/* This function is responsible for building the trees in case of fast
* weighted least-conns. It also sets p->lbprm.wdiv to the eweight to
* uweight ratio. Both active and backup groups are initialized.
*/
void fas_init_server_tree(struct proxy *p)
{
struct server *srv;
struct eb_root init_head = EB_ROOT;
p->lbprm.set_server_status_up = fas_set_server_status_up;
p->lbprm.set_server_status_down = fas_set_server_status_down;
p->lbprm.update_server_eweight = fas_update_server_weight;
p->lbprm.server_take_conn = fas_srv_reposition;
p->lbprm.server_drop_conn = fas_srv_reposition;
p->lbprm.wdiv = BE_WEIGHT_SCALE;
for (srv = p->srv; srv; srv = srv->next) {
srv->eweight = (srv->uweight * p->lbprm.wdiv + p->lbprm.wmult - 1) / p->lbprm.wmult;
srv_lb_commit_status(srv);
}
recount_servers(p);
update_backend_weight(p);
p->lbprm.fas.act = init_head;
p->lbprm.fas.bck = init_head;
/* queue active and backup servers in two distinct groups */
for (srv = p->srv; srv; srv = srv->next) {
if (!srv_is_usable(srv))
continue;
srv->lb_tree = (srv->state & SRV_BACKUP) ? &p->lbprm.fas.bck : &p->lbprm.fas.act;
fas_queue_srv(srv);
}
}
/* This function is responsible for building the weight trees in case of fast
* weighted round-robin. It also sets p->lbprm.wdiv to the eweight to uweight
* ratio. Both active and backup groups are initialized.
*/
void fwrr_init_server_groups(struct proxy *p)
{
struct server *srv;
struct eb_root init_head = EB_ROOT;
p->lbprm.set_server_status_up = fwrr_set_server_status_up;
p->lbprm.set_server_status_down = fwrr_set_server_status_down;
p->lbprm.update_server_eweight = fwrr_update_server_weight;
p->lbprm.wdiv = BE_WEIGHT_SCALE;
for (srv = p->srv; srv; srv = srv->next) {
srv->prev_eweight = srv->eweight = srv->uweight * BE_WEIGHT_SCALE;
srv->prev_state = srv->state;
}
recount_servers(p);
update_backend_weight(p);
/* prepare the active servers group */
p->lbprm.fwrr.act.curr_pos = p->lbprm.fwrr.act.curr_weight =
p->lbprm.fwrr.act.next_weight = p->lbprm.tot_wact;
p->lbprm.fwrr.act.curr = p->lbprm.fwrr.act.t0 =
p->lbprm.fwrr.act.t1 = init_head;
p->lbprm.fwrr.act.init = &p->lbprm.fwrr.act.t0;
p->lbprm.fwrr.act.next = &p->lbprm.fwrr.act.t1;
/* prepare the backup servers group */
p->lbprm.fwrr.bck.curr_pos = p->lbprm.fwrr.bck.curr_weight =
p->lbprm.fwrr.bck.next_weight = p->lbprm.tot_wbck;
p->lbprm.fwrr.bck.curr = p->lbprm.fwrr.bck.t0 =
p->lbprm.fwrr.bck.t1 = init_head;
p->lbprm.fwrr.bck.init = &p->lbprm.fwrr.bck.t0;
p->lbprm.fwrr.bck.next = &p->lbprm.fwrr.bck.t1;
/* queue active and backup servers in two distinct groups */
for (srv = p->srv; srv; srv = srv->next) {
if (!srv_is_usable(srv->state, srv->eweight))
continue;
fwrr_queue_by_weight((srv->state & SRV_BACKUP) ?
p->lbprm.fwrr.bck.init :
p->lbprm.fwrr.act.init,
srv);
}
}
/* This function updates the map according to server <srv>'s new state */
static void map_set_server_status_up(struct server *srv)
{
struct proxy *p = srv->proxy;
if (srv->state == srv->prev_state &&
srv->eweight == srv->prev_eweight)
return;
if (!srv_is_usable(srv->state, srv->eweight))
goto out_update_state;
/* FIXME: could be optimized since we know what changed */
recount_servers(p);
update_backend_weight(p);
p->lbprm.map.state |= LB_MAP_RECALC;
out_update_state:
srv->prev_state = srv->state;
srv->prev_eweight = srv->eweight;
}
/* This function is responsible of building the server MAP for map-based LB
* algorithms, allocating the map, and setting p->lbprm.wmult to the GCD of the
* weights if applicable. It should be called only once per proxy, at config
* time.
*/
void init_server_map(struct proxy *p)
{
struct server *srv;
int pgcd;
int act, bck;
p->lbprm.set_server_status_up = map_set_server_status_up;
p->lbprm.set_server_status_down = map_set_server_status_down;
p->lbprm.update_server_eweight = NULL;
if (!p->srv)
return;
/* We will factor the weights to reduce the table,
* using Euclide's largest common divisor algorithm.
* Since we may have zero weights, we have to first
* find a non-zero weight server.
*/
pgcd = 1;
srv = p->srv;
while (srv && !srv->uweight)
srv = srv->next;
if (srv) {
pgcd = srv->uweight; /* note: cannot be zero */
while (pgcd > 1 && (srv = srv->next)) {
int w = srv->uweight;
while (w) {
int t = pgcd % w;
pgcd = w;
w = t;
}
}
}
/* It is sometimes useful to know what factor to apply
* to the backend's effective weight to know its real
* weight.
*/
p->lbprm.wmult = pgcd;
act = bck = 0;
for (srv = p->srv; srv; srv = srv->next) {
srv->eweight = srv->uweight / pgcd;
srv->prev_eweight = srv->eweight;
srv->prev_state = srv->state;
if (srv->state & SRV_BACKUP)
bck += srv->eweight;
else
act += srv->eweight;
}
/* this is the largest map we will ever need for this servers list */
if (act < bck)
act = bck;
if (!act)
act = 1;
p->lbprm.map.srv = (struct server **)calloc(act, sizeof(struct server *));
/* recounts servers and their weights */
p->lbprm.map.state = LB_MAP_RECALC;
recount_servers(p);
update_backend_weight(p);
recalc_server_map(p);
}
