name>
</input>
<output participant="domain1">
<registered_type_name>
ShapeType
</registered_type_name>
<topic_name>Circle</topic_name>
</output>
</topic_route>
</session>
</domain_route>
</routing_service>
</dds>
3.4. XML Syntax and Validation¶
The XML representation of DDS-related resources must follow these syntax rules:
- It shall be a well-formed XML document according to the criteria defined in clause 2.1 of the Extensible Markup Language standard.
- It shall use UTF-8 character encoding for XML elements and values.
- It shall use <dds> as the root tag of every document.
To validate the loaded configuration, Routing Service relies on an XSD file that describes the format of the XML content. We recommend including a reference to this document in the XML file that contains the service’s configuration; this provides helpful features in code editors such as Visual Studio®, Eclipse®, and NetBeans®, including validation and auto-completion while you are editing the XML file.
The XSD definitions of the XML elements are in
[NDDSHOME]/resources/schema/rti_routing_service.xsd
.
To include a reference to the XSD document in your XML file, use the attribute
xsi:noNamespaceSchemaLocation
in the <dds>
tag. For example:
<?xml version="1.0" encoding="UTF-8"?>
<dds xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="[NDDSHOME]/resource/schema/rti_routing_service.xsd">
<!-- ... -->
</dds>
Note
The tag [NDDSHOME]
indicates the path to your Connext DDS installation.
3.5. XML Tags for Configuring RTI Routing Service¶
This section describes the XML tags you can use in a Routing Service configuration file.
The following diagram and Table 3.1 describe the top-level
tags allowed within the root <dds>
tag.
Tags within <dds> | Description | Multiplicity |
---|---|---|
<qos_library> | Specifies a QoS library and profiles. The contents of this tag are specified in the same manner as for a Connext DDS application. See Configuring QoS with XML, in the Connext DDS Core Libraries User’s Manual. |
0..* |
<types> | Defines types that can be used by Routing Service. See Section 3.5.6.1. |
0..1 |
<plugin_library> | Specifies a library of Routing Service plugins. Available plug-ins are Adapters, Transformations and Processors. See Section 3.5.9. |
0..* |
<routing_service> | Specifies a Routing Service configuration. Attributes
|
1..* |
3.5.1. Routing Service Tag¶
A configuration file must have at least one <routing_service>
tag. This
tag is used to configure an execution of Routing Service. A configuration file may
contain multiple <routing_service>
tags.
When you start Routing Service, you can specify which <routing_service>
tag
to use to configure the service using the -cfgName
command-line parameter.
Because a configuration file may contain multiple <routing_service>
tags, one file can be used to configure multiple Routing Service executions.
Figure 3.2 and
Table 3.2 describes the tags allowed within a
<routing_service>
tag.
Tags within <routing_service> | Description | Multiplicity |
---|---|---|
<annotation> | Contains a <documentation> tag that can be used to provide a configuration description. | 0..1 |
<administration> | Enables and configures remote administration. See Section 3.5.2 and Section 4. |
0..1 |
<monitoring> | Enables and configures general remote monitoring. General monitoring settings are applicable to all the Routing Service entities unless they are explicitly overridden. See Section 3.5.3 and Section 5. |
0..1 |
<entity_monitoring> | Enables and configures remote monitoring for the service entity. See Section 3.5.3.1 and Section 5. |
0..1 |
<jvm> | Configures the Java JVM used to load and run Java adapters.
For example:
You can use the |
0..1 |
<domain_route> | Defines a mapping between two or more data domains. Attributes
|
0..1 |
3.5.1.1. Example: Specifying a configuration in XML¶
<dds>
<routing_service name="EmptyConfiguration"/>
<routing_service name="ShapesDemoConfiguration">
<!--...-->
</routing_service>
</dds>
Starting Routing Service with the following command will use the
<routing_service>
tag with the name EmptyConfiguration
.
$NDDSHOME/bin/rtiroutingservice \
-cfgFile file.xml -cfgName EmptyConfiguration
3.5.2. Administration¶
You can create a Connext DDS application that can remotely control Routing Service. The
<administration>
tag is used to enable remote administration and configure
its behavior. By default, remote administration is turned off in Routing Service for
security reasons. A remote administration section is not required in the
configuration file.
When remote administration is enabled, Routing Service will create a DomainParticipant, Publisher, Subscriber,
DataWriter, and DataReader. These entities are used to receive commands and send responses.
