doc/release-notes/release-3.0.man

   1 Squid 3.0.RC1 release notesSquid Developers$Id$
   2 Squid is a WWW Cache application developed by the National Laboratory
   3 for Applied Network Research and members of the Web Caching community.Notice
   4
   5 .Pp
   6 The Squid Team are pleased to announce the release of Squid-3.0.RC1 for pre-release testing.
   7 .Pp
   8 This new release is available for download from  or the \&.
   9 .Pp
  10 A large number of the show-stopper bugs have been fixed along with general improvements to the ICAP support.
  11 While this release is not deemed ready for production use, we believe it is ready for wider testing by the community.
  12 .Pp
  13 We welcome feedback and bug reports. If you find a bug, please see  for how to submit a report with a stack trace.
  14 .Pp
  15 Known issues
  16
  17 .Pp
  18 Although this release is deemed good enough for testing in many setups, please note the existence of \&.
  19 .Pp
  20 Changes since earlier PRE releases of Squid-3.0
  21
  22 .Pp
  23 The 3.0 change history can be \&.
  24 .Pp
  25 Changes since Squid-2.6
  26
  27 .SH Major new features
  28
  29 .Pp
  30 Squid 3.0 represents a major rewrite of Squid and has a number of new features.
  31 .Pp
  32 The most important of these are:
  33 .Pp
  34 .nr ll +1
  35 .nr t\n(ll 0
  36 .if \n(ll>1 .RS
  37 .nr bi 1
  38 .Pp
  39 Code converted to C++, with significant internal restructuring and rewrites.
  40 .nr bi 1
  41 .Pp
  42 ICAP implementation (RFC 3507 and www.icap-forum.org)
  43 .nr bi 1
  44 .Pp
  45 Edge Side Includes (ESI) implementation (www.esi.org)
  46 .if \n(ll>1 .RE
  47 .nr ll -1
  48 .Pp
  49 Most user-facing changes are reflected in squid.conf (see below).
  50 .Pp
  51 Internet Content Adaptation Protocol (ICAP)
  52
  53 .Pp
  54 Squid 3.0 supports ICAP/1.0. To enable ICAP support, use the --enable-icap-client ./configure option and icap_enable squid.conf option. You will also need to configure ICAP services in your squid.conf using icap_service, icap_class, and icap_access options. The following example instructs Squid to talk to two ICAP services, one for request and one for response adaptation:
  55 .Pp
  56 .DS
  57 .sp
  58 .ft RR
  59 .nf
  60 icap_enable on
  61 icap_service service_req reqmod_precache 1 icap://127.0.0.1:1344/request
  62 icap_service service_resp respmod_precache 0 icap://127.0.0.1:1344/response
  63 icap_class class_req service_req
  64 icap_class class_resp service_resp
  65 icap_access class_req allow all
  66 icap_access class_resp allow all
  67 .DE
  68 .fi
  69 .ec
  70 .ft P
  71 .sp
  72 .Pp
  73 .Pp
  74 Please see squid.conf.default for more details about these and many other icap_* options.
  75 .Pp
  76 .Pp
  77 Squid supports pre-cache request and pre-cache response vectoring points. The following ICAP features are supported: message preview, 204 responses outside of preview, request satisfaction, X-Transfer-* negotiation, persistent ICAP connections, client IP/credentials sharing, and optional bypass of certain service failures.
  78 .Pp
  79 .Pp
  80 No more than one ICAP service can be applied to an HTTP message. In other words, chaining or load balancing multiple services is not yet supported.
  81 .Pp
  82 .Pp
  83 Proxy-directed data trickling and patience pages are not supported yet.
  84 .Pp
  85 .Pp
  86 Following ICAP requirements, Squid never performs HTTP message adaptation without a successful and fresh ICAP OPTIONS response on file. A REQMOD or RESPMOD request will not be sent to a configured ICAP service until Squid receives a valid OPTIONS response from that service. If a service malfunctions or goes down, Squid may stop talking to the service for a while. Several squid.conf options can be used to tune the failure bypass algorithm (e.g., icap_service_failure_limit and icap_service_revival_delay).
