Mercurial > hg > nginx
view src/http/modules/ngx_http_range_filter_module.c @ 4207:4fc91bae6f83
Better recheck of dead upstream servers.
Previously nginx used to mark backend again as live as soon as fail_timeout
passes (10s by default) since last failure. On the other hand, detecting
dead backend takes up to 60s (proxy_connect_timeout) in typical situation
"backend is down and doesn't respond to any packets". This resulted in
suboptimal behaviour in the above situation (up to 23% of requests were
directed to dead backend with default settings).
More detailed description of the problem may be found here (in Russian):
http://mailman.nginx.org/pipermail/nginx-ru/2011-August/042172.html
Fix is to only allow one request after fail_timeout passes, and
mark backend as "live" only if this request succeeds.
Note that with new code backend will not be marked "live" unless "check"
request is completed, and this may take a while in some specific workloads
(e.g. streaming). This is believed to be acceptable.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 12 Oct 2011 14:22:48 +0000 |
parents | 8d70904b6c48 |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> /* * the single part format: * * "HTTP/1.0 206 Partial Content" CRLF * ... header ... * "Content-Type: image/jpeg" CRLF * "Content-Length: SIZE" CRLF * "Content-Range: bytes START-END/SIZE" CRLF * CRLF * ... data ... * * * the mutlipart format: * * "HTTP/1.0 206 Partial Content" CRLF * ... header ... * "Content-Type: multipart/byteranges; boundary=0123456789" CRLF * CRLF * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes START0-END0/SIZE" CRLF * CRLF * ... data ... * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes START1-END1/SIZE" CRLF * CRLF * ... data ... * CRLF * "--0123456789--" CRLF */ typedef struct { off_t start; off_t end; ngx_str_t content_range; } ngx_http_range_t; typedef struct { off_t offset; ngx_str_t boundary_header; ngx_array_t ranges; } ngx_http_range_filter_ctx_t; static ngx_int_t ngx_http_range_parse(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_uint_t ranges); static ngx_int_t ngx_http_range_singlepart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx); static ngx_int_t ngx_http_range_multipart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx); static ngx_int_t ngx_http_range_not_satisfiable(ngx_http_request_t *r); static ngx_int_t ngx_http_range_test_overlapped(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in); static ngx_int_t ngx_http_range_singlepart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in); static ngx_int_t ngx_http_range_multipart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in); static ngx_int_t ngx_http_range_header_filter_init(ngx_conf_t *cf); static ngx_int_t ngx_http_range_body_filter_init(ngx_conf_t *cf); static ngx_http_module_t ngx_http_range_header_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_range_header_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL, /* merge location configuration */ }; ngx_module_t ngx_http_range_header_filter_module = { NGX_MODULE_V1, &ngx_http_range_header_filter_module_ctx, /* module context */ NULL, /* 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_http_module_t ngx_http_range_body_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_range_body_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL, /* merge location configuration */ }; ngx_module_t ngx_http_range_body_filter_module = { NGX_MODULE_V1, &ngx_http_range_body_filter_module_ctx, /* module context */ NULL, /* 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_http_output_header_filter_pt ngx_http_next_header_filter; static ngx_http_output_body_filter_pt ngx_http_next_body_filter; static ngx_int_t ngx_http_range_header_filter(ngx_http_request_t *r) { time_t if_range; ngx_http_core_loc_conf_t *clcf; ngx_http_range_filter_ctx_t *ctx; if (r->http_version < NGX_HTTP_VERSION_10 || r->headers_out.status != NGX_HTTP_OK || r != r->main || r->headers_out.content_length_n == -1 || !r->allow_ranges) { return ngx_http_next_header_filter(r); } clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (clcf->max_ranges == 0) { return ngx_http_next_header_filter(r); } if (r->headers_in.range == NULL || r->headers_in.range->value.len < 7 || ngx_strncasecmp(r->headers_in.range->value.data, (u_char *) "bytes=", 6) != 0) { goto next_filter; } if (r->headers_in.if_range && r->headers_out.last_modified_time != -1) { if_range = ngx_http_parse_time(r->headers_in.if_range->value.data, r->headers_in.if_range->value.len); ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http ir:%d lm:%d", if_range, r->headers_out.last_modified_time); if (if_range != r->headers_out.last_modified_time) { goto next_filter; } } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_range_filter_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } if (ngx_array_init(&ctx->ranges, r->pool, 1, sizeof(ngx_http_range_t)) != NGX_OK) { return NGX_ERROR; } switch (ngx_http_range_parse(r, ctx, clcf->max_ranges)) { case NGX_OK: ngx_http_set_ctx(r, ctx, ngx_http_range_body_filter_module); r->headers_out.status = NGX_HTTP_PARTIAL_CONTENT; r->headers_out.status_line.len = 0; if (ctx->ranges.nelts == 1) { return ngx_http_range_singlepart_header(r, ctx); } return ngx_http_range_multipart_header(r, ctx); case NGX_HTTP_RANGE_NOT_SATISFIABLE: return ngx_http_range_not_satisfiable(r); case NGX_ERROR: return NGX_ERROR; default: /* NGX_DECLINED */ break; } next_filter: r->headers_out.accept_ranges = ngx_list_push(&r->headers_out.headers); if (r->headers_out.accept_ranges == NULL) { return NGX_ERROR; } r->headers_out.accept_ranges->hash = 1; ngx_str_set(&r->headers_out.accept_ranges->key, "Accept-Ranges"); ngx_str_set(&r->headers_out.accept_ranges->value, "bytes"); return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_range_parse(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_uint_t ranges) { u_char *p; off_t start, end, size, content_length; ngx_uint_t suffix; ngx_http_range_t *range; p = r->headers_in.range->value.data + 6; size = 0; content_length = r->headers_out.content_length_n; for ( ;; ) { start = 0; end = 0; suffix = 0; while (*p == ' ') { p++; } if (*p != '-') { if (*p < '0' || *p > '9') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } while (*p >= '0' && *p <= '9') { start = start * 10 + *p++ - '0'; } while (*p == ' ') { p++; } if (*p++ != '-') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } while (*p == ' ') { p++; } if (*p == ',' || *p == '\0') { end = content_length; goto found; } } else { suffix = 1; p++; } if (*p < '0' || *p > '9') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } while (*p >= '0' && *p <= '9') { end = end * 10 + *p++ - '0'; } while (*p == ' ') { p++; } if (*p != ',' && *p != '\0') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } if (suffix) { start = content_length - end; end = content_length - 1; } if (end >= content_length) { end = content_length; } else { end++; } found: if (start < end) { range = ngx_array_push(&ctx->ranges); if (range == NULL) { return NGX_ERROR; } range->start = start; range->end = end; size += end - start; if (ranges-- == 0) { return NGX_DECLINED; } } if (*p++ != ',') { break; } } if (ctx->ranges.nelts == 0) { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } if (size > content_length) { return NGX_DECLINED; } return NGX_OK; } static ngx_int_t ngx_http_range_singlepart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx) { ngx_table_elt_t *content_range; ngx_http_range_t *range; content_range = ngx_list_push(&r->headers_out.headers); if (content_range == NULL) { return NGX_ERROR; } r->headers_out.content_range = content_range; content_range->hash = 1; ngx_str_set(&content_range->key, "Content-Range"); content_range->value.data = ngx_pnalloc(r->pool, sizeof("bytes -/") - 1 + 3 * NGX_OFF_T_LEN); if (content_range->value.data == NULL) { return NGX_ERROR; } /* "Content-Range: bytes SSSS-EEEE/TTTT" header */ range = ctx->ranges.elts; content_range->value.len = ngx_sprintf(content_range->value.data, "bytes %O-%O/%O", range->start, range->end - 1, r->headers_out.content_length_n) - content_range->value.data; r->headers_out.content_length_n = range->end - range->start; if (r->headers_out.content_length) { r->headers_out.content_length->hash = 0; r->headers_out.content_length = NULL; } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_range_multipart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx) { size_t len; ngx_uint_t i; ngx_http_range_t *range; ngx_atomic_uint_t boundary; len = sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN + sizeof(CRLF "Content-Type: ") - 1 + r->headers_out.content_type.len + sizeof(CRLF "Content-Range: bytes ") - 1; if (r->headers_out.charset.len) { len += sizeof("; charset=") - 1 + r->headers_out.charset.len; } ctx->boundary_header.data = ngx_pnalloc(r->pool, len); if (ctx->boundary_header.data == NULL) { return NGX_ERROR; } boundary = ngx_next_temp_number(0); /* * The boundary header of the range: * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes " */ if (r->headers_out.charset.len) { ctx->boundary_header.len = ngx_sprintf(ctx->boundary_header.data, CRLF "--%0muA" CRLF "Content-Type: %V; charset=%V" CRLF "Content-Range: bytes ", boundary, &r->headers_out.content_type, &r->headers_out.charset) - ctx->boundary_header.data; r->headers_out.charset.len = 0; } else if (r->headers_out.content_type.len) { ctx->boundary_header.len = ngx_sprintf(ctx->boundary_header.data, CRLF "--%0muA" CRLF "Content-Type: %V" CRLF "Content-Range: bytes ", boundary, &r->headers_out.content_type) - ctx->boundary_header.data; } else { ctx->boundary_header.len = ngx_sprintf(ctx->boundary_header.data, CRLF "--%0muA" CRLF "Content-Range: bytes ", boundary) - ctx->boundary_header.data; } r->headers_out.content_type.data = ngx_pnalloc(r->pool, sizeof("Content-Type: multipart/byteranges; boundary=") - 1 + NGX_ATOMIC_T_LEN); if (r->headers_out.content_type.data == NULL) { return NGX_ERROR; } r->headers_out.content_type_lowcase = NULL; /* "Content-Type: multipart/byteranges; boundary=0123456789" */ r->headers_out.content_type.len = ngx_sprintf(r->headers_out.content_type.data, "multipart/byteranges; boundary=%0muA", boundary) - r->headers_out.content_type.data; r->headers_out.content_type_len = r->headers_out.content_type.len; /* the size of the last boundary CRLF "--0123456789--" CRLF */ len = sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN + sizeof("--" CRLF) - 1; range = ctx->ranges.elts; for (i = 0; i < ctx->ranges.nelts; i++) { /* the size of the range: "SSSS-EEEE/TTTT" CRLF CRLF */ range[i].content_range.data = ngx_pnalloc(r->pool, 3 * NGX_OFF_T_LEN + 2 + 4); if (range[i].content_range.data == NULL) { return NGX_ERROR; } range[i].content_range.len = ngx_sprintf(range[i].content_range.data, "%O-%O/%O" CRLF CRLF, range[i].start, range[i].end - 1, r->headers_out.content_length_n) - range[i].content_range.data; len += ctx->boundary_header.len + range[i].content_range.len + (size_t) (range[i].end - range[i].start); } r->headers_out.content_length_n = len; if (r->headers_out.content_length) { r->headers_out.content_length->hash = 0; r->headers_out.content_length = NULL; } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_range_not_satisfiable(ngx_http_request_t *r) { ngx_table_elt_t *content_range; r->headers_out.status = NGX_HTTP_RANGE_NOT_SATISFIABLE; content_range = ngx_list_push(&r->headers_out.headers); if (content_range == NULL) { return NGX_ERROR; } r->headers_out.content_range = content_range; content_range->hash = 1; ngx_str_set(&content_range->key, "Content-Range"); content_range->value.data = ngx_pnalloc(r->pool, sizeof("bytes */") - 1 + NGX_OFF_T_LEN); if (content_range->value.data == NULL) { return NGX_ERROR; } content_range->value.len = ngx_sprintf(content_range->value.data, "bytes */%O", r->headers_out.content_length_n) - content_range->value.data; ngx_http_clear_content_length(r); return NGX_HTTP_RANGE_NOT_SATISFIABLE; } static ngx_int_t ngx_http_range_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_http_range_filter_ctx_t *ctx; if (in == NULL) { return ngx_http_next_body_filter(r, in); } ctx = ngx_http_get_module_ctx(r, ngx_http_range_body_filter_module); if (ctx == NULL) { return ngx_http_next_body_filter(r, in); } if (ctx->ranges.nelts == 1) { return ngx_http_range_singlepart_body(r, ctx, in); } /* * multipart ranges are supported only if whole body is in a single buffer */ if (ngx_buf_special(in->buf)) { return ngx_http_next_body_filter(r, in); } if (ngx_http_range_test_overlapped(r, ctx, in) != NGX_OK) { return NGX_ERROR; } return ngx_http_range_multipart_body(r, ctx, in); } static ngx_int_t ngx_http_range_test_overlapped(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in) { off_t start, last; ngx_buf_t *buf; ngx_uint_t i; ngx_http_range_t *range; if (ctx->offset) { goto overlapped; } buf = in->buf; if (!buf->last_buf) { if (buf->in_file) { start = buf->file_pos + ctx->offset; last = buf->file_last + ctx->offset; } else { start = buf->pos - buf->start + ctx->offset; last = buf->last - buf->start + ctx->offset; } range = ctx->ranges.elts; for (i = 0; i < ctx->ranges.nelts; i++) { if (start > range[i].start || last < range[i].end) { goto overlapped; } } } ctx->offset = ngx_buf_size(buf); return NGX_OK; overlapped: ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, "range in overlapped buffers"); return NGX_ERROR; } static ngx_int_t ngx_http_range_singlepart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in) { off_t start, last; ngx_buf_t *buf; ngx_chain_t *out, *cl, **ll; ngx_http_range_t *range; out = NULL; ll = &out; range = ctx->ranges.elts; for (cl = in; cl; cl = cl->next) { buf = cl->buf; start = ctx->offset; last = ctx->offset + ngx_buf_size(buf); ctx->offset = last; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http range body buf: %O-%O", start, last); if (ngx_buf_special(buf)) { *ll = cl; ll = &cl->next; continue; } if (range->end <= start || range->start >= last) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http range body skip"); if (buf->in_file) { buf->file_pos = buf->file_last; } buf->pos = buf->last; buf->sync = 1; continue; } if (range->start > start) { if (buf->in_file) { buf->file_pos += range->start - start; } if (ngx_buf_in_memory(buf)) { buf->pos += (size_t) (range->start - start); } } if (range->end <= last) { if (buf->in_file) { buf->file_last -= last - range->end; } if (ngx_buf_in_memory(buf)) { buf->last -= (size_t) (last - range->end); } buf->last_buf = 1; *ll = cl; cl->next = NULL; break; } *ll = cl; ll = &cl->next; } if (out == NULL) { return NGX_OK; } return ngx_http_next_body_filter(r, out); } static ngx_int_t ngx_http_range_multipart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in) { off_t body_start; ngx_buf_t *b, *buf; ngx_uint_t i; ngx_chain_t *out, *hcl, *rcl, *dcl, **ll; ngx_http_range_t *range; ll = &out; buf = in->buf; range = ctx->ranges.elts; #if (NGX_HTTP_CACHE) body_start = r->cached ? r->cache->body_start : 0; #else body_start = 0; #endif for (i = 0; i < ctx->ranges.nelts; i++) { /* * The boundary header of the range: * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes " */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->memory = 1; b->pos = ctx->boundary_header.data; b->last = ctx->boundary_header.data + ctx->boundary_header.len; hcl = ngx_alloc_chain_link(r->pool); if (hcl == NULL) { return NGX_ERROR; } hcl->buf = b; /* "SSSS-EEEE/TTTT" CRLF CRLF */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->temporary = 1; b->pos = range[i].content_range.data; b->last = range[i].content_range.data + range[i].content_range.len; rcl = ngx_alloc_chain_link(r->pool); if (rcl == NULL) { return NGX_ERROR; } rcl->buf = b; /* the range data */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->in_file = buf->in_file; b->temporary = buf->temporary; b->memory = buf->memory; b->mmap = buf->mmap; b->file = buf->file; if (buf->in_file) { b->file_pos = body_start + range[i].start; b->file_last = body_start + range[i].end; } if (ngx_buf_in_memory(buf)) { b->pos = buf->start + (size_t) range[i].start; b->last = buf->start + (size_t) range[i].end; } dcl = ngx_alloc_chain_link(r->pool); if (dcl == NULL) { return NGX_ERROR; } dcl->buf = b; *ll = hcl; hcl->next = rcl; rcl->next = dcl; ll = &dcl->next; } /* the last boundary CRLF "--0123456789--" CRLF */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->temporary = 1; b->last_buf = 1; b->pos = ngx_pnalloc(r->pool, sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN + sizeof("--" CRLF) - 1); if (b->pos == NULL) { return NGX_ERROR; } b->last = ngx_cpymem(b->pos, ctx->boundary_header.data, sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN); *b->last++ = '-'; *b->last++ = '-'; *b->last++ = CR; *b->last++ = LF; hcl = ngx_alloc_chain_link(r->pool); if (hcl == NULL) { return NGX_ERROR; } hcl->buf = b; hcl->next = NULL; *ll = hcl; return ngx_http_next_body_filter(r, out); } static ngx_int_t ngx_http_range_header_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_range_header_filter; return NGX_OK; } static ngx_int_t ngx_http_range_body_filter_init(ngx_conf_t *cf) { ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_range_body_filter; return NGX_OK; }