Mercurial > hg > nginx-site
annotate xml/en/docs/http/ngx_http_scgi_module.xml @ 1189:f25d00109de0
Documented cache keys_zone memory estimates.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Thu, 15 May 2014 20:58:55 +0400 |
| parents | f9c8336fe43c |
| children | dd4cfc6ce770 |
| rev | line source |
|---|---|
| 1180 | 1 <?xml version="1.0"?> |
| 2 | |
| 3 <!-- | |
| 4 Copyright (C) Igor Sysoev | |
| 5 Copyright (C) Nginx, Inc. | |
| 6 --> | |
| 7 | |
| 8 <!DOCTYPE module SYSTEM "../../../../dtd/module.dtd"> | |
| 9 | |
| 10 <module name="Module ngx_http_scgi_module" | |
| 11 link="/en/docs/http/ngx_http_scgi_module.html" | |
| 12 lang="en" | |
|
1189
f25d00109de0
Documented cache keys_zone memory estimates.
Maxim Dounin <mdounin@mdounin.ru>
parents:
1185
diff
changeset
|
13 rev="2"> |
| 1180 | 14 |
| 15 <section id="summary"> | |
| 16 | |
| 17 <para> | |
| 18 The <literal>ngx_http_scgi_module</literal> module allows passing | |
| 19 requests to an SCGI server. | |
| 20 </para> | |
| 21 | |
| 22 </section> | |
| 23 | |
| 24 | |
| 25 <section id="example" name="Example Configuration"> | |
| 26 | |
| 27 <para> | |
| 28 <example> | |
| 29 location / { | |
| 30 include scgi_params; | |
| 31 scgi_pass localhost:9000; | |
| 32 } | |
| 33 </example> | |
| 34 </para> | |
| 35 | |
| 36 </section> | |
| 37 | |
| 38 | |
| 39 <section id="directives" name="Directives"> | |
| 40 | |
| 41 <directive name="scgi_bind"> | |
| 42 <syntax><value>address</value> | <literal>off</literal></syntax> | |
| 43 <default/> | |
| 44 <context>http</context> | |
| 45 <context>server</context> | |
| 46 <context>location</context> | |
| 47 | |
| 48 <para> | |
| 49 Makes outgoing connections to an SCGI server originate | |
| 50 from the specified local IP <value>address</value>. | |
| 51 Parameter value can contain variables (1.3.12). | |
| 52 The special value <literal>off</literal> (1.3.12) cancels the effect | |
| 53 of the <literal>scgi_bind</literal> directive | |
| 54 inherited from the previous configuration level, which allows the | |
| 55 system to auto-assign the local IP address. | |
| 56 </para> | |
| 57 | |
| 58 </directive> | |
| 59 | |
| 60 | |
| 61 <directive name="scgi_buffer_size"> | |
| 62 <syntax><value>size</value></syntax> | |
| 63 <default>4k|8k</default> | |
| 64 <context>http</context> | |
| 65 <context>server</context> | |
| 66 <context>location</context> | |
| 67 | |
| 68 <para> | |
| 69 Sets the <value>size</value> of the buffer used for reading the first part | |
| 70 of the response received from the SCGI server. | |
| 71 This part usually contains a small response header. | |
| 72 By default, the buffer size is equal to the size of one | |
| 73 buffer set by the <link id="scgi_buffers"/> directive. | |
| 74 It can be made smaller, however. | |
| 75 </para> | |
| 76 | |
| 77 </directive> | |
| 78 | |
| 79 | |
| 80 <directive name="scgi_buffering"> | |
| 81 <syntax><literal>on</literal> | <literal>off</literal></syntax> | |
| 82 <default>on</default> | |
| 83 <context>http</context> | |
| 84 <context>server</context> | |
| 85 <context>location</context> | |
| 86 | |
| 87 <para> | |
| 88 Enables or disables buffering of responses from the SCGI server. | |
| 89 </para> | |
| 90 | |
| 91 <para> | |
| 92 When buffering is enabled, nginx receives a response from the SCGI server | |
| 93 as soon as possible, saving it into the buffers set by the | |
| 94 <link id="scgi_buffer_size"/> and <link id="scgi_buffers"/> directives. | |
| 95 If the whole response does not fit into memory, a part of it can be saved | |
| 96 to a <link id="scgi_temp_path">temporary file</link> on the disk. | |
| 97 Writing to temporary files is controlled by the | |
| 98 <link id="scgi_max_temp_file_size"/> and | |
| 99 <link id="scgi_temp_file_write_size"/> directives. | |
| 100 </para> | |
| 101 | |
| 102 <para> | |
| 103 When buffering is disabled, the response is passed to a client synchronously, | |
| 104 immediately as it is received. | |
| 105 nginx will not try to read the whole response from the SCGI server. | |
| 106 The maximum size of the data that nginx can receive from the server | |
| 107 at a time is set by the <link id="scgi_buffer_size"/> directive. | |
| 108 </para> | |
| 109 | |
| 110 <para> | |
| 111 Buffering can also be enabled or disabled by passing | |
| 112 “<literal>yes</literal>” or “<literal>no</literal>” in the | |
| 113 <header>X-Accel-Buffering</header> response header field. | |
| 114 This capability can be disabled using the | |
| 115 <link id="scgi_ignore_headers"/> directive. | |
| 116 </para> | |
| 117 | |
| 118 </directive> | |
| 119 | |
| 120 | |
| 121 <directive name="scgi_buffers"> | |
| 122 <syntax><value>number</value> <value>size</value></syntax> | |
| 123 <default>8 4k|8k</default> | |
| 124 <context>http</context> | |
| 125 <context>server</context> | |
| 126 <context>location</context> | |
| 127 | |
| 128 <para> | |
| 129 Sets the <value>number</value> and <value>size</value> of the | |
| 130 buffers used for reading a response from the SCGI server, | |
| 131 for a single connection. | |
| 132 By default, the buffer size is equal to one memory page. | |
| 133 This is either 4K or 8K, depending on a platform. | |
| 134 </para> | |
| 135 | |
| 136 </directive> | |
| 137 | |
| 138 | |
| 139 <directive name="scgi_busy_buffers_size"> | |
| 140 <syntax><value>size</value></syntax> | |
| 141 <default>8k|16k</default> | |
