Mercurial > hg > nginx
view src/http/modules/ngx_http_upstream_hash_module.c @ 7235:c2a0a838c40f
gRPC: special handling of "trailer only" responses.
The gRPC protocol makes a distinction between HEADERS frame with
the END_STREAM flag set, and a HEADERS frame followed by an empty
DATA frame with the END_STREAM flag. The latter is not permitted,
and results in errors not being propagated through nginx. Instead,
gRPC clients complain that "server closed the stream without sending
trailers" (seen in grpc-go) or "13: Received RST_STREAM with error
code 2" (seen in grpc-c).
To fix this, nginx now returns HEADERS with the END_STREAM flag if
the response length is known to be 0, and we are not expecting
any trailer headers to be added. And the response length is
explicitly set to 0 in the gRPC proxy if we see initial HEADERS frame
with the END_STREAM flag set.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Sat, 17 Mar 2018 23:04:26 +0300 |
parents | 3b4fa572d56d |
children | ed599ea6c1f1 |
line wrap: on
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { uint32_t hash; ngx_str_t *server; } ngx_http_upstream_chash_point_t; typedef struct { ngx_uint_t number; ngx_http_upstream_chash_point_t point[1]; } ngx_http_upstream_chash_points_t; typedef struct { ngx_http_complex_value_t key; ngx_http_upstream_chash_points_t *points; } ngx_http_upstream_hash_srv_conf_t; typedef struct { /* the round robin data must be first */ ngx_http_upstream_rr_peer_data_t rrp; ngx_http_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_http_upstream_hash_peer_data_t; static ngx_int_t ngx_http_upstream_init_hash(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_init_hash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data); static ngx_int_t ngx_http_upstream_init_chash(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us); static int ngx_libc_cdecl ngx_http_upstream_chash_cmp_points(const void *one, const void *two); static ngx_uint_t ngx_http_upstream_find_chash_point( ngx_http_upstream_chash_points_t *points, uint32_t hash); static ngx_int_t ngx_http_upstream_init_chash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data); static void *ngx_http_upstream_hash_create_conf(ngx_conf_t *cf); static char *ngx_http_upstream_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_upstream_hash_commands[] = { { ngx_string("hash"), NGX_HTTP_UPS_CONF|NGX_CONF_TAKE12, ngx_http_upstream_hash, NGX_HTTP_SRV_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_upstream_hash_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_http_upstream_hash_create_conf, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_upstream_hash_module = { NGX_MODULE_V1, &ngx_http_upstream_hash_module_ctx, /* module context */ ngx_http_upstream_hash_commands, /* module directives */ NGX_HTTP_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_http_upstream_init_hash(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us) { if (ngx_http_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_http_upstream_init_hash_peer; return NGX_OK; } static ngx_int_t ngx_http_upstream_init_hash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us) { ngx_http_upstream_hash_srv_conf_t *hcf; ngx_http_upstream_hash_peer_data_t *hp; hp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_hash_peer_data_t)); if (hp == NULL) { return NGX_ERROR; } r->upstream->peer.data = &hp->rrp; if (ngx_http_upstream_init_round_robin_peer(r, us) != NGX_OK) { return NGX_ERROR; } r->upstream->peer.get = ngx_http_upstream_get_hash_peer; hcf = ngx_http_conf_upstream_srv_conf(us, ngx_http_upstream_hash_module); if (ngx_http_complex_value(r, &hcf->key, &hp->key) != NGX_OK) { return NGX_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->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_http_upstream_get_round_robin_peer; return NGX_OK; } static ngx_int_t ngx_http_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_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_http_upstream_rr_peer_t *peer; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get hash peer, try: %ui", pc->tries); ngx_http_upstream_rr_peers_wlock(hp->rrp.peers); if (hp->tries > 20 || hp->rrp.peers->single) { ngx_http_upstream_rr_peers_unlock(hp->rrp.peers); return hp->get_rr_peer(pc, &hp->rrp); } now = ngx_time(); pc->cached = 0; 