This source file includes following definitions.
- ngx_stream_upstream_init_round_robin
 
- ngx_stream_upstream_init_round_robin_peer
 
- ngx_stream_upstream_get_round_robin_peer
 
- ngx_stream_upstream_get_peer
 
- ngx_stream_upstream_free_round_robin_peer
 
- ngx_stream_upstream_set_round_robin_peer_session
 
- ngx_stream_upstream_save_round_robin_peer_session
 
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_stream.h>
#define ngx_stream_upstream_tries(p) ((p)->number                             \
                                      + ((p)->next ? (p)->next->number : 0))
static ngx_stream_upstream_rr_peer_t *ngx_stream_upstream_get_peer(
    ngx_stream_upstream_rr_peer_data_t *rrp);
#if (NGX_STREAM_SSL)
static ngx_int_t ngx_stream_upstream_set_round_robin_peer_session(
    ngx_peer_connection_t *pc, void *data);
static void ngx_stream_upstream_save_round_robin_peer_session(
    ngx_peer_connection_t *pc, void *data);
#endif
ngx_int_t
ngx_stream_upstream_init_round_robin(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us)
{
    ngx_url_t                        u;
    ngx_uint_t                       i, j, n, w;
    ngx_stream_upstream_server_t    *server;
    ngx_stream_upstream_rr_peer_t   *peer, **peerp;
    ngx_stream_upstream_rr_peers_t  *peers, *backup;
    us->peer.init = ngx_stream_upstream_init_round_robin_peer;
    if (us->servers) {
        server = us->servers->elts;
        n = 0;
        w = 0;
        for (i = 0; i < us->servers->nelts; i++) {
            if (server[i].backup) {
                continue;
            }
            n += server[i].naddrs;
            w += server[i].naddrs * server[i].weight;
        }
        if (n == 0) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "no servers in upstream \"%V\" in %s:%ui",
                          &us->host, us->file_name, us->line);
            return NGX_ERROR;
        }
        peers = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peers_t));
        if (peers == NULL) {
            return NGX_ERROR;
        }
        peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peer_t) * n);
        if (peer == NULL) {
            return NGX_ERROR;
        }
        peers->single = (n == 1);
        peers->number = n;
        peers->weighted = (w != n);
        peers->total_weight = w;
        peers->name = &us->host;
        n = 0;
        peerp = &peers->peer;
        for (i = 0; i < us->servers->nelts; i++) {
            if (server[i].backup) {
                continue;
            }
            for (j = 0; j < server[i].naddrs; j++) {
                peer[n].sockaddr = server[i].addrs[j].sockaddr;
                peer[n].socklen = server[i].addrs[j].socklen;
                peer[n].name = server[i].addrs[j].name;
                peer[n].weight = server[i].weight;
                peer[n].effective_weight = server[i].weight;
                peer[n].current_weight = 0;
                peer[n].max_fails = server[i].max_fails;
                peer[n].fail_timeout = server[i].fail_timeout;
                peer[n].down = server[i].down;
                peer[n].server = server[i].name;
                *peerp = &peer[n];
                peerp = &peer[n].next;
                n++;
            }
        }
        us->peer.data = peers;
        
        n = 0;
        w = 0;
        for (i = 0; i < us->servers->nelts; i++) {
            if (!server[i].backup) {
                continue;
            }
            n += server[i].naddrs;
            w += server[i].naddrs * server[i].weight;
        }
        if (n == 0) {
            return NGX_OK;
        }
        backup = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peers_t));
        if (backup == NULL) {
            return NGX_ERROR;
        }
        peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peer_t) * n);
        if (peer == NULL) {
            return NGX_ERROR;
        }
        peers->single = 0;
        backup->single = 0;
        backup->number = n;
        backup->weighted = (w != n);
        backup->total_weight = w;
        backup->name = &us->host;
        n = 0;
        peerp = &backup->peer;
        for (i = 0; i < us->servers->nelts; i++) {
            if (!server[i].backup) {
                continue;
            }
            for (j = 0; j < server[i].naddrs; j++) {
                peer[n].sockaddr = server[i].addrs[j].sockaddr;
                peer[n].socklen = server[i].addrs[j].socklen;
                peer[n].name = server[i].addrs[j].name;
                peer[n].weight = server[i].weight;
                peer[n].effective_weight = server[i].weight;
                peer[n].current_weight = 0;
                peer[n].max_fails = server[i].max_fails;
                peer[n].fail_timeout = server[i].fail_timeout;
                peer[n].down = server[i].down;
                peer[n].server = server[i].name;
                *peerp = &peer[n];
                peerp = &peer[n].next;
                n++;
            }
        }
        peers->next = backup;
        return NGX_OK;
    }
    
