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/*
* include/haproxy/backend-t.h
* This file assembles definitions for backends
*
* 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 _HAPROXY_BACKEND_T_H
#define _HAPROXY_BACKEND_T_H
#include <haproxy/api-t.h>
#include <haproxy/lb_chash-t.h>
#include <haproxy/lb_fas-t.h>
#include <haproxy/lb_fwlc-t.h>
#include <haproxy/lb_fwrr-t.h>
#include <haproxy/lb_map-t.h>
#include <haproxy/server-t.h>
#include <haproxy/thread-t.h>
/* Parameters for lbprm.algo */
/* Lower bits define the kind of load balancing method, which means the type of
* algorithm, and which criterion it is based on. For this reason, those bits
* also include information about dependencies, so that the config parser can
* detect incompatibilities.
*/
/* LB parameters are on the lower 8 bits. Depends on the LB kind. */
/* BE_LB_HASH_* is used with BE_LB_KIND_HI */
#define BE_LB_HASH_SRC 0x00000000 /* hash source IP */
#define BE_LB_HASH_URI 0x00000001 /* hash HTTP URI */
#define BE_LB_HASH_PRM 0x00000002 /* hash HTTP URL parameter */
#define BE_LB_HASH_HDR 0x00000003 /* hash HTTP header value */
#define BE_LB_HASH_RDP 0x00000004 /* hash RDP cookie value */
#define BE_LB_HASH_SMP 0x00000005 /* hash a sample expression */
/* BE_LB_RR_* is used with BE_LB_KIND_RR */
#define BE_LB_RR_DYN 0x00000000 /* dynamic round robin (default) */
#define BE_LB_RR_STATIC 0x00000001 /* static round robin */
#define BE_LB_RR_RANDOM 0x00000002 /* random round robin */
/* BE_LB_CB_* is used with BE_LB_KIND_CB */
#define BE_LB_CB_LC 0x00000000 /* least-connections */
#define BE_LB_CB_FAS 0x00000001 /* first available server (opposite of leastconn) */
#define BE_LB_PARM 0x000000FF /* mask to get/clear the LB param */
/* Required input(s) */
#define BE_LB_NEED_NONE 0x00000000 /* no input needed */
#define BE_LB_NEED_ADDR 0x00000100 /* only source address needed */
#define BE_LB_NEED_DATA 0x00000200 /* some payload is needed */
#define BE_LB_NEED_HTTP 0x00000400 /* an HTTP request is needed */
#define BE_LB_NEED_LOG 0x00000800 /* LOG backend required */
#define BE_LB_NEED 0x0000FF00 /* mask to get/clear dependencies */
/* Algorithm */
#define BE_LB_KIND_NONE 0x00000000 /* algorithm not set */
#define BE_LB_KIND_RR 0x00010000 /* round-robin */
#define BE_LB_KIND_CB 0x00020000 /* connection-based */
#define BE_LB_KIND_HI 0x00030000 /* hash of input (see hash inputs above) */
#define BE_LB_KIND 0x00070000 /* mask to get/clear LB algorithm */
/* All known variants of load balancing algorithms. These can be cleared using
* the BE_LB_ALGO mask. For a check, using BE_LB_KIND is preferred.
*/
#define BE_LB_ALGO_NONE (BE_LB_KIND_NONE | BE_LB_NEED_NONE) /* not defined */
#define BE_LB_ALGO_RR (BE_LB_KIND_RR | BE_LB_NEED_NONE) /* round robin */
#define BE_LB_ALGO_RND (BE_LB_KIND_RR | BE_LB_NEED_NONE | BE_LB_RR_RANDOM) /* random value */
#define BE_LB_ALGO_LC (BE_LB_KIND_CB | BE_LB_NEED_NONE | BE_LB_CB_LC) /* least connections */
#define BE_LB_ALGO_FAS (BE_LB_KIND_CB | BE_LB_NEED_NONE | BE_LB_CB_FAS) /* first available server */
#define BE_LB_ALGO_SRR (BE_LB_KIND_RR | BE_LB_NEED_NONE | BE_LB_RR_STATIC) /* static round robin */
#define BE_LB_ALGO_SH (BE_LB_KIND_HI | BE_LB_NEED_ADDR | BE_LB_HASH_SRC) /* hash: source IP */
#define BE_LB_ALGO_UH (BE_LB_KIND_HI | BE_LB_NEED_HTTP | BE_LB_HASH_URI) /* hash: HTTP URI */
#define BE_LB_ALGO_PH (BE_LB_KIND_HI | BE_LB_NEED_HTTP | BE_LB_HASH_PRM) /* hash: HTTP URL parameter */
#define BE_LB_ALGO_HH (BE_LB_KIND_HI | BE_LB_NEED_HTTP | BE_LB_HASH_HDR) /* hash: HTTP header value */
#define BE_LB_ALGO_RCH (BE_LB_KIND_HI | BE_LB_NEED_DATA | BE_LB_HASH_RDP) /* hash: RDP cookie value */
#define BE_LB_ALGO_SMP (BE_LB_KIND_HI | BE_LB_NEED_DATA | BE_LB_HASH_SMP) /* hash: sample expression */
#define BE_LB_ALGO_LH (BE_LB_KIND_HI | BE_LB_NEED_LOG | BE_LB_HASH_SMP) /* log hash: sample expression */
#define BE_LB_ALGO_LS (BE_LB_KIND_CB | BE_LB_NEED_LOG | BE_LB_CB_FAS) /* log sticky */
#define BE_LB_ALGO (BE_LB_KIND | BE_LB_NEED | BE_LB_PARM ) /* mask to clear algo */
/* Higher bits define how a given criterion is mapped to a server. In fact it
* designates the LB function by itself. The dynamic algorithms will also have
* the DYN bit set. These flags are automatically set at the end of the parsing.
