Overview
Say you come up with a wonderful idea such as a really great phone service. You would want this phone service to be available to the APIs in various languages. Whether people are using Python, C++, Java or any other programming language, the users should be able to use your service. Also, you would want the users to be able to access globally. In such scenarios, you should create the Thrift Service. Thrift lets you create a generic interface which can be implemented on the server. The clients of this generic interface can be automatically generated in all kinds of languages.
Let us get started! Here we are going to create a very simple service that just prints the server time.
Step 0: Install Thrift
This step is not required if you are using CloudxLab. You can just log in to the web console. In case you want to set up Apache Thrift on your own machine please follow these instructions: https://thrift.apache.org/docs/install/
Step 1: Create the interface definition
Let us create a file with name Example.thrift with the following code in it:
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namespace php Example service Example{ // return current time stamp string showCurrentTimestamp() // wait for 10 seconds, but work asynchronously oneway void asynchronousJob() } |
Step 2: Generate the server and client side code in python
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thrift --gen py Example.thrift |
At this point, you will observe a folder with the name “gen-py” created in your current directory. Inside gen-py, you would notice that a folder with name “Example” has been created with all sorts of code.
Step3: Create Server
First, create a directory with the name “server” and go into that directory:
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mkdir server cd server |
Inside this folder create a file with the name PythonServer.py and the following contents:
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#!/usr/bin/env python # This server demonstrates Thrift's connection and "oneway" asynchronous jobs # showCurrentTimestamp : which returns current time stamp from server # asynchronousJob() : prints something, waits 10 secs and print another string # port = 9090 import sys # your gen-py dir sys.path.append('../gen-py') import time # Example files from Example import * from Example.ttypes import * # Thrift files from thrift.transport import TSocket from thrift.transport import TTransport from thrift.protocol import TBinaryProtocol from thrift.server import TServer # Server implementation class ExampleHandler: # return current time stamp def showCurrentTimestamp(self): timeStamp = time.time() return str(timeStamp) # print something to string, wait 10 secs, than print something again def asynchronousJob(self): print 'Assume that this work takes 10 seconds' time.sleep(10) print 'Job finished, but client didn\'t wait for 10 seconds' # set handler to our implementation handler = ExampleHandler() processor = Example.Processor(handler) transport = TSocket.TServerSocket("0.0.0.0", port) tfactory = TTransport.TBufferedTransportFactory() pfactory = TBinaryProtocol.TBinaryProtocolFactory() # set server server = TServer.TThreadedServer(processor, transport, tfactory, pfactory) print 'Starting server' server.serve() |
Notice that we are implementing service by the way of the class ExampleHandler.
Step 4: Now start the server:
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python PythonServer.py |
Step 5: Create a client
Let the server run and open a new terminal. In the new terminal follow the instructions from here onwards. Create a folder with the name “client”. Inside that folder create a file with name PythonClient.py and the following code:
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#!/usr/bin/env python # This client demonstrates Thrift's connection and "oneway" asynchronous jobs # Client connects to server host:port and calls 2 methods # showCurrentTimestamp : which returns current time stamp from server # asynchronousJob() : which calls a "oneway" method # host = "localhost" port = 9090 import sys # your gen-py dir sys.path.append('../gen-py') # Example files from Example import * from Example.ttypes import * # Thrift files from thrift import Thrift from thrift.transport import TSocket from thrift.transport import TTransport from thrift.protocol import TBinaryProtocol try: # Init thrift connection and protocol handlers transport = TSocket.TSocket( host , port) transport = TTransport.TBufferedTransport(transport) protocol = TBinaryProtocol.TBinaryProtocol(transport) # Set client to our Example client = Example.Client(protocol) # Connect to server transport.open() # Run showCurrentTimestamp() method on server currentTime = client.showCurrentTimestamp() print currentTime # Assume that you have a job which takes some time # but client sholdn't have to wait for job to finish # ie. Creating 10 thumbnails and putting these files to sepeate folders client.asynchronousJob() # Close connection transport.close() except Thrift.TException, tx: print 'Something went wrong : %s' % (tx.message) |
Step 6: Run the client
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python PythonClient.py |
It should print the current time such as:
1549721664.93
It is an extremely simple example. You can extend it to add more functions and objects.
The code for the whole project is available here: https://github.com/cloudxlab/thrift-examples