You can configure these entities with QoS tags within the <administration>
tag. The following table lists the tags allowed within
<administration>
tag. Notice that the <domain_id>
tag is required.
For more details, please see Section 4.
Note
The command-line options used to configure remote administration take precedence over the XML configuration (see Section 2).
Tags within <administration> | Description | Multiplicity |
---|---|---|
<enabled> | Enables/disables administration. Default: true |
0..1 |
<domain_id> | Specifies which domain ID Routing Service will use to enable remote
administration. |
0..1 |
<participant_qos> | Configures the DomainParticipant QoS for remote administration. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..1 |
<publisher_qos> | Configures the Publisher QoS for remote administration. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..1 |
<subscriber_qos> | Configures the Subscriber QoS for remote administration. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..1 |
<datawriter_qos> | Configures the DataWriter QoS for remote administration.
|
0..1 |
<datareader_qos> | Configures the DataReader QoS for remote administration.
|
0..1 |
<distributed_logger> | Configures RTI Distributed Logger.
|
0..1 |
<autosave_on_update> | A boolean that, if true, automatically triggers a save command when
configuration updates are received. This value is sent as part of the monitoring configuration data for the Routing Service. Default: false. |
0..1 |
<save_path> | Specifies the file that will contain the saved configuration. A <save_path> must be specified if you want to use the save
command. If the specified file already exists, the file will be
overwritten when save is executed. Default: [CURRENT DIRECTORY]. |
0..1 |
3.5.3. Monitoring¶
You can create a Connext DDS application that can remotely monitor the status of
Routing Service. To enable remote monitoring and configure its behavior, use the
<monitoring>
and <entity_monitoring>
tags.
By default, remote monitoring is turned off in Routing Service for security and performance reasons. A remote monitoring section is not required in the configuration file.
When remote monitoring is enabled, Routing Service will create one DomainParticipant, one Publisher, five
DataWriters for data publication (one for each kind of entity), and five DataWriters for
status publication (one for each kind of entity). You can configure the QoS of
these entities with the <monitoring>
tag defined under <routing_service>
.
The general remote monitoring parameters specified using the <monitoring>
tag in <routing_service>
can be overwritten on a per entity basis using the
<entity_monitoring>
tag.
For more details, please see Section 5.
Note
The command-line options used to configure remote monitoring take precedence over the XML configuration (See Section 2).
Tags within <monitoring> | Description | Multiplicity |
---|---|---|
<enabled> | Enables/disables general remote monitoring. Setting this tag to false disables monitoring in all the entities. In this case, any monitoring configuration settings in the entities are ignored. Default: true |
0..1 |
<domain_id> | Specifies which domain ID Routing Service will use to enable remote
monitoring. |
1 |
<participant_qos> | Configures the DomainParticipant QoS for remote monitoring.
|
0..1 |
<publisher_qos> | Configures the Publisher QoS for remote monitoring. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..1 |
<datawriter_qos> | Configures the DataWriter QoS for remote monitoring.
|
0..1 |
<statistics_sampling_period> | Specifies the frequency, in seconds, at which status statistics are gathered.
The statistics period for a given entity should be smaller than the
publication period. |
0..1 |
<statistics_publication_period> | Specifies the frequency, in seconds, at which the status of an entity is published.
The statistics sampling period defined in |
0..1 |
3.5.3.1. Monitoring Configuration Inheritance¶
The monitoring configuration defined in <routing_service>
is inherited by all the
entities defined inside the tag.
An entity can overwrite three elements of the monitoring configuration:
- The status publication period
- The statistics sampling period
- The historical statistics windows
Each one of these three elements is inherited and can be overwritten
independently using the <entity_monitoring>
tag.
Tags within <entity_monitoring> | Description | Multiplicity |
---|---|---|
<enabled> | Enables/disables remote monitoring for a given entity. Default: true |
0..1 |
<statistics_sampling_period> | Specifies the frequency at which status statistics are gathered.
The statistics period for a given entity should be smaller than the
publication period. If this tag is not defined, historical statistics are inherited from the general monitoring settings. Default: 1 second. |
0..1 |
<statistics_publication_period> | Specifies the frequency at which the status of an entity is published.
If this tag is not defined, historical statistics are inherited from the general monitoring settings. Default: 5 seconds. |
0..1 |
3.5.3.1.1. Example: Overriding Publication Period¶
<routing_service name="MonitoringExample">
<monitoring>
<domain_id>55</domain_id>
<status_publication_period>
<sec>1</sec>
</status_publication_period>
<statistics_sampling_period>
<sec>1</sec>
<nanosec>0</nanosec>
</statistics_sampling_period>
</monitoring>
...
