程序代写代做 distributed system Java database graph data structure You are required to implement a fault-tolerant distributed system, called “Just Hungry”, based on passive replication, supporting online food ordering and delivery. You are expected to use RMI in either Java or Python implementing the system. There are various aspects for constructing such a system, including client and server implementation, operation workflow design, data integrity, message design, etc. Your implementation should comprise at least three back-end servers, one front-end server, supporting a client to retrieve and submit food orders. The coursework allows you to demonstrate your competence in developing distributed systems.

You are required to implement a fault-tolerant distributed system, called “Just Hungry”, based on passive replication, supporting online food ordering and delivery. You are expected to use RMI in either Java or Python implementing the system. There are various aspects for constructing such a system, including client and server implementation, operation workflow design, data integrity, message design, etc. Your implementation should comprise at least three back-end servers, one front-end server, supporting a client to retrieve and submit food orders. The coursework allows you to demonstrate your competence in developing distributed systems.
• System Design (10 marks): Using a diagram, illustrate major operation workflow flows among back-end servers, the front-end server and a client, and show how they work together as a distributed system.
• Back-end Server Implementation (40 marks): With passive replication, implement at least three back-end servers to accept, process and make responses to user orders. The implementation should fulfill the location, relocation, replication and failure transparency requirements.
• Front-end Server Implementation (20 marks): Implement a front-end server to provide one system access, preventing a client to have direct access to individual system components and supporting transparency requirements.
• Client Implementation (15 marks): Implement a client program to allow a user to access the required distributed system by making food ordering requests and receiving system responses.
• Use of Web Services (15 marks): Incorporate external Web Services to support delivery address retrieval by postal code. The implementation should treat Web Services as distributed system components and fulfill suitable transparency requirements.
Your submission should include the system design diagram, all source codes and resource files, a readme file showing instructions of how to run your system and what external resources you have adopted.
Your implementation is expected to focus on the distributed system aspects. You may create a minimal amount of sample data to help you demonstrate the system functionalities and how the system meets the requirements. You may also implement your work using a text-based user interface and a memorybased data structure (e.g. array) to store and update system information. Other irrelevant features including database design and graphical user interface are not required.
You can use RMI instead of network sockets to support this type of communication for the sake of simplicity. And use pyro4 if you choose python.