apache/pulsar · error · IllegalArgumentException

Malformed configuration file

Error message

Malformed configuration file

What it means

readBookieConfFile catches ConfigurationException from bookieConf.loadConf/bookieConf.validate and rethrows it as 'Malformed configuration file'. It means the Bookie configuration file exists but cannot be parsed or fails validation by the configuration framework.

Solutions

1. Fix the syntax/values in the bookie configuration file; compare against conf/bookie.conf shipped with your Pulsar version
2. Check the logged ConfigurationException (stack trace shows the offending property)
3. Validate types of numeric/boolean properties and remove unsupported keys from old versions

Example fix

// before (bookie.conf)
bookiePort=not-a-number
// after
bookiePort=3181

// Pre-parse check in the caller
Properties props = new Properties();
try (InputStream in = Files.newInputStream(Path.of(bookieConfigFile))) {
    props.load(in);
    if (!props.stringPropertyNames().contains("bookiePort")) {
        throw new IllegalStateException("bookie.conf missing required keys");
    }
}

try {
    BookKeeperConfiguration conf = readBookieConfFile(bookieConfigFile);
} catch (IllegalArgumentException e) {
    if (e.getMessage().equals("Malformed configuration file")) {
        throw new IllegalStateException("Invalid bookie.conf " + bookieConfigFile + ": fix syntax/types", e);
    }
    throw e;
}

When it happens

Trigger: Bookie config file contains invalid syntax, wrong value types (e.g. non-numeric port), or a value that fails BookKeeper's Configuration validate() step; thrown when --bookie-config points to a parseable-path but invalid-content file.

Common situations: Hand-edited bookie.conf with typos; copying an incompatible bookkeeper config across versions; missing required properties; wrong encoding or stray characters in the file.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• brokerCloseInactiveTopicsEnabled only supports…
• brokerDeleteInactiveTopicsEnabled and…
• Can't get Kerberos configuration
• Config file not specified. Please use -c, --config-file or…
• Could not open configuration file

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/15371dcccd3a89c1. Report an issue: GitHub.

Appendix: source

Thrown at pulsar-broker/src/main/java/org/apache/pulsar/PulsarBrokerStarter.java:120

        @Option(names = {"-h", "--help"}, usageHelp = true, description = "Show this help message")
        private boolean help = false;

        @Option(names = {"-g", "--generate-docs"}, description = "Generate docs")
        private boolean generateDocs = false;
    }

    private static ServerConfiguration readBookieConfFile(String bookieConfigFile) throws IllegalArgumentException {
        ServerConfiguration bookieConf = new ServerConfiguration();
        try {
            bookieConf.loadConf(new File(bookieConfigFile).toURI().toURL());
            bookieConf.validate();
            log.info().attr("file", bookieConfigFile).log("Using bookie configuration file");
        } catch (MalformedURLException e) {
            log.error().attr("file", bookieConfigFile).exception(e).log("Could not open configuration file");
            throw new IllegalArgumentException("Could not open configuration file");
        } catch (ConfigurationException e) {
            log.error().attr("file", bookieConfigFile).exception(e).log("Malformed configuration file");
            throw new IllegalArgumentException("Malformed configuration file");
        }

        if (bookieConf.getMaxPendingReadRequestPerThread() < bookieConf.getRereplicationEntryBatchSize()) {
            throw new IllegalArgumentException(
                "rereplicationEntryBatchSize should be smaller than " + "maxPendingReadRequestPerThread");
        }
        return bookieConf;
    }

    protected static class BrokerStarter implements Callable<Integer> {
        private ServiceConfiguration brokerConfig;
        private PulsarService pulsarService;
        private LifecycleComponent bookieServer;
        private volatile CompletableFuture<Void> bookieStartFuture;
        private AutoRecoveryMain autoRecoveryMain;
        private StatsProvider bookieStatsProvider;
        private ServerConfiguration bookieConfig;
        private WorkerService functionsWorkerService;

View on GitHub (pinned to 820761864e)