roundrobin.h

/*
 * roundrobin.h
 *
 *  Created on: 2016年5月6日
 *      Author: xie
 */

#ifndef PLUGINS_EXPERIMENTAL_BALANCER_ROUNDROBIN_H_
#define PLUGINS_EXPERIMENTAL_BALANCER_ROUNDROBIN_H_

#include <stdlib.h>
#include <string.h>
#include <map>
#include <string>
#include <vector>
#include "balancer.h"



#define MAX_FAIL_TIME  30
#define FAIL_STATUS 500
#define OS_SINGLE 1

class RoundRobinBalancer {

public:
	RoundRobinBalancer();
	~RoundRobinBalancer();

	void hold() {
	   ink_atomic_increment(&_ref_count, 1);
//	   TSDebug(PLUGIN_NAME,"----------hold  _ref_count---------------%d",_ref_count);
	}

	void release() {
	   if (1 >= ink_atomic_decrement(&_ref_count, 1)) {
//		   TSDebug(PLUGIN_NAME,"----------release  _ref_count---------------%d",_ref_count);
		   delete this;
	   }

	}

	void push_target(BalancerTarget *target);

	//获取一个后端
	BalancerTarget *balance(bool follow_https);

	//清除peer 的fails 和 timeout_fails状态
	void clean_peer_status();

	//首先给down状态下的服务器一次机会 now - check >= fail_timeout * timeout_fails
	//如果主还有存活的，就不用考虑down状态下冷却超时的备用，只有当主都不存活，才考虑
	BalancerTarget *get_down_timeout_peer(time_t now);

	//获取最优的target 此处参考nginx rr 算法
	BalancerTarget *get_healthy_peer(std::vector<BalancerTarget *> &targets, time_t now);

	//更改后端状态,后端返回5xx，就认为失败
	TSReturnCode os_response_back_status(uint target_id, TSHttpStatus status);

	BalancerTarget * MakeBalancerTarget(const char *strval);

	void set_path(char *path) {
		this->path = path;
	}

	char *get_path() const {
		return this->path;
	}

	void set_backend_tag(bool is_need, bool is_need_health_check, bool is_follow_model) {
		this->need_https_backend = is_need;
		this->need_health_check = is_need_health_check;
		this->follow_model = is_follow_model;
	}

	bool get_https_backend_tag() {
		return this->need_https_backend;
	}

	bool get_health_check_tag() {
		return this->need_health_check;
	}

	bool is_need_follow_model() {
		return this->follow_model;
	}

private:
	std::vector<BalancerTarget *> targets_s; //主线路   如果是follow模式  为http源

	std::vector<BalancerTarget *> targets_b; //备用线路 如果是follow模式  为https源
	uint peersS_number;
	uint peersB_number;
	unsigned next;
	char *path;
	bool need_https_backend;
	bool need_health_check;
	bool follow_model;
	volatile int _ref_count;
};



#endif /* PLUGINS_EXPERIMENTAL_BALANCER_ROUNDROBIN_H_ */