<domain_route>
<entity_monitoring>
<status_publication_period>
<sec>4</sec>
</status_publication_period>
</entity_monitoring>
...
</domain_route>
</routing_service>
3.5.4. Domain Route¶
A <domain_route>
defines a mapping between different data domains. Data
available in any of these data domains can be routed to other data domains.
For example, a DomainRoute could define a mapping among multiple DDS domains,
or between a DDS domain and a MQTT provider’s network. How this data is actually
read and written is defined in specific Routes.
A <domain_route>
creates one or more Connections. Each Connection
typically belongs to a different data domain. The <connection>
tag requires
the specification of the attribute name
, which will be used by the Route
to select input and output domains, and the plugin_name
, which will be
used to associate a Connection with an adapter plugin defined within
<adapter_library>
.
Routing Service comes with a builtin implementation of a DDS adapter, which can be
used by specifying the <participant>
tag. Each tag corresponds to exactly
one DomainParticipant. A DomainRoute can include both <connection>
and <participant>
tags to provide communication between DDS domains and other data domains.
Tags within <domain_route> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the DomainRoute. See Section 5. |
0..1 |
<connection> | Applicable to non-DDS domains. Attributes
See Table 3.7. |
0..* |
<participant> | Applicable to DDS domains. Configures a DDS adapter DomainParticipant. See Table 3.8. |
0..* |
<session> | Defines a multi-threaded context in which data is routed according to specified routes. See Section 3.5.5. Attributes
|
0..* |
Tags within <connection> | Description | Multiplicity |
---|---|---|
<property> | A sequence of name-value string pairs that allows you to configure the Connection instance.
|
0..1 |
<registered_type> | Registers a type name and associates it with a type representation. When you define a type in the configuration file, you have to register the type in order to use it in Routes. See Section 3.5.6. |
0..* |
Tags within <participant> | Description | Multiplicity |
---|---|---|
<domain_id> | Sets the domain ID associated with the DomainParticipant. Default: 0 |
0..1 |
<participant_qos> | Sets the participant QoS. Note Changing the default participant name may prevent Routing Service from being detected by Admin Console. You can use a
See Configuring QoS with XML, in the Connext DDS Core Libraries User’s Manual. |
0..1 |
<memory_management> | Configures certain aspects of how Connext DDS allocates internal memory.
The configuration is per DomainParticipant and therefore affects all the contained
DDS entities.
This feature is useful when a data type has a very high maximum size (e.g., megabytes) but most of the samples sent are much smaller than the maximum possible size (e.g., kilobytes). In this case, the memory footprint is reduced dramatically, while still correctly handling the rare cases in which very large samples are published. |
0..1 |
<registered_type> | Registers a type name and associates it with a type representation. When you define a type in the configuration file, you have to register the type in order to use it in Routes. See Section 3.5.6. |
0..* |
3.5.4.1. Example: Mapping between Two DDS Domains¶
<domain_route name="DdsDomainRoute">
<participant name="domain54">
<domain_id>54</domain_id>
...
</participant>
<articipant name="domain55">
<domain_id>55</domain_id>
...
</participant>
...
</domain_route>
3.5.4.2. Example: Mapping between a DDS Domain and raw Sockets¶
<domain_route name="DomainRoute">
<connection name="SocketAdapter">
...
</connection>
<participant name="domain55">
<domain_id>55</domain_id>
...
</participant>
...
</domain_route>
3.5.5. Session¶
A <session>
tag defines a multi-threaded context for route processing,
including data forwarding. The data is routed according to specified Routes
and AutoRoutes.
Each Session will have an associated thread pool to process Routes concurrently, preserving Route safety. Multiple Routes can be processed concurrently, but a single Route can be processed only by one thread at time. By default, the session thread pool has a single thread, which serializes the processing of all the Routes.
Sessions that bridge domains will create a Publisher and a Subscriber from the DomainParticipants
associated with the domains. Table 3.9 lists the tags
allowed within a <session>
tag.
Tags within <session> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the Session. See Section 5. |
0..1 |
<thread_pool> | Defines the number of threads to process Routes and sets the mask, priority, and stack size of each thread.
|
0..1 |
<periodic_action> | Enables the periodic event dispatching to Processors. If enabled, the Session will wake up and notify the installed Processor specified period. Default: INFINITE (no periodic notification) |
0..1 |
<property> | A sequence of name-value string pairs that allows you to configure the Session instance.
These properties are only used in non-DDS domains. |
0..1 |
<subscriber_qos> | Only applicable to Routes that are Connext DDS Routes. Sets the QoS associated with the session Subscribers. There is one Subscriber per DomainParticipant. The contents of this tag are specified in the same manner as a Connext DDS QoS profile. See Configuring QoS with XML, in the Connext DDS Core Libraries User’s Manual. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..1 |
<publisher_qos> | Only applicable to Routes that are Connext DDS Routes. Sets the QoS associated with the session Publisher. There is one Publisher per DomainParticipant. The contents of this tag are specified in the same manner as a Connext DDS QoS profile. See Configuring QoS with XML, in the Connext DDS Core Libraries User’s Manual. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..* |
<topic_route> or <route> | Defines a mapping between multiple input and output streams. Attributes
See Section 3.5.6. |
0..* |
<auto_topic_route> or <auto_route> | Defines a factory for Route based on type and stream filters. Attributes
|
0..* |
3.5.6. Route¶
A Route explicitly defines a mapping between one or more input data streams and one or more output data streams. The input and output streams may belong to different data domains.
Route events are processed in the context of the thread belonging to the parent Session. Route event processing includes, among others, calls to the StreamReader read and StreamWriter write operations.
Table 3.10 lists the tags allowed within a <route>
.
Table 3.11 lists the tags allowed within a <topic_route>
.
Tags within <route> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the Route. See Section 5. |
0..1 |
<route_types> | Defines if the input connection will use types discovered in the output
connection and vice versa for the creation of StreamWriters and StreamReaders in the
Route. See Section 3.5.6.1.2. Default: false |
0..1 |
<publish_with_original_timestamp> | When this tag is true, the data samples read from the input stream are
written into the output stream with the same timestamp that was
associated with them when they were made available in the input domain. This option may not be applicable in some adapter implementations in
which the concept of timestamp is unsupported. |
0..1 |
<processor> | Sets a custom Processor for handling the data forwarding process.
|
0..1 |
<dds_input> | Only applicable to DDS inputs. Defines an input topic. See Section 3.5.7.
|
0..* |
<dds_output> | Only applicable to DDS outputs. Defines an output topic. See Section 3.5.7.
|
0..* |
<input> | Only applicable to non-DDS inputs. Defines an input stream. See Section 3.5.7.
|
0..* |
<output> | Only applicable to non-DDS outputs. Defines an output stream. See Section 3.5.7.
|
0..* |
Tags within <topic_route> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the TopicRoute. See Section 5. | 0..1 |
<route_types> | Defines if the input connection will use types discovered in the output
connection and vice versa for the creation of DataReaders and DataWriters in the
Route. See Section 3.5.6.1.2. Default: false |
0..1 |
<publish_with_original_info> | Writes the data sample as if they came from its original writer. Setting this option to true allows having redundant routing services and prevents the applications from receiving duplicate samples. Default: false |
0..1 |
<publish_with_original_timestamp> | Indicates if the data samples are written with their original source
timestamp. Default: false |
0..1 |
<propagate_dispose> | Indicates whether or not disposed samples (NOT_ALIVE_DISPOSE) must be
propagated by the TopicRoute. This action may be overwritten by the execution of a transformation. Default: true |
0..1 |
<propagate_unregister> | Indicates whether or not disposed samples (NOT_ALIVE_NO_WRITERS) must be
propagated by the TopicRoute. This action may be overwritten by the execution of a transformation. Default: true |
0..1 |
<topic_query_proxy> | Configures the forwarding of TopicQueries. See Section 8 for detailed information on how Routing Service processes TopicQueries. The snippet below shows that topic query proxy is enabled in propagation mode, which causes the creation of a TopicQuery on the route’s input for each TopicQuery that an output’s matching DataReader creates.
|
0..1 |
<filter_propagation> | Configures the propagation of content filters. Specifies whether the feature is enabled and when events are processed. The snippet below shows that filter propagation is enabled, and a filter update is propagated on the StreamReader only after the occurrence of every three filter events (see Section 7).
|
0..1 |
<processor> | Sets a custom Processor for handling the data forwarding process. See Section 6.
|
0..1 |
<input> | Defines an input topic. See Section 3.5.7.
|
0..* |
<output> | Defines an output topic. See Section 3.5.7.
|
0..* |
3.5.6.1. Route Types¶
The tag <registered_type_name>
within the <input>
and <output>
tags
contains the registered type name of the stream. The actual definition of that
type can be set in the configuration file or it can be discovered by the
connections.
