frankmowj/distributed-dns

中山大学分布式系统大作业

README

This project has implemented a simple distributed DNS using Chord to organize the servers and using gRPC as the tool for communication between clients and servers. The functions implemented are as follows:

• add, update, delete, query (domain name, IP)
• add, delete server
• simple implement of cache

System Structure

In this project, there are mainly three parts:

• Central Server: maintain the global view of DNS server in Chord
• DNS Server: response to the request from clients, when the (domain name, IP) pair is not in a server, it will transmit the request to another server based on the finger table
• Client: raise requests

File Structure

• dns.proto: protocol file containing all the service of the server
• centralserver.py: class of central server
• server.py: class of DNS server
• client.py: raise requests
• utils.py: contain hash function and some (domain name, IP) pair for testing

Test Example

We offer a test example. We let $m$ as 5, which means the Chord structure can maintain $2^5=32$ nodes at most. And some test (domain name, IP) pair are listed as follow.

domain name	IP	hash value	node
www.google.com	172.217.3.100	20	21
www.baidu.com	220.181.38.148	24	31
www.yahoo.com	98.137.11.163	16	16
www.microsoft.com	40.76.4.15	26	31
www.twitter.com	104.244.42.65	30	31
www.instagram.com	52.200.238.83	10	12

The finger tables of Chord are as follow.

The ports are allocated as follow.

server	port
central server	50050
node 12	50053
node 16	50054
node 19	50055
node 21	50056
node 31	50057

How to Run

• compile the protocol file

  make sure you have installed grpcio and grpcio-tools library.

python -m grpc_tools.protoc -I . --python_out=. --grpc_python_out=. dns.proto

• start up the central server

python centralserver.py

• add DNS server to Chord

  for each server, we open a new terminal, and make sure that different servers must have their unique port.

python server.py

• initialize DNS

python initial.py

• add, update, delete (domain name, IP)

  ​ To unify different types of requests into one interface, the project defines

  • '0': search for IP given domain name

  • '1': add (domain name, IP) pair

  • '2': delete (domain name, IP) pair pair

  • '3': update IP of the given domain name

python client.py

• simulate a server quit

  press Ctrl+c to shut down a server terminal.

Please give me a star ✨if you find this is beneficial to you。

​