DAD2425

Project course for DAD 2024-25

This repository holds the base code required to implement the project. Students are free to improve on the following code.

Requirements

The project requires the following packages:

• Java 22
• Maven 3.8.4
• Protoc 3.12

Compiling

To compile the project, students must run the command mvn clean install in the root directory

WARNING - Compilation Environment

The project requires different pom.xml for the contract module depending on the CPU architecture/OS distribution. The project currently has two pre-pepared poms:

• One for ARM/M4 Mac-OS based systems, named arm-pom.xml;
• One for Intel/Linux based systems, named intel-pom.xml;

Before the first compilation, copy your required contract pom and rename it to pom.xml.

Deployment

Current implementation assumes that all modules run on the same physical machine and requires 5 active servers.

The project is composed of three main components:

• Servers
• Clients
• ConsoleClient

Servers

The servers run the base implementation. They are executed running the following command in the server directory:

mvn exec:java -Dexec.args="{port} {id}"

Where you must fill in the following arguments:

• {id}: Sequential id of the server. Current implementation requires servers to be ID'ed starting from 0 to N-1 servers.
• {port}: Base port of all servers. All servers should use the same port. The Server binded port will be {port} + {id}.

Client

A client that executes transactions. It is executed by running the following command in the client directory:

mvn exec:java

The client module opens a terminal from where students may issue commands. The following commands are available:

• help - Shows the full command list;
• read {read_key_1} - Reads a key (useful for debug);
• tx {read_key_1} {read_key_2} {write_key} - Takes as input 3 keys and executes a transaction with 2 reads and 1 write respectively;
• loop - Runs multiple transactions, one after another, in a loop;
• lenght {loop-lenght} - Defines the number of transactions executed when looping;
• time {sleep-range} - Slows down transactions by sleeping a random amount of time in sleep-range between reads and commit;
• exit - Gracefully finishes the client.

ConsoleClient

The console client servers as a front-end to issue configuration settings to servers. It is executed by running the following command in the consoleclient directory:

mvn exec:java

The console client opens a terminal from where students may issue configuration changes to servers. The following commands are available:

• help - Shows the full command list;
• leader on/off replica_id - Instructs a replica to strat/stop acting as a Paxos leader;
• debug mode replica_id - Activates debug on a given replica;
• reconfig configuration - Executes a transaction on key 0 to change the configuration;
• exit - Gracefully finishes the console.

Protobuffs and Utils

To support these modules, the project has two additional directories:

• contract, holding the required .proto files;
• util, holding the general classes to collect RPC responses