3.5.6.1.1. Defining Types in the Configuration File¶
To define and use a type in your XML configuration file:
- Define your type within the
<types>
tag. The type description is done using the Connext DDS XML format for type definitions. See Creating User Data Types with Extensible Markup Language (XML), in the RTI Connext DDS Core Libraries User’s Manual. - Register it in the
<connection>
/<participant>
where you will use it. - Refer to it in the domain route(s) that will use it.
3.5.6.1.1.1. Example: Type Registration in XML¶
<dds>
...
<types>
<struct name="PointType">
...
</struct>
</types>
...
<routing_service name=”MyRoutingService”>
...
<domain_route>
<connection name="MyConnection">
...
<registered_type name="Position" type_name="PointType"/>
</connection>
<participant name="MyParticipant">
...
<registered_type name="Position" type_name="PointType"/>
</participant>
...
<session>
<topic_route>
<input participant="2">
<registered_type_name>Position</registered_type_name>
</input>
...
</topic_route>
</session>
...
</domain_route>
...
</routing_service>
...
<dds>
3.5.6.1.2. Discovering Types¶
If a Route refers to types that are not defined in the configuration file, Routing Service has to discover their type representation (e.g. typecode). A Route cannot be created without the type representation information.
By default, the StreamReader creation will be tied to the discovery of types in the
input domain and the StreamWriter creation will be tied to the discovery of types in
the output domain. If you want to use types discovered in either one of the
domains for the creation of both the StreamReader and StreamWriter, you must set the
<route_types>
tag to true.
3.5.6.1.2.1. Example: Route Creation with Type Obtained from Discovery¶
<dds>
...
<routing_service name=”MyRoutingService”>
...
<domain_route>
<participant name="MyParticipant"/>
...
<session>
<topic_route>
<input participant="domain1">
<registered_type_name>Position</registered_type_name>
</input>
...
</topic_route>
</session>
...
</domain_route>
...
</routing_service>
...
<dds>
3.5.7. Input/Output¶
Inputs and outputs in a Route or TopicRoute have an associated StreamReader and StreamWriter, respectively. For DDS domains, the StreamReader will contain a DataReader and the StreamWriter will contain a DataWriter. The DataReaders and DataWriters belong to the corresponding Session Subscriber and Publisher.
DDS inputs and outputs within a Route are defined using the <dds_input>
and <dds_output>
tags. Inputs and outputs from other data domains are
defined using the <input>
and <output>
tags. A TopicRoute is a special kind
of Route that allows defining mapping between DDS topics only.
Tags within <input> and <output> of <route> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the Input/Output. See Section 5. |
0..1 |
<stream_name> | Specifies the stream name. | 1 |
<registered_type_name> | Specifies the registered type name of the stream. | 1 |
<creation_mode> | Specifies when to create the StreamReader/StreamWriter. Default: IMMEDIATE See Section 3.5.7.1. |
0..1 |
<property> | A sequence of name-value string pairs that allows you to configure the
StreamReader/StreamWriter.
|
0..1 |
<transformation> (within <output> only) | Sets a data transformation to be applied for every data sample. Attributes
|
0..1 |
Tags within <input> and <output> (in <topic_route>) and <dds_input> and <dds_output> (in <route>) | Description | Multiplicity |
---|---|---|
<topic_name> | Specifies the topic name. | 1 |
<registered_type_name> | Specifies the registered type name of the topic. | 1 |
<creation_mode> | Specifies when to create the StreamReader/StreamWriter. Default: IMMEDIATE See Section 3.5.7.1. |
0..1 |
<datareader_qos> or <datawriter_qos> | Sets the DataReader or DataWriter QoS. The contents of this tag are specified in the same manner as a Connext DDS QoS profile. See Configuring QoS with XML, in the Connext DDS Core Libraries User’s Manual. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..1 |
<content_filter> | Defines a SQL content filter for the DataReader.
|
0..1 |
<transformation>` (within <output> only) | Sets a data transformation to be applied for every data sample. Attributes
|
0..1 |
3.5.7.1. Creation Modes¶
The way a Route creates its StreamReaders and StreamWriters and starts reading and writing data can be configured.
The <creation_mode>
tag in a Route’s <input>
and <output>
tags
controls when StreamReaders/StreamWriters are created.
