Package io.microraft.transport

Interface Transport

public interface Transport

Used for communicating Raft nodes with each other.

Transport implementations must be non-blocking. A Raft node must be able to send a Raft message to another Raft node and continue without blocking. This is required because Raft nodes run concurrently with the Actor model.

Transport implementations must be able to serialize RaftMessage objects created by RaftModelFactory.

A Transport implementation can implement RaftNodeLifecycleAware to perform initialization and clean up work during RaftNode startup and termination. RaftNode calls RaftNodeLifecycleAware.onRaftNodeStart() before calling any other method on Transport, and finally calls RaftNodeLifecycleAware.onRaftNodeTerminate() on termination.

See Also:

RaftModel, RaftMessage, RaftModelFactory, RaftNode, RaftNodeExecutor, RaftNodeLifecycleAware

Method Summary

Modifier and Type	Method	Description
boolean	isReachable(RaftEndpoint endpoint)	Returns true if the given endpoint is supposedly reachable by the time this method is called, false otherwise.
void	send(RaftEndpoint target, RaftMessage message)	Sends the given RaftMessage object to the given endpoint.

Method Detail

send

void send(@Nonnull
          RaftEndpoint target,
          @Nonnull
          RaftMessage message)

Sends the given RaftMessage object to the given endpoint. This method must not block the caller Raft node instance and return promptly so that the caller can continue its execution.

This method must not throw an exception, for example if the given RaftMessage object has not been sent to the given endpoint or an internal error has occurred. The handling of RaftMessage objects are designed idempotently. Therefore, if a RaftMessage object is not sent to the given endpoint, it implies that the source Raft node will not receive a RaftMessage as response, hence it will re-send the failed RaftMessage again.

Parameters:

target - the target endpoint to send the Raft message

message - the Raft message object to be sent

isReachable

boolean isReachable(@Nonnull
                    RaftEndpoint endpoint)

Returns true if the given endpoint is supposedly reachable by the time this method is called, false otherwise.

This method is not required to return a precise information. For instance, the Transport implementation does not need to ping the given endpoint to check if it is reachable when this method is called. Instead, the local Raft node could use a local information, such as recency of a message sent by or having a TCP connection to the given Raft endpoint.

Parameters:

endpoint - the Raft endpoint to check reachability

Returns:

true if given endpoint is reachable, false otherwise