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view src/stream/ngx_stream_upstream_hash_module.c @ 8122:106328a70f4e

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Added warning about redefinition of listen socket protocol options. The "listen" directive in the http module can be used multiple times in different server blocks. Originally, it was supposed to be specified once with various socket options, and without any parameters in virtual server blocks. For example: server { listen 80 backlog=1024; server_name foo; ... } server { listen 80; server_name bar; ... } server { listen 80; server_name bazz; ... } The address part of the syntax ("address[:port]" / "port" / "unix:path") uniquely identifies the listening socket, and therefore is enough for name-based virtual servers (to let nginx know that the virtual server accepts requests on the listening socket in question). To ensure that listening options do not conflict between virtual servers, they were allowed only once. For example, the following configuration will be rejected ("duplicate listen options for 0.0.0.0:80 in ..."): server { listen 80 backlog=1024; server_name foo; ... } server { listen 80 backlog=512; server_name bar; ... } At some point it was, however, noticed, that it is sometimes convenient to repeat some options for clarity. In nginx 0.8.51 the "ssl" parameter was allowed to be specified multiple times, e.g.: server { listen 443 ssl backlog=1024; server_name foo; ... } server { listen 443 ssl; server_name bar; ... } server { listen 443 ssl; server_name bazz; ... } This approach makes configuration more readable, since SSL sockets are immediately visible in the configuration. If this is not needed, just the address can still be used. Later, additional protocol-specific options similar to "ssl" were introduced, notably "http2" and "proxy_protocol". With these options, one can write: server { listen 443 ssl backlog=1024; server_name foo; ... } server { listen 443 http2; server_name bar; ... } server { listen 443 proxy_protocol; server_name bazz; ... } The resulting socket will use ssl, http2, and proxy_protocol, but this is not really obvious from the configuration. To emphasize such misleading configurations are discouraged, nginx now warns as long as the "listen" directive is used with options different from the options previously used if this is potentially confusing. In particular, the following configurations are allowed: server { listen 8401 ssl backlog=1024; server_name foo; } server { listen 8401 ssl; server_name bar; } server { listen 8401 ssl; server_name bazz; } server { listen 8402 ssl http2 backlog=1024; server_name foo; } server { listen 8402 ssl; server_name bar; } server { listen 8402 ssl; server_name bazz; } server { listen 8403 ssl; server_name bar; } server { listen 8403 ssl; server_name bazz; } server { listen 8403 ssl http2; server_name foo; } server { listen 8404 ssl http2 backlog=1024; server_name foo; } server { listen 8404 http2; server_name bar; } server { listen 8404 http2; server_name bazz; } server { listen 8405 ssl http2 backlog=1024; server_name foo; } server { listen 8405 ssl http2; server_name bar; } server { listen 8405 ssl http2; server_name bazz; } server { listen 8406 ssl; server_name foo; } server { listen 8406; server_name bar; } server { listen 8406; server_name bazz; } And the following configurations will generate warnings: server { listen 8501 ssl http2 backlog=1024; server_name foo; } server { listen 8501 http2; server_name bar; } server { listen 8501 ssl; server_name bazz; } server { listen 8502 backlog=1024; server_name foo; } server { listen 8502 ssl; server_name bar; } server { listen 8503 ssl; server_name foo; } server { listen 8503 http2; server_name bar; } server { listen 8504 ssl; server_name foo; } server { listen 8504 http2; server_name bar; } server { listen 8504 proxy_protocol; server_name bazz; } server { listen 8505 ssl http2 proxy_protocol; server_name foo; } server { listen 8505 ssl http2; server_name bar; } server { listen 8505 ssl; server_name bazz; } server { listen 8506 ssl http2; server_name foo; } server { listen 8506 ssl; server_name bar; } server { listen 8506; server_name bazz; } server { listen 8507 ssl; server_name bar; } server { listen 8507; server_name bazz; } server { listen 8507 ssl http2; server_name foo; } server { listen 8508 ssl; server_name bar; } server { listen 8508; server_name bazz; } server { listen 8508 ssl backlog=1024; server_name foo; } server { listen 8509; server_name bazz; } server { listen 8509 ssl; server_name bar; } server { listen 8509 ssl backlog=1024; server_name foo; } The basic idea is that at most two sets of protocol options are allowed: the main one (with socket options, if any), and a shorter one, with options being a subset of the main options, repeated for clarity. As long as the shorter set of protocol options is used, all listen directives except the main one should use it.
author Maxim Dounin <mdounin@mdounin.ru>
date Sat, 28 Jan 2023 01:29:45 +0300
parents d964b0aee8e7
children
line wrap: on
line source