<creation_mode> values | Description |
---|---|
IMMEDIATE | The StreamReader/StreamWriter is created as soon as possible; that is, as soon as the types are available. Note that if the type is defined in the configuration file, the creation will occur when the service starts. |
ON_DOMAIN_MATCH | The StreamReader is not created until the associated connection discovers a
data Producer on the same stream. If the adapter supports partition,
the discovered Producer must also belong to the same partition for a
match to occur. For example, a DDS input will not create a DataReader until a DataWriter for the same topic and partition is discovered on the same domain. The StreamWriter is not created until the associated connection discovers a
data Consumer on the same stream. If the adapter supports partition,
the discovered Producer must also belong to the same partition for a
match to occur. For example, a DDS output will not create a DataWriter until a DataReader for the same topic and partition is discovered on the same domain. |
ON_ROUTE_MATCH | The StreamReader/StreamWriter is not created until all its counterparts in the Route are created. |
ON_DOMAIN_AND_ROUTE_MATCH | Both conditions must be true. |
ON_DOMAIN_OR_ROUTE_MATCH | At least one of the conditions must be true. |
The same rules also apply to the StreamReader/StreamWriter destruction. When the condition that triggered the creation of that entity becomes false, the entity is destroyed. Note that IMMEDIATE will never become false.
For example, if the creation mode of an <input>
tag is ON_DOMAIN_MATCH, when
all the matching user DataWriters in the input domain are deleted, the input
DataReader is deleted.
3.5.7.1.1. Example: Route Starts as Soon as a User DataWriter is Publishing on 1st Domain¶
<topic_route>
<input participant="domain1">
<creation_mode>ON_DOMAIN_MATCH</creation_mode>
...
</input>
<output participant="domain2">
<creation_mode>ON_ROUTE_MATCH</creation_mode>
...
</output>
</topic_route>
3.5.7.1.2. Example: Route Starts when Both User DataWriter Appears in 1st Domain and User DataReader Appears in 2nd Domain¶
<topic_route>
<input participant="domain1">
<creation_mode>ON_DOMAIN_AND_ROUTE_MATCH</creation_mode>
...
</input>
<output participant="domain2">
<creation_mode>ON_DOMAIN_AND_ROUTE_MATCH</creation_mode>
...
</output>
</topic_route>
3.5.7.2. Data Transformation¶
An Output can transform the incoming data using a Transformation. To instantiate a Transformation:
- Implement the transformation plugin API and register in a plug-in library, or attach it to a service instance if you are using the Service API. See Section 6.
- Instantiate a Transformation object by specifying a
<transformation>
tag inside a<output>
or<dds_output>
.
Table 3.15 lists the tags allowed within a
<transformation>
tag.
Tags within <transformation> | Description | Multiplicity |
---|---|---|
<property> | A sequence of name-value string pairs that allows you to configure the
custom Transformation plug-in object.
|
0..1 |
3.5.8. Auto Route¶
The tag <auto_route>
defines a set of potential Routes, with single input
and output, both with the same registered type and stream name. A Route can
eventually be instantiated when a new stream is discovered with a type name
and a stream name that match the filters in the AutoRoute. When this happens,
a Route is created with the configuration defined by the AutoRoute.
DDS inputs and outputs within an AutoRoute are defined using the XML tags
<dds_input>
and <dds_output>
. Input and outputs from other data domains
are defined using the tags <input>
and <output>
.
An AutoTopicRoute is a special kind of AutoRoute that defines a mapping between two DDS domains.
See the following tables for more information on allowable tags:
- Table 3.16 lists the tags allowed within a
<auto_route>
.- Table 3.17 lists the tags allowed within a
<auto_topic_route>
.
