Revert "implemented the weighted load balancing based on a server map."
This reverts e0fa4965762fad998f214e30ec8f85b04e83130e commit.
diff --git a/haproxy.c b/haproxy.c
index b8cc48d..81e7934 100644
--- a/haproxy.c
+++ b/haproxy.c
@@ -514,7 +514,7 @@
int cur_sess; /* number of currently active sessions (including syn_sent) */
unsigned int cum_sess; /* cumulated number of sessions really sent to this server */
unsigned char uweight, eweight; /* user-specified weight-1, and effective weight-1 */
- unsigned int wscore; /* weight score, used during srv map computation */
+ unsigned short wsquare; /* eweight*eweight, to speed up map computation */
struct proxy *proxy; /* the proxy this server belongs to */
};
@@ -581,12 +581,8 @@
struct in_addr mon_net, mon_mask; /* don't forward connections from this net (network order) FIXME: should support IPv6 */
int state; /* proxy state */
struct sockaddr_in dispatch_addr; /* the default address to connect to */
- struct server *srv; /* known servers */
- int srv_act, srv_bck; /* # of running servers */
- int tot_wact, tot_wbck; /* total weights of active and backup servers */
- struct server **srv_map; /* the server map used to apply weights */
- int srv_map_sz; /* the size of the effective server map */
- int srv_rr_idx; /* next server to be elected in round robin mode */
+ struct server *srv, *cursrv; /* known servers, current server */
+ int srv_act, srv_bck; /* # of servers */
char *cookie_name; /* name of the cookie to look for */
int cookie_len; /* strlen(cookie_name), computed only once */
char *appsession_name; /* name of the cookie to look for */
@@ -1816,101 +1812,77 @@
/*
* This function recounts the number of usable active and backup servers for
* proxy <p>. These numbers are returned into the p->srv_act and p->srv_bck.
- * This function also recomputes the total active and backup weights.
*/
-static void recount_servers(struct proxy *px) {
+static inline void recount_servers(struct proxy *px) {
struct server *srv;
- px->srv_act = 0; px->srv_bck = px->tot_wact = px->tot_wbck = 0;
+ px->srv_act = 0; px->srv_bck = 0;
for (srv = px->srv; srv != NULL; srv = srv->next) {
if (srv->state & SRV_RUNNING) {
- if (srv->state & SRV_BACKUP) {
+ if (srv->state & SRV_BACKUP)
px->srv_bck++;
- px->tot_wbck += srv->eweight + 1;
- } else {
+ else
px->srv_act++;
- px->tot_wact += srv->eweight + 1;
- }
}
}
-}
-
-/* This function recomputes the server map for proxy px. It
- * relies on px->tot_wact and px->tot_wbck, so it must be
- * called after recount_servers(). It also expects px->srv_map
- * to be initialized to the largest value needed.
- */
-static void recalc_server_map(struct proxy *px) {
- int o, tot, flag;
- struct server *cur, *best;
-
- if (px->srv_act) {
- flag = SRV_RUNNING;
- tot = px->tot_wact;
- } else if (px->srv_bck) {
- flag = SRV_RUNNING | SRV_BACKUP;
- if (px->options & PR_O_USE_ALL_BK)
- tot = px->tot_wbck;
- else
- tot = 1; /* the first server is enough */
- } else {
- px->srv_map_sz = 0;
- return;
- }
-
- /* this algorithm gives priority to the first server, which means that
- * it will respect the declaration order for equivalent weights, and
- * that whatever the weights, the first server called will always be
- * the first declard. This is an important asumption for the backup
- * case, where we want the first server only.
- */
- for (cur = px->srv; cur; cur = cur->next)
- cur->wscore = 0;
-
- for (o = 0; o < tot; o++) {
- int max = 0;
- best = NULL;
- for (cur = px->srv; cur; cur = cur->next) {
- if ((cur->state & (SRV_RUNNING | SRV_BACKUP)) == flag) {
- int v;
-
- /* If we are forced to return only one server, we don't want to
- * go further, because we would return the wrong one due to
- * divide overflow.