*/
#define BE_LB_LKUP_NONE 0x00000000 /* not defined */
#define BE_LB_LKUP_MAP 0x00100000 /* static map based lookup */
#define BE_LB_LKUP_RRTREE 0x00200000 /* FWRR tree lookup */
#define BE_LB_LKUP_LCTREE 0x00300000 /* FWLC tree lookup */
#define BE_LB_LKUP_CHTREE 0x00400000 /* consistent hash */
#define BE_LB_LKUP_FSTREE 0x00500000 /* FAS tree lookup */
#define BE_LB_LKUP 0x00700000 /* mask to get just the LKUP value */
/* additional properties */
#define BE_LB_PROP_DYN 0x00800000 /* bit to indicate a dynamic algorithm */
/* hash types */
#define BE_LB_HASH_MAP 0x00000000 /* map-based hash (default) */
#define BE_LB_HASH_CONS 0x01000000 /* consistent hashbit to indicate a dynamic algorithm */
#define BE_LB_HASH_TYPE 0x01000000 /* get/clear hash types */
/* additional modifier on top of the hash function (only avalanche right now) */
#define BE_LB_HMOD_AVAL 0x02000000 /* avalanche modifier */
#define BE_LB_HASH_MOD 0x02000000 /* get/clear hash modifier */
/* BE_LB_HFCN_* is the hash function, to be used with BE_LB_HASH_FUNC */
#define BE_LB_HFCN_SDBM 0x00000000 /* sdbm hash */
#define BE_LB_HFCN_DJB2 0x04000000 /* djb2 hash */
#define BE_LB_HFCN_WT6 0x08000000 /* wt6 hash */
#define BE_LB_HFCN_CRC32 0x0C000000 /* crc32 hash */
#define BE_LB_HFCN_NONE 0x10000000 /* none - no hash */
#define BE_LB_HASH_FUNC 0x1C000000 /* get/clear hash function */
/* various constants */
/* The scale factor between user weight and effective weight allows smooth
* weight modulation even with small weights (eg: 1). It should not be too high
* though because it limits the number of servers in FWRR mode in order to
* prevent any integer overflow. The max number of servers per backend is
* limited to about (2^32-1)/256^2/scale ~= 65535.9999/scale. A scale of 16
* looks like a good value, as it allows 4095 servers per backend while leaving
* modulation steps of about 6% for servers with the lowest weight (1).
*/
#define BE_WEIGHT_SCALE 16
/* LB parameters for all algorithms */
struct lbprm {
union { /* LB parameters depending on the algo type */
struct lb_map map;
struct lb_fwrr fwrr;
struct lb_fwlc fwlc;
struct lb_chash chash;
struct lb_fas fas;
struct {
struct server **srv; /* array containing in-use log servers */
struct list avail; /* servers available for lb are registered in this list */
uint32_t lastid; /* last relative id used */
} log; /* used in log-balancing context (PR_MODE_SYSLOG backend) */
};
uint32_t algo; /* load balancing algorithm and variants: BE_LB_* */
int tot_wact, tot_wbck; /* total effective weights of active and backup servers */
int tot_weight; /* total effective weight of servers participating to LB */
int tot_uweight; /* total user weight of servers participating to LB (for reporting) */
int tot_used; /* total number of servers used for LB */
int wmult; /* ratio between user weight and effective weight */
int wdiv; /* ratio between effective weight and user weight */
int hash_balance_factor; /* load balancing factor * 100, 0 if disabled */
struct sample_expr *expr; /* sample expression for "balance hash" */
char *arg_str; /* name of the URL parameter/header/cookie used for hashing */
int arg_len; /* strlen(arg_str), computed only once */
int arg_opt1; /* extra option 1 for the LB algo (algo-specific) */
int arg_opt2; /* extra option 2 for the LB algo (algo-specific) */
int arg_opt3; /* extra option 3 for the LB algo (algo-specific) */
__decl_thread(HA_RWLOCK_T lock);
struct server *fbck; /* first backup server when !PR_O_USE_ALL_BK, or NULL */
/* Call backs for some actions. Any of them may be NULL (thus should be ignored).
* Those marked "srvlock" will need to be called with the server lock held.
* The other ones might take it themselves if needed.
*/
void (*update_server_eweight)(struct server *); /* to be called after eweight change // srvlock */
void (*set_server_status_up)(struct server *); /* to be called after status changes to UP // srvlock */
void (*set_server_status_down)(struct server *); /* to be called after status changes to DOWN // srvlock */
void (*server_take_conn)(struct server *); /* to be called when connection is assigned */
void (*server_drop_conn)(struct server *); /* to be called when connection is dropped */
};
#endif /* _HAPROXY_BACKEND_T_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/
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