| 142 <context>http</context> | |
| 143 <context>server</context> | |
| 144 <context>location</context> | |
| 145 | |
| 146 <para> | |
| 147 When <link id="scgi_buffering">buffering</link> of responses from the SCGI | |
| 148 server is enabled, limits the total <value>size</value> of buffers that | |
| 149 can be busy sending a response to the client while the response is not | |
| 150 yet fully read. | |
| 151 In the meantime, the rest of the buffers can be used for reading the response | |
| 152 and, if needed, buffering part of the response to a temporary file. | |
| 153 By default, <value>size</value> is limited by the size of two buffers set by the | |
| 154 <link id="scgi_buffer_size"/> and <link id="scgi_buffers"/> directives. | |
| 155 </para> | |
| 156 | |
| 157 </directive> | |
| 158 | |
| 159 | |
| 160 <directive name="scgi_cache"> | |
| 161 <syntax><value>zone</value> | <literal>off</literal></syntax> | |
| 162 <default>off</default> | |
| 163 <context>http</context> | |
| 164 <context>server</context> | |
| 165 <context>location</context> | |
| 166 | |
| 167 <para> | |
| 168 Defines a shared memory zone used for caching. | |
| 169 The same zone can be used in several places. | |
| 170 The <literal>off</literal> parameter disables caching inherited | |
| 171 from the previous configuration level. | |
| 172 </para> | |
| 173 | |
| 174 </directive> | |
| 175 | |
| 176 | |
| 177 <directive name="scgi_cache_bypass"> | |
| 178 <syntax><value>string</value> ...</syntax> | |
| 179 <default/> | |
| 180 <context>http</context> | |
| 181 <context>server</context> | |
| 182 <context>location</context> | |
| 183 | |
| 184 <para> | |
| 185 Defines conditions under which the response will not be taken from a cache. | |
| 186 If at least one value of the string parameters is not empty and is not | |
| 187 equal to “0” then the response will not be taken from the cache: | |
| 188 <example> | |
| 189 scgi_cache_bypass $cookie_nocache $arg_nocache$arg_comment; | |
| 190 scgi_cache_bypass $http_pragma $http_authorization; | |
| 191 </example> | |
| 192 Can be used along with the <link id="scgi_no_cache"/> directive. | |
| 193 </para> | |
| 194 | |
| 195 </directive> | |
| 196 | |
| 197 | |
| 198 <directive name="scgi_cache_key"> | |
| 199 <syntax><value>string</value></syntax> | |
| 200 <default/> | |
| 201 <context>http</context> | |
| 202 <context>server</context> | |
| 203 <context>location</context> | |
| 204 | |
| 205 <para> | |
| 206 Defines a key for caching, for example | |
| 207 <example> | |
| 208 scgi_cache_key localhost:9000$request_uri; | |
| 209 </example> | |
| 210 </para> | |
| 211 | |
| 212 </directive> | |
| 213 | |
| 214 | |
| 215 <directive name="scgi_cache_lock"> | |
| 216 <syntax><literal>on</literal> | <literal>off</literal></syntax> | |
| 217 <default>off</default> | |
| 218 <context>http</context> | |
| 219 <context>server</context> | |
| 220 <context>location</context> | |
| 221 <appeared-in>1.1.12</appeared-in> | |
| 222 | |
| 223 <para> | |
| 224 When enabled, only one request at a time will be allowed to populate | |
| 225 a new cache element identified according to the <link id="scgi_cache_key"/> | |
| 226 directive by passing a request to an SCGI server. | |
| 227 Other requests of the same cache element will either wait | |
| 228 for a response to appear in the cache or the cache lock for | |
| 229 this element to be released, up to the time set by the | |
| 230 <link id="scgi_cache_lock_timeout"/> directive. | |
| 231 </para> | |
| 232 | |
| 233 </directive> | |
| 234 | |
| 235 | |
| 236 <directive name="scgi_cache_lock_timeout"> | |
| 237 <syntax><value>time</value></syntax> | |
| 238 <default>5s</default> | |
| 239 <context>http</context> | |
| 240 <context>server</context> | |
| 241 <context>location</context> | |
| 242 <appeared-in>1.1.12</appeared-in> | |
| 243 | |
| 244 <para> | |
| 245 Sets a timeout for <link id="scgi_cache_lock"/>. | |
| 246 </para> | |
| 247 | |
| 248 </directive> | |
| 249 | |
| 250 | |
| 251 <directive name="scgi_cache_methods"> | |
| 252 <syntax> | |
| 253 <literal>GET</literal> | | |
| 254 <literal>HEAD</literal> | | |
| 255 <literal>POST</literal> | |
| 256 ...</syntax> | |
| 257 <default>GET HEAD</default> | |
| 258 <context>http</context> | |
| 259 <context>server</context> | |
| 260 <context>location</context> | |
| 261 | |
| 262 <para> | |
| 263 If the client request method is listed in this directive then | |
| 264 the response will be cached. | |
| 265 “<literal>GET</literal>” and “<literal>HEAD</literal>” methods are always | |
| 266 added to the list, though it is recommended to specify them explicitly. | |
| 267 See also the <link id="scgi_no_cache"/> directive. | |
| 268 </para> | |
| 269 | |
| 270 </directive> | |
| 271 | |
| 272 | |
| 273 <directive name="scgi_cache_min_uses"> | |
| 274 <syntax><value>number</value></syntax> | |
| 275 <default>1</default> | |
| 276 <context>http</context> | |
| 277 <context>server</context> | |
| 278 <context>location</context> | |
| 279 | |
| 280 <para> | |
| 281 Sets the <value>number</value> of requests after which the response | |
| 282 will be cached. | |
| 283 </para> | |
| 284 | |
| 285 </directive> | |
| 286 | |
| 287 | |
| 288 <directive name="scgi_cache_path"> | |
| 289 <syntax> | |
| 290 <value>path</value> | |
| 291 [<literal>levels</literal>=<value>levels</value>] | |