- */
- if (tot == 1) {
- best = cur;
- break;
- }
-
- cur->wscore += cur->eweight + 1;
- v = (cur->wscore + tot) / tot; /* result between 0 and 3 */
- if (best == NULL || v > max) {
- max = v;
- best = cur;
- }
- }
- }
- px->srv_map[o] = best;
- best->wscore -= tot;
- }
- px->srv_map_sz = tot;
}
/*
* This function tries to find a running server for the proxy <px> following
* the round-robin method. Depending on the number of active/backup servers,
* it will either look for active servers, or for backup servers.
- * If any server is found, it will be returned and px->srv_rr_idx will be updated
+ * If any server is found, it will be returned and px->cursrv will be updated
* to point to the next server. If no valid server is found, NULL is returned.
*/
static inline struct server *get_server_rr(struct proxy *px) {
- if (px->srv_map_sz == 0)
- return NULL;
+ struct server *srv;
+ struct server *end;
+
+ if (px->srv_act) {
+ srv = px->cursrv;
+ if (srv == NULL)
+ srv = px->srv;
+ end = srv;
+ do {
+ if ((srv->state & (SRV_RUNNING | SRV_BACKUP)) == SRV_RUNNING) {
+ px->cursrv = srv->next;
+ return srv;
+ }
- if (px->srv_rr_idx < 0 || px->srv_rr_idx >= px->srv_map_sz)
- px->srv_rr_idx = 0;
- return px->srv_map[px->srv_rr_idx++];
+ srv = srv->next;
+ if (srv == NULL)
+ srv = px->srv;
+ } while (srv != end);
+ /* note that theorically we should not get there */
+ }
+
+ if (px->srv_bck) {
+ /* By default, we look for the first backup server if all others are
+ * DOWN. But in some cases, it may be desirable to load-balance across
+ * all backup servers.
+ */
+ if (px->options & PR_O_USE_ALL_BK)
+ srv = px->cursrv;
+ else
+ srv = px->srv;
+
+ if (srv == NULL)
+ srv = px->srv;
+ end = srv;
+ do {
+ if (srv->state & SRV_RUNNING) {
+ px->cursrv = srv->next;
+ return srv;
+ }
+ srv = srv->next;
+ if (srv == NULL)
+ srv = px->srv;
+ } while (srv != end);
+ /* note that theorically we should not get there */
+ }
+
+ /* if we get there, it means there are no available servers at all */
+ return NULL;
}
@@ -1922,20 +1894,58 @@
* NULL is returned.
*/
static inline struct server *get_server_sh(struct proxy *px, char *addr, int len) {
- unsigned int h, l;
+ struct server *srv;
- if (px->srv_map_sz == 0)
- return NULL;
+ if (px->srv_act) {
+ unsigned int h, l;
+
+ l = h = 0;
+ if (px->srv_act > 1) {
+ while ((l + sizeof (int)) <= len) {
+ h ^= ntohl(*(unsigned int *)(&addr[l]));
+ l += sizeof (int);
+ }
+ h %= px->srv_act;
+ }
+
+ for (srv = px->srv; srv; srv = srv->next) {
+ if ((srv->state & (SRV_RUNNING | SRV_BACKUP)) == SRV_RUNNING) {
+ if (!h)
+ return srv;
+ h--;
+ }
+ }
+ /* note that theorically we should not get there */
+ }
- l = h = 0;
- if (px->srv_act > 1) {
- while ((l + sizeof (int)) <= len) {
- h ^= ntohl(*(unsigned int *)(&addr[l]));
- l += sizeof (int);
+ if (px->srv_bck) {
+ unsigned int h, l;
+
+ /* By default, we look for the first backup server if all others are
+ * DOWN. But in some cases, it may be desirable to load-balance across
+ * all backup servers.
