async-cse535

PROJECT INFO

Byzantine Chain Replication implementation on DistAlgo(Python3).

Team Members -
Yogesh Agrawal (111493656)
Fan Wang (111104886)

PLATFORM

DistAlgo Version: 1.0.9
Python Implementation: CPython
Python Version: 3.6.2
OS: macOS Sierra Type of hosts: Two different laptops Platform for each host: Windows and macOS Sierra

INSTRUCTIONS

Instructions to build and run your system.

PreRequisites

1. python ( version 3 )
2. pip

Download

1. DistAlgo ( http://distalgo.cs.stonybrook.edu/tutorial )
2. pip install pynacl  ( to download Libsodium crypto library which is used for signatures and crypto hashing )

Setup

1. Add DistAlgo <DAROOT>/bin to your PATH environmental variable. This folder contains 'dar' and 'dac' executables.

Executing the scripts

1. dar -H <local_ip> -n OlympusNode --message-buffer-size 8000 -f -F output --logfilename <olympus_log_file_name> bcr.da <config_file>
2. dar -H <local_ip> -R <olympus_ip> -n ClientNode --message-buffer-size 8000 --idle -f -F output --logfilename <client_log_file_name> bcr.da
3. dar -H <local_ip> -R <olympus_ip> -n ReplicaNode --message-buffer-size 8000 --idle -f -F output --logfilename <replica_log_file_name> bcr.da

We need to create 3 nodes, one each for olympus, replica and client.

<config_file> contains the test case and needs to be passed only to the olympus node ( or more generically, the node which runs 'main').

Example -

1.dar -H 1.0.0.1 -n OlympusNode --message-buffer-size 8000 -f -F output --logfilename olympus.log bcr.da config.txt
2. dar -H 2.0.0.2 -R 1.0.0.1 -n ClientNode --message-buffer-size 8000 --idle -f -F output --logfilename client.log bcr.da
3. dar -H 3.0.0.3 -R 1.0.0.1 -n ReplicaNode --message-buffer-size 8000 --idle -f -F output --logfilename replica.log bcr.da

WORKLOAD GENERATION

We generate the pseudorandom workload by using random number generator in pyhton with a seed.

1. Initialise operations array, key array and value arrays.
2. Generate 3 random numbers(with seed) within limits of array size of above mentioned arrays.
3. Pick element from each array corresponding to the generated random numbers used as index for that array.
4. Create 1 operation from above selected values. If operation is slice(), generate two more random numbers within a specified limit.
5. Repeat 2-4 for generating n operations.

Arrays are pre-defined to accomodate the needs including operations, values, keys, and etc.
Note that the seed has to be an integer and number of operations has to be a positive number.

BUGS AND LIMITATIONS

There is no automated way to verify the final state of the replicas, after running mulitple operartions from different clients. However this limitation can be overcome by designing test cases where sequencing of the clients' operations is not a factor of the final state of the replica and then can be verified from the logs directly. One simple way to implement this is by using unique and distinct 'key' for all operations from a client. For example, client C1 will always send operations for key 'hello' while another client C2 will always send operations for the key 'world'.

Note - The above limitation has now been taken care by verifying the response at the client. Client maintains its own dictionary of operations.

CONTRIBUTIONS

Phase 2 - Yogesh Agrawal completed the parts of code in replica, olympus and bcr.da, logging and partially in testing and documentation. Fan Wang completed the parts of code in client, multi-host setup and partially in testing and documentation.

Phase 3 - Yogesh Agrawal completed the parts of code in client, replica and bcr.da, logging and partially in testing and documentation. Fan Wang completed the parts of code in olympus, performance evaluation and partially in testing and documentation.

MAIN FILES

The root folder of the submission is termed as ROOT. ROOT/bcr.da -> implements main function of the program, which inherits the other three modules. ROOT/client.da -> da_module code for Client, imported by bcr.da ROOT/replica.da -> da_module code for Replica, imported by bcr.da ROOT/olympus.da -> da_module code for Olympus, imported by bcr.da

CODE SIZE

(1) number of non-blank non-comment lines of codes (LOC)

• Algorithm: 843
• Other: 500
• Total: 1343 CLOC (https://github.com/AlDanial/cloc) is used to derive the numbers above. Installed via 'brew install cloc'.

(2)
Approximately 440 Lines are the main algorithm. Remaining 400 functionalities interleaved with the algorithm.

LANGUAGE FEATURE USAGE.

• number of list comprehensions: 0
• number of dictionary comprehensions: 0
• number of set comprehensions: 0
• number of aggregations: 0
• number of quantifications: 0

PERFORMANCE EVALUATION

1. with Raft - 20.77 secs
2. peform900.txt with single host - 44.3 secs
3. peform900.txt with multi host - 52.7 secs