apache/cassandra · error · ConfigurationException

Unable to create instance of IAuditLogger.

Error message

Unable to create instance of IAuditLogger.

What it means

newAuditLogger instantiates the configured IAuditLogger implementation reflectively from its class name plus a Map of parameters. Any failure to load, access, or construct the class is wrapped in a ConfigurationException. This runs at audit-logging startup, so it blocks node start when audit logging is enabled with a bad class.

Solutions

1. Fix logger_class to the correct fully-qualified class name (default: org.apache.cassandra.audit.AuditLogger)
2. Ensure the class's jar is on the classpath (lib/) on every node
3. Verify the class has a public constructor accepting Map<String,String>
4. Check logger constructor/parameters for errors in the server log (root cause is chained as the exception cause)

Example fix

// before (cassandra.yaml)
audit_logging_options:
  logger_class: com.mycompany.MyAuditLoggr
// after
audit_logging_options:
  logger_class: com.mycompany.MyAuditLogger

String cls = auditOptions.get("logger_class");
try { Class.forName(cls).getConstructor(Map.class); }
catch (ClassNotFoundException | NoSuchMethodException e) { throw new IllegalArgumentException("Bad IAuditLogger class: " + cls, e); }

boolean isValidAuditLogger(String cn) {
    try { return IAuditLogger.class.isAssignableFrom(Class.forName(cn)); }
    catch (Throwable t) { return false; }
}

try {
    AuditLogManager.instance.initialize();
} catch (ConfigurationException e) {
    logger.error("Audit logger setup failed", e); // falls back / aborts start with clear cause
}

When it happens

Trigger: audit_logging_options with a logger_class that does not exist, lacks a (Map) constructor, has wrong visibility, or whose constructor throws; called from AuditLogManager when initializing audit logging.

Common situations: Typo in the fully-qualified class name; custom audit logger jar missing from lib/; constructor signature changed after an upgrade; custom logger throws in its constructor due to bad parameters.

Related errors

• Unable to find class
• Could not create memtable factory for class
• create method not found
• Invalid auth provider class:
• Invalid parameterized class <providerClass.getName()>: must…

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/56ee803978df080e. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/utils/FBUtilities.java:698

            return new LocalPartitioner(comparator.get());
        }
        return FBUtilities.instanceOrConstruct(partitionerClassName, "partitioner", IPartitioner.class);
    }

    public static IAuditLogger newAuditLogger(String className, Map<String, String> parameters) throws ConfigurationException
    {
        if (!className.contains("."))
            className = "org.apache.cassandra.audit." + className;

        try
        {
            Class<? extends IAuditLogger> auditLoggerClass =
                FBUtilities.classForNameWithoutInitialization(className, "Audit logger", IAuditLogger.class);
            return auditLoggerClass.getConstructor(Map.class).newInstance(parameters);
        }
        catch (Exception ex)
        {
            throw new ConfigurationException("Unable to create instance of IAuditLogger.", ex);
        }
    }

    public static ISslContextFactory newSslContextFactory(String className, Map<String,Object> parameters) throws ConfigurationException
    {
        if (!className.contains("."))
            className = "org.apache.cassandra.security." + className;

        try
        {
            Class<? extends ISslContextFactory> sslContextFactoryClass =
                FBUtilities.classForNameWithoutInitialization(className, "ISslContextFactory", ISslContextFactory.class);
            return sslContextFactoryClass.getConstructor(Map.class).newInstance(parameters);
        }
        catch (Exception ex)
        {
            // Surface the underlying load failure (e.g. ClassNotFoundException) as the direct cause rather than the
            // intermediate ConfigurationException that reports it.

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