Tags within <auto_route> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the Session. See Section 5. |
0..1 |
<publish_with_original_timestamp> | When this tag is true, the data samples read from the input stream are
written into the output stream with the same timestamp that was
associated with them when they were made available in the input domain. This option may not be applicable in some adapter implementations in
which the concept of timestamp is unsupported. |
0..1 |
<processor> | Sets a custom Processor for handling the data forwarding process. Attributes
|
0..1 |
<dds_input> | Only applicable to DDS inputs. Defines an input topic. | 0..* |
<dds_output> | Only applicable to DDS outputs. Defines an output topic. | 0..* |
<input> | Only applicable to non-DDS inputs. Defines an input stream. | 0..* |
<output> | Only applicable to non-DDS outputs. Defines an output stream. | 0..* |
Tags within <auto_topic_route> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the Session. See Section 5. |
0..1 |
<publish_with_original_info> | Writes the data sample as if they came from its original writer. Setting this option to true allows having redundant routing services and prevents the applications from receiving duplicate samples. Default: false |
0..1 |
<publish_with_original_timestamp> | Indicates if the data samples are written with their original source
timestamp. Default: false |
0..1 |
<propagate_dispose> | Indicates whether or not disposed samples (NOT_ALIVE_DISPOSE) must be
propagated by the TopicRoute. This action may be overwritten by the execution of a transformation. Default: true |
0..1 |
<propagate_unregister> | Indicates whether or not disposed samples (NOT_ALIVE_NO_WRITERS) must be
propagated by the TopicRoute. This action may be overwritten by the execution of a transformation. Default: true |
0..1 |
<topic_query_proxy> | Configures the forwarding of TopicQueries. See Section 8 for detailed information on how Routing Service processes TopicQueries. The snippet below shows that topic query proxy is enabled in propagation mode, which causes the creation of a TopicQuery on the route’s input for each TopicQuery that an output’s matching DataReader creates.
|
0..1 |
<filter_propagation> | Configures the propagation of content filters. Specifies whether the feature is enabled and when events are processed. The snippet below shows that filter propagation is enabled, and a filter update is propagated on the StreamReader only after the occurrence of every three filter events (see Section 7).
|
0..1 |
<processor> | Sets a custom Processor for handling the data forwarding process. Attributes
|
0..1 |
<input> | Defines an input topic. | 0..* |
<output> | Defines an output topic. | 0..* |
Tags within <input> and <output> of <auto_route> | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the Input/Output. See Section 5. |
0..1 |
<allow_stream_name_filter> | A stream name filter. You may use a comma-separated list to specify more than one filter. Default: * (allow all) |
0..1 |
<allow_registered_type_name_filter> | A registered type name filter. You may use a comma-separated list to specify more than one filter. Default: * (allow all) |
0..1 |
<deny_stream_name_filter> | A stream name filter that should be denied (excluded). This is applied
after the <allow_stream_name_filter> . Default: empty (not applied) |
1 |
<deny_registered_type_filter> | A registered type name filter that should be denied (excluded). This is applied
after the <allow_registered_type_name_filter> . Default: empty (not applied) |
0..1 |
<creation_mode> | Specifies when to create the StreamReader/StreamWriter. Default: IMMEDIATE See Section 3.5.7.1. |
0..1 |
<property> | A sequence of name-value string pairs that allows you to configure the
StreamReader/StreamWriter.
|
0..1 |
Tags within <input> and <output> (in <auto_topic_route>) <dds_input> and <dds_output> (in <auto_route>) | Description | Multiplicity |
---|---|---|
<entity_monitoring> | Enables and configures remote monitoring for the Input/Output. See Section 5. |
0..1 |
<allow_topic_name_filter> | A Topic name filter. You may use a comma-separated list to specify more than one filter. Default: * (allow all) |
0..1 |
<allow_registered_type_name_filter> | A registered type name filter. You may use a comma-separated list to specify more than one filter. Default: * (allow all) |
0..1 |
<deny_topic_name_filter> | A Topic name filter that should be denied (excluded). This is applied
after the <allow_stream_name_filter> . Default: empty (not applied) |
1 |
<deny_registered_type_filter> | A registered type name filter that should be denied (excluded). This is applied
after the <allow_registered_type_name_filter> . Default: empty (not applied) |
0..1 |
<creation_mode> | Specifies when to create the StreamReader/StreamWriter. Default: IMMEDIATE See Section 3.5.7.1. |
0..1 |
<datareader_qos> or <datawriter_qos> | Sets the DataReader or DataWriter QoS. The contents of this tag are specified in the same manner as a Connext DDS QoS profile. See Configuring QoS with XML, in the Connext DDS Core Libraries User’s Manual. If the tag is not defined, Routing Service will use the Connext DDS defaults. |
0..1 |
<content_filter> | Defines a SQL content filter for the DataReader.
|
0..1 |
3.5.9. Plugins¶
All the pluggable components specific to Routing Service are configured within the
<plugin_library>
tag. Table 3.20 describes the
available tags.
Plug-ins are categorized and configured based on the source language. Routing Service supports C/C++ and Java plug-ins. See Section 6 for further infomration on developing Routing Service plug-ins.
