Pulsar Producer

The Pulsar Producer target writes data to topics in an Apache Pulsar cluster. The Pulsar Producer target attaches to one or more topics and publishes messages to a Pulsar broker for processing. For information about supported versions, see Supported systems and versions.

When you configure a Pulsar Producer target, you define the URL to connect to Pulsar, and you configure the Pulsar security features to use when connecting. You can also use a connection to configure the target.

You define the topics to publish messages to, either a single topic or multiple topics by including an expression in the configured topic name. In addition, you define the schema Pulsar uses to validate the messages that the target writes to the topic.

You can configure advanced properties as needed, such as the partition or compression type to use when publishing messages or whether the target publishes messages asynchronously or synchronously.

Schema properties

The target contains properties to specify a schema on the Schema tab and the Data Format tab:

Schema tab: The schema specified on the Schema tab is used to validate messages written to Pulsar.
If the target writes to a topic in a Pulsar namespace configured to enforce schema validation, then you must specify a schema on the Schema tab. The target passes the schema to Pulsar. Then Pulsar uses the schema to validate written messages.
Data Format tab: The schema specified on the Data Format tab supports message processing.
If you configure the target to write messages in Avro or XML format, then you can specify a schema on the Data Format tab. The target uses the specified schema to format and write messages.

If you specify a schema on both tabs, then specify the same schema.

Security

Configure the Pulsar Producer target to use the security features available in the Pulsar cluster.

About this task

The target supports the following security features:

TLS transport encryption: The Pulsar cluster encrypts all traffic between the Pulsar server and the stage. The Pulsar server provides a key and certificate, which the stage uses to verify the server's identity.
TLS authentication: The stage provides keys and certificates, which the Pulsar server uses to verify the stage's identity. TLS authentication requires TLS transport encryption.
JWT authentication: The stage provides Pulsar a JSON Web Token (JWT), which identifies the stage and grants permission for some actions. JWT authentication requires TLS transport encryption.
OAuth authentication: The stage provides Pulsar an OAuth 2.0 access token, which identifies the stage and associates the stage with a role.

Enabling TLS transport encryption

Enable TLS transport encryption to encrypt all traffic between the Pulsar server and the stage.

Procedure

On the Pulsar tab of the stage, set the Pulsar URL property to the secure URL for the broker service.
Use the following format for the URL:
```
pulsar+ssl://<host name>:<broker service TLS port>/
```
For example:
```
pulsar+ssl://pulsar.us-west.example.com:6651/
```
On the Security tab of the stage, select Enable TLS.
Store the PEM file that contains the certificate authority (CA) that signed the Pulsar cluster certificate in the Data Collector resources directory, $SDC_RESOURCES.
On the Security tab of the stage, enter the name of the CA certificate PEM file in the CA Certificate PEM property.

Enabling TLS authentication

Enable TLS authentication so that Pulsar can authenticate the stage with certificates.

Procedure

Enable TLS transport encryption.
On the Security tab of the stage, select Enable Mutual Authentication.
Create the client certificate and client private key PEM files for the stage to use.
Store the client certificate and client private key PEM files created for the stage in the Data Collector resources directory, $SDC_RESOURCES.
On the Security tab of the stage, enter the name of the client files in the Client Certificate PEM and Client Key PEM properties.

Enabling JWT authentication

Enable JWT authentication so that Pulsar can authenticate the stage with a JSON Web Token (JWT).

Before you begin

Before you start, contact the Pulsar administrator for a token string that represents a signed JWT for the stage.

Procedure

Enable TLS transport encryption.
On the Security tab, select Use JWT.
In the Token property, enter the token string that represents a signed JWT for the stage.

Enabling OAuth authentication

Enable OAuth authentication so that Pulsar can authenticate the stage with an access token.