    if (us->port == 0) {
        ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                      "no port in upstream \"%V\" in %s:%ui",
                      &us->host, us->file_name, us->line);
        return NGX_ERROR;
    }
    ngx_memzero(&u, sizeof(ngx_url_t));
    u.host = us->host;
    u.port = us->port;
    if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) {
        if (u.err) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "%s in upstream \"%V\" in %s:%ui",
                          u.err, &us->host, us->file_name, us->line);
        }
        return NGX_ERROR;
    }
    n = u.naddrs;
    peers = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peers_t));
    if (peers == NULL) {
        return NGX_ERROR;
    }
    peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peer_t) * n);
    if (peer == NULL) {
        return NGX_ERROR;
    }
    peers->single = (n == 1);
    peers->number = n;
    peers->weighted = 0;
    peers->total_weight = n;
    peers->name = &us->host;
    peerp = &peers->peer;
    for (i = 0; i < u.naddrs; i++) {
        peer[i].sockaddr = u.addrs[i].sockaddr;
        peer[i].socklen = u.addrs[i].socklen;
        peer[i].name = u.addrs[i].name;
        peer[i].weight = 1;
        peer[i].effective_weight = 1;
        peer[i].current_weight = 0;
        peer[i].max_fails = 1;
        peer[i].fail_timeout = 10;
        *peerp = &peer[i];
        peerp = &peer[i].next;
    }
    us->peer.data = peers;
    
    return NGX_OK;
}
ngx_int_t
ngx_stream_upstream_init_round_robin_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us)
{
    ngx_uint_t                           n;
    ngx_stream_upstream_rr_peer_data_t  *rrp;
    rrp = s->upstream->peer.data;
    if (rrp == NULL) {
        rrp = ngx_palloc(s->connection->pool,
                         sizeof(ngx_stream_upstream_rr_peer_data_t));
        if (rrp == NULL) {
            return NGX_ERROR;
        }
        s->upstream->peer.data = rrp;
    }
    rrp->peers = us->peer.data;
    rrp->current = NULL;
    n = rrp->peers->number;
    if (rrp->peers->next && rrp->peers->next->number > n) {
        n = rrp->peers->next->number;
    }
    if (n <= 8 * sizeof(uintptr_t)) {
        rrp->tried = &rrp->data;
        rrp->data = 0;
    } else {
        n = (n + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t));
        rrp->tried = ngx_pcalloc(s->connection->pool, n * sizeof(uintptr_t));
        if (rrp->tried == NULL) {
            return NGX_ERROR;
        }
    }
    s->upstream->peer.get = ngx_stream_upstream_get_round_robin_peer;
    s->upstream->peer.free = ngx_stream_upstream_free_round_robin_peer;
    s->upstream->peer.tries = ngx_stream_upstream_tries(rrp->peers);
#if (NGX_STREAM_SSL)
    s->upstream->peer.set_session =
                             ngx_stream_upstream_set_round_robin_peer_session;
    s->upstream->peer.save_session =
                             ngx_stream_upstream_save_round_robin_peer_session;
#endif
    return NGX_OK;
}
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 {
        
        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);
    }
    
    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_stream_upstream_rr_peer_t *
ngx_stream_upstream_get_peer(ngx_stream_upstream_rr_peer_data_t *rrp)
{
    time_t                          now;
    uintptr_t                       m;
    ngx_int_t                       total;
    ngx_uint_t                      i, n, p;
    ngx_stream_upstream_rr_peer_t  *peer, *best;
    now = ngx_time();
    best = NULL;
    total = 0;
#if (NGX_SUPPRESS_WARN)
    p = 0;
#endif
    for (peer = rrp->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;
        }
        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;
            p = i;
        }
    }
    if (best == NULL) {
        return NULL;
    }
    rrp->current = best;
    n = p / (8 * sizeof(uintptr_t));
    m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));
    rrp->tried[n] |= m;
    best->current_weight -= total;
    if (now - best->checked > best->fail_timeout) {
        best->checked = now;
    }
    return best;
}
void
ngx_stream_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data,
    ngx_uint_t state)
{
    ngx_stream_upstream_rr_peer_data_t  *rrp = data;
    time_t                          now;
    ngx_stream_upstream_rr_peer_t  *peer;
    ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                   "free rr peer %ui %ui", pc->tries, state);
    peer = rrp->current;
    ngx_stream_upstream_rr_peers_rlock(rrp->peers);
    ngx_stream_upstream_rr_peer_lock(rrp->peers, peer);
    if (rrp->peers->single) {
        peer->conns--;
        ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer);
        ngx_stream_upstream_rr_peers_unlock(rrp->peers);
        pc->tries = 0;
        return;
    }
    if (state & NGX_PEER_FAILED) {
        now = ngx_time();
        peer->fails++;
        peer->accessed = now;
        peer->checked = now;
        if (peer->max_fails) {
            peer->effective_weight -= peer->weight / peer->max_fails;
            if (peer->fails >= peer->max_fails) {
                ngx_log_error(NGX_LOG_WARN, pc->log, 0,
                              "upstream server temporarily disabled");
            }
        }
        ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                       "free rr peer failed: %p %i",
                       peer, peer->effective_weight);
        if (peer->effective_weight < 0) {
            peer->effective_weight = 0;
        }
    } else {
        