| 292 <literal>keys_zone</literal>=<value>name</value>:<value>size</value> | |
| 293 [<literal>inactive</literal>=<value>time</value>] | |
| 294 [<literal>max_size</literal>=<value>size</value>] | |
| 295 [<literal>loader_files</literal>=<value>number</value>] | |
| 296 [<literal>loader_sleep</literal>=<value>time</value>] | |
| 297 [<literal>loader_threshold</literal>=<value>time</value>]</syntax> | |
| 298 <default/> | |
| 299 <context>http</context> | |
| 300 | |
| 301 <para> | |
| 302 Sets the path and other parameters of a cache. | |
| 303 Cache data are stored in files. | |
| 304 Both the key and file name in a cache are a result of | |
| 305 applying the MD5 function to the proxied URL. | |
| 306 The <literal>levels</literal> parameter defines hierarchy levels of a cache. | |
| 307 For example, in the following configuration | |
| 308 <example> | |
| 309 scgi_cache_path /data/nginx/cache levels=1:2 keys_zone=one:10m; | |
| 310 </example> | |
| 311 file names in a cache will look like this: | |
| 312 <example> | |
| 313 /data/nginx/cache/<emphasis>c</emphasis>/<emphasis>29</emphasis>/b7f54b2df7773722d382f4809d650<emphasis>29c</emphasis> | |
| 314 </example> | |
| 315 </para> | |
| 316 | |
| 317 <para> | |
| 318 A cached response is first written to a temporary file, | |
| 319 and then the file is renamed. | |
| 320 Starting from version 0.8.9, temporary files and the cache can be put on | |
| 321 different file systems. | |
| 322 However, be aware that in this case a file is copied | |
| 323 across two file systems instead of the cheap renaming operation. | |
| 324 It is thus recommended that for any given location both cache and a directory | |
| 325 holding temporary files, set by the <link id="scgi_temp_path"/> directive, | |
| 326 are put on the same file system. | |
| 327 </para> | |
| 328 | |
| 329 <para> | |
| 330 In addition, all active keys and information about data are stored | |
| 331 in a shared memory zone, whose <value>name</value> and <value>size</value> | |
| 332 are configured by the <literal>keys_zone</literal> parameter. | |
|
1189
f25d00109de0
Documented cache keys_zone memory estimates.
Maxim Dounin <mdounin@mdounin.ru>
parents:
1185
diff
changeset
|
333 One megabyte zone can store about 8 thousand keys. |
|
f25d00109de0
Documented cache keys_zone memory estimates.
Maxim Dounin <mdounin@mdounin.ru>
parents:
1185
diff
changeset
|
334 </para> |
|
f25d00109de0
Documented cache keys_zone memory estimates.
Maxim Dounin <mdounin@mdounin.ru>
parents:
1185
diff
changeset
|
335 |
|
f25d00109de0
Documented cache keys_zone memory estimates.
Maxim Dounin <mdounin@mdounin.ru>
parents:
1185
diff
changeset
|
336 <para> |
| 1180 | 337 Cached data that are not accessed during the time specified by the |
| 338 <literal>inactive</literal> parameter get removed from the cache | |
| 339 regardless of their freshness. | |
| 340 By default, <literal>inactive</literal> is set to 10 minutes. | |
| 341 </para> | |
| 342 | |
| 343 <para> | |
| 344 The special “cache manager” process monitors the maximum cache size set | |
| 345 by the <literal>max_size</literal> parameter. | |
| 346 When this size is exceeded, it removes the least recently used data. | |
| 347 </para> | |
| 348 | |
| 349 <para> | |
| 350 A minute after the start the special “cache loader” process is activated. | |
| 351 It loads information about previously cached data stored on file system | |
| 352 into a cache zone. | |
| 353 The loading is done in iterations. | |
| 354 During one iteration no more than <literal>loader_files</literal> items | |
| 355 are loaded (by default, 100). | |
| 356 Besides, the duration of one iteration is limited by the | |
| 357 <literal>loader_threshold</literal> parameter (by default, 200 milliseconds). | |
| 358 Between iterations, a pause configured by the <literal>loader_sleep</literal> | |
| 359 parameter (by default, 50 milliseconds) is made. | |
| 360 </para> | |
| 361 | |
| 362 </directive> | |
| 363 | |
| 364 | |
| 365 <directive name="scgi_cache_purge"> | |
| 366 <syntax>string ...</syntax> | |
| 367 <default/> | |
| 368 <context>http</context> | |
| 369 <context>server</context> | |
| 370 <context>location</context> | |
| 371 <appeared-in>1.5.7</appeared-in> | |
| 372 | |
| 373 <para> | |
| 374 Defines conditions under which the request will be considered a cache | |
| 375 purge request. | |
| 376 If at least one value of the string parameters is not empty and is not equal | |
| 377 to “0” then the cache entry with a corresponding | |
| 378 <link id="scgi_cache_key">cache key</link> is removed. | |
| 379 The result of successful operation is indicated by returning | |
| 380 the <http-status code="204" text="No Content"/> response. | |
| 381 </para> | |
| 382 | |
| 383 <para> | |
| 384 If the <link id="scgi_cache_key">cache key</link> of a purge request ends | |
| 385 with an asterisk (“<literal>*</literal>”), all cache entries matching the | |
| 386 wildcard key will be removed from the cache. | |
| 387 </para> | |
| 388 | |
| 389 <para> | |
| 390 Example configuration: | |
| 391 <example> | |
| 392 scgi_cache_path /data/nginx/cache keys_zone=cache_zone:10m; | |
| 393 | |
| 394 map $request_method $purge_method { | |
| 395 PURGE 1; | |
| 396 default 0; | |
| 397 } | |
| 398 | |
| 399 server { | |
| 400 ... | |
| 401 location / { | |
|
1185
f9c8336fe43c
Aligned configuration examples with fastcgi/scgi_cache_purge.
