apache/pulsar · error · IOException

Command Factory `${name}` does NOT provide a Command Factory

Error message

Command Factory `${name}` does NOT provide a Command Factory implementation

What it means

NAR loading failure in CustomCommandFactoryProvider.load: the archive defined in the factory metadata was loaded, but its configuration/NAR does not yield a CustomCommandFactory implementation (missing or wrong service entry), so the CLI extension cannot be instantiated; the named NAR is the faulty artifact.

Source

Thrown at pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/utils/CustomCommandFactoryProvider.java:156

        return ObjectMapperFactory.getYamlMapper().reader().readValue(
                configStr, CustomCommandFactoryDefinition.class
        );
    }

    @SuppressWarnings("unchecked")
    private static CustomCommandFactory load(CustomCommandFactoryMetaData metadata,
                                                   String narExtractionDirectory)
            throws IOException {
        final File narFile = metadata.getArchivePath().toAbsolutePath().normalize().toFile();
        NarClassLoader ncl = NarClassLoaderBuilder.builder()
                .narFile(narFile)
                .parentClassLoader(CustomCommandFactory.class.getClassLoader())
                .extractionDirectory(narExtractionDirectory)
                .build();
        CustomCommandFactoryDefinition def = getCustomCommandFactoryDefinition(ncl);
        if (StringUtils.isBlank(def.getFactoryClass())) {
            throw new IOException("Command Factory `" + def.getName() + "` does NOT provide a Command Factory"
                    + " implementation");
        }

        try {
            Class commandFactoryClass = ncl.loadClass(def.getFactoryClass());
            Object factory = commandFactoryClass.getDeclaredConstructor().newInstance();
            if (!(factory instanceof CustomCommandFactory)) {
                throw new IOException("Class " + def.getFactoryClass()
                        + " does not implement CustomCommandFactory interface");
            }
           return (CustomCommandFactory) factory;
        } catch (Exception e) {
            if (e instanceof IOException) {
                throw (IOException) e;
            }
            log.error().exception(e).attr("factoryClass", def.getFactoryClass())
                    .log("Failed to load class");
            throw new IOException(e);

View on GitHub (pinned to 820761864e)

Solutions

1. Fix the factory definition in the NAR's config to name the implementation class
2. Rebuild the extension NAR with a proper CustomCommandFactory implementation

When it happens

Trigger: Thrown at pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/utils/CustomCommandFactoryProvider.java:156 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/7b1e20f68d59926b. Report an issue: GitHub.