Procedure

Create a JSON credentials file and store in the Data Collector resources directory, $SDC_RESOURCES, or in a relative directory.
The credentials file contains service account credentials for authenticating the stage. For example, you might create a credentials file named credentials_file.json:
```
{
  "type": "client_credentials",
  "client_id": "d9ZyX97q1ef8Cr81WHVC4hFQ64vSlDK3",
  "client_secret": "on1uJ...k6F6R",
  "client_email": "1234567890-abcdefghijklmnopqrstuvwxyz@developer.gserviceaccount.com",
  "issuer_url": "https://accounts.google.com"
}
```
On the Security tab, select Use OAuth.
In the Issuer URL property, enter the URL of the authentication provider that provides Pulsar clients with access tokens.
In the Credentials URL property, enter the path of the JSON credentials file, relative to the Data Collector resources directory, $SDC_RESOURCES.
For example, if you created the credentials_file.json file in the $SDC_RESOURCES directory, enter /credentials_file.json.
In the Audience property, enter the URL that the stage uses to reach the Pulsar cluster.

Data formats

The Pulsar Producer target writes data to Pulsar based on the data format that you select. You can use the following data formats:

Avro

The stage writes records based on the Avro schema. You can use one of the following methods to specify the location of the Avro schema definition:

In Flow Configuration - Use the schema that you provide in the stage configuration.
In Record Header - Use the schema included in the avroSchema record header attribute.
Confluent Schema Registry - Retrieve the schema from Confluent Schema Registry. The Confluent Schema Registry is a distributed storage layer for Avro schemas. You can configure the target to look up the schema in the Confluent Schema Registry by the schema ID or subject.
If using the Avro schema in the stage or in the record header attribute, you can optionally configure the stage to register the Avro schema with the Confluent Schema Registry. You can also optionally include the schema definition in the message. Omitting the schema definition can improve performance, but requires the appropriate schema management to avoid losing track of the schema associated with the data.

You can include the Avro schema in the output.

You can also compress data with an Avro-supported compression codec. When using Avro compression, avoid configuring any other compression properties in the stage.

Binary

The stage writes binary data to a single field in the record.

Delimited

The target writes records as delimited data. When you use this data format, the root field must be list or list-map.

You can use the following delimited format types:

Default CSV - File that includes comma-separated values. Ignores empty lines in the file.
RFC4180 CSV - Comma-separated file that strictly follows RFC4180 guidelines.
MS Excel CSV - Microsoft Excel comma-separated file.
MySQL CSV - MySQL comma-separated file.
Tab-Separated Values - File that includes tab-separated values.
PostgreSQL CSV - PostgreSQL comma-separated file.
PostgreSQL Text - PostgreSQL text file.
Custom - File that uses user-defined delimiter, escape, and quote characters.
Multi Character Delimited - File that uses multiple user-defined characters to delimit fields and lines, and single user-defined escape and quote characters.

JSON

The target writes records as JSON data. You can use one of the following formats:

Array - Each file includes a single array. In the array, each element is a JSON representation of each record.
Multiple objects - Each file includes multiple JSON objects. Each object is a JSON representation of a record.

Protobuf

Writes one record in a message. Uses the user-defined message type and the definition of the message type in the descriptor file to generate the message.

For information about generating the descriptor file, see Protobuf data format prerequisites.

SDC Record

The target writes records in the SDC Record data format.

Text

The target writes data from a single text field to the target system. When you configure the stage, you select the field to use.

You can configure the characters to use as record separators. By default, the target uses a UNIX-style line ending (\n) to separate records.

When a record does not contain the selected text field, the target can report the missing field as an error or to ignore the missing field. By default, the target reports an error.

When configured to ignore a missing text field, the target can discard the record or write the record separator characters to create an empty line for the record. By default, the target discards the record.

XML

The target creates a valid XML document for each record. The target requires the record to have a single root field that contains the rest of the record data. For details and suggestions for how to accomplish this, see Record structure requirement.

The target can include indentation to produce human-readable documents. It can also validate that the generated XML conforms to the specified schema definition. Records with invalid schemas are handled based on the error handling that is configured for the target.

Configuring a Pulsar Producer target

About this task

Configure a Pulsar Producer target to write data to Pulsar topics.

Procedure

In the Properties panel, on the General tab, configure the following properties:

General Property	Description
Name	Stage name.
Description	Optional description.
Required Fields	Fields that must include data for the record to be passed into the stage. Tip: You might include fields that the stage uses. Records that do not include all required fields are processed based on the error handling configured for the flow.
Preconditions	Conditions that must evaluate to TRUE to allow a record to enter the stage for processing. Click Add to create additional preconditions. Records that do not meet all preconditions are processed based on the error handling configured for the stage.
On Record Error	Error record handling for the stage: Discard - Discards the record. Send to Error - Sends the record to the flow for error handling. Stop Flow - Stops the flow.

