include/proto/server.h

/*
 * include/proto/server.h
 * This file defines everything related to servers.
 *
 * Copyright (C) 2000-2009 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 _PROTO_SERVER_H
#define _PROTO_SERVER_H

#include <unistd.h>

#include <common/config.h>
#include <common/time.h>
#include <types/dns.h>
#include <types/proxy.h>
#include <types/queue.h>
#include <types/server.h>

#include <proto/queue.h>
#include <proto/log.h>
#include <proto/freq_ctr.h>

int srv_downtime(const struct server *s);
int srv_lastsession(const struct server *s);
int srv_getinter(const struct check *check);
int parse_server(const char *file, int linenum, char **args, struct proxy *curproxy, struct proxy *defproxy);
int update_server_addr(struct server *s, void *ip, int ip_sin_family, char *updater);
struct server *server_find_by_id(struct proxy *bk, int id);
struct server *server_find_by_name(struct proxy *bk, const char *name);
struct server *server_find_best_match(struct proxy *bk, char *name, int id, int *diff);

/* functions related to server name resolution */
int snr_update_srv_status(struct server *s);
int snr_resolution_cb(struct dns_resolution *resolution, struct dns_nameserver *nameserver, unsigned char *response, int response_len);
int snr_resolution_error_cb(struct dns_resolution *resolution, int error_code);

/* increase the number of cumulated connections on the designated server */
static void inline srv_inc_sess_ctr(struct server *s)
{
	s->counters.cum_sess++;
	update_freq_ctr(&s->sess_per_sec, 1);
	if (s->sess_per_sec.curr_ctr > s->counters.sps_max)
		s->counters.sps_max = s->sess_per_sec.curr_ctr;
}

/* set the time of last session on the designated server */
static void inline srv_set_sess_last(struct server *s)
{
	s->counters.last_sess = now.tv_sec;
}

/*
 * Registers the server keyword list <kwl> as a list of valid keywords for next
 * parsing sessions.
 */
void srv_register_keywords(struct srv_kw_list *kwl);

/* Return a pointer to the server keyword <kw>, or NULL if not found. */
struct srv_kw *srv_find_kw(const char *kw);

/* Dumps all registered "server" keywords to the <out> string pointer. */
void srv_dump_kws(char **out);

/* Recomputes the server's eweight based on its state, uweight, the current time,
 * and the proxy's algorihtm. To be used after updating sv->uweight. The warmup
 * state is automatically disabled if the time is elapsed.
 */
void server_recalc_eweight(struct server *sv);

/* returns the current server throttle rate between 0 and 100% */
static inline unsigned int server_throttle_rate(struct server *sv)
{
	struct proxy *px = sv->proxy;

	/* when uweight is 0, we're in soft-stop so that cannot be a slowstart,
	 * thus the throttle is 100%.
	 */
	if (!sv->uweight)
		return 100;

	return (100U * px->lbprm.wmult * sv->eweight + px->lbprm.wdiv - 1) / (px->lbprm.wdiv * sv->uweight);
}

/*
 * Parses weight_str and configures sv accordingly.
 * Returns NULL on success, error message string otherwise.
 */
const char *server_parse_weight_change_request(struct server *sv,
					       const char *weight_str);

/*
 * Parses addr_str and configures sv accordingly.
 * Returns NULL on success, error message string otherwise.
 */
const char *server_parse_addr_change_request(struct server *sv,
                                             const char *addr_str);

/*
 * Return true if the server has a zero user-weight, meaning it's in draining
 * mode (ie: not taking new non-persistent connections).
 */
static inline int server_is_draining(const struct server *s)
{
	return !s->uweight || (s->admin & SRV_ADMF_DRAIN);
}

/* Shutdown all connections of a server. The caller must pass a termination
 * code in <why>, which must be one of SF_ERR_* indicating the reason for the
 * shutdown.
 */
void srv_shutdown_sessions(struct server *srv, int why);