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_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get hash peer, value:%uD, peer:%ui", hp->hash, p); 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; } break; next: if (++hp->tries > 20) { ngx_http_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_http_upstream_rr_peers_unlock(hp->rrp.peers); hp->rrp.tried[n] |= m; return NGX_OK; } static ngx_int_t ngx_http_upstream_init_chash(ngx_conf_t *cf, ngx_http_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_http_upstream_rr_peer_t *peer; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_chash_points_t *points; ngx_http_upstream_hash_srv_conf_t *hcf; union { uint32_t value; u_char byte[4]; } prev_hash; if (ngx_http_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_http_upstream_init_chash_peer; peers = us->peer.data; npoints = peers->total_weight * 160; size = sizeof(ngx_http_upstream_chash_points_t) + sizeof(ngx_http_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_http_upstream_chash_point_t), ngx_http_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_http_conf_upstream_srv_conf(us, ngx_http_upstream_hash_module); hcf->points = points; return NGX_OK; } static int ngx_libc_cdecl ngx_http_upstream_chash_cmp_points(const void *one, const void *two) { ngx_http_upstream_chash_point_t *first = (ngx_http_upstream_chash_point_t *) one; ngx_http_upstream_chash_point_t *second = (ngx_http_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_http_upstream_find_chash_point(ngx_http_upstream_chash_points_t *points, uint32_t hash) { ngx_uint_t i, j, k; ngx_http_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_http_upstream_init_chash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us) { uint32_t hash; ngx_http_upstream_hash_srv_conf_t *hcf; ngx_http_upstream_hash_peer_data_t *hp; if (ngx_http_upstream_init_hash_peer(r, us) != NGX_OK) { return NGX_ERROR; } r->upstream->peer.get = ngx_http_upstream_get_chash_peer; hp = r->upstream->peer.data; hcf = ngx_http_conf_upstream_srv_conf(us, ngx_http_upstream_hash_module); hash = ngx_crc32_long(hp->key.data, hp->key.len); ngx_http_upstream_rr_peers_rlock(hp->rrp.peers); hp->hash = ngx_http_upstream_find_chash_point(hcf->points, hash); ngx_http_upstream_rr_peers_unlock(hp->rrp.peers); return NGX_OK; } static ngx_int_t ngx_http_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_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_http_upstream_rr_peer_t *peer, *best; ngx_http_upstream_chash_point_t *point; ngx_http_upstream_chash_points_t *points; ngx_http_upstream_hash_srv_conf_t *hcf; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get consistent hash peer, try: %ui", pc->tries); ngx_http_upstream_rr_peers_wlock(hp->rrp.peers); if (hp->tries > 20 || hp->rrp.peers->single) { ngx_http_upstream_rr_peers_unlock(hp->rrp.peers); return hp->get_rr_peer(pc, &hp->rrp); } pc->cached = 0; 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_HTTP, 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; goto found; } hp->hash++; hp->tries++; if (hp->tries > 20) { ngx_http_upstream_rr_peers_unlock(hp->rrp.peers); return hp->get_rr_peer(pc, &hp->rrp); } } found: 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_http_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_http_upstream_hash_create_conf(ngx_conf_t *cf) { ngx_http_upstream_hash_srv_conf_t *conf; conf = ngx_palloc(cf->pool, sizeof(ngx_http_upstream_hash_srv_conf_t)); if (conf == NULL) { return NULL; } conf->points = NULL; return conf; } static char * ngx_http_upstream_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_upstream_hash_srv_conf_t *hcf = conf; ngx_str_t *value; ngx_http_upstream_srv_conf_t *uscf; ngx_http_compile_complex_value_t ccv; value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &hcf->key; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module); if (uscf->peer.init_upstream) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "load balancing method redefined"); } uscf->flags = NGX_HTTP_UPSTREAM_CREATE |NGX_HTTP_UPSTREAM_WEIGHT |NGX_HTTP_UPSTREAM_MAX_CONNS |NGX_HTTP_UPSTREAM_MAX_FAILS |NGX_HTTP_UPSTREAM_FAIL_TIMEOUT |NGX_HTTP_UPSTREAM_DOWN; if (cf->args->nelts == 2) { uscf->peer.init_upstream = ngx_http_upstream_init_hash; } else if (ngx_strcmp(value[2].data, "consistent") == 0) { uscf->peer.init_upstream = ngx_http_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; }