Tags within <plugin_library> | Description | Multiplicity |
---|---|---|
<adapter_plugin> | Specifies a C/C++ Adapter plug-in. Attributes
|
0..* |
<java_adapter_plugin> | Specifies a Java Adapter plug-in. Attributes (See |
0..* |
<transformation_plugin> | Specifies a C/C++ Transformation plug-in. Attributes
|
0..* |
<processor_plugin> | Specifies a C/C++ Processor plug-in. Attributes
|
0..* |
Table 3.21 and Table 3.22 describe the configuration of each different type of plug-in.
Tags within <adapter_plugin>,
<transformation_plugin> ,
<processor_plugin> |
Description | Multiplicity |
---|---|---|
<dll> | Shared library containing the implementation of the adapter plugin. If no extension is provided, the path will be completed based on the running platform. For example, assuming a value for this tag of dir/myplugin:
If the library specified in this tag cannot be loaded (because the environment library path is not pointing to the path where the library is located), Routing Service will look for the library in <NDDSHOME>/lib/<architecture>. |
1 |
<create_function> | This tag must contain the name of the function used to create the
plugin instance. The function synmbol must be present in the shared
library specified in <dll> . |
1 |
<property> | A sequence of name-value string pairs that allows you to configure the
plug-in instance.
|
0..1 |
Tags within <java_adapter_plugin> | Description | Multiplicity |
---|---|---|
<class_name> | Name of the class that implements the plugin. For example: com.myadapters.CustomAdapter The classpath required to run the Java plugin must be part of the Routing Service JVM configuration. See Table 3.2 for additional information on JVM creation and configuration. |
1 |
<property> | A sequence of name-value string pairs that allows you to configure the
plug-in instance.
|
0..1 |
3.6. Enabling Distributed Logger¶
Routing Service provides integrated support for RTI Distributed Logger.
Distributed Logger is included in Connext DDS but it is not supported on all platforms; see the Connext DDS Core Libraries Platform Notes to see which platforms support Distributed Logger.
When you enable Distributed Logger, Routing Service will publish its log messages to Connext DDS. Then you can use RTI Admin Console to visualize the log message data. Since the data is provided in a topic, you can also use rtiddsspy or even write your own visualization tool.
To enable Distributed Logger, use the tag <distributed_logger>
within
<adminstration>
. For example:
<routing_service name="default">
<administration>
...
<distributed_logger>
<enabled>true</enabled>
</distributed_logger>
</administration>
...
</routing_service>
For the list of elements that configure Distributed Logger see Section 3.5.2. For more details about Distributed Logger, see Enabling Distributed Logger in RTI Services.
3.7. Support for Extensible Types¶
Routing Service includes partial support for the ‘“Extensible and Dynamic Topic Types for DDS” specification <http://www.omg.org/spec/DDS-XTypes>’ from the Object Management Group (OMG). This section assumes that you are familiar with Extensible Types and you have read the Connext DDS Core Libraries Getting Started Guide Addendum for Extensible Types.
- TopicRoutes can subscribe to and publish topics associated with final and extensible types.
- You can select the type version associated with a topic route by providing the type description in the XML configuration file. The XML description supports structure inheritance. You can learn more about structure inheritance in the Connext DDS Getting Started Guide Addendum for Extensible Types.
- The TypeConsistencyEnforcementQosPolicy can be specified on a per-topic-route basis, in the same way as other QoS policies.
- Within a DomainParticipant, a topic cannot be associated with more than one type version. This prevents the same DomainParticipant from having two Route DataReader or DataWriter with different versions of a type for the same Topic. To achieve this behavior, create two different DomainParticipant, each associating the topic with a different type version.
The type declared in a TopicRoute input is the version that is passed to the output (or to a transformation). The TopicRoute can subscribe to different-but-compatible types, but those samples are translated to the TopicRoute input type.
3.7.1. Example: Samples Published by Two Writers of Type A and B, Respectively¶
struct A {
long x;
};
struct B {
long x;
long y;
};
Samples published by two DataWriters of types A and B, respectively | Samples forwarded by a TopicRoute for type A in both input and output | Samples received by a B reader |
---|---|---|
A [x=1] | A [x=1] | B [x=1, y=0] |
B [x=10, y=11] | A [x=10] | B [x=10, y=0] |
Samples published by two DataWriters of types A and B, respectively | Samples forwarded by a TopicRoute for type B in both input and output | Samples received by a B reader |
---|---|---|
A [x=1] | B [x=1, y=0] | B [x=1, y=0] |
B [x=10, y=11] | B [x=10, y=11] | B [x=10, y=11] |
_section-Config-EnablingLargedataFeatures