Caching problem(?)

[karel1980]

TLDR; client.getBooleanValue(...) always returns the same value even after changing flagd.json.
Is there a 'maximum cache duration' that I can configure or am doing something wrong?

What I'm doing:

I'm running flagd in docker, and I'm creating an OpenFeaturesAPI instance as a spring bean my kotlin application like this:
My (spring boot) application uses this:

@Bean
fun api() = OpenFeatureAPI.getInstance().apply {
        provider = FlagdProvider(
            FlagdOptions.builder()
                .host("localhost")
                .port(8013)
                .build()
        )

When I run api.client.getBooleanValue('show-welcome-banner', false) the grpc lookup works, but when I change defaultVariant in flagd.json I keep getting the first value back until I restart my application.

What I've tried:

• looked for caching configuration in the documentation but didn't see what I was looking for
• waited a long time but it's just stuck on the first value

What I haven't tried yet:

• debugging to see if I can figure it out myself

[karel1980]

After some debugging and reading more documentation,
I have confirmation that the configuration change is picked up by my application, simply by adding this hook:

        client.onProviderConfigurationChanged {
            println("configuration changed $it")
        }

Confused as to why the cache is not invalidated. When I change defaultVariant I expect the application to behave differently for each new evaluation.

[aepfli]

First recommendation, can you debug with getBooleanDetails and see what the resolution type is - maybe there is an error in your resolution, and it always returns the code default as a fallback. - besides that, the cache should be cleared, and we are also testing this with our e2e tests. hence my first assumption is that there is an error during flag evaluation. - please let me know, the result. thank you.

[karel1980]

I tried getBooleanDetails and it's indeed showing CACHED.

I didn't notice it before, but when I update my flags json file, I see an error in the flagd logs.

For the record, here's the version info that's logged at startup time:

flagd-1  | 2026-02-13T14:30:21.240Z     info    cmd/start.go:143        flagd version: v0.13.3 (47f904b3a5a5a6e4389de6201bef3c15158dbc97), built at: 2026-02-09 {"component": "start"}

flagd-1  | 2026-02-13T14:32:10.253Z     info    file/filepath_sync.go:108       filepath event: ./flags/mira.flagd.json WRITE   {"component": "sync", "sync": "fileinfo"}
flagd-1  | 2026-02-13T14:32:10.254Z     error   flag-evaluation/flag_evaluator_v2.go:187        proto: invalid type: notifications.Notifications        {"component": "flagd.evaluation.v1"}
flagd-1  | github.com/open-feature/flagd/flagd/pkg/service/flag-evaluation.(*FlagEvaluationService).EventStream
flagd-1  |      /src/flagd/pkg/service/flag-evaluation/flag_evaluator_v2.go:187
flagd-1  | connectrpc.com/connect.NewServerStreamHandler[...].func1
flagd-1  |      /go/pkg/mod/connectrpc.com/connect@v1.18.1/handler.go:132
flagd-1  | connectrpc.com/otelconnect.(*Interceptor).WrapStreamingHandler.func1
flagd-1  |      /go/pkg/mod/connectrpc.com/otelconnect@v0.7.2/interceptor.go:325
flagd-1  | connectrpc.com/connect.(*Handler).ServeHTTP
flagd-1  |      /go/pkg/mod/connectrpc.com/connect@v1.18.1/handler.go:237
flagd-1  | buf.build/gen/go/open-feature/flagd/connectrpc/go/flagd/evaluation/v1/evaluationv1connect.NewServiceHandler.func1
flagd-1  |      /go/pkg/mod/buf.build/gen/go/open-feature/flagd/connectrpc/go@v1.18.1-20250529171031-ebdc14163473.1/flagd/evaluation/v1/evaluationv1connect/evaluation.connect.go:247
flagd-1  | net/http.HandlerFunc.ServeHTTP
flagd-1  |      /usr/local/go/src/net/http/server.go:2322
flagd-1  | github.com/open-feature/flagd/flagd/pkg/service/flag-evaluation.bufSwitchHandler.ServeHTTP
flagd-1  |      /src/flagd/pkg/service/flag-evaluation/connect_service.go:52
flagd-1  | github.com/open-feature/flagd/flagd/pkg/service/flag-evaluation.(*ConnectService).setupServer.(*ConnectService).AddMiddleware.Middleware.Handler.func1.1
flagd-1  |      /src/flagd/pkg/service/middleware/metrics/http_metrics.go:106
flagd-1  | github.com/open-feature/flagd/flagd/pkg/service/middleware/metrics.Middleware.Measure
flagd-1  |      /src/flagd/pkg/service/middleware/metrics/http_metrics.go:91
flagd-1  | github.com/open-feature/flagd/flagd/pkg/service/flag-evaluation.(*ConnectService).setupServer.(*ConnectService).AddMiddleware.Middleware.Handler.func1
flagd-1  |      /src/flagd/pkg/service/middleware/metrics/http_metrics.go:105
flagd-1  | net/http.HandlerFunc.ServeHTTP
flagd-1  |      /usr/local/go/src/net/http/server.go:2322
flagd-1  | github.com/open-feature/flagd/flagd/pkg/service/flag-evaluation.(*ConnectService).setupServer.(*ConnectService).AddMiddleware.Middleware.Handler.(*Cors).Handler.func2
flagd-1  |      /go/pkg/mod/github.com/rs/cors@v1.11.1/cors.go:289
flagd-1  | net/http.HandlerFunc.ServeHTTP
flagd-1  |      /usr/local/go/src/net/http/server.go:2322
flagd-1  | golang.org/x/net/http2.(*serverConn).runHandler
flagd-1  |      /go/pkg/mod/golang.org/x/net@v0.47.0/http2/server.go:2424

[karel1980]

This error is not logged when I do not start up my application (my own java application, not flagd)
I guess that's because in that case there's nowhere to send these notifications to.

My application is using these version, which are the latest according to maven central:
dependency("dev.openfeature:sdk:1.20.1")
dependency("dev.openfeature.contrib.providers:flagd:0.11.20")

Maybe there's a version compatibility matrix I should have consulted, but I don't believe I have encountered one yet.

[karel1980]

FTR I created a PR for this...
#1871

[karel1980]

Hi there. Did you have time to look at this?
If it helps I've added a minimal reproducible example that demonstrates the problem I'm facing. Just to make sure it's not something unique to my machine: https://github.com/karel1980/flagd-poc

[toddbaert]

Sorry - will try to get this merged today! Thanks for this fix.

[karel1980]

Lovely, thanks for letting me know.