Control Hub API

The Control Hub API processor sends requests to the Control Hub REST API and writes data from the response to a specified output field.

The Control Hub API processor is an orchestration stage that you use in orchestration pipelines. Orchestration stages perform tasks, such as schedule and start pipelines and Control Hub jobs, that you can use to create an orchestrated workflow across IBM StreamSets. For example, an orchestration pipeline can use the Cron Scheduler origin to generate a record every weekday at 5 PM and trigger the Control Hub API processor, which calls a Control Hub REST API to stop a Control Hub job that runs during business hours.

When you configure the Control Hub API processor, you specify the URL for the API, the field to write the response to, any headers to include with the request, and the method to use. The method can specify a standard HTTP request or an expression that determines the request for each record. For some methods, you can specify data to include with the request.

You can configure the processor to log request and response information.

You can also configure the timeout and maximum number of parallel requests. You can optionally use an HTTP proxy and configure SSL/TLS properties.

You can also use a connection to configure the processor.

Finding the URL to a Control Hub REST API

Each Control Hub REST API has a unique URL. The URL contains the Control Hub URL and the path to the API.

You can find the URL in Control Hub.

From the Help menu, click RESTful API.
The page lists the APIs by category.
In the list of APIs, expand the API to view API details, including the URL.

HTTP Method

The Control Hub API processor supports the following HTTP methods:

GET
PUT
POST
DELETE
Expression - An expression that evaluates to one of the other methods.

Specify a method valid for the API call.

You can use the Expression method to set the HTTP method based on the data in a field. For example, the same API call, /pipelinestore/rest/v1/pipelineCommit/{commitId}, can either retrieve, save, or delete a pipeline commit, depending on the specified method. Therefore, you might configure the Control Hub API processor to use that API call with an expression that returns either the GET, POST, or DELETE method based on data in a field.

Parallel Requests

The Control Hub API processor can send multiple requests simultaneously.

To preserve record order, the processor waits until all the requests from an entire batch are completed before sending requests from the next batch.

You can specify the maximum number of parallel requests. Default is 1. Increasing the number of parallel requests can improve performance but increases the load on the Control Hub server. Network latency can also significantly impact the performance of this processor.

Logging Request and Response Data

The Control Hub API processor can log request and response data to the Data Collector log.

When enabling logging, you configure the following properties:

Verbosity

The type of data to include in logged messages:

Headers_Only - Includes request and response headers.
Payload_Text - Includes request and response headers as well as any text payloads.
Payload_Any - Includes request and response headers and the payload, regardless of type.

Log Level

The level of messages to include in the Data Collector log. When you select a level, higher level messages are also logged. That is, if you select the Warning log level, then Severe and Warning messages are written to the Data Collector log.

Note: The configured log level for Data Collector can limit the level of detail that is logged. For example, if you set the log level to Finest to log detailed trace information, but Data Collector is configured for ERROR, then the origin only writes Severe level messages.

The following table describes the stage log levels and the corresponding Data Collector log levels needed to enable the logging:


Stage Log Level	Data Collector	Description
Severe	ERROR	Only messages indicating serious failures.
Warning	WARN	Messages warning of potential problems.
Info	INFO	Informational messages.
Fine	DEBUG	Basic tracing information.
Finer	DEBUG	Detailed tracing information.
Finest	TRACE	Highly detailed tracing information.

The name of this stage logger is com.streamsets.http.RequestLogger.

Max entity size

The maximum size of message data to write to the log. Use to limit the volume of data written to the Data Collector log for any single message.

Generated Record

The Control Hub API processor updates the orchestration record that it receives with the response from the Control Hub REST API. The response is placed in the output field specified in the stage properties. The fields included in the response depends on the API that the Control Hub API processor calls.

For example, the following preview shows the currentStatus field that was added to the orchestration record by the Control Hub API processor. The field contains the response from a currentStatus API call. The call requests the status of the job that completed earlier in the orchestration pipeline and returns additional information about the job:

Configuring a Control Hub API Processor

Configure a Control Hub API processor to call a Control Hub REST API. The Control Hub API processor is an orchestration stage that you use in orchestration pipelines.

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 pipeline.
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 pipeline for error handling. Stop Pipeline - Stops the pipeline.

On the HTTP tab, configure the following properties:


HTTP Property	Description
Connection	Connection that defines the information 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 directly enter the details in the pipeline. When you select a connection, Control Hub hides other properties so that you cannot directly enter connection details in the pipeline. To create a new connection, click the Add New Connection icon: . To view and edit the details of the selected connection, click the Edit Connection icon: .
Control Hub URL	URL to the Control Hub REST API. Enter the Control Hub URL and path to a specific API.
Output Field	Field to store the response. You can use a new or existing field.
Headers	Headers to include in the request. In simple or bulk edit mode, click the Add icon to add additional headers.
HTTP Method	HTTP method for the request. Select one of the standard methods or select Expression to enter an expression.
HTTP Method Expression	Expression that evaluates to a standard HTTP method. Available when HTTP Method is set to Expression.
Request Data	Data to include with the request. Available for the PUT, POST, DELETE, and Expression methods.
Use Proxy	Enables using an HTTP proxy to connect to Control Hub.
Connection Timeout	Maximum number of milliseconds to wait for a connection.
Read Timeout	Maximum number of milliseconds to wait for data.
Maximum Parallel Requests	Maximum number of requests to send to the server at one time.
Maximum Request Time	Maximum number of seconds to wait for a request to complete.