Ruslan Ermilov <ru@nginx.com>
parents:
1184
diff
changeset
|
402 scgi_pass backend; |
|
f9c8336fe43c
Aligned configuration examples with fastcgi/scgi_cache_purge.
Ruslan Ermilov <ru@nginx.com>
parents:
1184
diff
changeset
|
403 scgi_cache cache_zone; |
|
f9c8336fe43c
Aligned configuration examples with fastcgi/scgi_cache_purge.
Ruslan Ermilov <ru@nginx.com>
parents:
1184
diff
changeset
|
404 scgi_cache_key $uri; |
| 1180 | 405 scgi_cache_purge $purge_method; |
| 406 } | |
| 407 } | |
| 408 </example> | |
| 409 <note> | |
| 410 This functionality is available as part of our | |
| 411 <commercial_version>commercial subscription</commercial_version>. | |
| 412 </note> | |
| 413 </para> | |
| 414 | |
| 415 </directive> | |
| 416 | |
| 417 | |
| 418 <directive name="scgi_cache_revalidate"> | |
| 419 <syntax><literal>on</literal> | <literal>off</literal></syntax> | |
| 420 <default>off</default> | |
| 421 <context>http</context> | |
| 422 <context>server</context> | |
| 423 <context>location</context> | |
| 424 <appeared-in>1.5.7</appeared-in> | |
| 425 | |
| 426 <para> | |
| 427 Enables revalidation of expired cache items using conditional requests with | |
| 428 the <header>If-Modified-Since</header> header field. | |
| 429 </para> | |
| 430 | |
| 431 </directive> | |
| 432 | |
| 433 | |
| 434 <directive name="scgi_cache_use_stale"> | |
| 435 <syntax> | |
| 436 <literal>error</literal> | | |
| 437 <literal>timeout</literal> | | |
| 438 <literal>invalid_header</literal> | | |
| 439 <literal>updating</literal> | | |
| 440 <literal>http_500</literal> | | |
| 441 <literal>http_503</literal> | | |
| 442 <literal>http_403</literal> | | |
| 443 <literal>http_404</literal> | | |
| 444 <literal>off</literal> | |
| 445 ...</syntax> | |
| 446 <default>off</default> | |
| 447 <context>http</context> | |
| 448 <context>server</context> | |
| 449 <context>location</context> | |
| 450 | |
| 451 <para> | |
| 452 Determines in which cases a stale cached response can be used | |
| 453 when an error occurs during communication with the SCGI server. | |
| 454 The directive’s parameters match the parameters of the | |
| 455 <link id="scgi_next_upstream"/> directive. | |
| 456 </para> | |
| 457 | |
| 458 <para> | |
| 459 Additionally, the <literal>updating</literal> parameter permits | |
| 460 using a stale cached response if it is currently being updated. | |
| 461 This allows minimizing the number of accesses to SCGI servers | |
| 462 when updating cached data. | |
| 463 </para> | |
| 464 | |
| 465 <para> | |
| 466 To minimize the number of accesses to SCGI servers when | |
| 467 populating a new cache element, the <link id="scgi_cache_lock"/> | |
| 468 directive can be used. | |
| 469 </para> | |
| 470 | |
| 471 </directive> | |
| 472 | |
| 473 | |
| 474 <directive name="scgi_cache_valid"> | |
| 475 <syntax>[<value>code</value> ...] <value>time</value></syntax> | |
| 476 <default/> | |
| 477 <context>http</context> | |
| 478 <context>server</context> | |
| 479 <context>location</context> | |
| 480 | |
| 481 <para> | |
| 482 Sets caching time for different response codes. | |
| 483 For example, the following directives | |
| 484 <example> | |
| 485 scgi_cache_valid 200 302 10m; | |
| 486 scgi_cache_valid 404 1m; | |
| 487 </example> | |
| 488 set 10 minutes of caching for responses with codes 200 and 302 | |
| 489 and 1 minute for responses with code 404. | |
| 490 </para> | |
| 491 | |
| 492 <para> | |
| 493 If only caching <value>time</value> is specified | |
| 494 <example> | |
| 495 scgi_cache_valid 5m; | |
| 496 </example> | |
| 497 then only 200, 301, and 302 responses are cached. | |
| 498 </para> | |
| 499 | |
| 500 <para> | |
| 501 In addition, the <literal>any</literal> parameter can be specified | |
| 502 to cache any responses: | |
| 503 <example> | |
| 504 scgi_cache_valid 200 302 10m; | |
| 505 scgi_cache_valid 301 1h; | |
| 506 scgi_cache_valid any 1m; | |
| 507 </example> | |
| 508 </para> | |
| 509 | |
| 510 <para> | |
| 511 Parameters of caching can also be set directly | |
| 512 in the response header. | |
| 513 This has higher priority than setting of caching time using the directive. | |
| 514 The <header>X-Accel-Expires</header> header field sets caching time of a | |
| 515 response in seconds. | |
| 516 The zero value disables caching for a response. | |
| 517 If the value starts with the <literal>@</literal> prefix, it sets an absolute | |
| 518 time in seconds since Epoch, up to which the response may be cached. | |
| 519 If the header does not include the <header>X-Accel-Expires</header> field, | |
| 520 parameters of caching may be set in the header fields | |
| 521 <header>Expires</header> or <header>Cache-Control</header>. | |
| 522 If the header includes the <header>Set-Cookie</header> field, such a | |
| 523 response will not be cached. | |
| 524 Processing of one or more of these response header fields can be disabled | |
| 525 using the <link id="scgi_ignore_headers"/> directive. | |
| 526 </para> | |
| 527 | |
| 528 </directive> | |
| 529 | |
| 530 | |
| 531 <directive name="scgi_connect_timeout"> | |