/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    uint32_t                              hash;
    ngx_str_t                            *server;
} ngx_stream_upstream_chash_point_t;


typedef struct {
    ngx_uint_t                            number;
    ngx_stream_upstream_chash_point_t     point[1];
} ngx_stream_upstream_chash_points_t;


typedef struct {
    ngx_stream_complex_value_t            key;
    ngx_stream_upstream_chash_points_t   *points;
} ngx_stream_upstream_hash_srv_conf_t;


typedef struct {
    /* the round robin data must be first */
    ngx_stream_upstream_rr_peer_data_t    rrp;
    ngx_stream_upstream_hash_srv_conf_t  *conf;
    ngx_str_t                             key;
    ngx_uint_t                            tries;
    ngx_uint_t                            rehash;
    uint32_t                              hash;
    ngx_event_get_peer_pt                 get_rr_peer;
} ngx_stream_upstream_hash_peer_data_t;


static ngx_int_t ngx_stream_upstream_init_hash(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us);
static ngx_int_t ngx_stream_upstream_init_hash_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us);
static ngx_int_t ngx_stream_upstream_get_hash_peer(ngx_peer_connection_t *pc,
    void *data);

static ngx_int_t ngx_stream_upstream_init_chash(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us);
static int ngx_libc_cdecl
    ngx_stream_upstream_chash_cmp_points(const void *one, const void *two);
static ngx_uint_t ngx_stream_upstream_find_chash_point(
    ngx_stream_upstream_chash_points_t *points, uint32_t hash);
static ngx_int_t ngx_stream_upstream_init_chash_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us);
static ngx_int_t ngx_stream_upstream_get_chash_peer(ngx_peer_connection_t *pc,
    void *data);

static void *ngx_stream_upstream_hash_create_conf(ngx_conf_t *cf);
static char *ngx_stream_upstream_hash(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_command_t  ngx_stream_upstream_hash_commands[] = {

    { ngx_string("hash"),
      NGX_STREAM_UPS_CONF|NGX_CONF_TAKE12,
      ngx_stream_upstream_hash,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_upstream_hash_module_ctx = {
    NULL,                                  /* preconfiguration */
    NULL,                                  /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    ngx_stream_upstream_hash_create_conf,  /* create server configuration */
    NULL                                   /* merge server configuration */
};


ngx_module_t  ngx_stream_upstream_hash_module = {
    NGX_MODULE_V1,
    &ngx_stream_upstream_hash_module_ctx,  /* module context */
    ngx_stream_upstream_hash_commands,     /* module directives */
    NGX_STREAM_MODULE,                     /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_int_t
ngx_stream_upstream_init_hash(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us)
{
    if (ngx_stream_upstream_init_round_robin(cf, us) != NGX_OK) {
        return NGX_ERROR;
    }

    us->peer.init = ngx_stream_upstream_init_hash_peer;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_upstream_init_hash_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us)
{
    ngx_stream_upstream_hash_srv_conf_t   *hcf;
    ngx_stream_upstream_hash_peer_data_t  *hp;

    hp = ngx_palloc(s->connection->pool,
                    sizeof(ngx_stream_upstream_hash_peer_data_t));
    if (hp == NULL) {
        return NGX_ERROR;
    }

    s->upstream->peer.data = &hp->rrp;

    if (ngx_stream_upstream_init_round_robin_peer(s, us) != NGX_OK) {
        return NGX_ERROR;
    }

    s->upstream->peer.get = ngx_stream_upstream_get_hash_peer;

    hcf = ngx_stream_conf_upstream_srv_conf(us,
                                            ngx_stream_upstream_hash_module);

    if (ngx_stream_complex_value(s, &hcf->key, &hp->key) != NGX_OK) {
        return NGX_ERROR;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "upstream hash key:\"%V\"", &hp->key);

    hp->conf = hcf;
    hp->tries = 0;
    hp->rehash = 0;
    hp->hash = 0;
    hp->get_rr_peer = ngx_stream_upstream_get_round_robin_peer;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data)
{
    ngx_stream_upstream_hash_peer_data_t *hp = data;

    time_t                          now;
    u_char                          buf[NGX_INT_T_LEN];
    size_t                          size;
    uint32_t                        hash;
    ngx_int_t                       w;
    uintptr_t                       m;
    ngx_uint_t                      n, p;
    ngx_stream_upstream_rr_peer_t  *peer;

