org.corfudb.infrastructure

Class SequencerServer

java.lang.Object

org.corfudb.infrastructure.AbstractServer

org.corfudb.infrastructure.SequencerServer

public class SequencerServer
extends AbstractServer

This server implements the sequencer functionality of Corfu.

It currently supports a single operation, which is a incoming request:

TOKEN_REQ - Request the next address.

The sequencer server maintains the current tail of the log, the current tail of every stream, and a cache of timestamps of updates on recent conflict-parameters.

A token request can be of several sub-types, which are defined in TokenRequest:

TokenRequest::TK_QUERY - used for only querying the current tail of the log and/or the tails of specific streams

TokenRequest::TK_RAW - reserved for getting a "raw" token in the global log

TokenRequest::TK_MULTI_STREAM - used for logging across one or more streams

TokenRequest::TK_TX - used for reserving an address for transaction commit.

The transaction commit is the most sophisticated functaionality of the sequencer. The sequencer reserves an address for the transaction only on if it knows that it can commit.

The TK_TX request contains a conflict-set and a write-set. The sequencer checks the conflict-set against the stream-tails and against the conflict-parameters timestamp cache it maintains. If the transaction commits, the sequencer updates the tails of all the streams and the cache of conflict parameters.

Created by mwei on 12/8/15.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SequencerServer.Config Sequencer server configuration

Nested classes/interfaces inherited from class org.corfudb.infrastructure.AbstractServer

AbstractServer.ServerState

Constructor Summary

Constructors

Constructor and Description
SequencerServer(ServerContext serverContext) Returns a new SequencerServer.

Method Summary

Modifier and Type	Method and Description
ExecutorService	getExecutor()
void	handleMetricsRequest(CorfuMsg msg, io.netty.channel.ChannelHandlerContext ctx, IServerRouter r) Service an incoming metrics request with the metrics response.
boolean	isServerReadyToHandleMsg(CorfuMsg msg)
void	resetServer(CorfuPayloadMsg<SequencerRecoveryMsg> msg, io.netty.channel.ChannelHandlerContext ctx, IServerRouter r) Service an incoming request to reset the sequencer.
void	shutdown() Shutdown the server.
void	tokenRequest(CorfuPayloadMsg<TokenRequest> msg, io.netty.channel.ChannelHandlerContext ctx, IServerRouter r) Service an incoming token request.
void	trimCache(CorfuPayloadMsg<Long> msg, io.netty.channel.ChannelHandlerContext ctx, IServerRouter r)

Methods inherited from class org.corfudb.infrastructure.AbstractServer

getHandler, getState, handleMessage, sealServerWithEpoch, setState

Methods inherited from class java.lang.Object

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

Constructor Detail

SequencerServer

public SequencerServer(ServerContext serverContext)

Returns a new SequencerServer.

Parameters:

serverContext - context object providing parameters and objects

Method Detail

isServerReadyToHandleMsg

public boolean isServerReadyToHandleMsg(CorfuMsg msg)

Specified by:

isServerReadyToHandleMsg in class AbstractServer

getExecutor

public ExecutorService getExecutor()

Specified by:

getExecutor in class AbstractServer

trimCache

public void trimCache(CorfuPayloadMsg<Long> msg,
                      io.netty.channel.ChannelHandlerContext ctx,
                      IServerRouter r)

resetServer

public void resetServer(CorfuPayloadMsg<SequencerRecoveryMsg> msg,
                        io.netty.channel.ChannelHandlerContext ctx,
                        IServerRouter r)

Service an incoming request to reset the sequencer.

handleMetricsRequest

public void handleMetricsRequest(CorfuMsg msg,
                                 io.netty.channel.ChannelHandlerContext ctx,
                                 IServerRouter r)

Service an incoming metrics request with the metrics response.

tokenRequest

public void tokenRequest(CorfuPayloadMsg<TokenRequest> msg,
                         io.netty.channel.ChannelHandlerContext ctx,
                         IServerRouter r)

Service an incoming token request.

shutdown

public void shutdown()

Description copied from class: AbstractServer

Shutdown the server.

Overrides:

shutdown in class AbstractServer