static ngx_http_upstream_rr_peer_t *
ngx_http_upstream_get_peer(ngx_http_upstream_rr_peer_data_t *rrp)
{
time_t now;
uintptr_t m;
ngx_int_t total;
ngx_uint_t i, n;
ngx_http_upstream_rr_peer_t *peer, *best;
#if (NGX_HTTP_PERSISTENCE)
ngx_int_t persist_index;
persist_index = ngx_http_upstream_ps_get(rrp->request,
rrp->peers->number, rrp->group);
#endif
now = ngx_time();
best = NULL;
total = 0;
for (i = 0; i < rrp->peers->number; i++) {
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
i = persist_index;
}
#endif
n = i / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t));
if (rrp->tried[n] & m) {
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
persist_index = -1;
i = 0;
}
#endif
continue;
}
peer = &rrp->peers->peer[i];
if (peer->down) {
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
persist_index = -1;
i = 0;
}
#endif
continue;
}
#if (NGX_HTTP_UPSTREAM_CHECK)
if (ngx_http_upstream_check_peer_down(peer->check_index)) {
continue;
}
#endif
if (peer->max_fails
&& peer->fails >= peer->max_fails
&& now - peer->checked <= peer->fail_timeout)
{
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
persist_index = -1;
i = 0;
}
#endif
continue;
}
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
best = peer;
break;
}
#endif
peer->current_weight += peer->effective_weight;
total += peer->effective_weight;
if (peer->effective_weight < peer->weight) {
peer->effective_weight++;
}
if (best == NULL || peer->current_weight > best->current_weight) {
best = peer;
}
}
if (best == NULL) {
return NULL;
}
i = best - &rrp->peers->peer[0];
rrp->current = i;
n = i / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t));
rrp->tried[n] |= m;
best->current_weight -= total;
if (now - best->checked > best->fail_timeout) {
best->checked = now;
}
#if (NGX_HTTP_PERSISTENCE)
ngx_http_upstream_ps_set(rrp->request, rrp->current, rrp->group);
#endif
return best;
}
static ngx_int_t
ngx_http_upstream_get_least_conn_peer(ngx_peer_connection_t *pc, void *data)
{
ngx_http_upstream_lc_peer_data_t *lcp = data;
time_t now;
uintptr_t m;
ngx_int_t rc, total;
ngx_uint_t i, n, p, many;
ngx_http_upstream_rr_peer_t *peer, *best;
ngx_http_upstream_rr_peers_t *peers;
#if (NGX_HTTP_PERSISTENCE)
ngx_int_t persist_index;
#endif
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get least conn peer, try: %ui", pc->tries);
if (lcp->rrp.peers->single) {
return lcp->get_rr_peer(pc, &lcp->rrp);
}
pc->cached = 0;
pc->connection = NULL;
now = ngx_time();
peers = lcp->rrp.peers;
best = NULL;
total = 0;
#if (NGX_SUPPRESS_WARN)
many = 0;
p = 0;
#endif
#if (NGX_HTTP_PERSISTENCE)
persist_index = ngx_http_upstream_ps_get(lcp->rrp.request,
lcp->rrp.peers->number, lcp->rrp.group);
#endif
for (i = 0; i < peers->number; i++) {
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
i = persist_index;
}
#endif
n = i / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t));
if (lcp->rrp.tried[n] & m) {
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
persist_index = -1;
i = 0;
}
#endif
continue;
}
peer = &peers->peer[i];
if (peer->down) {
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
persist_index = -1;
i = 0;
}
#endif
continue;
}
#if (NGX_HTTP_UPSTREAM_CHECK)
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get least_conn peer, check_index: %ui",
peer->check_index);
if (ngx_http_upstream_check_peer_down(peer->check_index)) {
continue;
}
#endif
if (peer->max_fails
&& peer->fails >= peer->max_fails
&& now - peer->checked <= peer->fail_timeout)
{
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
persist_index = -1;
i = 0;
}
#endif
continue;
}
#if (NGX_HTTP_PERSISTENCE)
if(persist_index >= 0) {
best = peer;
p = persist_index;
break;
}
#endif
/*
* select peer with least number of connections; if there are
* multiple peers with the same number of connections, select
* based on round-robin
*/
if (best == NULL
|| lcp->conns[i] * best->weight < lcp->conns[p] * peer->weight)
{
best = peer;
many = 0;
p = i;
} else if (lcp->conns[i] * best->weight
== lcp->conns[p] * peer->weight)
{
many = 1;
}
}
if (best == NULL) {
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get least conn peer, no peer found");
goto failed;
}
if (many) {
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get least conn peer, many");
for (i = p; i < peers->number; i++) {
n = i / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t));
if (lcp->rrp.tried[n] & m) {
continue;
}
peer = &peers->peer[i];
if (peer->down) {
continue;
}
#if (NGX_HTTP_UPSTREAM_CHECK)
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get least_conn peer, check_index: %ui",
peer->check_index);
if (ngx_http_upstream_check_peer_down(peer->check_index)) {
continue;
}
#endif
if (lcp->conns[i] * best->weight != lcp->conns[p] * peer->weight) {
continue;
}
if (peer->max_fails
&& peer->fails >= peer->max_fails
&& now - peer->checked <= peer->fail_timeout)
{
continue;
}
peer->current_weight += peer->effective_weight;
total += peer->effective_weight;
if (peer->effective_weight < peer->weight) {
peer->effective_weight++;
}
if (peer->current_weight > best->current_weight) {
best = peer;
p = i;
}
}
}
best->current_weight -= total;
if (now - best->checked > best->fail_timeout) {
best->checked = now;
}
pc->sockaddr = best->sockaddr;
pc->socklen = best->socklen;
pc->name = &best->name;
pc->host = &best->host;
pc->dyn_resolve = best->dyn_resolve;
lcp->rrp.current = p;
n = p / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));
lcp->rrp.tried[n] |= m;
lcp->conns[p]++;
if (pc->tries == 1 && peers->next) {
pc->tries += peers->next->number;
}
#if (NGX_HTTP_PERSISTENCE)
ngx_http_upstream_ps_set(lcp->rrp.request, lcp->rrp.current,
lcp->rrp.group);
#endif
return NGX_OK;
failed:
if (peers->next) {
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get least conn peer, backup servers");
lcp->conns += peers->number;
lcp->rrp.peers = peers->next;
pc->tries = lcp->rrp.peers->number;
n = (lcp->rrp.peers->number + (8 * sizeof(uintptr_t) - 1))
/ (8 * sizeof(uintptr_t));
for (i = 0; i < n; i++) {
lcp->rrp.tried[i] = 0;
}
rc = ngx_http_upstream_get_least_conn_peer(pc, lcp);
if (rc != NGX_BUSY) {
return rc;
}
}
/* all peers failed, mark them as live for quick recovery */
for (i = 0; i < peers->number; i++) {
peers->peer[i].fails = 0;
}
pc->name = peers->name;
return NGX_BUSY;
}