---
metadata:
  - name: generator
    content: Diplodoc Platform v5.50.4
alternate:
  - https://ydb.tech/docs/en/recipes/ydb-sdk/config-publication.md
  - https://ydb.tech/docs/ru/recipes/ydb-sdk/config-publication.md
sourcePath: en/core/recipes/ydb-sdk/config-publication.md
---
> **Documentation Index:** Fetch the complete configuration index at https://ydb.tech/docs/en/llms.txt

# Configuration publication

Let's consider a scenario where we need to publish a small configuration for multiple application instances that should promptly react to its changes.

This scenario can be implemented using semaphores in [YDB coordination nodes](https://ydb.tech/docs/en/reference/ydb-sdk/coordination.md) as follows:

1. A semaphore is created (for example, named `my-service-config`).
1. The updated configuration is published through `UpdateSemaphore`.
1. Application instances call `DescribeSemaphore` with `WatchData=true`. In the result, the `Data` field will contain the current version of the configuration.
1. When the configuration changes, `OnChanged` is called. In this case, application instances make a similar `DescribeSemaphore` call and receive the updated configuration.