B_heartbeat_interval
SPIN Parameters
Number of blocks between leader liveness heartbeats sent to parachain
Comment: Ensures leader availability monitoring
SPIN Parameters
Terms (A–Z)
Section titled “Terms (A–Z)”B
B_recovery_delay
SPIN Parameters
Number of parachain blocks after the last FCFP before the parachain initiates Finality Recovery Mode.
Comment: Controls when recovery mode triggers due to missing FCFPs.
B_recovery_duration
SPIN Parameters
Number of parachain blocks that Finality Recovery Mode continues before transitioning back to operational mode.
Comment: Controls duration of recovery procedures.
N
N_slashing
SPIN Parameters
Percentage of stake slashed for proven censorship or malicious behavior by validators.
Comment: Economic penalty for protocol violations.
N_validators_max
SPIN Parameters
Maximum number of validators allowed in the active set
Comment: Upper bound for validator set scaling
N_validators_min
SPIN Parameters
Minimum number of validators required for secure network operation.
Comment: Safety threshold for validator set size.
N_validators_quorum
SPIN Parameters
Percentage of validators required to validate and finalize blocks.
Comment: Consensus threshold for block finalization.
R
R_bridging_missed
SPIN Parameters
Ratio of slots missed by the Bridging Gadget Operator during an Epoch, calculated as missed slots divided by total slots.
Comment: Performance metric for leader accountability. Previously uses "Collation Leader" in older drafts.
R_bridging_missed_max
SPIN Parameters
Maximum allowed ratio of missed slots before Bridging Gadget Operator is penalized and disabled in the next epoch.
Comment: Threshold for leader performance penalties. Previously uses "Collation Leader" in older drafts.
S
S_batch_size
SPIN Parameters
Number of Fast Chain blocks included in a single FCFP before submission to Bridging Gadget.
Comment: Controls batching efficiency for cross-chain proofs.
S_checkpoint_interval
SPIN Parameters
Number of blocks between state checkpoints for fast synchronization
Comment: Enables rapid node sync without full history replay
S_election_finalization
SPIN Parameters
Number of blocks before epoch end when validator election results must be finalized.
Comment: Deadline for completing validator elections.
S_epoch_duration
SPIN Parameters
Duration between validator set elections, encompassing the full governance and nomination cycle.
Comment: Fundamental timing for governance cycles.
S_fc_block_time
SPIN Parameters
Target time between blocks during normal operation on Fast Chain, currently set to 100ms.
Comment: Core performance target for Fast Chain block production.
S_last_voting_block
SPIN Parameters
Number of blocks before epoch end after which no more nominator votes are accepted.
Comment: Voting deadline for validator elections.
S_secondary_delay
SPIN Parameters
Number of consecutive slots the Primary Leader may miss before the Secondary Leader starts block production.
Comment: Core timing parameter for leader failover mechanism and Finality Recovery Mode activation.
S_tenure_duration
SPIN Parameters
Duration for which a single Primary Leader produces blocks before rotation to the next validator.
Comment: Leadership rotation timing to balance performance and decentralization.
S_witness_delay
SPIN Parameters
Time allocated for validators to submit witness messages during Finality Recovery Mode.
Comment: Timeout for accountability messages during recovery.
S_yell_response_delay
SPIN Parameters
Number of slots validators wait for the Primary Leader to include Yell Query transaction and provide inclusion proof.
Comment: Core anti-censorship timing parameter.
S_yell_user_delay
SPIN Parameters
Number of slots user waits before submitting Yell Query, noted as unused due to mempool visibility subjectivity.
Comment: Deprecated parameter, replaced by parachain fee mechanism.