+ */
+ l = h = 0;
+ if (px->srv_bck > 1 && px->options & PR_O_USE_ALL_BK) {
+ while ((l + sizeof (int)) <= len) {
+ h ^= ntohl(*(unsigned int *)(&addr[l]));
+ l += sizeof (int);
+ }
+ h %= px->srv_bck;
+ }
+
+ for (srv = px->srv; srv; srv = srv->next) {
+ if (srv->state & SRV_RUNNING) {
+ if (!h)
+ return srv;
+ h--;
+ }
}
- h %= px->srv_map_sz;
+ /* note that theorically we should not get there */
}
- return px->srv_map[h];
+
+ /* if we get there, it means there are no available servers at all */
+ return NULL;
}
@@ -5332,7 +5342,6 @@
s->state &= ~SRV_RUNNING;
if (s->health == s->rise) {
recount_servers(s->proxy);
- recalc_server_map(s->proxy);
Warning("%sServer %s/%s DOWN. %d active and %d backup servers left.%s\n",
s->state & SRV_BACKUP ? "Backup " : "",
s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
@@ -5368,7 +5377,6 @@
if (s->health == s->rise) {
recount_servers(s->proxy);
- recalc_server_map(s->proxy);
Warning("%sServer %s/%s UP. %d active and %d backup servers online.%s\n",
s->state & SRV_BACKUP ? "Backup " : "",
s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
@@ -5399,7 +5407,6 @@
if (s->health == s->rise) {
recount_servers(s->proxy);
- recalc_server_map(s->proxy);
Warning("%sServer %s/%s DOWN. %d active and %d backup servers left.%s\n",
s->state & SRV_BACKUP ? "Backup " : "",
s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
@@ -7016,9 +7023,13 @@
return -1;
}
+ if (curproxy->srv == NULL)
+ curproxy->srv = newsrv;
+ else
+ curproxy->cursrv->next = newsrv;
+ curproxy->cursrv = newsrv;
+
- /* the servers are linked backwards first */
- newsrv->next = curproxy->srv;
- curproxy->srv = newsrv;
+ newsrv->next = NULL;
newsrv->proxy = curproxy;
do_check = 0;
@@ -7832,6 +7843,7 @@
}
while (curproxy != NULL) {
+ curproxy->cursrv = NULL;
if (curproxy->state == PR_STSTOPPED) {
curproxy = curproxy->next;
continue;
@@ -7888,59 +7900,29 @@
file, curproxy->id);
cfgerr++;
}
- }
-
- /* first, we will invert the servers list order */
- newsrv = NULL;
- while (curproxy->srv) {
- struct server *next;
-
- next = curproxy->srv->next;
- curproxy->srv->next = newsrv;
- newsrv = curproxy->srv;
- if (!next)
- break;
- curproxy->srv = next;
- }
+ else {
+ struct server *srv;
+ int pgcd;
- /* now, newsrv == curproxy->srv */
- if (newsrv) {
- struct server *srv;
- int pgcd;
- int act, bck;
+ if (newsrv) {
+ /* We will factor the weights to reduce the table,
+ * using Euclide's largest common divisor algorithm
+ */
+ pgcd = newsrv->uweight + 1;
+ for (srv = newsrv->next; srv && pgcd > 1; srv = srv->next) {
+ int t, w;
- /* We will factor the weights to reduce the table,
- * using Euclide's largest common divisor algorithm
- */
- pgcd = newsrv->uweight + 1;
- for (srv = newsrv->next; srv && pgcd > 1; srv = srv->next) {
- int t, w;
-
- w = srv->uweight + 1;
- while (w) {
- t = pgcd % w;
- pgcd = w;
- w = t;
+ w = srv->uweight + 1;
+ while (w) {
+ t = pgcd % w;
+ pgcd = w;
+ w = t;
}
- }
-
- act = bck = 0;
- for (srv = newsrv; srv; srv = srv->next) {
- srv->eweight = ((srv->uweight + 1) / pgcd) - 1;
- if (srv->state & SRV_BACKUP)
- bck += srv->eweight + 1;
- else
- act += srv->eweight + 1;
+ }
+ for (srv = newsrv; srv; srv = srv->next)
+ srv->eweight = ((srv->uweight + 1) / pgcd) - 1;
+ }
}
-
- /* this is the largest map we will ever need for this servers list */
- if (act < bck)
- act = bck;
-
- curproxy->srv_map = (struct server **)calloc(act, sizeof(struct server *));
- /* recounts servers and their weights */
- recount_servers(curproxy);
- recalc_server_map(curproxy);
}
if (curproxy->options & PR_O_LOGASAP)