  87 .Pp
  88 .Pp
  89 The bypass parameter of the icap_service squid.conf option determines whether Squid will try to bypass service failures. Most connectivity and preview-stage failures can be bypassed.
  90 .Pp
  91 .Pp
  92 More information about ICAP can be found from the ICAP-forum website
  93 .Pp
  94 Edge Side Includes (ESI)
  95
  96 .Pp
  97 ESI is an open specification of an markup language enabling reverse proxies
  98 to perform some simple XML based processing, offloading the final page assembly from the webserver and similar tasks.
  99 .Pp
 100 .Pp
 101 More information about ESI can be found from the ESI website
 102 .Pp
 103 .SH 2.6 features not found in Squid-3.0
 104
 105 .Pp
 106 Some of the features found in Squid-2.6 is not available in Squid-3.
 107 Some has been dropped as they are not needed. Some has not yet been forward-ported to Squid-3 and may appear in a later release.
 108 .Pp
 109 .nr ll +1
 110 .nr t\n(ll 0
 111 .if \n(ll>1 .RS
 112 .nr bi 1
 113 .Pp
 114 refresh_stale_hit option. Not yet ported.
 115 .nr bi 1
 116 .Pp
 117 ability to follow X-Forwarded-For. Not yet ported.
 118 .nr bi 1
 119 .Pp
 120 Full caching of Vary/ETag using If-None-Match. Only basic Vary cache supported. Not yet ported.
 121 .nr bi 1
 122 .Pp
 123 Mapping of server error messages. Not yet ported.
 124 .nr bi 1
 125 .Pp
 126 http_access2 access directive. Not yet ported.
 127 .nr bi 1
 128 .Pp
 129 Location header rewrites. Not yet ported.
 130 .nr bi 1
 131 .Pp
 132 umask directive. Not yet ported.
 133 .nr bi 1
 134 .Pp
 135 wais_relay. Feature dropped as it's equivalent to cache_peer + cache_peer_access.
 136 .nr bi 1
 137 .Pp
 138 urlgroup. Not yet ported.
 139 .nr bi 1
 140 .Pp
 141 collapsed forwarding. Not yet ported.
 142 .nr bi 1
 143 .Pp
 144 stable Windows support. Irregularly maintained.
 145 .if \n(ll>1 .RE
 146 .nr ll -1
 147 .Pp
 148 .SH Logging changes
 149
 150 access.log
 151
 152 .Pp
 153 The TCP_REFRESH_HIT and TCP_REFRESH_MISS log types have been replaced because they were misleading (all refreshes need to query the origin server, so they could never be hits). The following log types have been introduced to replace them:
 154 .Pp
 155 .nr ll +1
 156 .nr t\n(ll 2
 157 .if \n(ll>1 .RS
 158 .IP "TCP_REFRESH_UNMODIFIED"
 159 .nr bi 1
 160 .Pp
 161 The requested object was cached but STALE. The IMS query for the object resulted in \&"304 not modified\&".
 162 .IP "TCP_REFRESH_MODIFIED"
