Mercurial > hg > nginx-quic
view src/http/ngx_http_request_body.c @ 4667:d05ab8793a69 stable-1.2
Merge of r4622, r4623: balancing changes.
*) Upstream: smooth weighted round-robin balancing.
For edge case weights like { 5, 1, 1 } we now produce { a, a, b, a, c, a, a }
sequence instead of { c, b, a, a, a, a, a } produced previously.
Algorithm is as follows: on each peer selection we increase current_weight
of each eligible peer by its weight, select peer with greatest current_weight
and reduce its current_weight by total number of weight points distributed
among peers.
In case of { 5, 1, 1 } weights this gives the following sequence of
current_weight's:
a b c
0 0 0 (initial state)
5 1 1 (a selected)
-2 1 1
3 2 2 (a selected)
-4 2 2
1 3 3 (b selected)
1 -4 3
6 -3 4 (a selected)
-1 -3 4
4 -2 5 (c selected)
4 -2 -2
9 -1 -1 (a selected)
2 -1 -1
7 0 0 (a selected)
0 0 0
To preserve weight reduction in case of failures the effective_weight
variable was introduced, which usually matches peer's weight, but is
reduced temporarily on peer failures.
This change also fixes loop with backup servers and proxy_next_upstream
http_404 (ticket #47), and skipping alive upstreams in some cases if there
are multiple dead ones (ticket #64).
*) Upstream: fixed ip_hash rebalancing with the "down" flag.
Due to weight being set to 0 for down peers, order of peers after sorting
wasn't the same as without the "down" flag (with down peers at the end),
resulting in client rebalancing for clients on other servers. The only
rebalancing which should happen after adding "down" to a server is one
for clients on the server.
The problem was introduced in r1377 (which fixed endless loop by setting
weight to 0 for down servers). The loop is no longer possible with new
smooth algorithm, so preserving original weight is safe.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 04 Jun 2012 11:21:58 +0000 |
parents | 834049edae24 |
children | dfa586842962 7556a7acb14f |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static void ngx_http_read_client_request_body_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_do_read_client_request_body(ngx_http_request_t *r); static ngx_int_t ngx_http_write_request_body(ngx_http_request_t *r, ngx_chain_t *body); static ngx_int_t ngx_http_read_discarded_request_body(ngx_http_request_t *r); static ngx_int_t ngx_http_test_expect(ngx_http_request_t *r); /* * on completion ngx_http_read_client_request_body() adds to * r->request_body->bufs one or two bufs: * *) one memory buf that was preread in r->header_in; * *) one memory or file buf that contains the rest of the body */ ngx_int_t ngx_http_read_client_request_body(ngx_http_request_t *r, ngx_http_client_body_handler_pt post_handler) { size_t preread; ssize_t size; ngx_buf_t *b; ngx_chain_t *cl, **next; ngx_temp_file_t *tf; ngx_http_request_body_t *rb; ngx_http_core_loc_conf_t *clcf; r->main->count++; if (r->request_body || r->discard_body) { post_handler(r); return NGX_OK; } if (ngx_http_test_expect(r) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t)); if (rb == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } r->request_body = rb; if (r->headers_in.content_length_n < 0) { post_handler(r); return NGX_OK; } clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (r->headers_in.content_length_n == 0) { if (r->request_body_in_file_only) { tf = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t)); if (tf == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } tf->file.fd = NGX_INVALID_FILE; tf->file.log = r->connection->log; tf->path = clcf->client_body_temp_path; tf->pool = r->pool; tf->warn = "a client request body is buffered to a temporary file"; tf->log_level = r->request_body_file_log_level; tf->persistent = r->request_body_in_persistent_file; tf->clean = r->request_body_in_clean_file; if (r->request_body_file_group_access) { tf->access = 0660; } rb->temp_file = tf; if (ngx_create_temp_file(&tf->file, tf->path, tf->pool, tf->persistent, tf->clean, tf->access) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } } post_handler(r); return NGX_OK; } rb->post_handler = post_handler; /* * set by ngx_pcalloc(): * * rb->bufs = NULL; * rb->buf = NULL; * rb->rest = 0; */ preread = r->header_in->last - r->header_in->pos; if (preread) { /* there is the pre-read part of the request body */ ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http client request body preread %uz", preread); b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } b->temporary = 1; b->start = r->header_in->pos; b->pos = r->header_in->pos; b->last = r->header_in->last; b->end = r->header_in->end; rb->bufs = ngx_alloc_chain_link(r->pool); if (rb->bufs == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } rb->bufs->buf = b; rb->bufs->next = NULL; rb->buf = b; if ((off_t) preread >= r->headers_in.content_length_n) { /* the whole request body was pre-read */ r->header_in->pos += (size_t) r->headers_in.content_length_n; r->request_length += r->headers_in.content_length_n; b->last = r->header_in->pos; if (r->request_body_in_file_only) { if (ngx_http_write_request_body(r, rb->bufs) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } } post_handler(r); return NGX_OK; } /* * to not consider the body as pipelined request in * ngx_http_set_keepalive() */ r->header_in->pos = r->header_in->last; r->request_length += preread; rb->rest = r->headers_in.content_length_n - preread; if (rb->rest <= (off_t) (b->end - b->last)) { /* the whole request body may be placed in r->header_in */ rb->to_write = rb->bufs; r->read_event_handler = ngx_http_read_client_request_body_handler; return ngx_http_do_read_client_request_body(r); } next = &rb->bufs->next; } else { b = NULL; rb->rest = r->headers_in.content_length_n; next = &rb->bufs; } size = clcf->client_body_buffer_size; size += size >> 2; if (rb->rest < size) { size = (ssize_t) rb->rest; if (r->request_body_in_single_buf) { size += preread; } } else { size = clcf->client_body_buffer_size; /* disable copying buffer for r->request_body_in_single_buf */ b = NULL; } rb->buf = ngx_create_temp_buf(r->pool, size); if (rb->buf == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } cl = ngx_alloc_chain_link(r->pool); if (cl == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } cl->buf = rb->buf; cl->next = NULL; if (b && r->request_body_in_single_buf) { size = b->last - b->pos; ngx_memcpy(rb->buf->pos, b->pos, size); rb->buf->last += size; next = &rb->bufs; } *next = cl; if (r->request_body_in_file_only || r->request_body_in_single_buf) { rb->to_write = rb->bufs; } else { rb->to_write = rb->bufs->next ? rb->bufs->next : rb->bufs; } r->read_event_handler = ngx_http_read_client_request_body_handler; return ngx_http_do_read_client_request_body(r); } static void ngx_http_read_client_request_body_handler(ngx_http_request_t *r) { ngx_int_t rc; if (r->connection->read->timedout) { r->connection->timedout = 1; ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT); return; } rc = ngx_http_do_read_client_request_body(r); if (rc >= NGX_HTTP_SPECIAL_RESPONSE) { ngx_http_finalize_request(r, rc); } } static ngx_int_t ngx_http_do_read_client_request_body(ngx_http_request_t *r) { size_t size; ssize_t n; ngx_buf_t *b; ngx_connection_t *c; ngx_http_request_body_t *rb; ngx_http_core_loc_conf_t *clcf; c = r->connection; rb = r->request_body; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http read client request body"); for ( ;; ) { for ( ;; ) { if (rb->buf->last == rb->buf->end) { if (ngx_http_write_request_body(r, rb->to_write) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } rb->to_write = rb->bufs->next ? rb->bufs->next : rb->bufs; rb->buf->last = rb->buf->start; } size = rb->buf->end - rb->buf->last; if ((off_t) size > rb->rest) { size = (size_t) rb->rest; } n = c->recv(c, rb->buf->last, size); ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "http client request body recv %z", n); if (n == NGX_AGAIN) { break; } if (n == 0) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client prematurely closed connection"); } if (n == 0 || n == NGX_ERROR) { c->error = 1; return NGX_HTTP_BAD_REQUEST; } rb->buf->last += n; rb->rest -= n; r->request_length += n; if (rb->rest == 0) { break; } if (rb->buf->last < rb->buf->end) { break; } } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "http client request body rest %O", rb->rest); if (rb->rest == 0) { break; } if (!c->read->ready) { clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); ngx_add_timer(c->read, clcf->client_body_timeout); if (ngx_handle_read_event(c->read, 0) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } return NGX_AGAIN; } } if (c->read->timer_set) { ngx_del_timer(c->read); } if (rb->temp_file || r->request_body_in_file_only) { /* save the last part */ if (ngx_http_write_request_body(r, rb->to_write) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } b->in_file = 1; b->file_pos = 0; b->file_last = rb->temp_file->file.offset; b->file = &rb->temp_file->file; if (rb->bufs->next) { rb->bufs->next->buf = b; } else { rb->bufs->buf = b; } } if (rb->bufs->next && (r->request_body_in_file_only || r->request_body_in_single_buf)) { rb->bufs = rb->bufs->next; } r->read_event_handler = ngx_http_block_reading; rb->post_handler(r); return NGX_OK; } static ngx_int_t