| 532 <syntax><value>time</value></syntax> | |
| 533 <default>60s</default> | |
| 534 <context>http</context> | |
| 535 <context>server</context> | |
| 536 <context>location</context> | |
| 537 | |
| 538 <para> | |
| 539 Defines a timeout for establishing a connection with an SCGI server. | |
| 540 It should be noted that this timeout cannot usually exceed 75 seconds. | |
| 541 </para> | |
| 542 | |
| 543 </directive> | |
| 544 | |
| 545 | |
| 546 <directive name="scgi_hide_header"> | |
| 547 <syntax><value>field</value></syntax> | |
| 548 <default/> | |
| 549 <context>http</context> | |
| 550 <context>server</context> | |
| 551 <context>location</context> | |
| 552 | |
| 553 <para> | |
| 554 By default, | |
| 555 nginx does not pass the header fields <header>Status</header> and | |
| 556 <header>X-Accel-...</header> from the response of an SCGI | |
| 557 server to a client. | |
| 558 The <literal>scgi_hide_header</literal> directive sets additional fields | |
| 559 that will not be passed. | |
| 560 If, on the contrary, the passing of fields needs to be permitted, | |
| 561 the <link id="scgi_pass_header"/> directive can be used. | |
| 562 </para> | |
| 563 | |
| 564 </directive> | |
| 565 | |
| 566 | |
| 567 <directive name="scgi_ignore_client_abort"> | |
| 568 <syntax><literal>on</literal> | <literal>off</literal></syntax> | |
| 569 <default>off</default> | |
| 570 <context>http</context> | |
| 571 <context>server</context> | |
| 572 <context>location</context> | |
| 573 | |
| 574 <para> | |
| 575 Determines whether the connection with an SCGI server should be | |
| 576 closed when a client closes the connection without waiting | |
| 577 for a response. | |
| 578 </para> | |
| 579 | |
| 580 </directive> | |
| 581 | |
| 582 | |
| 583 <directive name="scgi_ignore_headers"> | |
| 584 <syntax><value>field</value> ...</syntax> | |
| 585 <default/> | |
| 586 <context>http</context> | |
| 587 <context>server</context> | |
| 588 <context>location</context> | |
| 589 | |
| 590 <para> | |
| 591 Disables processing of certain response header fields from the SCGI server. | |
| 592 The following fields can be ignored: <header>X-Accel-Redirect</header>, | |
| 593 <header>X-Accel-Expires</header>, <header>X-Accel-Limit-Rate</header> (1.1.6), | |
| 594 <header>X-Accel-Buffering</header> (1.1.6), | |
| 595 <header>X-Accel-Charset</header> (1.1.6), <header>Expires</header>, | |
| 596 <header>Cache-Control</header>, and <header>Set-Cookie</header> (0.8.44). | |
| 597 </para> | |
| 598 | |
| 599 <para> | |
| 600 If not disabled, processing of these header fields has the following | |
| 601 effect: | |
| 602 <list type="bullet" compact="no"> | |
| 603 | |
| 604 <listitem> | |
| 605 <header>X-Accel-Expires</header>, <header>Expires</header>, | |
| 606 <header>Cache-Control</header>, and <header>Set-Cookie</header> | |
| 607 set the parameters of response <link id="scgi_cache_valid">caching</link>; | |
| 608 </listitem> | |
| 609 | |
| 610 <listitem> | |
| 611 <header>X-Accel-Redirect</header> performs an | |
| 612 <link doc="ngx_http_core_module.xml" id="internal">internal | |
| 613 redirect</link> to the specified URI; | |
| 614 </listitem> | |
| 615 | |
| 616 <listitem> | |
| 617 <header>X-Accel-Limit-Rate</header> sets the | |
| 618 <link doc="ngx_http_core_module.xml" id="limit_rate">rate | |
| 619 limit</link> for transmission of a response to a client; | |
| 620 </listitem> | |
| 621 | |
| 622 <listitem> | |
| 623 <header>X-Accel-Buffering</header> enables or disables | |
| 624 <link id="scgi_buffering">buffering</link> of a response; | |
| 625 </listitem> | |
| 626 | |
| 627 <listitem> | |
| 628 <header>X-Accel-Charset</header> sets the desired | |
| 629 <link doc="ngx_http_charset_module.xml" id="charset"/> | |
| 630 of a response. | |
| 631 </listitem> | |
| 632 | |
| 633 </list> | |
| 634 </para> | |
| 635 | |
| 636 </directive> | |
| 637 | |
| 638 | |
| 639 <directive name="scgi_intercept_errors"> | |
| 640 <syntax><literal>on</literal> | <literal>off</literal></syntax> | |
| 641 <default>off</default> | |
| 642 <context>http</context> | |
| 643 <context>server</context> | |
| 644 <context>location</context> | |
| 645 | |
| 646 <para> | |
| 647 Determines whether an SCGI server responses with codes greater than or equal | |
| 648 to 300 should be passed to a client or be redirected to nginx for processing | |
| 649 with the <link doc="ngx_http_core_module.xml" id="error_page"/> directive. | |
| 650 </para> | |
| 651 | |
| 652 </directive> | |
| 653 | |
| 654 | |
| 655 <directive name="scgi_max_temp_file_size"> | |
| 656 <syntax><value>size</value></syntax> | |
| 657 <default>1024m</default> | |
| 658 <context>http</context> | |
| 659 <context>server</context> | |
| 660 <context>location</context> | |
| 661 | |
| 662 <para> | |
| 663 When <link id="scgi_buffering">buffering</link> of responses from the SCGI | |
| 664 server is enabled, and the whole response does not fit into the buffers | |
| 665 set by the <link id="scgi_buffer_size"/> and <link id="scgi_buffers"/> | |
| 666 directives, a part of the response can be saved to a temporary file. | |
