What's supported in Harness Feature Flags
Harness Feature Flags support client-side and server-side SDKs for a number of programming languages.
Supported client-side SDKs
The following table lists the client-side Feature Flag SDKs that Harness supports.
Supported server-side SDKs
The following table lists the server-side Feature Flag SDKs that Harness supports.
Relay Proxy
The Relay Proxy, which allows for offline and hybrid Feature Flags usage, is provided as a Docker image and can be used in any environment where the Docker image can be run. The Relay Proxy can be enhanced with Redis as a cache in environments where this is possible.
Hybrid and offline usage
Harness Feature Flags allows for both completely offline usage as well as hybrid usage via the relay proxy. Hybrid usage can be in the form of:
- The application is online and only talks to the Relay Proxy, while the Relay Proxy has connectivity to Harness.
- The Relay Proxy is bundled with the application at build-time with a working configuration file, and neither the application nor the Relay Proxy have connectivity to Harness.
Cloud limitations
There are no limitations for using Feature Flags in any cloud or non-cloud environment as long as the languages needed are supported with an SDK, and connectivity to either Harness or the Relay Proxy can be established.
For information about what's supported for other Harness modules and the Harness Platform overall, go to Supported platforms and technologies.
Resource Limits
| Resource | Limit | Description |
|---|---|---|
| Flags | 1200 | Number of flags per project |
| Targets | 60 days | Number of targets per environment are retained for up to 60 days. Targets referenced in rules do not get removed |
| Target Groups | 1200 | Number of groups of targets per environment |
| API Keys | 10 | Number of api keys created per environment |
| Flag Target Rules | 2000 | Number of target rules on a flag (e.g. serve target x true) |
| Flag Target Group Rules | 1000 | Number of target group rules on a flag (e.g. server group beta true) |
| Target Group Include/Exclude Rules | 5000 | Number of targets directly included/excluded in a target group |
| Target Group Custom Rules | 5000 | Number of custom rules in a target group (e.g. if identifier == “foo”) |
| Target Group Clause Sizes | 5000 | Number of clauses in a group rule |