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view src/http/ngx_http_upstream_round_robin.c @ 6785:d1d0dd69a419

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Upstream: added the ngx_http_upstream_resolved_t.name field. This fixes inconsistency in what is stored in the "host" field. Normally it would contain the "host" part of the parsed URL (e.g., proxy_pass with variables), but for the case of an implicit upstream specified with literal address it contained the text representation of the socket address (that is, host including port for IP). Now the "host" field always contains the "host" part of the URL, while the text representation of the socket address is stored in the newly added "name" field. The ngx_http_upstream_create_round_robin_peer() function was modified accordingly in a way to be compatible with the code that does not know about the new "name" field. The "stream" code was similarly modified except for not adding compatibility in ngx_stream_upstream_create_round_robin_peer(). This change is also a prerequisite for the next change.
author Ruslan Ermilov <ru@nginx.com>
date Mon, 31 Oct 2016 18:33:33 +0300
parents fd5c2781460b
children 696df3ac27ac
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>


#define ngx_http_upstream_tries(p) ((p)->number                               \
                                    + ((p)->next ? (p)->next->number : 0))


static ngx_http_upstream_rr_peer_t *ngx_http_upstream_get_peer(
    ngx_http_upstream_rr_peer_data_t *rrp);

#if (NGX_HTTP_SSL)

static ngx_int_t ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc,
    void *data);
static void ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc,
    void *data);

#endif


ngx_int_t
ngx_http_upstream_init_round_robin(ngx_conf_t *cf,
    ngx_http_upstream_srv_conf_t *us)
{
    ngx_url_t                      u;
    ngx_uint_t                     i, j, n, w;
    ngx_http_upstream_server_t    *server;
    ngx_http_upstream_rr_peer_t   *peer, **peerp;
    ngx_http_upstream_rr_peers_t  *peers, *backup;

    us->peer.init = ngx_http_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_http_upstream_rr_peers_t));
        if (peers == NULL) {
            return NGX_ERROR;
        }

        peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_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_conns = server[i].max_conns;
                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;

        /* backup servers */

        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_http_upstream_rr_peers_t));
        if (backup == NULL) {
            return NGX_ERROR;
        }

        peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_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_conns = server[i].max_conns;
                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;
    }


    /* an upstream implicitly defined by proxy_pass, etc. */

    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_http_upstream_rr_peers_t));
    if (peers == NULL) {
        return NGX_ERROR;
    }

    peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_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_conns = 0;
        peer[i].max_fails = 1;
        peer[i].fail_timeout = 10;
        *peerp = &peer[i];
        peerp = &peer[i].next;
    }

    us->peer.data = peers;

    /* implicitly defined upstream has no backup servers */

    return NGX_OK;
}


ngx_int_t
ngx_http_upstream_init_round_robin_peer(ngx_http_request_t *r,
    ngx_http_upstream_srv_conf_t *us)
{
    ngx_uint_t                         n;
    ngx_http_upstream_rr_peer_data_t  *rrp;

    rrp = r->upstream->peer.data;

    if (rrp == NULL) {
        rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t));
        if (rrp == NULL) {
            return NGX_ERROR;
        }

        r->upstream->peer.data = rrp;
    }

    rrp->peers = us->peer.data;
    rrp->current = NULL;
    rrp->config = 0;

    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(r->pool, n * sizeof(uintptr_t));
        if (rrp->tried == NULL) {
            return NGX_ERROR;
        }
    }

    r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer;
    r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer;
    r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers);
#if (NGX_HTTP_SSL)
    r->upstream->peer.set_session =
                               ngx_http_upstream_set_round_robin_peer_session;
    r->upstream->peer.save_session =
                               ngx_http_upstream_save_round_robin_peer_session;
#endif

    return NGX_OK;
}


ngx_int_t
ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r,
    ngx_http_upstream_resolved_t *ur)
{
    u_char                            *p;
    size_t                             len;
    socklen_t                          socklen;
    ngx_uint_t                         i, n;
    struct sockaddr                   *sockaddr;
    ngx_http_upstream_rr_peer_t       *peer, **peerp;
    ngx_http_upstream_rr_peers_t      *peers;
    ngx_http_upstream_rr_peer_data_t  *rrp;

    rrp = r->upstream->peer.data;