| 667 This directive sets the maximum <value>size</value> of the temporary file. | |
| 668 The size of data written to the temporary file at a time is set | |
| 669 by the <link id="scgi_temp_file_write_size"/> directive. | |
| 670 </para> | |
| 671 | |
| 672 <para> | |
| 673 The zero value disables buffering of responses to temporary files. | |
| 674 </para> | |
| 675 | |
| 676 </directive> | |
| 677 | |
| 678 | |
| 679 <directive name="scgi_next_upstream"> | |
| 680 <syntax> | |
| 681 <literal>error</literal> | | |
| 682 <literal>timeout</literal> | | |
| 683 <literal>invalid_header</literal> | | |
| 684 <literal>http_500</literal> | | |
| 685 <literal>http_503</literal> | | |
| 686 <literal>http_403</literal> | | |
| 687 <literal>http_404</literal> | | |
| 688 <literal>off</literal> | |
| 689 ...</syntax> | |
| 690 <default>error timeout</default> | |
| 691 <context>http</context> | |
| 692 <context>server</context> | |
| 693 <context>location</context> | |
| 694 | |
| 695 <para> | |
| 696 Specifies in which cases a request should be passed to the next server: | |
| 697 <list type="tag"> | |
| 698 | |
| 699 <tag-name><literal>error</literal></tag-name> | |
| 700 <tag-desc>an error occurred while establishing a connection with the | |
| 701 server, passing a request to it, or reading the response header;</tag-desc> | |
| 702 | |
| 703 <tag-name><literal>timeout</literal></tag-name> | |
| 704 <tag-desc>a timeout has occurred while establishing a connection with the | |
| 705 server, passing a request to it, or reading the response header;</tag-desc> | |
| 706 | |
| 707 <tag-name><literal>invalid_header</literal></tag-name> | |
| 708 <tag-desc>a server returned an empty or invalid response;</tag-desc> | |
| 709 | |
| 710 <tag-name><literal>http_500</literal></tag-name> | |
| 711 <tag-desc>a server returned a response with the code 500;</tag-desc> | |
| 712 | |
| 713 <tag-name><literal>http_503</literal></tag-name> | |
| 714 <tag-desc>a server returned a response with the code 503;</tag-desc> | |
| 715 | |
| 716 <tag-name><literal>http_403</literal></tag-name> | |
| 717 <tag-desc>a server returned a response with the code 403;</tag-desc> | |
| 718 | |
| 719 <tag-name><literal>http_404</literal></tag-name> | |
| 720 <tag-desc>a server returned a response with the code 404;</tag-desc> | |
| 721 | |
| 722 <tag-name><literal>off</literal></tag-name> | |
| 723 <tag-desc>disables passing a request to the next server.</tag-desc> | |
| 724 | |
| 725 </list> | |
| 726 </para> | |
| 727 | |
| 728 <para> | |
| 729 One should bear in mind that passing a request to the next server is | |
| 730 only possible if nothing has been sent to a client yet. | |
| 731 That is, if an error or timeout occurs in the middle of the | |
| 732 transferring of a response, fixing this is impossible. | |
| 733 </para> | |
| 734 | |
| 735 <para> | |
| 736 The directive also defines what is considered an unsuccessful attempt | |
| 737 of communication with a | |
| 738 <link doc="ngx_http_upstream_module.xml" id="server"/>. | |
| 739 The cases of <literal>error</literal>, <literal>timeout</literal> and | |
| 740 <literal>invalid_header</literal> are always considered unsuccessful attempts, | |
| 741 even if they are not specified in the directive. | |
| 742 The cases of <literal>http_500</literal> and <literal>http_503</literal> are | |
| 743 considered unsuccessful attempts only if they are specified in the directive. | |
| 744 The cases of <literal>http_403</literal> and <literal>http_404</literal> | |
| 745 are never considered unsuccessful attempts. | |
| 746 </para> | |
| 747 | |
| 748 </directive> | |
| 749 | |
| 750 | |
| 751 <directive name="scgi_no_cache"> | |
| 752 <syntax><value>string</value> ...</syntax> | |
| 753 <default/> | |
| 754 <context>http</context> | |
| 755 <context>server</context> | |
| 756 <context>location</context> | |
| 757 | |
| 758 <para> | |
| 759 Defines conditions under which the response will not be saved to a cache. | |
| 760 If at least one value of the string parameters is not empty and is not | |
| 761 equal to “0” then the response will not be saved: | |
| 762 <example> | |
| 763 scgi_no_cache $cookie_nocache $arg_nocache$arg_comment; | |
| 764 scgi_no_cache $http_pragma $http_authorization; | |
| 765 </example> | |
| 766 Can be used along with the <link id="scgi_cache_bypass"/> directive. | |
| 767 </para> | |
| 768 | |
| 769 </directive> | |
| 770 | |
| 771 | |
| 772 <directive name="scgi_param"> | |
| 773 <syntax> | |
| 774 <value>parameter</value> <value>value</value> | |
| 775 [<literal>if_not_empty</literal>]</syntax> | |
| 776 <default/> | |
| 777 <context>http</context> | |
| 778 <context>server</context> | |
| 779 <context>location</context> | |
| 780 | |
| 781 <para> | |
| 782 Sets a <value>parameter</value> that should be passed to the SCGI server. | |
| 783 The <value>value</value> can contain text, variables, and their combination. | |
| 784 These directives are inherited from the previous level if and | |
| 785 only if there are no | |
| 786 <literal>scgi_param</literal> | |
| 787 directives defined on the current level. | |
