haproxy/include/proto/backend.h
Willy Tarreau c5150dafd8 MINOR: server: use functions to detect state changes and to update them
Detecting that a server's status has changed is a bit messy, as well
as it is to commit the status changes. We'll have to add new conditions
soon and we'd better avoid to multiply the number of touched locations
with the high risk of forgetting them.

This commit introduces :
  - srv_lb_status_changed() to report if the status changed from the
    previously committed one ;
  - svr_lb_commit_status() to commit the current status

The function is now used by all load-balancing algorithms.
2014-05-13 22:18:22 +02:00

95 lines
2.8 KiB
C

/*
* include/proto/backend.h
* Functions prototypes for the backend.
*
* Copyright (C) 2000-2012 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_BACKEND_H
#define _PROTO_BACKEND_H
#include <common/config.h>
#include <common/time.h>
#include <types/backend.h>
#include <types/proxy.h>
#include <types/server.h>
#include <types/session.h>
int assign_server(struct session *s);
int assign_server_address(struct session *s);
int assign_server_and_queue(struct session *s);
int connect_server(struct session *s);
int srv_redispatch_connect(struct session *t);
const char *backend_lb_algo_str(int algo);
int backend_parse_balance(const char **args, char **err, struct proxy *curproxy);
int tcp_persist_rdp_cookie(struct session *s, struct channel *req, int an_bit);
int be_downtime(struct proxy *px);
void recount_servers(struct proxy *px);
void update_backend_weight(struct proxy *px);
struct server *get_server_sh(struct proxy *px, const char *addr, int len);
struct server *get_server_uh(struct proxy *px, char *uri, int uri_len);
int be_lastsession(const struct proxy *be);
/* set the time of last session on the backend */
static void inline be_set_sess_last(struct proxy *be)
{
be->be_counters.last_sess = now.tv_sec;
}
/* This function returns non-zero if a server with the given weight and state
* is usable for LB, otherwise zero.
*/
static inline int srv_is_usable(int state, int weight)
{
if (!weight)
return 0;
if (state & (SRV_GOINGDOWN | SRV_MAINTAIN))
return 0;
if (!(state & SRV_RUNNING))
return 0;
return 1;
}
/* This function commits the current server state and weight onto the previous
* ones in order to detect future changes.
*/
static inline void srv_lb_commit_status(struct server *srv)
{
srv->prev_state = srv->state;
srv->prev_eweight = srv->eweight;
}
/* This function returns true when a server has experienced a change since last
* commit on its state or weight, otherwise zero.
*/
static inline int srv_lb_status_changed(const struct server *srv)
{
return (srv->state != srv->prev_state ||
srv->eweight != srv->prev_eweight);
}
#endif /* _PROTO_BACKEND_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/