ngx_http_write_request_body(ngx_http_request_t *r, ngx_chain_t *body) { ssize_t n; ngx_temp_file_t *tf; ngx_http_request_body_t *rb; ngx_http_core_loc_conf_t *clcf; rb = r->request_body; if (rb->temp_file == NULL) { tf = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t)); if (tf == NULL) { return NGX_ERROR; } clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); tf->file.fd = NGX_INVALID_FILE; tf->file.log = r->connection->log; tf->path = clcf->client_body_temp_path; tf->pool = r->pool; tf->warn = "a client request body is buffered to a temporary file"; tf->log_level = r->request_body_file_log_level; tf->persistent = r->request_body_in_persistent_file; tf->clean = r->request_body_in_clean_file; if (r->request_body_file_group_access) { tf->access = 0660; } rb->temp_file = tf; } n = ngx_write_chain_to_temp_file(rb->temp_file, body); /* TODO: n == 0 or not complete and level event */ if (n == NGX_ERROR) { return NGX_ERROR; } rb->temp_file->offset += n; return NGX_OK; } ngx_int_t ngx_http_discard_request_body(ngx_http_request_t *r) { ssize_t size; ngx_event_t *rev; if (r != r->main || r->discard_body) { return NGX_OK; } if (ngx_http_test_expect(r) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } rev = r->connection->read; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0, "http set discard body"); if (rev->timer_set) { ngx_del_timer(rev); } if (r->headers_in.content_length_n <= 0 || r->request_body) { return NGX_OK; } size = r->header_in->last - r->header_in->pos; if (size) { if (r->headers_in.content_length_n > size) { r->header_in->pos += size; r->headers_in.content_length_n -= size; } else { r->header_in->pos += (size_t) r->headers_in.content_length_n; r->headers_in.content_length_n = 0; return NGX_OK; } } r->read_event_handler = ngx_http_discarded_request_body_handler; if (ngx_handle_read_event(rev, 0) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (ngx_http_read_discarded_request_body(r) == NGX_OK) { r->lingering_close = 0; } else { r->count++; r->discard_body = 1; } return NGX_OK; } void ngx_http_discarded_request_body_handler(ngx_http_request_t *r) { ngx_int_t rc; ngx_msec_t timer; ngx_event_t *rev; ngx_connection_t *c; ngx_http_core_loc_conf_t *clcf; c = r->connection; rev = c->read; if (rev->timedout) { c->timedout = 1; c->error = 1; ngx_http_finalize_request(r, NGX_ERROR); return; } if (r->lingering_time) { timer = (ngx_msec_t) (r->lingering_time - ngx_time()); if (timer <= 0) { r->discard_body = 0; r->lingering_close = 0; ngx_http_finalize_request(r, NGX_ERROR); return; } } else { timer = 0; } rc = ngx_http_read_discarded_request_body(r); if (rc == NGX_OK) { r->discard_body = 0; r->lingering_close = 0; ngx_http_finalize_request(r, NGX_DONE); return; } /* rc == NGX_AGAIN */ if (ngx_handle_read_event(rev, 0) != NGX_OK) { c->error = 1; ngx_http_finalize_request(r, NGX_ERROR); return; } if (timer) { clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); timer *= 1000; if (timer > clcf->lingering_timeout) { timer = clcf->lingering_timeout; } ngx_add_timer(rev, timer); } } static ngx_int_t ngx_http_read_discarded_request_body(ngx_http_request_t *r) { size_t size; ssize_t n; u_char buffer[NGX_HTTP_DISCARD_BUFFER_SIZE]; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http read discarded body"); for ( ;; ) { if (r->headers_in.content_length_n == 0) { r->read_event_handler = ngx_http_block_reading; return NGX_OK; } if (!r->connection->read->ready) { return NGX_AGAIN; } size = (r->headers_in.content_length_n > NGX_HTTP_DISCARD_BUFFER_SIZE) ? NGX_HTTP_DISCARD_BUFFER_SIZE: (size_t) r->headers_in.content_length_n; n = r->connection->recv(r->connection, buffer, size); if (n == NGX_ERROR) { r->connection->error = 1; return NGX_OK; } if (n == NGX_AGAIN) { return NGX_AGAIN; } if (n == 0) { return NGX_OK; } r->headers_in.content_length_n -= n; } } static ngx_int_t ngx_http_test_expect(ngx_http_request_t *r) { ngx_int_t n; ngx_str_t *expect; if (r->expect_tested || r->headers_in.expect == NULL || r->http_version < NGX_HTTP_VERSION_11) { return NGX_OK; } r->expect_tested = 1; expect = &r->headers_in.expect->value; if (expect->len != sizeof("100-continue") - 1 || ngx_strncasecmp(expect->data, (u_char *) "100-continue", sizeof("100-continue") - 1) != 0) { return NGX_OK; } ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "send 100 Continue"); n = r->connection->send(r->connection, (u_char *) "HTTP/1.1 100 Continue" CRLF CRLF, sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1); if (n == sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1) { return NGX_OK; } /* we assume that such small packet should be send successfully */ return NGX_ERROR; }