| 788 </para> | |
| 789 | |
| 790 <para> | |
| 791 Standard | |
| 792 <link url="http://tools.ietf.org/html/rfc3875#section-4.1">CGI | |
| 793 environment variables</link> | |
| 794 should be provided as SCGI headers, see the <path>scgi_params</path> file | |
| 795 provided in the distribution: | |
| 796 <example> | |
| 797 location / { | |
| 798 include scgi_params; | |
| 799 ... | |
| 800 } | |
| 801 </example> | |
| 802 </para> | |
| 803 | |
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804 <para> |
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805 If a directive is specified with <literal>if_not_empty</literal> (1.1.11) then |
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806 such a parameter will not be passed to the server until its value is not empty: |
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807 <example> |
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808 scgi_param HTTPS $https if_not_empty; |
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809 </example> |
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810 </para> |
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811 |
| 1180 | 812 </directive> |
| 813 | |
| 814 | |
| 815 <directive name="scgi_pass"> | |
| 816 <syntax><value>address</value></syntax> | |
| 817 <default/> | |
| 818 <context>location</context> | |
| 819 <context>if in location</context> | |
| 820 | |
| 821 <para> | |
| 822 Sets the address of an SCGI server. | |
| 823 The address can be specified as a domain name or IP address, | |
| 824 and an optional port: | |
| 825 <example> | |
| 826 scgi_pass localhost:9000; | |
| 827 </example> | |
| 828 or as a UNIX-domain socket path: | |
| 829 <example> | |
| 830 scgi_pass unix:/tmp/scgi.socket; | |
| 831 </example> | |
| 832 </para> | |
| 833 | |
| 834 <para> | |
| 835 If a domain name resolves to several addresses, all of them will be | |
| 836 used in a round-robin fashion. | |
| 837 In addition, an address can be specified as a | |
| 838 <link doc="ngx_http_upstream_module.xml">server group</link>. | |
| 839 </para> | |
| 840 | |
| 841 </directive> | |
| 842 | |
| 843 | |
| 844 <directive name="scgi_pass_header"> | |
| 845 <syntax><value>field</value></syntax> | |
| 846 <default/> | |
| 847 <context>http</context> | |
| 848 <context>server</context> | |
| 849 <context>location</context> | |
| 850 | |
| 851 <para> | |
| 852 Permits passing <link id="scgi_hide_header">otherwise disabled</link> header | |
| 853 fields from an SCGI server to a client. | |
| 854 </para> | |
| 855 | |
| 856 </directive> | |
| 857 | |
| 858 | |
| 859 <directive name="scgi_read_timeout"> | |
| 860 <syntax><value>time</value></syntax> | |
| 861 <default>60s</default> | |
| 862 <context>http</context> | |
| 863 <context>server</context> | |
| 864 <context>location</context> | |
| 865 | |
| 866 <para> | |
| 867 Defines a timeout for reading a response from the SCGI server. | |
| 868 The timeout is set only between two successive read operations, | |
| 869 not for the transmission of the whole response. | |
| 870 If the SCGI server does not transmit anything within this time, | |
| 871 the connection is closed. | |
| 872 </para> | |
| 873 | |
| 874 </directive> | |
| 875 | |
| 876 | |
| 877 <directive name="scgi_pass_request_body"> | |
| 878 <syntax><literal>on</literal> | <literal>off</literal></syntax> | |
| 879 <default>on</default> | |
| 880 <context>http</context> | |
| 881 <context>server</context> | |
| 882 <context>location</context> | |
| 883 | |
| 884 <para> | |
| 885 Indicates whether the original request body is passed | |
| 886 to the SCGI server. | |
| 887 See also the <link id="scgi_pass_request_headers"/> directive. | |
| 888 </para> | |
| 889 | |
| 890 </directive> | |
| 891 | |
| 892 | |
| 893 <directive name="scgi_pass_request_headers"> | |
| 894 <syntax><literal>on</literal> | <literal>off</literal></syntax> | |
| 895 <default>on</default> | |
| 896 <context>http</context> | |
| 897 <context>server</context> | |
| 898 <context>location</context> | |
| 899 | |
| 900 <para> | |
| 901 Indicates whether the header fields of the original request are passed | |
| 902 to the SCGI server. | |
| 903 See also the <link id="scgi_pass_request_body"/> directive. | |
| 904 </para> | |
| 905 | |
| 906 </directive> | |
| 907 | |
| 908 | |
| 909 <directive name="scgi_send_timeout"> | |
| 910 <syntax><value>time</value></syntax> | |
| 911 <default>60s</default> | |
| 912 <context>http</context> | |
| 913 <context>server</context> | |
| 914 <context>location</context> | |
| 915 | |
| 916 <para> | |
| 917 Sets a timeout for transmitting a request to the SCGI server. | |
| 918 The timeout is set only between two successive write operations, | |
| 919 not for the transmission of the whole request. | |
| 920 If the SCGI server does not receive anything within this time, | |
| 921 the connection is closed. | |
| 922 </para> | |
| 923 | |
| 924 </directive> | |
| 925 | |
| 926 | |
| 927 <directive name="scgi_store"> | |
| 928 <syntax> | |
| 929 <literal>on</literal> | | |
| 930 <literal>off</literal> | | |
