Documentation
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Overview ¶
Package config contains functions and types used for managing dragonboat's configurations.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Config ¶
type Config struct {
// NodeID is a non-zero value used to identify a node within a Raft cluster.
NodeID uint64
// ClusterID is the unique value used to identify a Raft cluster.
ClusterID uint64
// IsObserver indicates whether this is an observer Raft node without voting
// power.
IsObserver bool
// CheckQuorum specifies whether the leader node should periodically check
// non-leader node status and step down to become a follower node when it no
// longer has the quorum.
CheckQuorum bool
// Quiesce specifies whether to let the Raft cluster enter quiesce mode when
// there is no cluster activity.
Quiesce bool
// ElectionRTT is the minimum number of message RTT between elections. Message
// RTT is defined by NodeHostConfig.RTTMillisecond. The Raft paper suggests it
// to be a magnitude greater than HeartbeatRTT, which is the interval between
// two heartbeats. In Raft, the actual interval between elections is
// randomized to be between ElectionRTT and 2 * ElectionRTT.
//
// As an example, assuming NodeHostConfig.RTTMillisecond is 100 millisecond,
// to set the election interval to be 1 second, then ElectionRTT should be set
// to 10.
//
// When CheckQuorum is enabled, ElectionRTT also defines the interval for
// checking leader quorum.
ElectionRTT uint64
// HeartbeatRTT is the number of message RTT between heartbeats. Message
// RTT is defined by NodeHostConfig.RTTMillisecond. The Raft paper suggest the
// heartbeat interval to be close to the average RTT between nodes.
HeartbeatRTT uint64
// SnapshotEntries defines how often state machine should be snapshotted
// defined in terms of number of applied entries. Set SnapshotEntries to 0 to
// disable Raft snapshotting and log compaction.
SnapshotEntries uint64
// CompactionOverhead defines the number of most recent entries to keep after
// Raft log compaction.
CompactionOverhead uint64
// OrderedConfigChange determines whether Raft membership change is enforced
// with ordered config change ID.
OrderedConfigChange bool
}
Config is used to configure Raft nodes.
type LogDBFactoryFunc ¶
LogDBFactoryFunc is the factory function that creates NodeHost's persistent storage module known as Log DB.
type NodeHostConfig ¶
type NodeHostConfig struct {
// DeploymentID is used to determine whether two NodeHost instances belong to
// the same deployment and thus allowed to communicate with each other. This
// helps to prvent accidentially misconfigured NodeHost instances to cause
// data corruption errors by sending out of context messages to unrelated
// Raft nodes.
// For a particular dragonboat based application, you can set DeploymentID
// to the same uint64 value on all production NodeHost instances, then use
// different DeploymentID values on your staging and dev environment. It is
// also recommended to use different DeploymentID values for different
// dragonboat based applications.
// When not set, the default value 0 will be used as the deployment ID and
// thus allowing all NodeHost instances with deployment ID 0 to communicate
// with each other.
DeploymentID uint64
// WALDir is the directory used for storing the WAL of Raft entries. It is
// recommended to use low latency storage such as NVME SSD with power loss
// protection to store such WAL data. Leave WALDir to have zero value will
// have everything stored in NodeHostDir.
WALDir string
// NodeHostDir is where everything else is stored.
NodeHostDir string
// RTTMillisecond defines the average Rround Trip Time (RTT) in milliseconds
// between two NodeHost instances. Such a RTT interval is internally used as
// a logical clock tick, Raft heartbeat and election intervals are both
// defined in term of how many such RTT intervals.
// Note that RTTMillisecond is the combined delays between two NodeHost
// instances including all delays caused by network transmission, delays
// caused by NodeHost queuing and processing. As an example, when fully
// loaded, the average Rround Trip Time between two of our NodeHost instances
// used for benchmarking purposes is up to 500 microseconds when the ping time
// between them is 100 microseconds.
RTTMillisecond uint64
// RaftAddress is a hostname:port address used by the Raft RPC module for
// exchanging Raft messages. This is also the identifier value to identify
// a NodeHost instance.
RaftAddress string
// APIAddress is the address used by the optional NodeHost RPC API. Empty
// value means NodeHost API RPC server is not used. This optional field
// only need to be set when using Master servers.
APIAddress string
// MasterServers is a list of Master server addresses to use. Master servers
// are optional component. Empty or nil value means that there is no Master
// server configured for this deployment.
MasterServers []string
// MutualTLS defines whether to use mutual TLS for authenticating servers
// and clients. Insecure communication is used when MutualTLS is set to
// False.
// See https://github.com/lni/dragonboat/wiki/TLS-in-Dragonboat for more
// details on how to use Mutual TLS.
MutualTLS bool
// CAFile is the path of the CA certificate file. This field is ignored when
// MutualTLS is false.
CAFile string
// CertFile is the path of the node certificate file. This field is ignored
// when MutualTLS is false.
CertFile string
// KeyFile is the path of the node key file. This field is ignored when
// MutualTLS is false.
KeyFile string
// LogDBFactory is the factory function used for creating the Log DB instance
// used by NodeHost. The default zero value causes the default built-in RocksDB
// based Log DB implementation to be used.
LogDBFactory LogDBFactoryFunc
// RaftRPCFactory is the factory function used for creating the Raft RPC
// instance for exchanging Raft message between NodeHost instances. The default
// zero value causes the built-in TCP based RPC module to be used.
RaftRPCFactory RaftRPCFactoryFunc
}
NodeHostConfig is the configuration used to configure NodeHost instances.
Example ¶
// import "github.com/lni/dragonboat/plugin/rpc"
nhc := NodeHostConfig{
WALDir: "/data/wal",
NodeHostDir: "/data/dragonboat-data",
RTTMillisecond: 200,
RaftAddress: "node01.raft.company.com:5012",
// set this if you want to use gRPC based RPC module for exchanging raft data between raft nodes.
// RaftRPCFactory: rpc.NewRaftGRPC,
}
_ = nhc
Output:
func (*NodeHostConfig) GetClientTLSConfig ¶
func (c *NodeHostConfig) GetClientTLSConfig(target string) (*tls.Config, error)
GetClientTLSConfig returns the client tls.Config instance for the specified target based on the TLS settings in NodeHostConfig.
func (*NodeHostConfig) GetServerTLSConfig ¶
func (c *NodeHostConfig) GetServerTLSConfig() (*tls.Config, error)
GetServerTLSConfig returns the server tls.Config instance based on the TLS settings in NodeHostConfig.
func (*NodeHostConfig) MasterMode ¶
func (c *NodeHostConfig) MasterMode() bool
MasterMode returns a boolean value indicating whether the NodeHost is set to run in Master mode.
func (*NodeHostConfig) Validate ¶
func (c *NodeHostConfig) Validate() error
Validate validates the NodeHostConfig instance and return an error when the configuration is considered as invalid.
type RaftRPCFactoryFunc ¶
type RaftRPCFactoryFunc func(NodeHostConfig, raftio.RequestHandler, raftio.ChunkSinkFactory) raftio.IRaftRPC
RaftRPCFactoryFunc is the factory function that creates the Raft RPC module instance for exchanging Raft messages between NodeHosts.
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