/* Shutdown all connections of all backup servers of a proxy. The caller must
 * pass a termination code in <why>, which must be one of SF_ERR_* indicating
 * the reason for the shutdown.
 */
void srv_shutdown_backup_sessions(struct proxy *px, int why);

/* Appends some information to a message string related to a server going UP or
 * DOWN.  If both <forced> and <reason> are null and the server tracks another
 * one, a "via" information will be provided to know where the status came from.
 * If <reason> is non-null, the entire string will be appended after a comma and
 * a space (eg: to report some information from the check that changed the state).
 * If <xferred> is non-negative, some information about requeued sessions are
 * provided.
 */
void srv_append_status(struct chunk *msg, struct server *s, const char *reason, int xferred, int forced);

/* Marks server <s> down, regardless of its checks' statuses, notifies by all
 * available means, recounts the remaining servers on the proxy and transfers
 * queued sessions whenever possible to other servers. It automatically
 * recomputes the number of servers, but not the map. Maintenance servers are
 * ignored. It reports <reason> if non-null as the reason for going down. Note
 * that it makes use of the trash to build the log strings, so <reason> must
 * not be placed there.
 */
void srv_set_stopped(struct server *s, const char *reason);

/* Marks server <s> up regardless of its checks' statuses and provided it isn't
 * in maintenance. Notifies by all available means, recounts the remaining
 * servers on the proxy and tries to grab requests from the proxy. It
 * automatically recomputes the number of servers, but not the map. Maintenance
 * servers are ignored. It reports <reason> if non-null as the reason for going
 * up. Note that it makes use of the trash to build the log strings, so <reason>
 * must not be placed there.
 */
void srv_set_running(struct server *s, const char *reason);

/* Marks server <s> stopping regardless of its checks' statuses and provided it
 * isn't in maintenance. Notifies by all available means, recounts the remaining
 * servers on the proxy and tries to grab requests from the proxy. It
 * automatically recomputes the number of servers, but not the map. Maintenance
 * servers are ignored. It reports <reason> if non-null as the reason for going
 * up. Note that it makes use of the trash to build the log strings, so <reason>
 * must not be placed there.
 */
void srv_set_stopping(struct server *s, const char *reason);

/* Enables admin flag <mode> (among SRV_ADMF_*) on server <s>. This is used to
 * enforce either maint mode or drain mode. It is not allowed to set more than
 * one flag at once. The equivalent "inherited" flag is propagated to all
 * tracking servers. Maintenance mode disables health checks (but not agent
 * checks). When either the flag is already set or no flag is passed, nothing
 * is done.
 */
void srv_set_admin_flag(struct server *s, enum srv_admin mode);

/* Disables admin flag <mode> (among SRV_ADMF_*) on server <s>. This is used to
 * stop enforcing either maint mode or drain mode. It is not allowed to set more
 * than one flag at once. The equivalent "inherited" flag is propagated to all
 * tracking servers. Leaving maintenance mode re-enables health checks. When
 * either the flag is already cleared or no flag is passed, nothing is done.
 */
void srv_clr_admin_flag(struct server *s, enum srv_admin mode);

/* Puts server <s> into maintenance mode, and propagate that status down to all
 * tracking servers.
 */
static inline void srv_adm_set_maint(struct server *s)
{
	srv_set_admin_flag(s, SRV_ADMF_FMAINT);
	srv_clr_admin_flag(s, SRV_ADMF_FDRAIN);
}

/* Puts server <s> into drain mode, and propagate that status down to all
 * tracking servers.
 */
static inline void srv_adm_set_drain(struct server *s)
{
	srv_set_admin_flag(s, SRV_ADMF_FDRAIN);
	srv_clr_admin_flag(s, SRV_ADMF_FMAINT);
}

/* Puts server <s> into ready mode, and propagate that status down to all
 * tracking servers.
 */
static inline void srv_adm_set_ready(struct server *s)
{
	srv_clr_admin_flag(s, SRV_ADMF_FDRAIN);
	srv_clr_admin_flag(s, SRV_ADMF_FMAINT);
}

#endif /* _PROTO_SERVER_H */

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