https://linear.app/unleash/issue/2-3406/hold-unknown-flags-in-memory-and-show-them-in-the-ui-somehow
This PR introduces a suggestion for a “unknown flags” feature.
When clients report metrics for flags that don’t exist in Unleash (e.g.
due to typos), we now track a limited set of these unknown flag names
along with the appnames that reported them. The goal is to help users
identify and clean up incorrect flag usage across their apps.
We store up to 10 unknown flag + appName combinations, keeping only the
most recent reports. Data is collected in-memory and flushed
periodically to the DB, with deduplication and merging to ensure we
don’t exceed the cap even across pods.
We were especially careful to make this implementation defensive, as
unknown flags could be reported in very high volumes. Writes are
batched, deduplicated, and hard-capped to avoid DB pressure.
No UI has been added yet — this is backend-only for now and intended as
a step toward better visibility into client misconfigurations.
I would suggest starting with a simple banner that opens a dialog
showing the list of unknown flags and which apps reported them.
<img width="497" alt="image"
src="https://github.com/user-attachments/assets/b7348e0d-0163-4be4-a7f8-c072e8464331"
/>
Spotted this in local dev mode:
```
[2025-04-17T15:10:21.036] [DEBUG] openapi-service.ts - Invalid response: {
"schema": "#/components/schemas/environmentsProjectSchema",
"errors": [
{
"instancePath": "/environments/0",
"schemaPath": "#/additionalProperties",
"keyword": "additionalProperties",
"params": {
"additionalProperty": "requiredApprovals"
},
"message": "must NOT have additional properties"
}
]
}
```
Enabling strictSchemaValidation in dev mode should help prevent these
issues from going out to prod as developers would identify them while
testing locally
## About the changes
Currently, we're running against the older version of our UI. When
making changes to it we want to make sure we're testing the current code
**Details in comments**
---------
Co-authored-by: Tymoteusz Czech <2625371+Tymek@users.noreply.github.com>
## About the changes
Initially at Unleash we started using `process.nextTick` inside
constructors to delay initialization of services.
Later we stared using a pattern where we instantiate services multiple
times.
The problem is the first pattern implies we have singleton services,
while the second pattern breaks the singleton.
There are reasons for both patterns, but we've decided that
`process.nextTick` inside constructors is not something we want to keep
as it creates side effects from creating objects. Instead this PR
proposes a more explicit approach.
Fixes#9775
In this PR I integrate the Unleash React SDK with the Admin UI.
We also take advantage of Unleash Hosted Edge behind the scenes with
multiple regions to get the evaluations close to the end user.
