apache/pulsar · warning · RestException

%s %s doesn't have instance with id %s

Error message

%s %s doesn't have instance with id %s

What it means

The parsed instanceId is out of range: it is negative or >= the function's configured parallelism, so getFunctionsInstanceStats throws HTTP 400 '%s %s doesn't have instance with id %s'. The function is valid but simply has no such instance.

Source

Thrown at pulsar-functions/worker/src/main/java/org/apache/pulsar/functions/worker/rest/api/ComponentImpl.java:1005

        }
        FunctionMetaData functionMetaData =
                functionMetaDataManager.getFunctionMetaData(tenant, namespace, componentName);
        if (!InstanceUtils.calculateSubjectType(functionMetaData.getFunctionDetails()).equals(componentType)) {
            log.error().attr("tenant", tenant).attr("namespace", namespace).attr("componentName", componentName)

                    .attr("componentType", ComponentTypeUtils.toString(componentType)).log("/ / is not a");
            throw new RestException(Status.NOT_FOUND,
                    String.format("%s %s doesn't exist", ComponentTypeUtils.toString(componentType), componentName));

        }
        int instanceIdInt = Integer.parseInt(instanceId);
        if (instanceIdInt < 0 || instanceIdInt >= functionMetaData.getFunctionDetails().getParallelism()) {
            log.error().attr("componentType", ComponentTypeUtils.toString(componentType)).attr("tenant", tenant)

                    .attr("namespace", namespace).attr("componentName", componentName)

                    .log("instanceId in get Stats out of bounds @ / / /");
            throw new RestException(Status.BAD_REQUEST,
                    String.format("%s %s doesn't have instance with id %s", ComponentTypeUtils.toString(componentType),
                            componentName, instanceId));
        }

        FunctionRuntimeManager functionRuntimeManager = worker().getFunctionRuntimeManager();
        FunctionInstanceStatsDataImpl functionInstanceStatsData;
        try {
            functionInstanceStatsData =
                    functionRuntimeManager.getFunctionInstanceStats(tenant, namespace, componentName,
                            Integer.parseInt(instanceId), uri);
        } catch (WebApplicationException we) {
            throw we;
        } catch (Exception e) {
            log.error().attr("tenant", tenant).attr("namespace", namespace).attr("componentName", componentName)

                    .exception(e).log("/ / Got Exception Getting Stats");
            throw new RestException(Status.INTERNAL_SERVER_ERROR, e.getMessage());
        }

View on GitHub (pinned to 820761864e)

Solutions

1. Fetch current parallelism via GET .../functions/{tenant}/{namespace}/{name} and only request instance ids in [0, parallelism)
2. If parallelism changed recently, refresh the instance list in clients/dashboards
3. Fix integer parsing so ids are non-numeric values are rejected client-side

Example fix

// before
curl 'http://worker:8080/admin/v3/functions/tenant/ns/fn/5/stats'  // 400, parallelism=2
// after
# enumerate instances 0..parallelism-1
for i in 0 1; do curl "http://worker:8080/admin/v3/functions/tenant/ns/fn/$i/stats"; done

// Java: bound-check instanceId against current parallelism
FunctionConfig cfg = admin.functions().getFunction(tenant, namespace, fn);
int parallelism = cfg.getParallelism();
if (instanceId < 0 || instanceId >= parallelism) {
    throw new IllegalArgumentException(
        "instanceId " + instanceId + " out of range [0," + parallelism + ")");
}

// Java
try {
    FunctionInstanceStatsData s = admin.functions().getFunctionInstanceStats(tenant, namespace, fn, id);
} catch (PulsarAdminException e) {
    if (e.getStatusCode() == 400) { /* refresh parallelism and re-derive valid instance ids */ }
}

When it happens

Trigger: GET .../{tenant}/{namespace}/{name}/{instanceId}/stats with instanceId >= parallelism (e.g. asking for instance 3 of a parallelism-1 function) or a negative/non-numeric id; also after parallelism was lowered while clients cache old instance counts.

Common situations: Dashboards that discover instance count once and keep polling after an update reduced parallelism; off-by-one loops (<= instead of <); deleting instances after update.

Related errors

• <validation message from IllegalArgumentException>
• Function in trigger function has more than 1 input topics
• Function in trigger function has unidentified topic
• %s Package is not provided
• {e.getMessage()}

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/8596b42eeb4695ef. Report an issue: GitHub.