view src/stream/ngx_stream_upstream_random_module.c @ 8442:b3f6ad181df4 quic

QUIC: refactored CRYPTO and STREAM buffer ordering. Generic function ngx_quic_order_bufs() is introduced. This function creates and maintains a chain of buffers with holes. Holes are marked with b->sync flag. Several buffers and holes in this chain may share the same underlying memory buffer. When processing STREAM frames with this function, frame data is copied only once to the right place in the stream input chain. Previously data could be copied twice. First when buffering an out-of-order frame data, and then when filling stream buffer from ordered frame queue. Now there's only one data chain for both tasks.
author Roman Arutyunyan <arut@nginx.com>
date Tue, 25 May 2021 13:55:12 +0300
parents f2396ecf608b
children
line wrap: on
line source


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


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


typedef struct {
    ngx_stream_upstream_rr_peer_t          *peer;
    ngx_uint_t                              range;
} ngx_stream_upstream_random_range_t;


typedef struct {
    ngx_uint_t                              two;
    ngx_stream_upstream_random_range_t     *ranges;
} ngx_stream_upstream_random_srv_conf_t;


typedef struct {
    /* the round robin data must be first */
    ngx_stream_upstream_rr_peer_data_t      rrp;

    ngx_stream_upstream_random_srv_conf_t  *conf;
    u_char                                  tries;
} ngx_stream_upstream_random_peer_data_t;


static ngx_int_t ngx_stream_upstream_init_random(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us);
static ngx_int_t ngx_stream_upstream_update_random(ngx_pool_t *pool,
    ngx_stream_upstream_srv_conf_t *us);

static ngx_int_t ngx_stream_upstream_init_random_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us);
static ngx_int_t ngx_stream_upstream_get_random_peer(ngx_peer_connection_t *pc,
    void *data);
static ngx_int_t ngx_stream_upstream_get_random2_peer(ngx_peer_connection_t *pc,
    void *data);
static ngx_uint_t ngx_stream_upstream_peek_random_peer(
    ngx_stream_upstream_rr_peers_t *peers,
    ngx_stream_upstream_random_peer_data_t *rp);
static void *ngx_stream_upstream_random_create_conf(ngx_conf_t *cf);
static char *ngx_stream_upstream_random(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_command_t  ngx_stream_upstream_random_commands[] = {

    { ngx_string("random"),
      NGX_STREAM_UPS_CONF|NGX_CONF_NOARGS|NGX_CONF_TAKE12,
      ngx_stream_upstream_random,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


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

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

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


ngx_module_t  ngx_stream_upstream_random_module = {
    NGX_MODULE_V1,
    &ngx_stream_upstream_random_module_ctx,  /* module context */
    ngx_stream_upstream_random_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_random(ngx_conf_t *cf,
    ngx_stream_upstream_srv_conf_t *us)
{
    ngx_log_debug0(NGX_LOG_DEBUG_STREAM, cf->log, 0, "init random");

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

    us->peer.init = ngx_stream_upstream_init_random_peer;

#if (NGX_STREAM_UPSTREAM_ZONE)
    if (us->shm_zone) {
        return NGX_OK;
    }
#endif

    return ngx_stream_upstream_update_random(cf->pool, us);
}


static ngx_int_t
ngx_stream_upstream_update_random(ngx_pool_t *pool,
    ngx_stream_upstream_srv_conf_t *us)
{
    size_t                                  size;
    ngx_uint_t                              i, total_weight;
    ngx_stream_upstream_rr_peer_t          *peer;
    ngx_stream_upstream_rr_peers_t         *peers;
    ngx_stream_upstream_random_range_t     *ranges;
    ngx_stream_upstream_random_srv_conf_t  *rcf;

    rcf = ngx_stream_conf_upstream_srv_conf(us,
                                            ngx_stream_upstream_random_module);
    peers = us->peer.data;

    size = peers->number * sizeof(ngx_stream_upstream_random_range_t);

    ranges = pool ? ngx_palloc(pool, size) : ngx_alloc(size, ngx_cycle->log);
    if (ranges == NULL) {
        return NGX_ERROR;
    }

    total_weight = 0;

    for (peer = peers->peer, i = 0; peer; peer = peer->next, i++) {
        ranges[i].peer = peer;
        ranges[i].range = total_weight;
        total_weight += peer->weight;
    }

    rcf->ranges = ranges;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_upstream_init_random_peer(ngx_stream_session_t *s,
    ngx_stream_upstream_srv_conf_t *us)
{
    ngx_stream_upstream_random_srv_conf_t   *rcf;
    ngx_stream_upstream_random_peer_data_t  *rp;

    ngx_log_debug0(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "init random peer");

    rcf = ngx_stream_conf_upstream_srv_conf(us,
                                            ngx_stream_upstream_random_module);

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

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

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

    if (rcf->two) {
        s->upstream->peer.get = ngx_stream_upstream_get_random2_peer;

    } else {
        s->upstream->peer.get = ngx_stream_upstream_get_random_peer;
    }

    rp->conf = rcf;
    rp->tries = 0;

    ngx_stream_upstream_rr_peers_rlock(rp->rrp.peers);

