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Adding data stores to services

Added in eventcatalog@2.59.0

Data stores in EventCatalog are a great way to document which data stores your services write to or read from.

What are data stores?

Data stores are containers that hold data in your architecture (e.g. databases, caches, object stores, search indexes, etc).

You can read more about data stores here.

Specifying read/write relationships to data stores​

To document the read/write relationships to data stores you need to specify the data stores in the writesTo or readsFrom array within your service frontmatter API.

In the example below the OrderService writes to the OrdersDatabase and reads from the ProductRedisCache.

/services/Orders/index.mdx (example)
---
id: OrderService
... # other service frontmatter
writesTo:
    # id of the data store this service writes to
    - id: OrdersDatabase
readsFrom:
    # id of the data store this service reads from
    - id: ProductRedisCache
      # optional version of the data store if none provided latest will be used
      version: 0.0.1
---

Using semver versioning​

Added in eventcatalog@2.4.0

You can use semver syntax when referencing your data stores in your services.

/domains/Orders/index.mdx (example)
---
id: PaymentDomain
... # other domain frontmatter
writesTo:
    # Latest minor version of OrdersDatabase will be added
    - id: OrdersDatabase
      version: 0.x.1
    # Minor and patches of this version will be linked
    - id: ProductRedisCache
      version: ^1.0.1
    # Latest version of this data store will be shown by default.
    - id: OrdersDatabase
---
<!-- Markdown contents... -->

You can choose not to provide a version for a data store. If no version is given latest is used by default.

Visualizing data stores within a service​

When data stores get added within your services EventCatalog will visualize this for you either using the NodeGraph component or through the visualizer.

Example

You can see an example of this here