    if (rrp == NULL) {
        rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t));
        if (rrp == NULL) {
            return NGX_ERROR;
        }

        r->upstream->peer.data = rrp;
    }

    peers = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peers_t));
    if (peers == NULL) {
        return NGX_ERROR;
    }

    peer = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peer_t)
                                * ur->naddrs);
    if (peer == NULL) {
        return NGX_ERROR;
    }

    peers->single = (ur->naddrs == 1);
    peers->number = ur->naddrs;
    peers->name = &ur->host;

    if (ur->sockaddr) {
        peer[0].sockaddr = ur->sockaddr;
        peer[0].socklen = ur->socklen;
        peer[0].name = ur->name.data ? ur->name : ur->host;
        peer[0].weight = 1;
        peer[0].effective_weight = 1;
        peer[0].current_weight = 0;
        peer[0].max_conns = 0;
        peer[0].max_fails = 1;
        peer[0].fail_timeout = 10;
        peers->peer = peer;

    } else {
        peerp = &peers->peer;

        for (i = 0; i < ur->naddrs; i++) {

            socklen = ur->addrs[i].socklen;

            sockaddr = ngx_palloc(r->pool, socklen);
            if (sockaddr == NULL) {
                return NGX_ERROR;
            }

            ngx_memcpy(sockaddr, ur->addrs[i].sockaddr, socklen);
            ngx_inet_set_port(sockaddr, ur->port);

            p = ngx_pnalloc(r->pool, NGX_SOCKADDR_STRLEN);
            if (p == NULL) {
                return NGX_ERROR;
            }

            len = ngx_sock_ntop(sockaddr, socklen, p, NGX_SOCKADDR_STRLEN, 1);

            peer[i].sockaddr = sockaddr;
            peer[i].socklen = socklen;
            peer[i].name.len = len;
            peer[i].name.data = p;
            peer[i].weight = 1;
            peer[i].effective_weight = 1;
            peer[i].current_weight = 0;
            peer[i].max_conns = 0;
            peer[i].max_fails = 1;
            peer[i].fail_timeout = 10;
            *peerp = &peer[i];
            peerp = &peer[i].next;
        }
    }

    rrp->peers = peers;
    rrp->current = NULL;
    rrp->config = 0;

    if (rrp->peers->number <= 8 * sizeof(uintptr_t)) {
        rrp->tried = &rrp->data;
        rrp->data = 0;

    } else {
        n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1))
                / (8 * sizeof(uintptr_t));

        rrp->tried = ngx_pcalloc(r->pool, n * sizeof(uintptr_t));
        if (rrp->tried == NULL) {
            return NGX_ERROR;
        }
    }

    r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer;
    r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer;
    r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers);
#if (NGX_HTTP_SSL)
    r->upstream->peer.set_session = ngx_http_upstream_empty_set_session;
    r->upstream->peer.save_session = ngx_http_upstream_empty_save_session;
#endif

    return NGX_OK;
}


ngx_int_t
ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    ngx_int_t                      rc;
    ngx_uint_t                     i, n;
    ngx_http_upstream_rr_peer_t   *peer;
    ngx_http_upstream_rr_peers_t  *peers;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "get rr peer, try: %ui", pc->tries);

    pc->cached = 0;
    pc->connection = NULL;

    peers = rrp->peers;
    ngx_http_upstream_rr_peers_wlock(peers);

    if (peers->single) {
        peer = peers->peer;

        if (peer->down) {
            goto failed;
        }

        if (peer->max_conns && peer->conns >= peer->max_conns) {
            goto failed;
        }

        rrp->current = peer;

    } else {

        /* there are several peers */

        peer = ngx_http_upstream_get_peer(rrp);

        if (peer == NULL) {
            goto failed;
        }

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, 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_http_upstream_rr_peers_unlock(peers);

    return NGX_OK;

failed:

    if (peers->next) {

        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, 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_http_upstream_rr_peers_unlock(peers);

        rc = ngx_http_upstream_get_round_robin_peer(pc, rrp);

        if (rc != NGX_BUSY) {
            return rc;
        }

        ngx_http_upstream_rr_peers_wlock(peers);
    }

    ngx_http_upstream_rr_peers_unlock(peers);

    pc->name = peers->name;

    return NGX_BUSY;
}


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, p;
    ngx_http_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;
        }

        if (peer->max_conns && peer->conns >= peer->max_conns) {
            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_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data,
    ngx_uint_t state)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    time_t                       now;
    ngx_http_upstream_rr_peer_t  *peer;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "free rr peer %ui %ui", pc->tries, state);