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

    ngx_stream_upstream_rr_peers_rlock(hp->rrp.peers);

    if (hp->tries > 20 || hp->rrp.peers->single || hp->key.len == 0) {
        ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers);
        return hp->get_rr_peer(pc, &hp->rrp);
    }

    now = ngx_time();

    pc->connection = NULL;

    for ( ;; ) {

        /*
         * Hash expression is compatible with Cache::Memcached:
         * ((crc32([REHASH] KEY) >> 16) & 0x7fff) + PREV_HASH
         * with REHASH omitted at the first iteration.
         */

        ngx_crc32_init(hash);

        if (hp->rehash > 0) {
            size = ngx_sprintf(buf, "%ui", hp->rehash) - buf;
            ngx_crc32_update(&hash, buf, size);
        }

        ngx_crc32_update(&hash, hp->key.data, hp->key.len);
        ngx_crc32_final(hash);

        hash = (hash >> 16) & 0x7fff;

        hp->hash += hash;
        hp->rehash++;

        w = hp->hash % hp->rrp.peers->total_weight;
        peer = hp->rrp.peers->peer;
        p = 0;

        while (w >= peer->weight) {
            w -= peer->weight;
            peer = peer->next;
            p++;
        }

        n = p / (8 * sizeof(uintptr_t));
        m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));

        if (hp->rrp.tried[n] & m) {
            goto next;
        }

        ngx_stream_upstream_rr_peer_lock(hp->rrp.peers, peer);

        ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                       "get hash peer, value:%uD, peer:%ui", hp->hash, p);

        if (peer->down) {
            ngx_stream_upstream_rr_peer_unlock(hp->rrp.peers, peer);
            goto next;
        }

        if (peer->max_fails
            && peer->fails >= peer->max_fails
            && now - peer->checked <= peer->fail_timeout)
        {
            ngx_stream_upstream_rr_peer_unlock(hp->rrp.peers, peer);
            goto next;
        }

        if (peer->max_conns && peer->conns >= peer->max_conns) {
            ngx_stream_upstream_rr_peer_unlock(hp->rrp.peers, peer);
            goto next;
        }

        break;

    next:

        if (++hp->tries > 20) {
            ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers);
            return hp->get_rr_peer(pc, &hp->rrp);
        }
    }

    hp->rrp.current = peer;

    pc->sockaddr = peer->sockaddr;
    pc->socklen = peer->socklen;
    pc->name = &peer->name;

    peer->conns++;

    if (now - peer->checked > peer->fail_timeout) {
        peer->checked = now;
    }

    ngx_stream_upstream_rr_peer_unlock(hp->rrp.peers, peer);
    ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers);

    hp->rrp.tried[n] |= m;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_upstream_init_chash(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us)
{
    u_char                               *host, *port, c;
    size_t                                host_len, port_len, size;
    uint32_t                              hash, base_hash;
    ngx_str_t                            *server;
    ngx_uint_t                            npoints, i, j;
    ngx_stream_upstream_rr_peer_t        *peer;
    ngx_stream_upstream_rr_peers_t       *peers;
    ngx_stream_upstream_chash_points_t   *points;
    ngx_stream_upstream_hash_srv_conf_t  *hcf;
    union {
        uint32_t                          value;
        u_char                            byte[4];
    } prev_hash;

    if (ngx_stream_upstream_init_round_robin(cf, us) != NGX_OK) {
        return NGX_ERROR;
    }

    us->peer.init = ngx_stream_upstream_init_chash_peer;

    peers = us->peer.data;
    npoints = peers->total_weight * 160;

    size = sizeof(ngx_stream_upstream_chash_points_t)
           + sizeof(ngx_stream_upstream_chash_point_t) * (npoints - 1);

    points = ngx_palloc(cf->pool, size);
    if (points == NULL) {
        return NGX_ERROR;
    }

    points->number = 0;

    for (peer = peers->peer; peer; peer = peer->next) {
        server = &peer->server;