 163 .nr bi 1
 164 .Pp
 165 The requested object was cached but STALE. The IMS query returned the new content.
 166 .if \n(ll>1 .RE
 167 .nr ll -1
 168 .Pp
 169 See  for a definition of all log types.
 170 .Pp
 171 .Pp
 172 .Pp
 173 .Pp
 174 .SH Changes to squid.conf
 175
 176 .Pp
 177 There have been many changes to Squid's configuration file since Squid-2.6.
 178 .Pp
 179 This section gives a thorough account of those changes in three categories:
 180 .Pp
 181 .nr ll +1
 182 .nr t\n(ll 0
 183 .if \n(ll>1 .RS
 184 .nr bi 1
 185 .Pp
 186 .nr bi 1
 187 .Pp
 188 .nr bi 1
 189 .Pp
 190 .if \n(ll>1 .RE
 191 .nr ll -1
 192 .Pp
 193 .Pp
 194 .Pp
 195 .Pp
 196 .Pp
 197 New tags
 198
 199 .Pp
 200 .nr ll +1
 201 .nr t\n(ll 2
 202 .if \n(ll>1 .RS
 203 .IP "minimum_icp_query_timeout (msec)"
 204 .nr bi 1
 205 .Pp
 206 .DS
 207 .sp
 208 .ft RR
 209 .nf
 210 Default: 5
 211
 212 Normally the ICP query timeout is determined dynamically.  But
 213 sometimes it can lead to very small timeouts, even lower than
 214 the normal latency variance on your link due to traffic.
 215 Use this option to put an lower limit on the dynamic timeout
 216 value.  Do NOT use this option to always use a fixed (instead
 217 of a dynamic) timeout value. To set a fixed timeout see the
 218 \&'icp_query_timeout' directive.
 219
 220 .DE
 221 .fi
 222 .ec
 223 .ft P
 224 .sp
 225 .IP "background_ping_rate"
 226 .nr bi 1
 227 .Pp
 228 .DS
 229 .sp
 230 .ft RR
 231 .nf
 232 Default: 10 seconds
 233
 234 Controls how often the ICP pings are sent to siblings that
 235 have background-ping set.
 236
 237 .DE
 238 .fi
 239 .ec
 240 .ft P
 241 .sp
 242 .Pp
 243 .IP "httpd_accel_surrogate_id"
 244 .nr bi 1
 245 .Pp
 246 .DS
 247 .sp
 248 .ft RR
 249 .nf
 250 Default: unset
 251
 252 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
 253 need an identification token to allow control targeting. Because
 254 a farm of surrogates may all perform the same tasks, they may share
 255 an identification token.
 256
 257 .DE
 258 .fi
 259 .ec
 260 .ft P
 261 .sp
 262 .Pp
 263 .IP "http_accel_surrogate_remote on\(broff"
 264 .nr bi 1
 265 .Pp
 266 .DS
 267 .sp
 268 .ft RR
 269 .nf
 270 Default: off
 271
 272 Remote surrogates (such as those in a CDN) honour Surrogate-Control: no-store-remote.
 273 Set this to on to have squid behave as a remote surrogate.
 274
 275 .DE
 276 .fi
 277 .ec
 278 .ft P
 279 .sp
 280 .Pp
 281 .IP "esi_parser libxml2\(brexpat\(brcustom"
 282 .nr bi 1
 283 .Pp
 284 .DS
 285 .sp
 286 .ft RR
 287 .nf
 288 Default: custom
 289
 290 ESI markup is not strictly XML compatible. The custom ESI parser
 291 will give higher performance, but cannot handle non ASCII character
 292 encodings.
 293
 294 .DE
 295 .fi
 296 .ec
 297 .ft P
 298 .sp
 299 .Pp
 300 .IP "email_err_data on\(broff"
 301 .nr bi 1
 302 .Pp
 303 .DS
 304 .sp
 305 .ft RR
 306 .nf
 307 Default: on
 308
 309 If enabled, information about the occurred error will be
 310 included in the mailto links of the ERR pages (if %W is set)
 311 so that the email body contains the data.
 312 Syntax is <A HREF=\&"mailto:%w%W\&">%w</A>
 313
 314 .DE
 315 .fi
 316 .ec
 317 .ft P
 318 .sp
 319 .Pp
 320 .IP "refresh_all_ims on\(broff"
 321 .nr bi 1
 322 .Pp
 323 .DS
 324 .sp
 325 .ft RR
 326 .nf
 327 Default: off
 328
 329 When you enable this option, squid will always check
 330 the origin server for an update when a client sends an
 331 If-Modified-Since request.  Many browsers use IMS
 332 requests when the user requests a reload, and this
 333 ensures those clients receive the latest version.
