prestodb/presto · error · RuntimeException

Error creating an instance of %s

Error message

Error creating an instance of %s

What it means

PrestoS3ClientFactory.getCustomAWSCredentialsProvider instantiates a user-configured AWSCredentialsProvider class reflectively (constructor taking (URI, Configuration)) via conf.getClassByName(...).getConstructor(...).newInstance(...). Any ReflectiveOperationException (class missing, no matching constructor, constructor threw) is rethrown as RuntimeException 'Error creating an instance of %s'.

Source

Thrown at presto-hive/src/main/java/com/facebook/presto/hive/s3/PrestoS3ClientFactory.java:163

        String providerClass = conf.get(S3_CREDENTIALS_PROVIDER);
        if (!isNullOrEmpty(providerClass)) {
            return getCustomAWSCredentialsProvider(conf, providerClass);
        }

        return DefaultAWSCredentialsProviderChain.getInstance();
    }

    private static AWSCredentialsProvider getCustomAWSCredentialsProvider(Configuration conf, String providerClass)
    {
        try {
            return conf.getClassByName(providerClass)
                    .asSubclass(AWSCredentialsProvider.class)
                    .getConstructor(URI.class, Configuration.class)
                    .newInstance(null, conf);
        }
        catch (ReflectiveOperationException e) {
            throw new RuntimeException(format("Error creating an instance of %s", providerClass), e);
        }
    }

    private static Optional<AWSCredentials> getAwsCredentials(Configuration conf)
    {
        String accessKey = conf.get(S3_ACCESS_KEY);
        String secretKey = conf.get(S3_SECRET_KEY);

        if (isNullOrEmpty(accessKey) || isNullOrEmpty(secretKey)) {
            return Optional.empty();
        }
        return Optional.of(new BasicAWSCredentials(accessKey, secretKey));
    }
}

View on GitHub (pinned to 55bb57d202)

Solutions

1. Check the wrapped cause in the message: ClassNotFoundException -> deploy the jar; NoSuchMethodException -> add a (URI, Configuration) constructor; InvocationTargetException -> fix the provider's constructor.
2. Implement the provider as public class X implements AWSCredentialsProvider with a public constructor (URI, Configuration).
3. Deploy the provider jar to the hive plugin directory (presto-hive/target or plugin/hive-hadoop2/...) on EVERY node and restart.
4. Verify the class name matches hive.s3.credentials-provider exactly (package + class, case-sensitive).

Example fix

// before: no (URI, Configuration) constructor
public class MyProvider implements AWSCredentialsProvider {
    public MyProvider() { ... }
}
// after
public class MyProvider implements AWSCredentialsProvider {
    public MyProvider(URI uri, Configuration conf) { ... }
    @Override public AWSCredentials getCredentials() { ... }
    @Override public void refresh() { ... }
}

// pre-check the configured credentials provider before wiring it into the catalog
Class<?> cls = Class.forName(conf.get("hive.s3.credentials-provider"));
if (!AWSCredentialsProvider.class.isAssignableFrom(cls)) throw new IllegalStateException("Not an AWSCredentialsProvider");
cls.getConstructor(URI.class, Configuration.class); // throws NoSuchMethodException if signature missing

boolean isValidCredentialsProvider(String className, ClassLoader cl) {
    try {
        Class<?> c = Class.forName(className, false, cl);
        return AWSCredentialsProvider.class.isAssignableFrom(c)
            && c.getConstructor(URI.class, Configuration.class) != null;
    } catch (ReflectiveOperationException e) { return false; }
}

try {
    AWSCredentialsProvider p = buildProvider(providerClass, uri, conf);
} catch (RuntimeException e) {
    if (e.getMessage() != null && e.getMessage().startsWith("Error creating an instance of ")) {
        Throwable cause = e.getCause();
        // ClassNotFoundException: deploy jar; NoSuchMethodException: fix constructor; InvocationTargetException: fix ctor internals
        throw new ProviderInitException("Fix provider " + providerClass + " (cause: " + cause + ")");
    }
    throw e;
}

When it happens

Trigger: hive.s3.credentials-provider is set to a class that: doesn't exist on the classpath (ClassNotFoundException), lacks a (URI, Configuration) constructor (NoSuchMethodException), isn't an AWSCredentialsProvider subclass, or whose constructor throws (InvocationTargetException) — e.g., reading a missing credentials file in its constructor.

Common situations: Typo in the fully-qualified class name; custom provider jar not deployed to the hive plugin directory on all nodes; provider written against a different SDK version where the constructor signature changed; provider fails at runtime because it depends on env vars/files absent on workers.

Related errors

• Invalid encryption materials provider class:
• Unable to load or create S3 encryption materials provider: $
• Error creating an instance of %s for URI %s
• Unknown file system type:
• EMR File System class not found:

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/35779e46ff526f69. Report an issue: GitHub.