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3c6dfa618a
log load-balancing implementation was not seamlessly integrated within lbprm API. The consequence is that it could become harder to maintain over time since it added some specific cases just for the log backend. Moreover, it resulted in some code duplication since balance algorithms that are common to logs and regular (tcp, http) backends were specifically rewritten for log backends. Thanks to the previous commit, we now have all the prerequisites to make log load-balancing fully leverage lbprm logic. Thus in this patch we make __do_send_log_backend() use existing lbprm algorithms, and we no longer require log-specific lbprm initialization in cfgparse.c and in postcheck_log_backend(). As a bonus, for log backends this allows weighed algorithms to properly support weights (ie: roundrobin, random and log-hash) since we now leverage the same lb algorithms that we use for tcp/http backends (doc was updated).
193 lines
9.4 KiB
C
193 lines
9.4 KiB
C
/*
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* include/haproxy/backend-t.h
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* This file assembles definitions for backends
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*
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* Copyright (C) 2000-2012 Willy Tarreau - w@1wt.eu
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation, version 2.1
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* exclusively.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef _HAPROXY_BACKEND_T_H
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#define _HAPROXY_BACKEND_T_H
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#include <haproxy/api-t.h>
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#include <haproxy/lb_chash-t.h>
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#include <haproxy/lb_fas-t.h>
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#include <haproxy/lb_fwlc-t.h>
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#include <haproxy/lb_fwrr-t.h>
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#include <haproxy/lb_map-t.h>
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#include <haproxy/lb_ss-t.h>
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#include <haproxy/server-t.h>
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#include <haproxy/thread-t.h>
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/* Parameters for lbprm.algo */
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/* Lower bits define the kind of load balancing method, which means the type of
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* algorithm, and which criterion it is based on. For this reason, those bits
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* also include information about dependencies, so that the config parser can
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* detect incompatibilities.
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*/
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/* LB parameters are on the lower 8 bits. Depends on the LB kind. */
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/* BE_LB_HASH_* is used with BE_LB_KIND_HI */
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#define BE_LB_HASH_SRC 0x00000000 /* hash source IP */
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#define BE_LB_HASH_URI 0x00000001 /* hash HTTP URI */
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#define BE_LB_HASH_PRM 0x00000002 /* hash HTTP URL parameter */
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#define BE_LB_HASH_HDR 0x00000003 /* hash HTTP header value */
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#define BE_LB_HASH_RDP 0x00000004 /* hash RDP cookie value */
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#define BE_LB_HASH_SMP 0x00000005 /* hash a sample expression */
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/* BE_LB_RR_* is used with BE_LB_KIND_RR */
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#define BE_LB_RR_DYN 0x00000000 /* dynamic round robin (default) */
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#define BE_LB_RR_STATIC 0x00000001 /* static round robin */
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#define BE_LB_RR_RANDOM 0x00000002 /* random round robin */
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/* BE_LB_CB_* is used with BE_LB_KIND_CB */
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#define BE_LB_CB_LC 0x00000000 /* least-connections */
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#define BE_LB_CB_FAS 0x00000001 /* first available server (opposite of leastconn) */
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/* BE_LB_SA_* is used with BE_LB_KIND_SA */
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#define BE_LB_SA_SS 0x00000000 /* stick to server as long as it is available */
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#define BE_LB_PARM 0x000000FF /* mask to get/clear the LB param */
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/* Required input(s) */
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#define BE_LB_NEED_NONE 0x00000000 /* no input needed */
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#define BE_LB_NEED_ADDR 0x00000100 /* only source address needed */
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#define BE_LB_NEED_DATA 0x00000200 /* some payload is needed */
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#define BE_LB_NEED_HTTP 0x00000400 /* an HTTP request is needed */
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#define BE_LB_NEED_LOG 0x00000800 /* LOG backend required */
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#define BE_LB_NEED 0x0000FF00 /* mask to get/clear dependencies */
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/* Algorithm */
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#define BE_LB_KIND_NONE 0x00000000 /* algorithm not set */
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#define BE_LB_KIND_RR 0x00010000 /* round-robin */
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#define BE_LB_KIND_CB 0x00020000 /* connection-based */
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#define BE_LB_KIND_HI 0x00030000 /* hash of input (see hash inputs above) */
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#define BE_LB_KIND_SA 0x00040000 /* standalone (specific algorithms, cannot be grouped) */
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#define BE_LB_KIND 0x00070000 /* mask to get/clear LB algorithm */
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/* All known variants of load balancing algorithms. These can be cleared using
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* the BE_LB_ALGO mask. For a check, using BE_LB_KIND is preferred.
