Implementation of a distributed system which handles transactions concurrently while guaranteeing strict serializability via a concurrent 2-Phase Commit protocol among multiple servers and coordinators.
The system is made by several clients which can start transactions by contacting a coordinatorand sending to it a sequence of read/write operations on resources. Upon receiving a request, thecoordinator forwards them to the servers holding the requested resource and forwards the answerback to the client if needed. The servers follow an optimistic concurrency control: they perform theoperations on a private copy of the database, and only after the client has said that the transactionhas ended, the updates can possibly be propagated to the official database. The latter phase is donethrough a validation process based on 2-PC, where servers agree on whether to commit or abortthe transaction, in such a way that concurrent transactions do not conflict and that the number ofcommitted transactions is maximized.
The file DS1_report.pdf contains a more detailed description of the system.
The project is implemented in Java using the Akka framework.
- Download and install Java SDK, Standard Edition. Version 11 is recommended for compatibility reasons.
- Install Gradle build tool
- In the command line, change dir to and run the project:
cd concurrent_2pc gradle run