| 931 <value>string</value></syntax> | |
| 932 <default>off</default> | |
| 933 <context>http</context> | |
| 934 <context>server</context> | |
| 935 <context>location</context> | |
| 936 | |
| 937 <para> | |
| 938 Enables saving of files to a disk. | |
| 939 The <literal>on</literal> parameter saves files with paths | |
| 940 corresponding to the directives | |
| 941 <link doc="ngx_http_core_module.xml" id="alias"/> or | |
| 942 <link doc="ngx_http_core_module.xml" id="root"/>. | |
| 943 The <literal>off</literal> parameter disables saving of files. | |
| 944 In addition, the file name can be set explicitly using the | |
| 945 <value>string</value> with variables: | |
| 946 <example> | |
| 947 scgi_store /data/www$original_uri; | |
| 948 </example> | |
| 949 </para> | |
| 950 | |
| 951 <para> | |
| 952 The modification time of files is set according to the received | |
| 953 <header>Last-Modified</header> response header field. | |
| 954 The response is first written to a temporary file, | |
| 955 and then the file is renamed. | |
| 956 Starting from version 0.8.9, temporary files and the persistent store | |
| 957 can be put on different file systems. | |
| 958 However, be aware that in this case a file is copied | |
| 959 across two file systems instead of the cheap renaming operation. | |
| 960 It is thus recommended that for any given location both saved files and a | |
| 961 directory holding temporary files, set by the <link id="scgi_temp_path"/> | |
| 962 directive, are put on the same file system. | |
| 963 </para> | |
| 964 | |
| 965 <para> | |
| 966 This directive can be used to create local copies of static unchangeable | |
| 967 files, e.g.: | |
| 968 <example> | |
| 969 location /images/ { | |
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970 root /data/www; |
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971 error_page 404 = /fetch$uri; |
| 1180 | 972 } |
| 973 | |
| 974 location /fetch/ { | |
| 975 internal; | |
| 976 | |
| 977 scgi_pass backend:9000; | |
| 978 ... | |
| 979 | |
| 980 scgi_store on; | |
| 981 scgi_store_access user:rw group:rw all:r; | |
| 982 scgi_temp_path /data/temp; | |
| 983 | |
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984 alias /data/www/; |
| 1180 | 985 } |
| 986 </example> | |
| 987 </para> | |
| 988 | |
| 989 </directive> | |
| 990 | |
| 991 | |
| 992 <directive name="scgi_store_access"> | |
| 993 <syntax><value>users</value>:<value>permissions</value> ...</syntax> | |
| 994 <default>user:rw</default> | |
| 995 <context>http</context> | |
| 996 <context>server</context> | |
| 997 <context>location</context> | |
| 998 | |
| 999 <para> | |
| 1000 Sets access permissions for newly created files and directories, e.g.: | |
| 1001 <example> | |
| 1002 scgi_store_access user:rw group:rw all:r; | |
| 1003 </example> | |
| 1004 </para> | |
| 1005 | |
| 1006 <para> | |
| 1007 If any <literal>group</literal> or <literal>all</literal> access permissions | |
| 1008 are specified then <literal>user</literal> permissions may be omitted: | |
| 1009 <example> | |
| 1010 scgi_store_access group:rw all:r; | |
| 1011 </example> | |
| 1012 </para> | |
| 1013 | |
| 1014 </directive> | |
| 1015 | |
| 1016 | |
| 1017 <directive name="scgi_temp_file_write_size"> | |
| 1018 <syntax><value>size</value></syntax> | |
| 1019 <default>8k|16k</default> | |
| 1020 <context>http</context> | |
| 1021 <context>server</context> | |
| 1022 <context>location</context> | |
| 1023 | |
| 1024 <para> | |
| 1025 Limits the <value>size</value> of data written to a temporary file | |
| 1026 at a time, when buffering of responses from the SCGI server | |
| 1027 to temporary files is enabled. | |
| 1028 By default, <value>size</value> is limited by two buffers set by the | |
| 1029 <link id="scgi_buffer_size"/> and <link id="scgi_buffers"/> directives. | |
| 1030 The maximum size of a temporary file is set by the | |
| 1031 <link id="scgi_max_temp_file_size"/> directive. | |
| 1032 </para> | |
| 1033 | |
| 1034 </directive> | |
| 1035 | |
| 1036 | |
| 1037 <directive name="scgi_temp_path"> | |
| 1038 <syntax> | |
| 1039 <value>path</value> | |
| 1040 [<value>level1</value> | |
| 1041 [<value>level2</value> | |
| 1042 [<value>level3</value>]]]</syntax> | |
| 1043 <default>scgi_temp</default> | |
| 1044 <context>http</context> | |
| 1045 <context>server</context> | |
| 1046 <context>location</context> | |
| 1047 | |
| 1048 <para> | |
| 1049 Defines a directory for storing temporary files | |
| 1050 with data received from SCGI servers. | |
| 1051 Up to three-level subdirectory hierarchy can be used underneath the specified | |
| 1052 directory. | |
| 1053 For example, in the following configuration | |
| 1054 <example> | |
| 1055 scgi_temp_path /spool/nginx/scgi_temp 1 2; | |
| 1056 </example> | |
| 1057 a temporary file might look like this: | |
| 1058 <example> | |
| 1059 /spool/nginx/scgi_temp/<emphasis>7</emphasis>/<emphasis>45</emphasis>/00000123<emphasis>457</emphasis> | |
| 1060 </example> | |
| 1061 </para> | |
| 1062 | |
| 1063 </directive> | |
| 1064 | |
| 1065 </section> | |
| 1066 | |
| 1067 </module> |