haproxy/include/types/server.h

/*
  include/types/server.h
  This file defines everything related to servers.

  Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation, version 2.1
  exclusively.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef _TYPES_SERVER_H
#define _TYPES_SERVER_H

#include <netinet/in.h>
#include <arpa/inet.h>

#include <common/config.h>
#include <common/eb32tree.h>
#include <common/mini-clist.h>

#include <types/buffers.h>
#include <types/proxy.h>
#include <types/queue.h>
#include <types/task.h>


/* server flags */
#define SRV_RUNNING	0x0001	/* the server is UP */
#define SRV_BACKUP	0x0002	/* this server is a backup server */
#define SRV_MAPPORTS	0x0004	/* this server uses mapped ports */
#define SRV_BIND_SRC	0x0008	/* this server uses a specific source address */
#define SRV_CHECKED	0x0010	/* this server needs to be checked */
#define SRV_GOINGDOWN	0x0020	/* this server says that it's going down (404) */
#define SRV_WARMINGUP	0x0040	/* this server is warming up after a failure */
/* unused: 0x0080 */
#define SRV_TPROXY_ADDR	0x0100	/* bind to this non-local address to reach this server */
#define SRV_TPROXY_CIP	0x0200	/* bind to the client's IP address to reach this server */
#define SRV_TPROXY_CLI	0x0300	/* bind to the client's IP+port to reach this server */
#define SRV_TPROXY_MASK	0x0300	/* bind to a non-local address to reach this server */

/* function which act on servers need to return various errors */
#define SRV_STATUS_OK       0   /* everything is OK. */
#define SRV_STATUS_INTERNAL 1   /* other unrecoverable errors. */
#define SRV_STATUS_NOSRV    2   /* no server is available */
#define SRV_STATUS_FULL     3   /* the/all server(s) are saturated */
#define SRV_STATUS_QUEUED   4   /* the/all server(s) are saturated but the connection was queued */

/* bits for s->result used for health-checks */
#define SRV_CHK_UNKNOWN 0x0000   /* initialized to this by default */
#define SRV_CHK_ERROR   0x0001   /* error encountered during the check; has precedence */
#define SRV_CHK_RUNNING 0x0002   /* server seen as running */
#define SRV_CHK_DISABLE 0x0004   /* server returned a "disable" code */

/* various constants */
#define SRV_UWGHT_RANGE 256
#define SRV_UWGHT_MAX   (SRV_UWGHT_RANGE - 1)
#define SRV_EWGHT_RANGE (SRV_UWGHT_RANGE * BE_WEIGHT_SCALE)
#define SRV_EWGHT_MAX   (SRV_UWGHT_MAX   * BE_WEIGHT_SCALE)

struct server {
	struct server *next;
	int state;				/* server state (SRV_*) */
	int prev_state;				/* server state before last change (SRV_*) */
	int  cklen;				/* the len of the cookie, to speed up checks */
	int rdr_len;				/* the length of the redirection prefix */
	char *cookie;				/* the id set in the cookie */
	char *rdr_pfx;				/* the redirection prefix */

	struct proxy *proxy;			/* the proxy this server belongs to */
	int served;				/* # of active sessions currently being served (ie not pending) */
	int cur_sess, cur_sess_max;		/* number of currently active sessions (including syn_sent) */
	unsigned maxconn, minconn;		/* max # of active sessions (0 = unlimited), min# for dynamic limit. */
	int nbpend, nbpend_max;			/* number of pending connections */
	int maxqueue;				/* maximum number of pending connections allowed */
	struct list pendconns;			/* pending connections */
	struct task *check;                     /* the task associated to the health check processing */

	struct sockaddr_in addr;		/* the address to connect to */
	struct sockaddr_in source_addr;		/* the address to which we want to bind for connect() */
#if defined(CONFIG_HAP_CTTPROXY) || defined(CONFIG_HAP_LINUX_TPROXY)
	struct sockaddr_in tproxy_addr;		/* non-local address we want to bind to for connect() */
#endif

	struct server *tracknext, *tracked;	/* next server in a tracking list, tracked server */
	char *trackit;				/* temporary variable to make assignment deferrable */
	struct sockaddr_in check_addr;		/* the address to check, if different from <addr> */
	short check_port;			/* the port to use for the health checks */
	int health;				/* 0->rise-1 = bad; rise->rise+fall-1 = good */
	int rise, fall;				/* time in iterations */
	int inter, fastinter, downinter;	/* checks: time in milliseconds */
	int slowstart;				/* slowstart time in seconds (ms in the conf) */
	int result;				/* health-check result : SRV_CHK_* */
	int curfd;				/* file desc used for current test, or -1 if not in test */

	char *id;				/* just for identification */
	unsigned uweight, eweight;		/* user-specified weight, and effective weight */
	unsigned wscore;			/* weight score, used during srv map computation */
	unsigned prev_eweight;			/* eweight before last change */
	unsigned rweight;			/* remainer of weight in the current LB tree */
	unsigned npos, lpos;			/* next and last positions in the LB tree */
	struct eb32_node lb_node;               /* node used for tree-based load balancing */
	struct eb_root *lb_tree;                /* we want to know in what tree the server is */
	struct server *next_full;               /* next server in the temporary full list */

	unsigned failed_checks, down_trans;	/* failed checks and up-down transitions */
	unsigned down_time;			/* total time the server was down */
	time_t last_change;			/* last time, when the state was changed */

	unsigned failed_conns, failed_resp;	/* failed connect() and responses */
	unsigned retries, redispatches;		/* retried and redispatched connections */
	unsigned failed_secu;			/* blocked responses because of security concerns */
	unsigned cum_sess;			/* cumulated number of sessions really sent to this server */
	unsigned cum_lbconn;			/* cumulated number of sessions directed by load balancing */

	long long bytes_in;			/* number of bytes transferred from the client to the server */
	long long bytes_out;			/* number of bytes transferred from the server to the client */
	int puid;				/* proxy-unique server ID, used for SNMP */
};


#endif /* _TYPES_SERVER_H */

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */