voldemort.store.slop
Class HintedHandoff

java.lang.Object
  voldemort.store.slop.HintedHandoff

public class HintedHandoff
extends java.lang.Object

Hinted handoff: if, when processing a pipeline for a given request, failures shall occur on specific nodes, the requests for these failed nodes should be queued up on other, currently available nodes. Semantics of the operation should not change i.e., if required-writes are not met, the request should still be considered a failure.

Constructor Summary

HintedHandoff(FailureDetector failureDetector, java.util.Map<java.lang.Integer,Store<ByteArray,Slop,byte[]>> slopStores, java.util.Map<java.lang.Integer,NonblockingStore> nonblockingSlopStores, HintedHandoffStrategy handoffStrategy, java.util.List<Node> failedNodes, long timeoutMs)
Create a Hinted Handoff object

Method Summary

void	sendHintParallel(Node failedNode, Version version, Slop slop) Like sendHintSerial(voldemort.cluster.Node, voldemort.versioning.Version, Slop) , but doesn't block the pipeline.
boolean	sendHintSerial(Node failedNode, Version version, Slop slop) Send a hint of a request originally meant for the failed node to another node in the ring, as selected by the HintedHandoffStrategy implementation passed in the constructor

Methods inherited from class java.lang.Object

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

Constructor Detail

HintedHandoff

public HintedHandoff(FailureDetector failureDetector,
                     java.util.Map<java.lang.Integer,Store<ByteArray,Slop,byte[]>> slopStores,
                     java.util.Map<java.lang.Integer,NonblockingStore> nonblockingSlopStores,
                     HintedHandoffStrategy handoffStrategy,
                     java.util.List<Node> failedNodes,
                     long timeoutMs)

Create a Hinted Handoff object

Parameters:

failureDetector - The failure detector

nonblockingSlopStores - A map of node ids to nonb-locking slop stores

slopStores - A map of node ids to blocking slop stores

handoffStrategy - The HintedHandoffStrategy implementation

failedNodes - A list of nodes in the original preflist for the request that have failed or are unavailable

timeoutMs - Timeout for slop stores

Method Detail

sendHintParallel

public void sendHintParallel(Node failedNode,
                             Version version,
                             Slop slop)

Like sendHintSerial(voldemort.cluster.Node, voldemort.versioning.Version, Slop) , but doesn't block the pipeline. Intended for handling prolonged failures without incurring a performance cost.

See Also:

sendHintSerial(voldemort.cluster.Node, voldemort.versioning.Version, Slop)

sendHintSerial

public boolean sendHintSerial(Node failedNode,
                              Version version,
                              Slop slop)

Send a hint of a request originally meant for the failed node to another node in the ring, as selected by the HintedHandoffStrategy implementation passed in the constructor

Parameters:

failedNode - The node the request was originally meant for

version - The version of the request's object

slop - The hint

Returns:

True if persisted on another node, false otherwise