This section contains information you need to think about before deploying CentraSite in your environment.
When developing Web services and other assets, most IT organizations follow a systems development life cycle (SDLC) that includes at least the following basic phases:
A development phase, when Web services and other assets are requested and developed, individual contributions are integrated and development tests are conducted.
A test phase, when services and other assets are tested in a controlled environment that mimics production scenarios.
A production phase, when services and other assets are made operational. Generally, when an asset reaches this stage the environment in which it resides is tightly controlled and access to the asset itself is very restricted.
In CentraSite, the series of steps that make up your SDLC are represented by a lifecycle model. The lifecycle model is customized to your environment and enables you to establish governance controls over all phases of the SDLC for different types of assets.
When planning your CentraSite implementation, the first thing you must do is choose a deployment strategy that supports your organization's SDLC and its implementation requirements. The strategy you choose will determine the number of stages (instances of a CentraSite registry) that your organization will maintain and how it will map the phases of its SDLC to these stages.
This section presents three basic deployment strategies and describes how you might map the phases of the SDLC to each of them. As a first step in planning your CentraSite implementation, you should review the following strategies and choose the strategy that best supports your organization's SDLC and its governance objectives.
Single-Stage Deployment: In a single stage deployment, the entire SDLC is represented within one instance of CentraSite. With this strategy, you deploy and maintain a single registry. The assets that you place in the registry remain there over their entire lifecycle.
When you use the single-stage strategy, you map all three basic phases of the SDLC to a single lifecycle model in CentraSite. To promote an asset through the SDLC (for example, to move it from the development phase to the test phase), you simply switch the asset's lifecycle state in the registry.
The following figure depicts a single-stage deployment. Note that the states that make up its lifecycle comprise the full SDLC (from request to retirement).
Single-Stage Deployment
Two-Stage Deployment: In a two-stage deployment, the SDLC is split between two instances of CentraSite. One instance, called the creation CentraSite, is used to manage assets during the development and test phases of the SDLC. The other instance, called the consumption CentraSite, manages assets that are in the production phase of the SDLC.
This strategy enables your organization to completely separate assets in the pre-production phases from assets that are actually operational. (In some organizations, the physical separation of development and production systems is necessary to satisfy legal regulations.)
When you use the two-stage approach, the SDLC is represented by two lifecycle models in CentraSite. One lifecycle model exists on the creation CentraSite. This model represents the states that make up the development and test phases of the SDLC. The other model exists on the consumption CentraSite. It represents the states that make up the production phase of the SDLC.
To promote an asset to a phase of its lifecycle that resides on another stage, you export the asset from its current registry and import it into the registry that hosts the next phase of its lifecycle.
Two-Stage Deployment
Three-Stage Deployment: In a three-stage deployment, you deploy a separate registry for each major phase of the SDLC (Development, Test, Production).
Each registry has a lifecycle model that represents the states that make up its phase of the SDLC. As with any approach that involves multiple stages, you promote an asset from one phase to the next by exporting the asset from its current registry and importing it into the registry that hosts the next phase of the SDLC.
Three-Stage Deployment
The deployment strategy you choose depends on factors such as your organization's policy requirements, standard processes and governance objectives. The following are points to consider when selecting a strategy for your organization:
Realize that any deployment that involves multiple stages requires additional effort to configure and administer. Also keep in mind that the promotion process for a multi-stage environment will be more complex and time-consuming, because it involves physically exporting objects from one registry and importing them into another. You should not deploy a multi-stage configuration unless your organization has a compelling reason to do so. Aim for a deployment strategy that aligns well with your organization's SDLC process, satisfies your organization's governance objectives and uses the fewest number of stages.
If you intend to use CentraSite for both design-time governance and run-time governance, consider using the two-stage deployment. This configuration enables you to maintain one registry for managing Web services (and associated assets) while they are in the development and testing phases of their lifecycle and another registry for configuring, deploying and monitoring Web services that are in the production phase of their lifecycle.
Although it is possible to use a single-stage deployment for both design-time and run-time governance, such a configuration is suitable only for small or mid-size environments. Do not use a single-stage deployment if you intend to use CentraSite to manage both the design-time and run-time aspects of a large number of assets.
Note:
If you expect your organization's registry to begin small and grow
over time, you are better off starting with a two-stage deployment rather than
attempting to switch when you outgrow the single-stage configuration.
If you will use CentraSite only for design-time governance, consider using a single-stage deployment. Deploying a multi-stage configuration for design-time governance does not generally offer any benefits. You should only consider a multi-stage deployment in a design-time implementation if your organization has a specific need to physically separate the registry of assets in the pre-production phases from the registry of assets in the production phase.