    /* TODO: NGX_PEER_KEEPALIVE */

    peer = rrp->current;

    ngx_http_upstream_rr_peers_rlock(rrp->peers);
    ngx_http_upstream_rr_peer_lock(rrp->peers, peer);

    if (rrp->peers->single) {

        peer->conns--;

        ngx_http_upstream_rr_peer_unlock(rrp->peers, peer);
        ngx_http_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_HTTP, pc->log, 0,
                       "free rr peer failed: %p %i",
                       peer, peer->effective_weight);

        if (peer->effective_weight < 0) {
            peer->effective_weight = 0;
        }

    } else {

        /* mark peer live if check passed */

        if (peer->accessed < peer->checked) {
            peer->fails = 0;
        }
    }

    peer->conns--;

    ngx_http_upstream_rr_peer_unlock(rrp->peers, peer);
    ngx_http_upstream_rr_peers_unlock(rrp->peers);

    if (pc->tries) {
        pc->tries--;
    }
}


#if (NGX_HTTP_SSL)

ngx_int_t
ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    ngx_int_t                      rc;
    ngx_ssl_session_t             *ssl_session;
    ngx_http_upstream_rr_peer_t   *peer;
#if (NGX_HTTP_UPSTREAM_ZONE)
    int                            len;
#if OPENSSL_VERSION_NUMBER >= 0x0090707fL
    const
#endif
    u_char                        *p;
    ngx_http_upstream_rr_peers_t  *peers;
    u_char                         buf[NGX_SSL_MAX_SESSION_SIZE];
#endif

    peer = rrp->current;

#if (NGX_HTTP_UPSTREAM_ZONE)
    peers = rrp->peers;

    if (peers->shpool) {
        ngx_http_upstream_rr_peers_rlock(peers);
        ngx_http_upstream_rr_peer_lock(peers, peer);

        if (peer->ssl_session == NULL) {
            ngx_http_upstream_rr_peer_unlock(peers, peer);
            ngx_http_upstream_rr_peers_unlock(peers);
            return NGX_OK;
        }

        len = peer->ssl_session_len;

        ngx_memcpy(buf, peer->ssl_session, len);

        ngx_http_upstream_rr_peer_unlock(peers, peer);
        ngx_http_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_HTTP, 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_HTTP, pc->log, 0,
                   "set session: %p", ssl_session);

    return rc;
}


void
ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc,
    void *data)
{
    ngx_http_upstream_rr_peer_data_t  *rrp = data;

    ngx_ssl_session_t             *old_ssl_session, *ssl_session;
    ngx_http_upstream_rr_peer_t   *peer;
#if (NGX_HTTP_UPSTREAM_ZONE)
    int                            len;
    u_char                        *p;
    ngx_http_upstream_rr_peers_t  *peers;
    u_char                         buf[NGX_SSL_MAX_SESSION_SIZE];
#endif

#if (NGX_HTTP_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_HTTP, pc->log, 0,
                       "save session: %p", ssl_session);

        len = i2d_SSL_SESSION(ssl_session, NULL);

        /* do not cache too big session */

        if (len > NGX_SSL_MAX_SESSION_SIZE) {
            return;
        }

        p = buf;
        (void) i2d_SSL_SESSION(ssl_session, &p);

        peer = rrp->current;

        ngx_http_upstream_rr_peers_rlock(peers);
        ngx_http_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_http_upstream_rr_peer_unlock(peers, peer);
                ngx_http_upstream_rr_peers_unlock(peers);
                return;
            }

            peer->ssl_session_len = len;
        }

        ngx_memcpy(peer->ssl_session, buf, len);

        ngx_http_upstream_rr_peer_unlock(peers, peer);
        ngx_http_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_HTTP, 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_HTTP, pc->log, 0,
                       "old session: %p", old_ssl_session);

        /* TODO: may block */

        ngx_ssl_free_session(old_ssl_session);
    }
}


static ngx_int_t
ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data)
{
    return NGX_OK;
}


static void
ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data)
{
    return;
}

#endif