ngx_int_t
ngx_stream_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data)
{
ngx_stream_upstream_rr_peer_data_t *rrp = data;
ngx_int_t rc;
ngx_uint_t i, n;
ngx_stream_upstream_rr_peer_t *peer;
ngx_stream_upstream_rr_peers_t *peers;
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"get rr peer, try: %ui", pc->tries);
pc->connection = NULL;
peers = rrp->peers;
ngx_stream_upstream_rr_peers_wlock(peers);
if (peers->single) {
peer = peers->peer;
if (peer->down) {
goto failed;
}
rrp->current = peer;
} else {
/* there are several peers */
peer = ngx_stream_upstream_get_peer(rrp);
if (peer == NULL) {
goto failed;
}
ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"get rr peer, current: %p %i",
peer, peer->current_weight);
}
pc->sockaddr = peer->sockaddr;
pc->socklen = peer->socklen;
pc->name = &peer->name;
peer->conns++;
ngx_stream_upstream_rr_peers_unlock(peers);
return NGX_OK;
failed:
if (peers->next) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, "backup servers");
rrp->peers = peers->next;
n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1))
/ (8 * sizeof(uintptr_t));
for (i = 0; i < n; i++) {
rrp->tried[i] = 0;
}
ngx_stream_upstream_rr_peers_unlock(peers);
rc = ngx_stream_upstream_get_round_robin_peer(pc, rrp);
if (rc != NGX_BUSY) {
return rc;
}
ngx_stream_upstream_rr_peers_wlock(peers);
}
/* all peers failed, mark them as live for quick recovery */
for (peer = peers->peer; peer; peer = peer->next) {
peer->fails = 0;
}
ngx_stream_upstream_rr_peers_unlock(peers);
pc->name = peers->name;
return NGX_BUSY;
}
static ngx_int_t
ngx_stream_upstream_get_least_conn_peer(ngx_peer_connection_t *pc, void *data)
{
ngx_stream_upstream_rr_peer_data_t *rrp = data;
time_t now;
uintptr_t m;
ngx_int_t rc, total;
ngx_uint_t i, n, p, many;
ngx_stream_upstream_rr_peer_t *peer, *best;
ngx_stream_upstream_rr_peers_t *peers;
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"get least conn peer, try: %ui", pc->tries);
if (rrp->peers->single)
{
return ngx_stream_upstream_get_round_robin_peer(pc, rrp);
}
pc->connection = NULL;
now = ngx_time();
peers = rrp->peers;
ngx_stream_upstream_rr_peers_wlock(peers);
best = NULL;
total = 0;
#if (NGX_SUPPRESS_WARN)
many = 0;
p = 0;
#endif
for (peer = peers->peer, i = 0;
peer;
peer = peer->next, i++)
{
n = i / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t));
if (rrp->tried[n] & m)
{
continue;
}
if (peer->down)
{
continue;
}
if (peer->max_fails
&& peer->fails >= peer->max_fails
&& now - peer->checked <= peer->fail_timeout)
{
continue;
}
/*
* 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
|| peer->conns * best->weight < best->conns * peer->weight)
{
best = peer;
many = 0;
p = i;
}
else if (peer->conns * best->weight == best->conns * peer->weight)
{
many = 1;
}
}
if (best == NULL)
{
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"get least conn peer, no peer found");
goto failed;
}
if (many)
{
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"get least conn peer, many");
for (peer = best, i = p;
peer;
peer = peer->next, i++)
{
n = i / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t));
if (rrp->tried[n] & m)
{
continue;
}
if (peer->down)
{
continue;
}
if (peer->conns * best->weight != best->conns * 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;
best->conns++;
rrp->current = best;
n = p / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));
rrp->tried[n] |= m;
ngx_stream_upstream_rr_peers_unlock(peers);
return NGX_OK;
failed:
if (peers->next)
{
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"get least conn peer, backup servers");
rrp->peers = peers->next;
n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1))
/ (8 * sizeof(uintptr_t));
for (i = 0; i < n; i++)
{
rrp->tried[i] = 0;
}
ngx_stream_upstream_rr_peers_unlock(peers);
rc = ngx_stream_upstream_get_least_conn_peer(pc, rrp);
if (rc != NGX_BUSY)
{
return rc;
}
ngx_stream_upstream_rr_peers_wlock(peers);
}
/* all peers failed, mark them as live for quick recovery */
for (peer = peers->peer; peer; peer = peer->next)
{
peer->fails = 0;
}
ngx_stream_upstream_rr_peers_unlock(peers);
pc->name = peers->name;
return NGX_BUSY;
}