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*/
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#define BE_LB_ALGO_NONE (BE_LB_KIND_NONE | BE_LB_NEED_NONE) /* not defined */
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#define BE_LB_ALGO_RR (BE_LB_KIND_RR | BE_LB_NEED_NONE) /* round robin */
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#define BE_LB_ALGO_RND (BE_LB_KIND_RR | BE_LB_NEED_NONE | BE_LB_RR_RANDOM) /* random value */
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#define BE_LB_ALGO_LC (BE_LB_KIND_CB | BE_LB_NEED_NONE | BE_LB_CB_LC) /* least connections */
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#define BE_LB_ALGO_FAS (BE_LB_KIND_CB | BE_LB_NEED_NONE | BE_LB_CB_FAS) /* first available server */
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#define BE_LB_ALGO_SS (BE_LB_KIND_SA | BE_LB_NEED_NONE | BE_LB_SA_SS) /* sticky */
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#define BE_LB_ALGO_SRR (BE_LB_KIND_RR | BE_LB_NEED_NONE | BE_LB_RR_STATIC) /* static round robin */
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#define BE_LB_ALGO_SH (BE_LB_KIND_HI | BE_LB_NEED_ADDR | BE_LB_HASH_SRC) /* hash: source IP */
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#define BE_LB_ALGO_UH (BE_LB_KIND_HI | BE_LB_NEED_HTTP | BE_LB_HASH_URI) /* hash: HTTP URI */
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#define BE_LB_ALGO_PH (BE_LB_KIND_HI | BE_LB_NEED_HTTP | BE_LB_HASH_PRM) /* hash: HTTP URL parameter */
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#define BE_LB_ALGO_HH (BE_LB_KIND_HI | BE_LB_NEED_HTTP | BE_LB_HASH_HDR) /* hash: HTTP header value */
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#define BE_LB_ALGO_RCH (BE_LB_KIND_HI | BE_LB_NEED_DATA | BE_LB_HASH_RDP) /* hash: RDP cookie value */
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#define BE_LB_ALGO_SMP (BE_LB_KIND_HI | BE_LB_NEED_DATA | BE_LB_HASH_SMP) /* hash: sample expression */
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#define BE_LB_ALGO_LH (BE_LB_KIND_HI | BE_LB_NEED_LOG | BE_LB_HASH_SMP) /* log hash: sample expression */
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#define BE_LB_ALGO (BE_LB_KIND | BE_LB_NEED | BE_LB_PARM ) /* mask to clear algo */
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/* Higher bits define how a given criterion is mapped to a server. In fact it
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* designates the LB function by itself. The dynamic algorithms will also have
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* the DYN bit set. These flags are automatically set at the end of the parsing.