        /*
         * Hash expression is compatible with Cache::Memcached::Fast:
         * crc32(HOST \0 PORT PREV_HASH).
         */

        if (server->len >= 5
            && ngx_strncasecmp(server->data, (u_char *) "unix:", 5) == 0)
        {
            host = server->data + 5;
            host_len = server->len - 5;
            port = NULL;
            port_len = 0;
            goto done;
        }

        for (j = 0; j < server->len; j++) {
            c = server->data[server->len - j - 1];

            if (c == ':') {
                host = server->data;
                host_len = server->len - j - 1;
                port = server->data + server->len - j;
                port_len = j;
                goto done;
            }

            if (c < '0' || c > '9') {
                break;
            }
        }

        host = server->data;
        host_len = server->len;
        port = NULL;
        port_len = 0;

    done:

        ngx_crc32_init(base_hash);
        ngx_crc32_update(&base_hash, host, host_len);
        ngx_crc32_update(&base_hash, (u_char *) "", 1);
        ngx_crc32_update(&base_hash, port, port_len);

        prev_hash.value = 0;
        npoints = peer->weight * 160;

        for (j = 0; j < npoints; j++) {
            hash = base_hash;

            ngx_crc32_update(&hash, prev_hash.byte, 4);
            ngx_crc32_final(hash);

            points->point[points->number].hash = hash;
            points->point[points->number].server = server;
            points->number++;

#if (NGX_HAVE_LITTLE_ENDIAN)
            prev_hash.value = hash;
#else
            prev_hash.byte[0] = (u_char) (hash & 0xff);
            prev_hash.byte[1] = (u_char) ((hash >> 8) & 0xff);
            prev_hash.byte[2] = (u_char) ((hash >> 16) & 0xff);
            prev_hash.byte[3] = (u_char) ((hash >> 24) & 0xff);
#endif
        }
    }

    ngx_qsort(points->point,
              points->number,
              sizeof(ngx_stream_upstream_chash_point_t),
              ngx_stream_upstream_chash_cmp_points);

    for (i = 0, j = 1; j < points->number; j++) {
        if (points->point[i].hash != points->point[j].hash) {
            points->point[++i] = points->point[j];
        }
    }

    points->number = i + 1;

    hcf = ngx_stream_conf_upstream_srv_conf(us,
                                            ngx_stream_upstream_hash_module);
    hcf->points = points;

    return NGX_OK;
}


static int ngx_libc_cdecl
ngx_stream_upstream_chash_cmp_points(const void *one, const void *two)
{
    ngx_stream_upstream_chash_point_t *first =
                                     (ngx_stream_upstream_chash_point_t *) one;
    ngx_stream_upstream_chash_point_t *second =
                                     (ngx_stream_upstream_chash_point_t *) two;

    if (first->hash < second->hash) {
        return -1;

    } else if (first->hash > second->hash) {
        return 1;

    } else {
        return 0;
    }
}


static ngx_uint_t
ngx_stream_upstream_find_chash_point(ngx_stream_upstream_chash_points_t *points,
    uint32_t hash)
{
    ngx_uint_t                          i, j, k;
    ngx_stream_upstream_chash_point_t  *point;

    /* find first point >= hash */

    point = &points->point[0];

    i = 0;
    j = points->number;

    while (i < j) {
        k = (i + j) / 2;

        if (hash > point[k].hash) {
            i = k + 1;

        } else if (hash < point[k].hash) {
            j = k;

        } else {
            return k;
        }
    }

    return i;
}


static ngx_int_t
ngx_stream_upstream_init_chash_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us)
{
    uint32_t                               hash;
    ngx_stream_upstream_hash_srv_conf_t   *hcf;
    ngx_stream_upstream_hash_peer_data_t  *hp;

    if (ngx_stream_upstream_init_hash_peer(s, us) != NGX_OK) {
        return NGX_ERROR;
    }

    s->upstream->peer.get = ngx_stream_upstream_get_chash_peer;

    hp = s->upstream->peer.data;
    hcf = ngx_stream_conf_upstream_srv_conf(us,
                                            ngx_stream_upstream_hash_module);

    hash = ngx_crc32_long(hp->key.data, hp->key.len);

    ngx_stream_upstream_rr_peers_rlock(hp->rrp.peers);

    hp->hash = ngx_stream_upstream_find_chash_point(hcf->points, hash);

    ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers);

    return NGX_OK;
}


static ngx_int_t
ngx_stream_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data)
{
    ngx_stream_upstream_hash_peer_data_t *hp = data;

    time_t                                now;
    intptr_t                              m;
    ngx_str_t                            *server;
    ngx_int_t                             total;
    ngx_uint_t                            i, n, best_i;
    ngx_stream_upstream_rr_peer_t        *peer, *best;
    ngx_stream_upstream_chash_point_t    *point;
    ngx_stream_upstream_chash_points_t   *points;
    ngx_stream_upstream_hash_srv_conf_t  *hcf;

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                   "get consistent hash peer, try: %ui", pc->tries);

    ngx_stream_upstream_rr_peers_wlock(hp->rrp.peers);

    if (hp->tries > 20 || hp->rrp.peers->single || hp->key.len == 0) {
        ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers);
        return hp->get_rr_peer(pc, &hp->rrp);
    }

    pc->connection = NULL;

    now = ngx_time();
    hcf = hp->conf;

    points = hcf->points;
    point = &points->point[0];

    for ( ;; ) {
        server = point[hp->hash % points->number].server;

        ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                       "consistent hash peer:%uD, server:\"%V\"",
                       hp->hash, server);

        best = NULL;
        best_i = 0;
        total = 0;

        for (peer = hp->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 (hp->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;
            }

            if (peer->server.len != server->len
                || ngx_strncmp(peer->server.data, server->data, server->len)
                   != 0)
            {
                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;
                best_i = i;
            }
        }

        if (best) {
            best->current_weight -= total;
            break;
        }

        hp->hash++;
        hp->tries++;

        if (hp->tries > 20) {
            ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers);
            return hp->get_rr_peer(pc, &hp->rrp);
        }
    }

    hp->rrp.current = best;

    pc->sockaddr = best->sockaddr;
    pc->socklen = best->socklen;
    pc->name = &best->name;

    best->conns++;

    if (now - best->checked > best->fail_timeout) {
        best->checked = now;
    }

    ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers);

    n = best_i / (8 * sizeof(uintptr_t));
    m = (uintptr_t) 1 << best_i % (8 * sizeof(uintptr_t));

    hp->rrp.tried[n] |= m;

    return NGX_OK;
}


static void *
ngx_stream_upstream_hash_create_conf(ngx_conf_t *cf)
{
    ngx_stream_upstream_hash_srv_conf_t  *conf;

    conf = ngx_palloc(cf->pool, sizeof(ngx_stream_upstream_hash_srv_conf_t));
    if (conf == NULL) {
        return NULL;
    }

    conf->points = NULL;

    return conf;
}


static char *
ngx_stream_upstream_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_upstream_hash_srv_conf_t  *hcf = conf;

    ngx_str_t                           *value;
    ngx_stream_upstream_srv_conf_t      *uscf;
    ngx_stream_compile_complex_value_t   ccv;

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &value[1];
    ccv.complex_value = &hcf->key;

    if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    uscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_upstream_module);

    if (uscf->peer.init_upstream) {
        ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                           "load balancing method redefined");
    }

    uscf->flags = NGX_STREAM_UPSTREAM_CREATE
                  |NGX_STREAM_UPSTREAM_WEIGHT
                  |NGX_STREAM_UPSTREAM_MAX_CONNS
                  |NGX_STREAM_UPSTREAM_MAX_FAILS
                  |NGX_STREAM_UPSTREAM_FAIL_TIMEOUT
                  |NGX_STREAM_UPSTREAM_DOWN;

    if (cf->args->nelts == 2) {
        uscf->peer.init_upstream = ngx_stream_upstream_init_hash;

    } else if (ngx_strcmp(value[2].data, "consistent") == 0) {
        uscf->peer.init_upstream = ngx_stream_upstream_init_chash;

    } else {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid parameter \"%V\"", &value[2]);
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}