apache/pulsar · error · IllegalArgumentException

Source name cannot be null

Error message

Source name cannot be null

What it means

validateAndExtractDetails enforces that SourceConfig.name is non-null and non-empty, since the name completes the mandatory tenant/namespace/name identity of a source connector. It is the third required-field check, thrown after tenant and namespace validation succeed.

Source

Thrown at pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/SourceConfigUtils.java:272

        if (!isEmpty(functionDetails.getCustomRuntimeOptions())) {
            sourceConfig.setCustomRuntimeOptions(functionDetails.getCustomRuntimeOptions());
        }

        return sourceConfig;
    }

    public static ExtractedSourceDetails validateAndExtractDetails(SourceConfig sourceConfig,
                                                                   ValidatableFunctionPackage sourceFunction,
                                                                   boolean validateConnectorConfig) {
        if (isEmpty(sourceConfig.getTenant())) {
            throw new IllegalArgumentException("Source tenant cannot be null");
        }
        if (isEmpty(sourceConfig.getNamespace())) {
            throw new IllegalArgumentException("Source namespace cannot be null");
        }
        if (isEmpty(sourceConfig.getName())) {
            throw new IllegalArgumentException("Source name cannot be null");
        }
        if (!isEmpty(sourceConfig.getTopicName()) && !TopicName.isValid(sourceConfig.getTopicName())) {
            throw new IllegalArgumentException("Topic name is invalid");
        }
        if (!isEmpty(sourceConfig.getLogTopic())) {
            if (!TopicName.isValid(sourceConfig.getLogTopic())) {
                throw new IllegalArgumentException(
                        String.format("LogTopic topic %s is invalid", sourceConfig.getLogTopic()));
            }
        }
        if (sourceConfig.getParallelism() != null && sourceConfig.getParallelism() <= 0) {
            throw new IllegalArgumentException("Source parallelism must be a positive number");
        }
        if (sourceConfig.getResources() != null) {
            ResourceConfigUtils.validate(sourceConfig.getResources());
        }

        String sourceClassName = sourceConfig.getClassName();

View on GitHub (pinned to 820761864e)

Solutions

1. Set a non-empty name on the SourceConfig, e.g. sourceConfig.setName("kafka-source")
2. If the name should be derived (e.g. from topic or connector), compute it before validation
3. Add pre-validation in your submission tooling to reject blank source names with a friendly message

Example fix

// before
SourceConfig cfg = new SourceConfig();
cfg.setTenant("public");
cfg.setNamespace("default");
// after
SourceConfig cfg = new SourceConfig();
cfg.setTenant("public");
cfg.setNamespace("default");
cfg.setName("kafka-source");

if (cfg.getName() == null || cfg.getName().trim().isEmpty()) {
    throw new IllegalArgumentException("sourceConfig.name must be a non-empty source name");
}

static boolean hasName(SourceConfig cfg) {
    return cfg != null && cfg.getName() != null && !cfg.getName().trim().isEmpty();
}

try {
    SourceConfigUtils.validateAndExtractDetails(cfg, pkg, true);
} catch (IllegalArgumentException e) {
    if (e.getMessage() != null && e.getMessage().contains("Source name cannot be null")) {
        // prompt for / default a source name before retrying
    }
}

When it happens

Trigger: Registering or validating a source whose SourceConfig has tenant and namespace set but name null or empty — e.g. a config file missing the 'name' key, or building SourceConfig dynamically and never calling setName().

Common situations: Generating SourceConfigs in loops where the name is derived from input that was blank; template configs with a placeholder name never substituted; REST/CLI callers omitting the name field.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

• When effectively once processing guarantee is specified, ret
• Only one of retain ordering or retain key ordering can be se
• Receiver queue size should be >= zero
• Source tenant cannot be null
• Source namespace cannot be null

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/9e4e15ba73ece06c. Report an issue: GitHub.