On-Premises Orchestration

Orchestration across Cloud-based and on-premises applications exposed on premises.

Pattern Definition

Problem	How do I incorporate Cloud-based applications and on-premises applications in an orchestration with minimal Cloud footprint?
Context	This pattern is applicable when there is a desire to create an orchestration incorporating Cloud-based applications and on-premises applications using only on-premises infrastructure.
Forces	Want to expose the orchestration on premises. Applications included in the orchestration are on premises and Cloud-based. In-house orchestration skills are readily available. Desire to leverage existing on-premises orchestrations.
Solution	This pattern employs an Application Integration Platform only on premises. This is likely the current situation in most IT environments. On-premises applications are integrated using the on-premises Application Integration Platform and there is a desire to add Cloud-based applications to this existing integration approach.
Consequences	Pros: Leverages existing investment in on-premises Application Integration Platform. Easiest way to add Cloud-based applications to exiting orchestrations. Best support for orchestration with many on-premises applications. Cons: Sub-optimal approach for orchestrations with multiple Cloud-based application participants. Does not take advantage of what public Cloud has to offer with respect to orchestration.

Interaction View

• Orchestration
• Composite Orchestration

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Orchestration

An orchestration incorporating on-premises applications and Cloud-based application. 

Interaction

1. The interface for the orchestration is exposed by the on-premises Application Integration Platform.
2. The on-premises Application Integration Platform calls an on-premises application as part of the orchestration.
3. The on-premises Application Integration Platform calls another on-premises application as part of the orchestration.
4. The on-premises Application Integration Platform calls a Cloud-based application as part of the orchestration.

Notes

1. The communication to the applications could use native APIs or adapters.
2. This interaction shows three applications included in the orchestration but there could be more or less. 

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Composite Orchestration

An orchestration incorporating on-premises applications and Cloud-based application. 

Interaction

1. The interface for the orchestration is exposed by the on-premises Application Integration Platform.
2. The on-premises Application Integration Platform calls an on-premises application as part of the orchestration.
3. The on-premises Application Integration Platform calls another on-premises application as part of the orchestration.
4. The on-premises Application Integration Platform calls a Cloud-based application as part of the orchestration.

Notes

1. The communication to the applications could use native APIs or adapters.
2. This interaction shows three applications included in the orchestration but there could be more or less. 

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