org.apache.zookeeper.server.quorum
Class Leader

java.lang.Object
  org.apache.zookeeper.server.quorum.Leader

public class Leader
extends Object

This class has the control logic for the Leader.

Nested Class Summary

static class

Leader.Proposal

Field Summary

HashSet<FollowerHandler>	followers
HashSet<FollowerHandler>	forwardingFollowers
HashMap<Long,List<FollowerSyncRequest>>	pendingSyncs
static int	PROPOSAL This message type is sent by a leader to propose a mutation.

Method Summary

void	commit(long zxid) Create a commit packet and send it to all the members of the quorum
void	processAck(long sid, long zxid, SocketAddress followerAddr) Keep a count of acks that are received by the leader for a particular proposal
void	processSync(FollowerSyncRequest r) Process sync requests
Leader.Proposal	propose(Request request) create a proposal and send it out to all the members
void	sendSync(FollowerSyncRequest r) Sends a sync message to the appropriate server
long	startForwarding(FollowerHandler handler, long lastSeenZxid) lets the leader know that a follower is capable of following and is done syncing

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

followers

public HashSet<FollowerHandler> followers

forwardingFollowers

public HashSet<FollowerHandler> forwardingFollowers

pendingSyncs

public HashMap<Long,List<FollowerSyncRequest>> pendingSyncs

PROPOSAL

public static final int PROPOSAL

This message type is sent by a leader to propose a mutation.

See Also:

Constant Field Values

Method Detail

processAck

public void processAck(long sid,
                       long zxid,
                       SocketAddress followerAddr)

Keep a count of acks that are received by the leader for a particular proposal

Parameters:

zxid - the zxid of the proposal sent out

followerAddr -

commit

public void commit(long zxid)

Create a commit packet and send it to all the members of the quorum

Parameters:

zxid -

propose

public Leader.Proposal propose(Request request)

create a proposal and send it out to all the members

Parameters:

request -

Returns:

the proposal that is queued to send to all the members

processSync

public void processSync(FollowerSyncRequest r)

Process sync requests

Parameters:

r - the request

sendSync

public void sendSync(FollowerSyncRequest r)

Sends a sync message to the appropriate server

Parameters:

f -

r -

startForwarding

public long startForwarding(FollowerHandler handler,
                            long lastSeenZxid)

lets the leader know that a follower is capable of following and is done syncing

Parameters:

handler - handler of the follower

Returns:

last proposed zxid