org.apache.cassandra.service
Class DatacenterReadCallback<TMessage,TResolved>

java.lang.Object
  org.apache.cassandra.service.ReadCallback<TMessage,TResolved>
      org.apache.cassandra.service.DatacenterReadCallback<TMessage,TResolved>

All Implemented Interfaces:

IAsyncCallback<TMessage>, IMessageCallback

public class DatacenterReadCallback<TMessage,TResolved>
extends ReadCallback<TMessage,TResolved>

Datacenter Quorum response handler blocks for a quorum of responses from the local DC

Field Summary

Fields inherited from class org.apache.cassandra.service.ReadCallback

blockfor, condition, consistencyLevel, localdc, logger, received, resolver, snitch

Constructor Summary

DatacenterReadCallback(IResponseResolver resolver, ConsistencyLevel consistencyLevel, IReadCommand command, java.util.List<java.net.InetAddress> endpoints)

Method Summary

void	assureSufficientLiveNodes()
protected void	sortForConsistencyLevel(java.util.List<java.net.InetAddress> endpoints) Endpoints is already restricted to live replicas, sorted by snitch preference.
protected boolean	waitingFor(MessageIn message)

Methods inherited from class org.apache.cassandra.service.ReadCallback

get, isLatencyForSnitch, maybeResolveForRepair, response, response

Methods inherited from class java.lang.Object

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

Constructor Detail

DatacenterReadCallback

public DatacenterReadCallback(IResponseResolver resolver,
                              ConsistencyLevel consistencyLevel,
                              IReadCommand command,
                              java.util.List<java.net.InetAddress> endpoints)

Method Detail

sortForConsistencyLevel

protected void sortForConsistencyLevel(java.util.List<java.net.InetAddress> endpoints)

Description copied from class: ReadCallback

Endpoints is already restricted to live replicas, sorted by snitch preference. This is a hook for DatacenterReadCallback to move local-DC replicas to the front of the list. We need this both when doing read repair (because the first replica gets the data read) and otherwise (because only the first 1..blockfor replicas will get digest reads).

Overrides:

sortForConsistencyLevel in class ReadCallback<TMessage,TResolved>

waitingFor

protected boolean waitingFor(MessageIn message)

Overrides:

waitingFor in class ReadCallback<TMessage,TResolved>

Returns:

true if the message counts towards the blockfor threshold

assureSufficientLiveNodes

public void assureSufficientLiveNodes()
                               throws UnavailableException

Overrides:

assureSufficientLiveNodes in class ReadCallback<TMessage,TResolved>

Throws:

UnavailableException