DiemBFT

• Implementation of DiemBFT : State Machine Replication in Diem Bloackchain as mentioned in https://developers.diem.com/papers/diem-consensus-state-machine-replication-in-the-diem-blockchain/2021-08-17.pdf . We have used DistAlgo high level language for implementation. DistAlgo's respository can be found on https://github.com/DistAlgo/distalgo and the home page for the same can be found on http://distalgo.cs.stonybrook.edu/.

1. Platform

Operating system

• Our Implmentation of DiemBFT has been tested on GNU/Linux only.

Python

• DiemBFT required python version 3.7.11 which can be obtained from http://www.python.org. 3.7.11 is mostly recommended since the latest version(Pre-Release) of DistAlgo runs smoothly on this version. Please note that it is mandatory to make sure that the default Python used by the system is python 3.7.11.
• This can be checked easily with the help of python --version command. It is highly recommended to use Anaconda(conda) virtual environment for managing different versions of python in a system. The steps for Anaconda installation is provided in Manual.

2. Workload generation

• In testdiem.da, we have included a dictionary which consists of the Workload generations parameters as mentioned in the example below. More details can be found in the test setup section in report.

  {
    'Name' : "Normal Replicas", 
    'faultyReplicas': 1,    # number of replicas which can go faulty
    'timeoutDelta'  : 2500, # Used by Pacemaker for timeout in milliseconds
    'clients'       : 1,    # Number of Client processes
    'requests'      : 10,   # Total Number of Requests by each client
    'clientTimeout' : 5,    # ClientTimeout in Seconds
    'testcase':{
      "type":"normal",
      "specialArguments": [] # Special Arguments included for different configurations
    }
  

3. Timeouts

• For get_round_timer in Pacemaker, We use the formula 4* delta where delta is passed as the timeout value from setup.

4. Bugs and Limitations

• Limitation 1 - Use of dummy blocks for chain termination. More details in Chain Termination under Implementation section in report.

5. Main files

• DiemBFT/src/diem_replica.da : Replica code . It mainly contains the Main fucntion as mentioned in the Pseudocode
• DiemBFT/src/testdiem.da : The Driver code that spawns the Clients and Replicas as per the configuaration. This is the Run class as mentioned in the phase doc
• DiemBFT/src/client.da : The client code which send and receives commans from the replica's
• DiemBFT/src/leader_election.py : The leader election code.
• DiemBFT/src/Pacemaker.py : The pacemaker code.
• DiemBFT/src/Ledger.py : The Ledger code.
• DiemBFT/src/BlockTree.py : Code for VoteInfo, LedgerCommitInfo, QC, VoteMsg, Block, PendingBlockTree, BlockTree. (included in one to avoid circular dependency)
• DiemBFT/src/mempool.py : Code for mempool.

6. Code Size

• Cloc report in codesize.txt
• Total code lines is 4048
• Non essential code (tests, helper methods etc) is 753

7. Language Feature usage

• List Comprehensions = Total 4 : 1 in client.da and 1 in diem_replica.da
• Dictionary Comprehensions = 0
• set comprehensions = 0
• aggregations = 0
• quantifications = 1 Quantification(some) in diem_replica.da
• await statements = Total 5: 2 each in diem_replica.da (not counting its variants), 2 in client.da and 1 in testdiem.da respectively
• receive handlers = Total 5 : 4 in diem_replica.da and 1 in client.da

8. Contributions

• Raj Patel (114363611)
  • Test Setup and event loop
  • Main Procedure
  • PaceMaker
  • LeaderElection
  • Clients
  • Synchronization
  • Mempool
  • TestCases
  • Bug fixes, all module integration and debugging
  • Test report and documentation
• Prince Kumar Maurya (114354075)
  • Ledger
  • BlockTree
  • Logging
  • Test Case
  • Debugging
  • Crytography
  • Block Sync
• Vishal Singh (114708875)
  • PaceMaker
  • Safety
  • Signature Verification
  • Test Cases
  • Readme and Manual

9. Other

Guide to TAs

1. report.pdf contains the test case report with detailed documentation of implementation
2. pseudo_code.pdf contains the pseudo_code requested.
3. src folder contains all the code files