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*/
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#define BE_LB_LKUP_NONE 0x00000000 /* not defined */
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#define BE_LB_LKUP_MAP 0x00100000 /* static map based lookup */
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#define BE_LB_LKUP_RRTREE 0x00200000 /* FWRR tree lookup */
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#define BE_LB_LKUP_LCTREE 0x00300000 /* FWLC tree lookup */
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#define BE_LB_LKUP_CHTREE 0x00400000 /* consistent hash */
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#define BE_LB_LKUP_FSTREE 0x00500000 /* FAS tree lookup */
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#define BE_LB_LKUP 0x00700000 /* mask to get just the LKUP value */
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/* additional properties */
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#define BE_LB_PROP_DYN 0x00800000 /* bit to indicate a dynamic algorithm */
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/* hash types */
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#define BE_LB_HASH_MAP 0x00000000 /* map-based hash (default) */
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#define BE_LB_HASH_CONS 0x01000000 /* consistent hashbit to indicate a dynamic algorithm */
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#define BE_LB_HASH_TYPE 0x01000000 /* get/clear hash types */
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/* additional modifier on top of the hash function (only avalanche right now) */
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#define BE_LB_HMOD_AVAL 0x02000000 /* avalanche modifier */
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#define BE_LB_HASH_MOD 0x02000000 /* get/clear hash modifier */
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/* BE_LB_HFCN_* is the hash function, to be used with BE_LB_HASH_FUNC */
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#define BE_LB_HFCN_SDBM 0x00000000 /* sdbm hash */
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#define BE_LB_HFCN_DJB2 0x04000000 /* djb2 hash */
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#define BE_LB_HFCN_WT6 0x08000000 /* wt6 hash */
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#define BE_LB_HFCN_CRC32 0x0C000000 /* crc32 hash */
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#define BE_LB_HFCN_NONE 0x10000000 /* none - no hash */
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#define BE_LB_HASH_FUNC 0x1C000000 /* get/clear hash function */
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/* various constants */
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/* The scale factor between user weight and effective weight allows smooth
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* weight modulation even with small weights (eg: 1). It should not be too high
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* though because it limits the number of servers in FWRR mode in order to
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* prevent any integer overflow. The max number of servers per backend is
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* limited to about (2^32-1)/256^2/scale ~= 65535.9999/scale. A scale of 16
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* looks like a good value, as it allows 4095 servers per backend while leaving
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* modulation steps of about 6% for servers with the lowest weight (1).
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*/
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#define BE_WEIGHT_SCALE 16
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/* LB parameters for all algorithms */
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struct lbprm {
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union { /* LB parameters depending on the algo type */
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struct lb_map map;
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struct lb_fwrr fwrr;
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struct lb_fwlc fwlc;
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struct lb_chash chash;
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struct lb_fas fas;
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struct lb_ss ss;
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};
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uint32_t algo; /* load balancing algorithm and variants: BE_LB_* */
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int tot_wact, tot_wbck; /* total effective weights of active and backup servers */
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int tot_weight; /* total effective weight of servers participating to LB */
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int tot_uweight; /* total user weight of servers participating to LB (for reporting) */
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int tot_used; /* total number of servers used for LB */
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int wmult; /* ratio between user weight and effective weight */
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int wdiv; /* ratio between effective weight and user weight */
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int hash_balance_factor; /* load balancing factor * 100, 0 if disabled */
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struct sample_expr *expr; /* sample expression for "balance (log-)hash" */
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char *arg_str; /* name of the URL parameter/header/cookie used for hashing */
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int arg_len; /* strlen(arg_str), computed only once */
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int arg_opt1; /* extra option 1 for the LB algo (algo-specific) */
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int arg_opt2; /* extra option 2 for the LB algo (algo-specific) */
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int arg_opt3; /* extra option 3 for the LB algo (algo-specific) */
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__decl_thread(HA_RWLOCK_T lock);
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struct server *fbck; /* first backup server when !PR_O_USE_ALL_BK, or NULL */
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/* Call backs for some actions. Any of them may be NULL (thus should be ignored).
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* Those marked "srvlock" will need to be called with the server lock held.
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* The other ones might take it themselves if needed.
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*/
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void (*update_server_eweight)(struct server *); /* to be called after eweight change // srvlock */
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void (*set_server_status_up)(struct server *); /* to be called after status changes to UP // srvlock */
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void (*set_server_status_down)(struct server *); /* to be called after status changes to DOWN // srvlock */
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void (*server_take_conn)(struct server *); /* to be called when connection is assigned */
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void (*server_drop_conn)(struct server *); /* to be called when connection is dropped */
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};
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#endif /* _HAPROXY_BACKEND_T_H */
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/*
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* Local variables:
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* c-indent-level: 8
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* c-basic-offset: 8
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* End:
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*/
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