On the Pulsar tab, configure the following properties:

Pulsar Property	Description
Connection 7.4 and later	Connection that defines the information that is required to connect to an external system. To connect to an external system, you can select a connection that contains the details, or you can specify the details in local properties. When you select a connection, the flow canvas hides properties that are defined in the connection.
Pulsar URL	URL to the Pulsar web service or broker service. If the Pulsar cluster is not enabled for TLS, enter either the web service or broker service URL in the following format: Web service URL - `http://<host name>:<web service port>`. For example: `http://pulsar.us-west.example.com:8080`. Broker service URL - `pulsar://<host name>:<broker service port>`. For example: `pulsar://pulsar.us-west.example.com:6650` If the Pulsar cluster is enabled for TLS, enter the secure broker service URL in the following format: `pulsar+ssl://<host name>:<broker service TLS port>` For example: `pulsar+ssl://pulsar.us-west.example.com:6651`
Topic	Name of the topic to publish messages to. Enter the topic name in the following format: `{persistent\|non-persistent}://<tenant>/<namespace>/<topic name>` For example, to publish to a persistent topic named `my-sdc-topic` in the `my-namespace` namespace within the `my-tenant` tenant, enter the following as the topic name: `persistent://my-tenant/my-namespace/my-sdc-topic` If you enter a topic name only, then Pulsar uses the default `persistent://public/default/` location. For example, to publish to a persistent topic belonging to the `public` tenant in the `default` namespace, simply enter the topic name as follows: `my-sdc-topic` If the specified topic does not exist, Pulsar creates the topic when the flow starts. You can use expressions to define the topic name. For example, if the `my-topic` field in the record contains the topic name, enter the following as the topic name: `persistent://my-tenant/my-namespace/${record:value("/my-topic")}`
Keep Alive Interval (ms)	Number of milliseconds to allow the connection to Pulsar to remain idle. After the target publishes no messages for this amount of time, the connection is closed. The target must reconnect to Pulsar. Default is 30,000 milliseconds.
Operation Timeout (ms)	Number of milliseconds to allow the Pulsar Producer-create operation to complete before marking the operation as failed. Default is 30,000 milliseconds.

On the Schema tab, configure the following properties:

Schema Property	Description
Schema	Schema that Pulsar uses to validate the messages that the target writes to a topic. The target passes the schema to Pulsar when attaching to a topic. Select one of the following options: No Schema - Use no schema. Select this option when the Pulsar namespace of the topic is not configured to enforce schema validation. Auto Schema - Use a generic schema created by Pulsar to validate messages. User-defined Schema - Use the schema specified in the Schema Info property. Valid for the Avro and Text data formats. Note: If the target writes to multiple topics, Pulsar uses this same schema to validate the messages sent to any of the topics. Schema in Record Headers - Use the schema from the record header attribute specified in the Header Attribute property. Valid for the Avro data format.
Schema Info	Schema definition to pass to Pulsar. Specify the schema using the `SchemaInfo` data structure. Available if Schema is set to User-defined Schema. Important: The target only supports Avro and string schemas. You must specify a corresponding data format on the Data Format tab, either Avro or Text. For Avro, specify the same schema on the Data Format tab.
Header Attribute	Record header attribute that contains the schema to pass to Pulsar. Default value is `avroSchema`. You can use the Schema Generator processor to generate the attribute. Available if Schema is set to Schema in Record Headers. Important: This option only supports an Avro schema. You must specify the Avro data format and the same schema on the Data Format tab.