#if (NGX_STREAM_UPSTREAM_ZONE)
    if (rp->rrp.peers->shpool && rcf->ranges == NULL) {
        if (ngx_stream_upstream_update_random(NULL, us) != NGX_OK) {
            ngx_stream_upstream_rr_peers_unlock(rp->rrp.peers);
            return NGX_ERROR;
        }
    }
#endif

    ngx_stream_upstream_rr_peers_unlock(rp->rrp.peers);

    return NGX_OK;
}


static ngx_int_t
ngx_stream_upstream_get_random_peer(ngx_peer_connection_t *pc, void *data)
{
    ngx_stream_upstream_random_peer_data_t  *rp = data;

    time_t                               now;
    uintptr_t                            m;
    ngx_uint_t                           i, n;
    ngx_stream_upstream_rr_peer_t       *peer;
    ngx_stream_upstream_rr_peers_t      *peers;
    ngx_stream_upstream_rr_peer_data_t  *rrp;

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

    rrp = &rp->rrp;
    peers = rrp->peers;

    ngx_stream_upstream_rr_peers_rlock(peers);

    if (rp->tries > 20 || peers->single) {
        ngx_stream_upstream_rr_peers_unlock(peers);
        return ngx_stream_upstream_get_round_robin_peer(pc, rrp);
    }

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

    now = ngx_time();

    for ( ;; ) {

        i = ngx_stream_upstream_peek_random_peer(peers, rp);

        peer = rp->conf->ranges[i].peer;

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

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

        ngx_stream_upstream_rr_peer_lock(peers, peer);

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

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

        break;

    next:

        if (++rp->tries > 20) {
            ngx_stream_upstream_rr_peers_unlock(peers);
            return ngx_stream_upstream_get_round_robin_peer(pc, rrp);
        }
    }

    rrp->current = peer;

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

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

    peer->conns++;

    ngx_stream_upstream_rr_peer_unlock(peers, peer);
    ngx_stream_upstream_rr_peers_unlock(peers);

    rrp->tried[n] |= m;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_upstream_get_random2_peer(ngx_peer_connection_t *pc, void *data)
{
    ngx_stream_upstream_random_peer_data_t  *rp = data;

    time_t                               now;
    uintptr_t                            m;
    ngx_uint_t                           i, n, p;
    ngx_stream_upstream_rr_peer_t       *peer, *prev;
    ngx_stream_upstream_rr_peers_t      *peers;
    ngx_stream_upstream_rr_peer_data_t  *rrp;

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
                   "get random2 peer, try: %ui", pc->tries);

    rrp = &rp->rrp;
    peers = rrp->peers;

    ngx_stream_upstream_rr_peers_wlock(peers);

    if (rp->tries > 20 || peers->single) {
        ngx_stream_upstream_rr_peers_unlock(peers);
        return ngx_stream_upstream_get_round_robin_peer(pc, rrp);
    }

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

    now = ngx_time();

    prev = NULL;

#if (NGX_SUPPRESS_WARN)
    p = 0;
#endif

    for ( ;; ) {

        i = ngx_stream_upstream_peek_random_peer(peers, rp);

        peer = rp->conf->ranges[i].peer;

        if (peer == prev) {
            goto next;
        }

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

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

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

        if (peer->max_fails
            && peer->fails >= peer->max_fails
            && now - peer->checked <= peer->fail_timeout)
        {
            goto next;
        }

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

        if (prev) {
            if (peer->conns * prev->weight > prev->conns * peer->weight) {
                peer = prev;
                n = p / (8 * sizeof(uintptr_t));
                m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));
            }

            break;
        }

        prev = peer;
        p = i;

    next:

        if (++rp->tries > 20) {
            ngx_stream_upstream_rr_peers_unlock(peers);
            return ngx_stream_upstream_get_round_robin_peer(pc, rrp);
        }
    }

    rrp->current = peer;

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

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

    peer->conns++;

    ngx_stream_upstream_rr_peers_unlock(peers);

    rrp->tried[n] |= m;

    return NGX_OK;
}


static ngx_uint_t
ngx_stream_upstream_peek_random_peer(ngx_stream_upstream_rr_peers_t *peers,
    ngx_stream_upstream_random_peer_data_t *rp)
{
    ngx_uint_t  i, j, k, x;

    x = ngx_random() % peers->total_weight;

    i = 0;
    j = peers->number;

    while (j - i > 1) {
        k = (i + j) / 2;

        if (x < rp->conf->ranges[k].range) {
            j = k;

        } else {
            i = k;
        }
    }

    return i;
}


static void *
ngx_stream_upstream_random_create_conf(ngx_conf_t *cf)
{
    ngx_stream_upstream_random_srv_conf_t  *conf;

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

    /*
     * set by ngx_pcalloc():
     *
     *     conf->two = 0;
     */

    return conf;
}


static char *
ngx_stream_upstream_random(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_upstream_random_srv_conf_t  *rcf = conf;

    ngx_str_t                       *value;
    ngx_stream_upstream_srv_conf_t  *uscf;

    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->peer.init_upstream = ngx_stream_upstream_init_random;

    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 == 1) {
        return NGX_CONF_OK;
    }

    value = cf->args->elts;

    if (ngx_strcmp(value[1].data, "two") == 0) {
        rcf->two = 1;

    } else {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid parameter \"%V\"", &value[1]);
        return NGX_CONF_ERROR;
    }

    if (cf->args->nelts == 2) {
        return NGX_CONF_OK;
    }

    if (ngx_strcmp(value[2].data, "least_conn") != 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid parameter \"%V\"", &value[2]);
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}