/* * 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 #include #include #include #include #include #include #include /* 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: */