 334
 335 By default (off), squid may return a Not Modified response
 336 based on the age of the cached version.
 337
 338 .DE
 339 .fi
 340 .ec
 341 .ft P
 342 .sp
 343 .IP "request_header_access"
 344 .nr bi 1
 345 .Pp
 346 Replaces the header_access directive of Squid-2.6 and earlier, but applies to requests only.
 347 .IP "reply_header_access"
 348 .nr bi 1
 349 .Pp
 350 Replaces the header_access directive of Squid-2.6 and earlier, but applies to replies only.
 351 .Pp
 352 .IP "icap_enable on\(broff"
 353 .nr bi 1
 354 .Pp
 355 .DS
 356 .sp
 357 .ft RR
 358 .nf
 359 Default: off
 360
 361 If you want to enable the ICAP module support, set this to on.
 362
 363 .DE
 364 .fi
 365 .ec
 366 .ft P
 367 .sp
 368 .IP "icap_preview_enable on\(broff"
 369 .nr bi 1
 370 .Pp
 371 .DS
 372 .sp
 373 .ft RR
 374 .nf
 375 Default: off
 376
 377 Set this to 'on' if you want to enable the ICAP preview
 378 feature in Squid.
 379
 380 .DE
 381 .fi
 382 .ec
 383 .ft P
 384 .sp
 385 .IP "icap_preview_size"
 386 .nr bi 1
 387 .Pp
 388 .DS
 389 .sp
 390 .ft RR
 391 .nf
 392 Default: -1
 393
 394 The default size of preview data to be sent to the ICAP server.
 395 -1 means no preview. This value might be overwritten on a per server
 396 basis by OPTIONS requests.
 397
 398 .DE
 399 .fi
 400 .ec
 401 .ft P
 402 .sp
 403 .IP "icap_default_options_ttl (seconds)"
 404 .nr bi 1
 405 .Pp
 406 .DS
 407 .sp
 408 .ft RR
 409 .nf
 410 Default: 60
 411
 412 The default TTL value for ICAP OPTIONS responses that don't have
 413 an Options-TTL header.
 414
 415 .DE
 416 .fi
 417 .ec
 418 .ft P
 419 .sp
 420 .IP "icap_persistent_connections on\(broff"
 421 .nr bi 1
 422 .Pp
 423 .DS
 424 .sp
 425 .ft RR
 426 .nf
 427 Default: on
 428
 429 Whether or not Squid should use persistent connections to
 430 an ICAP server.
 431
 432 .DE
 433 .fi
 434 .ec
 435 .ft P
 436 .sp
 437 .IP "icap_send_client_ip on\(broff"
 438 .nr bi 1
 439 .Pp
 440 .DS
 441 .sp
 442 .ft RR
 443 .nf
 444 Default: off
 445
 446 This adds the header \&"X-Client-IP\&" to ICAP requests.
 447
 448 .DE
 449 .fi
 450 .ec
 451 .ft P
 452 .sp
 453 .IP "icap_send_client_username on\(broff"
 454 .nr bi 1
 455 .Pp
 456 .DS
 457 .sp
 458 .ft RR
 459 .nf
 460 Default: off
 461
 462 This adds the header \&"X-Client-Username\&" to ICAP requests
 463 if proxy access is authentified.
 464
 465 .DE
 466 .fi
 467 .ec
 468 .ft P
 469 .sp
 470 .IP "icap_service"
 471 .nr bi 1
 472 .Pp
 473 .DS
 474 .sp
 475 .ft RR
 476 .nf
 477 Default: none
 478
 479 Defines a single ICAP service
 480
 481 icap_service servicename vectoring_point bypass service_url
 482
 483 vectoring_point = reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
 484 This specifies at which point of request processing the ICAP
 485 service should be plugged in.
