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scylladb/gms/i_failure_detector.hh
2015-05-14 17:01:18 +08:00

92 lines
3.1 KiB
C++

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Modified by Cloudius Systems.
* Copyright 2015 Cloudius Systems.
*/
#pragma once
#include "gms/inet_address.hh"
#include "gms/i_failure_detection_event_listener.hh"
namespace gms {
/**
* An interface that provides an application with the ability
* to query liveness information of a node in the cluster. It
* also exposes methods which help an application register callbacks
* for notifications of liveness information of nodes.
*/
class i_failure_detector {
public:
virtual ~i_failure_detector() {}
/**
* Failure Detector's knowledge of whether a node is up or
* down.
*
* @param ep endpoint in question.
* @return true if UP and false if DOWN.
*/
virtual bool is_alive(inet_address ep) = 0;
/**
* This method is invoked by any entity wanting to interrogate the status of an endpoint.
* In our case it would be the Gossiper. The Failure Detector will then calculate Phi and
* deem an endpoint as suspicious or alive as explained in the Hayashibara paper.
* <p/>
* param ep endpoint for which we interpret the inter arrival times.
*/
virtual void interpret(inet_address ep) = 0;
/**
* This method is invoked by the receiver of the heartbeat. In our case it would be
* the Gossiper. Gossiper inform the Failure Detector on receipt of a heartbeat. The
* FailureDetector will then sample the arrival time as explained in the paper.
* <p/>
* param ep endpoint being reported.
*/
virtual void report(inet_address ep) = 0;
/**
* remove endpoint from failure detector
*/
virtual void remove(inet_address ep) = 0;
/**
* force conviction of endpoint in the failure detector
*/
virtual void force_conviction(inet_address ep) = 0;
/**
* Register interest for Failure Detector events.
*
* @param listener implementation of an application provided IFailureDetectionEventListener
*/
virtual void register_failure_detection_event_listener(i_failure_detection_event_listener* listener) = 0;
/**
* Un-register interest for Failure Detector events.
*
* @param listener implementation of an application provided IFailureDetectionEventListener
*/
virtual void unregister_failure_detection_event_listener(i_failure_detection_event_listener* listener) = 0;
};
} // namespace gms