What causes "Unknown resource type: " in apache/pulsar?

Use only the built-in SharedResource constants/types from the same Pulsar version as the client library (check PulsarClientSharedResources.SharedResourceType).

apache/pulsar · error · IllegalArgumentException

Unknown resource type:

Error message

Unknown resource type:

What it means

getOrCreateConfig maps a SharedResource to its default ResourceConfig via a switch over SharedResourceType. A resource whose type is not one of the six known types (EventLoopGroup, DnsResolver, ThreadPool, Timer, MemoryLimitController, OpenTelemetry) reaches the default branch and throws IllegalArgumentException.

Source

Thrown at pulsar-client/src/main/java/org/apache/pulsar/client/impl/PulsarClientSharedResourcesBuilderImpl.java:282

    @SuppressWarnings("unchecked")
    private <T extends ResourceConfig> T getOrCreateConfig(PulsarClientSharedResources.SharedResource sharedResource) {
        return (T) resourceConfigs.computeIfAbsent(sharedResource, k -> {
            switch (sharedResource.getType()) {
                case EventLoopGroup:
                    return new EventLoopResourceConfig();
                case DnsResolver:
                    return new DnsResolverResourceConfig();
                case ThreadPool:
                    return new ThreadPoolResourceConfig();
                case Timer:
                    return new TimerResourceConfig();
                case MemoryLimitController:
                    return new MemoryLimitResourceConfig();
                case OpenTelemetry:
                    return new OpenTelemetryResourceConfig();
                default:
                    throw new IllegalArgumentException("Unknown resource type: " + sharedResource.getType());
            }
        });
    }

    @Override
    public PulsarClientSharedResourcesBuilder configureThreadPool(
            PulsarClientSharedResources.SharedResource sharedResource, Consumer<ThreadPoolConfig<?>> configurer) {
        if (sharedResource.getType() != PulsarClientSharedResources.SharedResourceType.ThreadPool) {
            throw new IllegalArgumentException("The shared resource " + sharedResource + " doesn't support thread pool"
                    + " configuration");
        }
        configurer.accept(getOrCreateConfig(sharedResource));
        return this;
    }

    @Override
    public PulsarClientSharedResourcesBuilder configureEventLoop(Consumer<EventLoopGroupConfig> configurer) {
        configurer.accept(getOrCreateConfig(PulsarClientSharedResources.SharedResource.EventLoopGroup));

View on GitHub (pinned to 820761864e)

Solutions

Use only the built-in SharedResource constants/types from the same Pulsar version as the client library (check PulsarClientSharedResources.SharedResourceType).
Align all Pulsar client jar versions on the classpath; duplicate shaded/unshaded jars cause enum mismatch.
Verify with a debug print that sharedResource.getType() is a known SharedResourceType before calling the configure method.
Upgrade the client library if the resource type is a newer addition not present in your current version.

Example fix

// before
SharedResource custom = SharedResource.of(myCustomType, "mine"); // custom type
builder.configureThreadPool(custom, cfg -> ...); // throws Unknown resource type
// after
builder.configureThreadPool(PulsarClientSharedResources.THREAD_POOL, cfg -> ...);

Defensive patterns

Strategy: validation

Validate before calling

PulsarClientSharedResources.SharedResourceType t = resource.getType();
boolean known = t == SharedResourceType.EventLoopGroup || t == SharedResourceType.DnsResolver
    || t == SharedResourceType.ThreadPool || t == SharedResourceType.Timer
    || t == SharedResourceType.MemoryLimitController || t == SharedResourceType.OpenTelemetry;
if (!known) throw new IllegalArgumentException("Unsupported shared resource type: " + t);

Type guard

static boolean isKnownResourceType(PulsarClientSharedResources.SharedResource r) {
    switch (r.getType()) {
        case EventLoopGroup: case DnsResolver: case ThreadPool:
        case Timer: case MemoryLimitController: case OpenTelemetry:
            return true;
        default:
            return false;
    }
}

Try / catch

try {
    builder.configureEventLoop(cfg -> cfg.numThreads(8));
} catch (IllegalArgumentException e) {
    if (e.getMessage().startsWith("Unknown resource type")) {
        log.error("SharedResource type not supported by this client version: {}", e.getMessage());
    } else { throw e; }
}

Prevention

Only use SharedResource constants shipped with the same Pulsar client version you compile against.
Check for duplicate/shaded pulsar-client jars on the classpath that could shadow enum values.
When upgrading, diff SharedResourceType enums between versions before feeding resources to configure* methods.
Never define custom SharedResourceType values; the builder switch cannot handle them.

When it happens

Trigger: Passing a SharedResource with a custom or unrecognized SharedResourceType to any configure* method (configureThreadPool, configureEventLoop, configureDnsResolver, configureTimer, configureMemoryLimitController, configureOpenTelemetry), typically because a SharedResource from a newer Pulsar version or a user-defined type is fed to an older builder.

Common situations: Upgrading/downgrading Pulsar client so a SharedResourceType enum constant exists in one jar but not the other; constructing a SharedResource with a hand-rolled type instead of using the provided constants; mixing client versions on the classpath (shaded vs non-shaded jars).

Related errors

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/a7993ee96ba03521. Report an issue: GitHub.