apache/dolphinscheduler · error · GrpcParserException

grpc task method name is invalid

Error message

grpc task method name is invalid

What it means

MethodName parses the task's method identifier string in the form '<serviceName>.<rpcName>' (split on GrpcConstants.SERVICE_METHOD_SEPERATOR). If the string does not split into exactly one or two non-empty parts, the constructor throws GrpcParserException('grpc task method name is invalid') without constructing a service/rpc pair. Note the check is structural: a well-formed-looking name can still pass and fail later with 'cannot find service/method'.

Source

Thrown at dolphinscheduler-task-plugin/dolphinscheduler-task-grpc/src/main/java/org/apache/dolphinscheduler/plugin/task/grpc/protobufjs/GrpcDynamicService.java:150

                && !methodDesc.isClientStreaming()) {
            return MethodDescriptor.MethodType.SERVER_STREAMING;
        } else if (!methodDesc.isServerStreaming()) {
            return MethodDescriptor.MethodType.CLIENT_STREAMING;
        } else {
            return MethodDescriptor.MethodType.BIDI_STREAMING;
        }
    }

    public static class MethodName {

        @Getter
        String serviceName = null;
        @Getter
        String rpcName = null;

        public MethodName(String methodNameWithService) {
            if (!checkMethodName(methodNameWithService))
                throw new GrpcParserException("grpc task method name is invalid");
        }

        private boolean checkMethodName(String methodNameWithService) {
            String[] path = methodNameWithService.split(GrpcConstants.SERVICE_METHOD_SEPERATOR);
            if (path.length == 0)
                return false;
            if (path.length == 1)
                rpcName = path[0];
            if (path.length == 2) {
                serviceName = path[0];
                rpcName = path[1];
            } else {
                return false;
            }
            if (serviceName == null || serviceName.isEmpty()) {
                return false;
            }
            return rpcName != null && !rpcName.isEmpty();

View on GitHub (pinned to 02eac45a1b)

Solutions

1. Use exactly 'ServiceName.RpcName' (one separator, both parts non-empty), e.g. 'Greeter.SayHello'.
2. Strip package prefixes and URL decorations: '/package.Greeter/SayHello' → 'Greeter.SayHello'.
3. Trim whitespace and verify the task-form field is not empty or parameter-substituted to blank.
4. If the proto uses nested services, use only the service's simple name; the descriptor lookup uses findServiceByName on the simple name.

Example fix

// before
new GrpcDynamicService.MethodName("/example.Greeter/SayHello"); // invalid
// after
new GrpcDynamicService.MethodName("Greeter.SayHello"); // ServiceName.RpcName

// Validate before constructing MethodName
boolean isValidMethodName(String s) {
    if (s == null) return false;
    String[] p = s.split("\\.");
    return p.length == 2 && !p[0].isEmpty() && !p[1].isEmpty();
}

try {
    service.call("Greeter.SayHello", json, 5000);
} catch (GrpcParserException e) {
    if (e.getMessage().contains("method name is invalid")) {
        log.error("Use ServiceName.RpcName format, e.g. Greeter.SayHello, got: {}", userInput);
    }
}

When it happens

Trigger: Passing a methodNameWithService to call() or mergeJSON() that is null/empty, contains more than one separator (e.g. 'a.b.c'), or contains only the separator ('.'), or has an empty service or rpc part (e.g. '.SayHello', 'Greeter.').

Common situations: User typed a full gRPC URL like '/package.Svc/Method' or 'package.Svc.Method' (three parts) in the task form instead of 'Svc.Method'; copy-paste with trailing dot; empty field because the workflow parameter substituted to blank.

Understand the failure class

Background: "invalid id" errors: invalid identifier format — why libraries reject IDs before lookup, and how to fix them — this error's family across 37 libraries.

Related errors

• gRPC task params is not valid, method definition may not cor
• grpc unrecogenized condition %s
• grpc check condition %s not supported
• cannot merge json message to protobuf definition type <messa
• grpc exception: Unrecognized field label:

AI-assisted analysis of apache/dolphinscheduler@02eac45a1b (2026-09-06). Data as JSON: /api/errors/0277353117a3f0a0. Report an issue: GitHub.