On the Credentials tab, configure the following properties:


Credentials Property	Description
Authentication Type	Method for specifying authentication details: User & Password (SCH 3.x only) - Use when Data Collector is registered with Control Hub cloud or Control Hub on-premises version 3.x. API User Credentials - Use when Data Collector is deployed from Control Hub in IBM StreamSets.
User Name	Control Hub user that calls the API. Enter in the following format: `<ID>@<organization ID>` Available when Authentication Type is set to User & Password.
Auth ID	ID of a Control Hub API credential for someone authorized to call the API. For information on creating a Control Hub API credential, see the Control Hub documentation. Available when Authentication Type is set to API User Credentials.
Password	Password for the specified Control Hub user or the token for the specified Control Hub API credential. Tip: To secure sensitive information such as user names and passwords, you can use runtime resources or credential stores.

To use an HTTP proxy, on the Proxy tab, configure the following properties:


Proxy Property	Description
Proxy URI	Proxy URI.
Username	Proxy user name.
Password	Proxy password. Tip: To secure sensitive information such as user names and passwords, you can use runtime resources or credential stores.

To use SSL/TLS, click the TLS tab and configure the following properties.


TLS Property	Description
Use TLS	Enables the use of TLS.
Use Remote Keystore	Enables loading the contents of the keystore from a remote credential store or from values entered in the stage properties. For more information, see Remote Keystore and Truststore.
Private Key	Private key used in the remote keystore. Enter a credential function that returns the key or enter the contents of the key.
Certificate Chain	Each PEM certificate used in the remote keystore. Enter a credential function that returns the certificate or enter the contents of the certificate.
Keystore File	Path to the local keystore file. Enter an absolute path to the file or enter the following expression to define the file stored in the Data Collector resources directory: `${runtime:resourcesDirPath()}/keystore.jks` By default, no keystore is used.
Keystore Type	Type of keystore to use. Use one of the following types: Java Keystore File (JKS) PKCS #12 (p12 file) Default is Java Keystore File (JKS).
Keystore Password	Password to the keystore file. A password is optional, but recommended. Tip: To secure sensitive information such as passwords, you can use runtime resources or credential stores.
Keystore Key Algorithm	Algorithm to manage the keystore. Default is SunX509.
Use Remote Truststore	Enables loading the contents of the truststore from a remote credential store or from values entered in the stage properties. For more information, see Remote Keystore and Truststore.
Trusted Certificates	Each PEM certificate used in the remote truststore. Enter a credential function that returns the certificate or enter the contents of the certificate. Using simple or bulk edit mode, click the Add icon to add additional certificates.
Truststore File	Path to the local truststore file. Enter an absolute path to the file or enter the following expression to define the file stored in the Data Collector resources directory: `${runtime:resourcesDirPath()}/truststore.jks` By default, no truststore is used.
Truststore Type	Type of truststore to use. Use one of the following types: Java Keystore File (JKS) PKCS #12 (p12 file) Default is Java Keystore File (JKS).
Truststore Password	Password to the truststore file. A password is optional, but recommended. Tip: To secure sensitive information such as passwords, you can use runtime resources or credential stores.
Truststore Trust Algorithm	Algorithm to manage the truststore. Default is SunX509.
Use Default Protocols	Uses the default TLSv1.2 transport layer security (TLS) protocol. To use a different protocol, clear this option.
Transport Protocols	TLS protocols to use. To use a protocol other than the default TLSv1.2, click the Add icon and enter the protocol name. You can use simple or bulk edit mode to add protocols. Note: Older protocols are not as secure as TLSv1.2.
Use Default Cipher Suites	Uses a default cipher suite for the SSL/TLS handshake. To use a different cipher suite, clear this option.
Cipher Suites	Cipher suites to use. To use a cipher suite that is not a part of the default set, click the Add icon and enter the name of the cipher suite. You can use simple or bulk edit mode to add cipher suites. Enter the Java Secure Socket Extension (JSSE) name for the additional cipher suites that you want to use.

On the Logging tab, configure the following properties to log request and response data:


Logging Property	Description
Enable Request Logging	Enables logging request and response data.
Log Level	The level of detail to be logged. Choose one of the available options. The following list is in order of lowest to highest level of logging. When you select a level, messages generated by the levels above the selected level are also written to the log: Severe - Only messages indicating serious failures. Warning - Messages warning of potential problems. Info - Informational messages. Fine - Basic tracing information. Finer - Detailed tracing information. Finest - Highly detailed tracing information. Note: The log level configured for Data Collector can limit the level of messages that the stage writes. Verify that the Data Collector log level supports the level that you want to use.
Verbosity	The type of data to include in logged messages: Headers_Only - Includes request and response headers. Payload_Text - Includes request and response headers as well as any text payloads. Payload_Any - Includes request and response headers and the payload, regardless of type.
Max Entity Size	The maximum size of message data to write to the log. Use to limit the volume of data written to the Data Collector log for any single message.