 486 bypass = 1|0
 487 If set to 1 and the ICAP server cannot be reached, the request will go
 488 through without being processed by an ICAP server
 489 service_url = icap://servername:port/service
 490
 491 Note: reqmod_precache and respmod_postcache is not yet implemented
 492
 493 Example:
 494 icap_service service_1 reqmod_precache 0 icap://icap1.mydomain.net:1344/reqmod
 495 icap_service service_2 respmod_precache 0 icap://icap2.mydomain.net:1344/respmod
 496
 497 .DE
 498 .fi
 499 .ec
 500 .ft P
 501 .sp
 502 .IP "icap_class"
 503 .nr bi 1
 504 .Pp
 505 .DS
 506 .sp
 507 .ft RR
 508 .nf
 509 Default: none
 510
 511 Defines an ICAP service chain. If there are multiple services per
 512 vectoring point, they are processed in the specified order.
 513
 514 icap_class classname servicename...
 515
 516 Example:
 517 icap_class class_1 service_1 service_2
 518 icap class class_2 service_1 service_3
 519
 520 .DE
 521 .fi
 522 .ec
 523 .ft P
 524 .sp
 525 .IP "icap_access"
 526 .nr bi 1
 527 .Pp
 528 .DS
 529 .sp
 530 .ft RR
 531 .nf
 532 Default: none
 533
 534 Redirects a request through an ICAP service class, depending
 535 on given acls
 536
 537 icap_access classname allow|deny [!]aclname...
 538
 539 The icap_access statements are processed in the order they appear in
 540 this configuration file. If an access list matches, the processing stops.
 541 For an \&"allow\&" rule, the specified class is used for the request. A \&"deny\&"
 542 rule simply stops processing without using the class. You can also use the
 543 special classname \&"None\&".
 544
 545 For backward compatibility, it is also possible to use services
 546 directly here.
 547
 548 Example:
 549 icap_access class_1 allow all
 550
 551 .DE
 552 .fi
 553 .ec
 554 .ft P
 555 .sp
 556 .Pp
 557 .IP "accept_filter"
 558 .nr bi 1
 559 .Pp
 560 .DS
 561 .sp
 562 .ft RR
 563 .nf
 564 The name of an accept(2) filter to install on Squid's
 565 listen socket(s).  This feature is perhaps specific to
 566 FreeBSD and requires support in the kernel.
 567
 568 The 'httpready' filter delays delivering new connections
 569 to Squid until a full HTTP request has been received.
 570 See the accf_http(9) man page.
 571
 572 .DE
 573 .fi
 574 .ec
 575 .ft P
 576 .sp
 577 .if \n(ll>1 .RE
 578 .nr ll -1
 579 .Pp
 580 .Pp
 581 Changes to existing tags
 582
 583 .Pp
 584 .nr ll +1
 585 .nr t\n(ll 2
 586 .if \n(ll>1 .RS
 587 .IP "http_port"
 588 .nr bi 1
 589 .Pp
 590 New options:
 591 .DS
 592 .sp
 593 .ft RR
 594 .nf
 595     disable-pmtu-discovery=
 596       Control Path-MTU discovery usage:
 597         off          lets OS decide on what to do (default).
 598         transparent  disable PMTU discovery when transparent support is enabled.
 599         always       disable always PMTU discovery.
 600
 601     In many setups of transparently intercepting proxies Path-MTU
 602     discovery can not work on traffic towards the clients. This is
 603     the case when the intercepting device does not fully track
 604     connections and fails to forward ICMP must fragment messages
 605     to the cache server. If you have such setup and experience that
 606     certain clients sporadically hang or never complete requests set
 607     disable-pmtu-discovery option to 'transparent'.
 608
 609 .DE
 610 .fi
 611 .ec
 612 .ft P
 613 .sp
 614 .Pp
 615 Removed options:
 616 .DS
 617 .sp
 618 .ft RR
 619 .nf
 620     urlgroup=, not yet ported to Squid-3.