        if (peer->accessed < peer->checked) {
            peer->fails = 0;
        }
    }
    peer->conns--;
    ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer);
    ngx_stream_upstream_rr_peers_unlock(rrp->peers);
    if (pc->tries) {
        pc->tries--;
    }
}
#if (NGX_STREAM_SSL)
static ngx_int_t
ngx_stream_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data)
{
    ngx_stream_upstream_rr_peer_data_t  *rrp = data;
    ngx_int_t                        rc;
    ngx_ssl_session_t               *ssl_session;
    ngx_stream_upstream_rr_peer_t   *peer;
#if (NGX_STREAM_UPSTREAM_ZONE)
    int                              len;
#if OPENSSL_VERSION_NUMBER >= 0x0090707fL
    const
#endif
    u_char                          *p;
    ngx_stream_upstream_rr_peers_t  *peers;
    u_char                           buf[NGX_SSL_MAX_SESSION_SIZE];
#endif
    peer = rrp->current;
#if (NGX_STREAM_UPSTREAM_ZONE)
    peers = rrp->peers;
    if (peers->shpool) {
        ngx_stream_upstream_rr_peers_rlock(peers);
        ngx_stream_upstream_rr_peer_lock(peers, peer);
        if (peer->ssl_session == NULL) {
            ngx_stream_upstream_rr_peer_unlock(peers, peer);
            ngx_stream_upstream_rr_peers_unlock(peers);
            return NGX_OK;
        }
        len = peer->ssl_session_len;
        ngx_memcpy(buf, peer->ssl_session, len);
        ngx_stream_upstream_rr_peer_unlock(peers, peer);
        ngx_stream_upstream_rr_peers_unlock(peers);
        p = buf;
        ssl_session = d2i_SSL_SESSION(NULL, &p, len);
        rc = ngx_ssl_set_session(pc->connection, ssl_session);
        ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                       "set session: %p", ssl_session);
        ngx_ssl_free_session(ssl_session);
        return rc;
    }
#endif
    ssl_session = peer->ssl_session;
    rc = ngx_ssl_set_session(pc->connection, ssl_session);
    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                   "set session: %p", ssl_session);
    return rc;
}
static void
ngx_stream_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data)
{
    ngx_stream_upstream_rr_peer_data_t  *rrp = data;
    ngx_ssl_session_t               *old_ssl_session, *ssl_session;
    ngx_stream_upstream_rr_peer_t   *peer;
#if (NGX_STREAM_UPSTREAM_ZONE)
    int                              len;
    u_char                          *p;
    ngx_stream_upstream_rr_peers_t  *peers;
    u_char                           buf[NGX_SSL_MAX_SESSION_SIZE];
#endif
#if (NGX_STREAM_UPSTREAM_ZONE)
    peers = rrp->peers;
    if (peers->shpool) {
        ssl_session = SSL_get0_session(pc->connection->ssl->connection);
        if (ssl_session == NULL) {
            return;
        }
        ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                       "save session: %p", ssl_session);
        len = i2d_SSL_SESSION(ssl_session, NULL);
        
        if (len > NGX_SSL_MAX_SESSION_SIZE) {
            return;
        }
        p = buf;
        (void) i2d_SSL_SESSION(ssl_session, &p);
        peer = rrp->current;
        ngx_stream_upstream_rr_peers_rlock(peers);
        ngx_stream_upstream_rr_peer_lock(peers, peer);
        if (len > peer->ssl_session_len) {
            ngx_shmtx_lock(&peers->shpool->mutex);
            if (peer->ssl_session) {
                ngx_slab_free_locked(peers->shpool, peer->ssl_session);
            }
            peer->ssl_session = ngx_slab_alloc_locked(peers->shpool, len);
            ngx_shmtx_unlock(&peers->shpool->mutex);
            if (peer->ssl_session == NULL) {
                peer->ssl_session_len = 0;
                ngx_stream_upstream_rr_peer_unlock(peers, peer);
                ngx_stream_upstream_rr_peers_unlock(peers);
                return;
            }
            peer->ssl_session_len = len;
        }
        ngx_memcpy(peer->ssl_session, buf, len);
        ngx_stream_upstream_rr_peer_unlock(peers, peer);
        ngx_stream_upstream_rr_peers_unlock(peers);
        return;
    }
#endif
    ssl_session = ngx_ssl_get_session(pc->connection);
    if (ssl_session == NULL) {
        return;
    }
    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                   "save session: %p", ssl_session);
    peer = rrp->current;
    old_ssl_session = peer->ssl_session;
    peer->ssl_session = ssl_session;
    if (old_ssl_session) {
        ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                       "old session: %p", old_ssl_session);
        
        ngx_ssl_free_session(old_ssl_session);
    }
}
#endif