Python SDK on Apache Dubbo

Quick Start

Mon, 01 Jan 0001 00:00:00 +0000

This guide will help you get started with Dubbo in Python with a simple working example. See the full example here.

1. Prerequisites

Python 3.11 or higher
Compatible pip version

2. Install Dubbo-Python

Install Directly
```
pip install apache-dubbo
```

Install from source

git clone https://github.com/apache/dubbo-python.git
cd dubbo-python && pip install .

3. Build a Dubbo Service

Building the Dubbo Server

import dubbo
from dubbo.configs import ServiceConfig
from dubbo.proxy.handlers import RpcMethodHandler, RpcServiceHandler

class UnaryServiceServicer:
 def say_hello(self, message: bytes) -> bytes:
 print(f"Received message from client: {message}")
 return b"Hello from server"

def build_service_handler():
 # build a method handler
 method_handler = RpcMethodHandler.unary(
 method=UnaryServiceServicer().say_hello, method_name="unary"
 )
 # build a service handler
 service_handler = RpcServiceHandler(
 service_name="org.apache.dubbo.samples.HelloWorld",
 method_handlers=[method_handler],
 )
 return service_handler

if __name__ == "__main__":
 # build service config
 service_handler = build_service_handler()
 service_config = ServiceConfig(
 service_handler=service_handler, host="127.0.0.1", port=50051
 )
 # start the server
 server = dubbo.Server(service_config).start()

 input("Press Enter to stop the server...\n")

Building the Dubbo Client

import dubbo
from dubbo.configs import ReferenceConfig

class UnaryServiceStub:
 def __init__(self, client: dubbo.Client):
 self.unary = client.unary(method_name="unary")

 def say_hello(self, message: bytes) -> bytes:
 return self.unary(message)

if __name__ == "__main__":
 # Create a client
 reference_config = ReferenceConfig.from_url(
 "tri://127.0.0.1:50051/org.apache.dubbo.samples.HelloWorld"
 )
 dubbo_client = dubbo.Client(reference_config)
 unary_service_stub = UnaryServiceStub(dubbo_client)

 # Call the remote method
 result = unary_service_stub.say_hello(b"Hello from client")
 print(result)

4. Run the Dubbo Service

Navigate to the Quick Start example directory:

Custom Serialization

Mon, 01 Jan 0001 00:00:00 +0000

See the full example here

Python is a dynamic language, and its flexibility makes it challenging to design a universal serialization layer as seen in other languages. Therefore, we have removed the “serialization layer” and left it to the users to implement (since users know the formats of the data they will pass).

Serialization typically consists of two parts: serialization and deserialization. We have defined the types for these functions, and custom serialization/deserialization functions must adhere to these “formats.”

Streaming Communication Model

Mon, 01 Jan 0001 00:00:00 +0000

See the full example here

Dubbo-Python supports streaming calls, including ClientStream, ServerStream, and BidirectionalStream modes.

Streaming calls can be divided into write-streams and read-streams. For ClientStream, it’s multiple writes with a single read; for ServerStream, a single write with multiple reads; and BidirectionalStream allows multiple writes and reads.

Write-Stream

Write operations in streaming calls can be divided into single write (ServerStream) and multiple writes (ClientStream and BidirectionalStream).

Single Write

Single write calls are similar to unary mode. For example:

Service Discovery

Mon, 01 Jan 0001 00:00:00 +0000

See the full example here

Using service registration and discovery is very simple. In fact, it only requires two additional lines of code compared to point-to-point calls. Before using this feature, we need to install the relevant registry client. Currently, Dubbo-python only supports Zookeeper, so the following demonstration will use Zookeeper.

Similar to before, we need to clone the Dubbo-python source code and install it. However, in this case, we also need to install the Zookeeper client. The commands are: