Configuring SymbChainSim simulations

Most of SymbChainSim’s components are controlled through the configuration yaml files found in the Configs directory. The yaml file is split into named categories according to the broad area they control. Specifically these are: simulation, application, execution, data, network, consensus, behaviour, dynamic_sim, and reconfiguration.

simulation

Parameter	Description
init_CP	Initial consensus protocol at simulation start (Options: "PBFT", "Tendermint", "BigFoot")
simTime	Stop simulation after this many seconds (-1 = no limit)
stop_after_blocks	Stop after this many blocks are produced (-1 = no limit)
stop_after_tx	Stop after this many transactions are processed (-1 = no limit)
debugging_mode	Enable detailed debugging mode (step-by-step event processing)
logging_level	Logging verbosity level ("DEBUG" or "INFO")
print_every	Print simulation progress every N seconds
snapshot_interval	Take snapshots of simulation state every N seconds
print_info	Print simulation information at the start of execution

application

Parameter	Description
Nn	Number of nodes in the blockchain network
workload	Workload generation mode: 'generate' (parameter based) or 'path_to_workload_trace' (trace-based)
TI_dur	Transaction generation interval (every N seconds generate transactions for the next N seconds)
Tn	Total number of transactions to generate per second
base_transaction_size	Base size of transactions in MB
Tsize	Transaction size variation in MB (standard deviation)
transaction_model	Transaction pool model: "global" (one pool) or "local" (each node has its own pool)

execution

Parameter	Description
creation_time	Time required to create a block (s)
block_val_delay	Time required for block validation (s)
msg_val_delay	Time required to validate a network message (s)
sync_message_request_delay	Time required to request missing data from a peer (s)
time_per_tx	Time required to validate each transaction in a received block (s)
proposer_selection	Proposer selection algorithm: "hash" (based on latest block hash) or "round_robin"

data

Parameter	Description
Bsize	Maximum block size in MB
base_block_size	Base block size in MB (excluding transactions)
block_time	Minimum time interval between blocks in seconds

network

Parameter	Description
base_msg_size	Base message size in MB
gossip	Enable gossip protocol for message propagation (True = cascading peer multicast, False = full broadcasts)
num_neighbours	Number of neighbors each node connects to
use_latency	Latency model: "measured", "distance", "local", or "off"
same_city_latency_ms	Latency for nodes in the same city (ms)
same_city_dev_ms	Standard deviation for same-city latency (ms)
queueing_delay	Additional queueing delay (s)
processing_delay	Additional processing delay (s)

bandwidth

Parameter	Description
mean	Mean bandwidth in Mbps
dev	Standard deviation of bandwidth in Mbps
min	Minimum bandwidth in Mbps
sample	Bandwidth sampling frequency: 'always', 'once', or 'scenario'

consensus

Links the protocol names to a path that contains a specific configuration file for that protocol.

Parameter	Description
BigFoot	Path to BigFoot consensus protocol configuration
PBFT	Path to PBFT consensus protocol configuration
Tendermint	Path to Tendermint consensus protocol configuration

behaviour

Parameter	Description
use	Enable behavioural modeling
config	Path to behaviour configuration file
print_updates	Print behaviour updates during simulation

dynamic_sim

Parameter	Description
use	Enable dynamic simulation features
config	Path to dynamic simulation configuration file
print_updates	Print dynamic simulation updates during execution

reconfiguration

Parameter	Description
reconfigure	Enable reconfiguration of blockchain system
reconfiguration_interval	How often to reconfigure the system (s)
reconfiguration_interval_range	Random range to adjust reconfiguration interval (s)
conf_block_size	Block size of produced configuration blocks in MB
reconfiguration_method	How to reconfigure the system (e.g., "random_centralised")
random_configuration	Parameters used for random reconfiguration (protocols, block_sizes, block_times)
propagation.model	If True, config block is propagated with delay; if False, instantly applied to all nodes
propagation.delay	Delay range for configuration block propagation (s)
propagation.per_cent_nodes	Percentage of nodes initially receiving the config block
print_updates	Print details of reconfiguration
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