To enable security, click the Security tab and configure the following properties:

Security Property	Description
Enable TLS	Enables the stage to connect securely to Pulsar through TLS encryption.
Use JWT	Enables the stage to use a JSON Web Token (JWT) to authenticate with Pulsar. Available if TLS encryption is enabled.
Token	If JWT is enabled, JWT to pass to Pulsar.
Enable Mutual Authentication	Enables the stage to use a key and certificate to authenticate with Pulsar. Available if TLS encryption is enabled.
CA Certificate PEM	Path to the PEM file containing the certificate authority (CA) that signed the Pulsar cluster certificate. Enter an absolute path to the file or a path relative to the Data Collector resources directory: $SDC_RESOURCES.
Client Certificate PEM	If mutual authentication is enabled, path to the PEM file containing the client certificate created for Data Collector. Enter an absolute path to the file or a path relative to the Data Collector resources directory: $SDC_RESOURCES.
Client Key PEM	If mutual authentication is enabled, path to the PEM file containing the client private key created for Data Collector. Enter an absolute path to the file or a path relative to the Data Collector resources directory: $SDC_RESOURCES.
Use OAuth	Enables the stage to use an OAuth 2 access token to authenticate with Pulsar.
Issuer URL	If OAuth is enabled, URL of the authentication provider that provides Pulsar clients with access tokens.
Credentials URL	If OAuth is enabled, path to the JSON credentials file. Enter a path relative to the Data Collector resources directory: $SDC_RESOURCES.
Audience	If OAuth is enabled, URI of the resource server that the stage wants to access.

On the Advanced tab, optionally configure advanced properties.

The defaults for these properties should work in most cases:

Advanced Property	Description
Partition Type	Partition type to use when publishing messages to a topic: Single Round Robin Default is Single.
Hashing Scheme	Hashing scheme to use when selecting which partition to write messages to.
Message Key	Message key used to compute the hash for partitioning. Enter the key or enter an expression that evaluates to the key.
Compression Type	Type of compression to apply to the published messages: None LZ4 ZLIB Default is None.
Async Send	Enables the target to publish messages asynchronously. Clear to publish messages synchronously. Default is enabled.
Max Pending Messages	When sending messages asynchronously, the maximum number of messages that can wait in the queue for an acknowledgement from the Pulsar broker. Default is 1,000.
Enable Batching	When sending messages asynchronously, enables sending a batch of messages in a single request. Clear to send a single message in each request. Default is enabled.
Max Batch Size (messages)	When sending messages asynchronously and batching is enabled, the maximum number of messages to include in a batch. Default is 2,000.
Batch Max Publish Latency (ms)	When sending messages asynchronously and batching is enabled, the maximum number of milliseconds to wait before sending the next batch. Default is 1,000 milliseconds.
Pulsar Configuration Properties	Additional Pulsar configuration properties to use. Using simple or bulk edit mode, click the Add icon to add properties. Define the Pulsar property name and value. Use the property names and values as expected by Pulsar.

On the Data Format tab, configure the following property:

Data Format Property	Description
Data Format	Type of data to be read. Use one of the following options: Avro Binary Delimited JSON Protobuf SDC Record Text XML

For Avro data, on the Data Format tab, configure the following properties:

Avro Property	Description
Avro Schema Location	Location of the Avro schema definition to use when writing data: In Flow Configuration - Use the schema that you provide in the stage configuration. In Record Header - Use the schema in the avroSchema record header attribute. Use only when the avroSchema attribute is defined for all records. Confluent Schema Registry - Retrieve the schema from Confluent Schema Registry.
Avro Schema	Avro schema definition used to write the data. You can optionally use the `runtime:loadResource` function to load a schema definition stored in a runtime resource file.
Register Schema	Registers a new Avro schema with Confluent Schema Registry.
Schema Registry URLs	Confluent Schema Registry URLs used to look up the schema or to register a new schema. To add a URL, click Add and then enter the URL in the following format: `http://<host name>:<port number>`
Basic Auth User Info	User information needed to connect to Confluent Schema Registry when using basic authentication. Enter the key and secret from the `schema.registry.basic.auth.user.info` setting in Schema Registry using the following format: `<key>:<secret>` Tip: To secure sensitive information such as user names and passwords, you can use runtime resources or credential stores.
Look Up Schema By	Method used to look up the schema in Confluent Schema Registry: Subject - Look up the specified Avro schema subject. Schema ID - Look up the specified Avro schema ID.
Schema Subject	Avro schema subject to look up or to register in Confluent Schema Registry. If the specified subject to look up has multiple schema versions, the stage uses the latest schema version for that subject. To use an older version, find the corresponding schema ID, and then set the Look Up Schema By property to Schema ID.
Schema ID	Avro schema ID to look up in Confluent Schema Registry.
Include Schema	Includes the schema in each message. Note: Omitting the schema definition can improve performance, but requires the appropriate schema management to avoid losing track of the schema associated with the data.
Avro Compression Codec	The Avro compression type to use. When using Avro compression, do not enable other compression available in the target.

