Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CheckParams ¶
func CheckParams(c *ModuleParams) error
CheckParams checks whether the given configuration satisfies all necessary constraints.
Types ¶
type ModuleParams ¶
type ModuleParams struct {
// The identities of all nodes that execute the protocol in the first epoch.
// Must not be empty.
InitialMembership *trantorpbtypes.Membership
// Number of epochs by which to delay configuration changes.
// If a configuration is agreed upon in epoch e, it will take effect in epoch e + 1 + configOffset.
// Thus, in the "current" configuration, ConfigOffset subsequent configurations are already known.
ConfigOffset int
// The length of an ISS segment, in sequence numbers.
// This is the number of commitLog entries each orderer needs to output in an epoch.
// Depending on the number of leaders (and thus orderers), this will result in epoch of different lengths.
// If set to 0, the EpochLength parameter must be non-zero and will be used to calculate the length of the segments
// such that their lengths sum up to EpochLength.
// Must not be negative.
SegmentLength int
// The length of an ISS epoch, in sequence numbers.
// If EpochLength is non-zero, the epoch will always have a fixed
// length, regardless of the number of leaders.
// In each epoch, the corresponding segment lengths will be calculated to sum up to EpochLength,
// potentially resulting in different segment length across epochs as well as within an epoch.
// If set to zero, SegmentLength must be non-zero and will be used directly to set the length of each segment.
// Must not be negative.
// TODO: That EpochLength is not implemented now. SegmentLength has to be used.
EpochLength int
// The maximum time duration between two proposals of an orderer, where applicable.
// For orderers that wait for an availability certificate to fill before proposing it (e.g. PBFT),
// this parameter caps the waiting time in order to bound latency.
// When MaxProposeDelay has elapsed since the last proposal made by an orderer,
// the orderer proposes a new availability certificate.
// Must not be negative.
MaxProposeDelay time.Duration
// Maximal number of bytes used for message backlogging buffers
// (only message payloads are counted towards MsgBufCapacity).
// On reception of a message that the node is not yet ready to process
// (e.g., a message from a future epoch received from another node that already transitioned to that epoch),
// the message is stored in a buffer for later processing (e.g., when this node also transitions to that epoch).
// This total buffer capacity is evenly split among multiple buffers, one for each node,
// so that one misbehaving node cannot exhaust the whole buffer space.
// The most recently received messages that together do not exceed the capacity are stored.
// If the capacity is set to 0, all messages that cannot yet be processed are dropped on reception.
// Must not be negative.
MsgBufCapacity int
// Number of most recent epochs that are older than the latest stable checkpoint.
RetainedEpochs int
// Every CatchUpTimerPeriod, a node checks whether other nodes have fallen behind
// and, if so, sends them the latest state.
CatchUpTimerPeriod time.Duration
// Time interval for repeated retransmission of checkpoint messages.
CheckpointResendPeriod time.Duration
// Leader selection policy to use for generating the initial state snapshot. See type for possible options.
// This field is only used for initialization of the state snapshot that might be provided to a new instance of ISS.
// It is the state snapshot (and not this value) that determines the protocol instance's leader selection policy.
LeaderSelectionPolicy lsp.LeaderPolicyType
// View change timeout for the PBFT sub-protocol, in ticks.
// TODO: Separate this in a sub-group of the ISS params, maybe even use a field of type PBFTConfig in ModuleParams.
PBFTDoneResendPeriod time.Duration
PBFTCatchUpDelay time.Duration
PBFTViewChangeSNTimeout time.Duration
PBFTViewChangeSegmentTimeout time.Duration
PBFTViewChangeResendPeriod time.Duration
}
The ModuleParams type defines all the ISS configuration parameters. Note that some fields specify delays in ticks of the logical clock. To obtain real time delays, these need to be multiplied by the period of the ticker provided to the Node at runtime.
func DefaultParams ¶
func DefaultParams(initialMembership *trantorpbtypes.Membership) *ModuleParams
DefaultParams returns the default configuration for a given membership. There is no guarantee that this configuration ensures good performance, but it will pass the CheckParams test. DefaultParams is intended for use during testing and hello-world examples. A proper deployment is expected to craft a custom configuration, for which DefaultParams can serve as a starting point.
func (*ModuleParams) AdjustSpeed ¶
func (mp *ModuleParams) AdjustSpeed(maxProposeDelay time.Duration) *ModuleParams
AdjustSpeed sets multiple ISS parameters (e.g. view change timeouts) to their default values relative to maxProposeDelay. It can be useful to make the whole protocol run faster or slower. For example, for a large maxProposeDelay, the view change timeouts must be increased correspondingly, otherwise the view change can kick in before a node makes a proposal. AdjustSpeed makes these adjustments automatically.
Source Files