quorum_vote

Benchmarking Quorum

Running multiple experiments using Python

To avoid manually changing settings in evn.sh, one can directly start multiple experiments using the following Python scripts:

1. config.py contains several important global variables to be imported to other Python's scripts:

   • NODES: the list of strings representing the server IP addresses.
   • parition_cmd: use to specify the script that simulate parition attacks.
   • TIMEOUT:

2. exps.py

3. partition.py

Parameters

There are a number of global variables that are to be set in env.sh:

• $QUO_HOME: NFS-mounted directory containing the scripts.
• $QUO_DATA: non-NFS directory for Quorum data
• SHOSTS: contains IP addresses of all nodes used for running the miners. The example file contains 32 hosts
• $CLIENTS: containing IP addresses of all nodes used by the clients. There are 2 clients per node. The example file contains 16 hosts
• $LOG_DIR: directory where the logs are stored. NFS-mounted directories are recommended.
• $EXE_HOME: containing the executable for driving the workloads (ycsb or smallbank). For Quorum, smallbank is simulated via ycsb, i.e. it is invoked via key-value operation but at the server side multiple read/write operations are performed.
  • YCSB: $QUO_HOME/../../src/kystore
  • Smallbank: $QUO_HOME/../../src/smallbank
• $BENCHMARK: name of the benchmark (ycsb or smallbank)
• $QUORUM: the directory of Quorum Binaries, which are placed in $QUORUM_REPO_ROOT/build/bin

Each network is initialized with different genesis block. There are a set of pre-defined genesis blocks for different network sizes:

Scripts

There are 4 steps in running an experiment: network initialization, miner startup, client startup, and finally cleaning up. Scripts for these steps are included in $QUO_HOME. The top-level script:

run-bench.sh <nservers> <nthreads> <nclients> [-drop]

will start nservers miners, nclients clients each running with nthreads. The outputs are stored in $LOG_DIR. If -drop is specified, 4 servers will be killed after the clients are running for about 250s.

Initilization

• init-all.sh <nservers>: go to each of nservers and invokes init.sh <nservers>
• init.sh <nservers> initializes quorum at a local node. It does 3 things:
  • Use keys/key$i for the key of the static account
  • Use $QUO_HOME/genesis_quorum.json to as the genesis block
  • Use $QUO_DATA for quorum data

Starting voting

• start-all.sh <nservers>: start a network of nservers miner in the following steps:
  1. Go to each of nservers node in hosts and invoke start-mining.sh. This involves:
     • Start quorum in vote mode

Starting the clients

• start-multi-clients.sh <nclients> <nservers> <nthreads> [-drop]: takes as input a number of clients and launch 2.nclients clients connecting to 2.nclients miners. It then performs the following:

  1. Go to each client node in clients and invoke start-client.sh

     • start-client.sh <nthreads> <client_index> <nservers>: start driver process at the client node client_index^{th} to connect to the server node of index 2.(client_index) and 2.(client_index)+1

     Different benchmark may expect different command line arguments for the driver process

  2. Let the clients run for M (seconds), a sufficiently long duration to collect enough data. Then kill all client processes. Particularly:

     M = 240 + 10*<nservers>

  3. When -drop is specified:

     • It starts the clients and sleep for 250 seconds
     • It then kills off the last 4 servers
     • It then continues to run (the remaining clients and servers) for another (M-150) seconds.

  So in total, when -drop is specified, the entire experiments runs for about (M+100) seconds.

Cleaning up

• stop-all.sh <nservers>: kill all server and client processes. Particularly:
  1. Go to each server and invoke stop.sh which kills quorum and remove all Quorum data.
  2. Go to each client (in $QUO_HOME/clients) and kill the ycsbc process.

When the experiment exits cleanly (normal case), the client processes are already killed in start-multi-client.sh and server processes in run-bench.sh. But if interrupted (Ctrl-C), both server and client processes should be killed explicitly with stop-all.sh.

Examples

1. Running with the same number of clients and servers:

   • Change LOG_DIR in env.sh to correct location, say result_same_s_same_c

   • Start it (e.g. X=8):

     . run-bench.sh 8 16 8 16

   This will start 8 miners (on first 8 nodes in $HOSTS) and 8 clients (on 4 first 4 nodes in $CLIENTS). Each client runs driver process with 16 threads. The clients output logs to result_same_s_same_c/exp_8_servers directory, with the file format client_<miner_host>_16.

2. Running with fixed number of clients and varying number of servers:

   • Change LOG_DIR in env.sh to correct location, say result_fixed_c

   • Start it (X=16):

     . run-bench.sh 16 16 8 16

   This will start 16 miners (on first 16 nodes in $HOSTS) and 8 clients (on 4 first 4 nodes in $CLIENTS). Each client runs driver process with 16 threads. The clients output logs to result_fixed_c/exp_16_servers directory, with the file format client_<miner_host>_16.

3. Drop off nodes:

   • Change LOG_DIR in env.sh to correct location, say result_fixed_c_drop_4

   • Start it (X=16):

     . run-bench.sh 16 16 8 16 -drop

   This will start 16 miners (on first 16 nodes in $HOSTS) and 8 clients (on 4 first 4 nodes in $CLIENTS). Each client runs driver process with 16 threads. At 250th second, 4 miners are killed off, while the rest continues to run. The clients output logs to result_fixed_c_drop_4/exp_16_servers directory, with the file format client_<miner_host>_16.

4. Running with different workloads:

Simply change $EXE_HOME and $BENCHMARK variables in env.sh. Then repeat the same steps as in the other examples.