For binary data, on the Data Format tab, configure the following property:

Binary Property	Description
Binary Field Path	Field that contains the binary data.

For delimited data, on the Data Format tab, configure the following properties:

Delimited Property	Description
Delimiter Format	Format for delimited data: Default CSV - File that includes comma-separated values. Ignores empty lines in the file. RFC4180 CSV - Comma-separated file that strictly follows RFC4180 guidelines. MS Excel CSV - Microsoft Excel comma-separated file. MySQL CSV - MySQL comma-separated file. Tab-Separated Values - File that includes tab-separated values. PostgreSQL CSV - PostgreSQL comma-separated file. PostgreSQL Text - PostgreSQL text file. Custom - File that uses user-defined delimiter, escape, and quote characters.
Header Line	Indicates whether to create a header line.
Delimiter Character	Delimiter character for a custom delimiter format. Select one of the available options or use Other to enter a custom character. You can enter a Unicode control character using the format \uNNNN, where N is a hexadecimal digit from the numbers 0-9 or the letters A-F. For example, enter \u0000 to use the null character as the delimiter or \u2028 to use a line separator as the delimiter. Default is the pipe character ( \| ).
Record Separator String	Characters to use to separate records. Use any valid Java string literal. For example, when writing to Windows, you might use `\r\n` to separate records. Available when using a custom delimiter format.
Escape Character	Escape character for a custom delimiter format. Select one of the available options or use Other to enter a custom character. Default is the backslash character ( \ ).
Quote Character	Quote character for a custom delimiter format. Select one of the available options or use Other to enter a custom character. Default is the quotation mark character ( " ).
Replace New Line Characters	Replaces new line characters with the configured string. Recommended when writing data as a single line of text.
New Line Character Replacement	String to replace each new line character. For example, enter a space to replace each new line character with a space. Leave empty to remove the new line characters.
Charset	Character set to use to write data.

For JSON data, on the Data Format tab, configure the following properties:

JSON Property	Description
JSON Content	Method to write JSON data: JSON Array of Objects - Each file includes a single array. In the array, each element is a JSON representation of each record. Multiple JSON Objects - Each file includes multiple JSON objects. Each object is a JSON representation of a record.
Charset	Character set to use to write data.

For protobuf data, on the Data Format tab, configure the following properties:

Protobuf Property	Description
Protobuf Descriptor File	Descriptor file (.desc) to use. The descriptor file must be in the Data Collector resources directory, `$SDC_RESOURCES`. For information about generating the descriptor file, see Protobuf data format prerequisites.
Message Type	Fully-qualified name for the message type to use when writing data. Use the following format: `<package name>.<message type>`. Use a message type defined in the descriptor file.

For text data, on the Data Format tab, configure the following properties:

Text Property	Description
Text Field Path	Field that contains the text data to be written. All data must be incorporated into the specified field.
Record Separator	Characters to use to separate records. Use any valid Java string literal. For example, when you write to Windows, you might use `\r\n` to separate records. By default, the target uses `\n`.
On Missing Field	When a record does not include the text field, determines whether the target reports the missing field as an error or ignores the missing field.
Insert Record Separator if No Text	When configured to ignore a missing text field, inserts the configured record separator string to create an empty line. When not selected, discards records without the text field.
Charset	Character set to use to write data.

For XML data, on the Data Format tab, configure the following properties:

XML Property	Description
Pretty Format	Adds indentation to make the resulting XML document easier to read, which also increases the record size.
Validate Schema	Validates that the generated XML conforms to the specified schema definition. Records with invalid schemas are handled based on the error handling that is configured for the target. Important: Regardless of whether you validate the XML schema, the target requires the record in a specific format. For more information, see Record structure requirement.
XML Schema	The XML schema to use to validate records.