 621
 622     no-connection-auth, not yet ported to Squid-3.
 623
 624 .DE
 625 .fi
 626 .ec
 627 .ft P
 628 .sp
 629
 630 .IP " https_port"
 631 .nr bi 1
 632 .Pp
 633 Removed options:
 634 .DS
 635 .sp
 636 .ft RR
 637 .nf
 638     urlgroup=, not yet ported to Squid-3.
 639
 640 .DE
 641 .fi
 642 .ec
 643 .ft P
 644 .sp
 645 .IP "cache_peer"
 646 .nr bi 1
 647 .Pp
 648 New options:
 649 .DS
 650 .sp
 651 .ft RR
 652 .nf
 653      basetime=n
 654
 655      background-ping
 656
 657      weighted-round-robin
 658
 659      use 'basetime=n' to specify a base amount to
 660      be subtracted from round trip times of parents.
 661      It is subtracted before division by weight in calculating
 662      which parent to fectch from. If the rtt is less than the
 663      base time the rtt is set to a minimal value.
 664
 665      use 'background-ping' to only send ICP queries to this
 666      neighbor infrequently. This is used to keep the neighbor
 667      round trip time updated and is usually used in
 668      conjunction with weighted-round-robin.
 669
 670      use 'weighted-round-robin' to define a set of parents
 671      which should be used in a round-robin fashion with the
 672      frequency of each parent being based on the round trip
 673      time. Closer parents are used more often.
 674      Usually used for background-ping parents.
 675
 676
 677 .DE
 678 .fi
 679 .ec
 680 .ft P
 681 .sp
 682 .Pp
 683 Removed options:
 684 .DS
 685 .sp
 686 .ft RR
 687 .nf
 688     userhash, not yet ported to Squid-3
 689
 690     sourcehash, not yet ported to Squid-2
 691
 692     monitorurl, monitorsize etc, not yet ported to Squid-3
 693
 694     connection-auth=, not yet ported to Squid-3
 695
 696 .DE
 697 .fi
 698 .ec
 699 .ft P
 700 .sp
 701 .IP "cache_dir"
 702 .nr bi 1
 703 .Pp
 704 Common options
 705 .DS
 706 .sp
 707 .ft RR
 708 .nf
 709     no-store, replaces the older read-only option
 710
 711     min-size, not yet portedto Squid-3
 712
 713 .DE
 714 .fi
 715 .ec
 716 .ft P
 717 .sp
 718 .Pp
 719 COSS file system:
 720 .DS
 721 .sp
 722 .ft RR
 723 .nf
 724     The coss file store is experimental, and still lacks much
 725     of the functionality found in 2.6.
 726
 727     overwrite-percent=n, not yet ported to Squid-3.
 728
 729     max-stripe-waste=n, not yet ported to Squid-3.
 730
 731     membufs=n, not yet ported to Squid-3.
 732
 733     maxfullbufs=n, not yet ported to Squid-3.
 734
 735 .DE
 736 .fi
 737 .ec
 738 .ft P
 739 .sp
 740 .IP "auth_param"
 741 .nr bi 1
 742 .Pp
 743 Removed Basic auth option
 744 .DS
 745 .sp
 746 .ft RR
 747 .nf
 748     blankpasswor, not yet ported to squid-3.
 749     auth_param basic concurrency 0
 750
 751 .DE
 752 .fi
 753 .ec
 754 .ft P
 755 .sp
 756 .Pp
 757 Removed digest options:
 758 .DS
 759 .sp
 760 .ft RR
 761 .nf
 762     concurrency, not yet ported to Squid-3.
 763
 764 .DE
 765 .fi
 766 .ec
 767 .ft P
 768 .sp
 769 .Pp
 770 .IP "external_acl_type"
 771 .nr bi 1
 772 .Pp
 773 New format specifications:
 774 .DS
 775 .sp
 776 .ft RR
 777 .nf
 778     %URI          Requested URI
 779
 780     %PATH         Requested URL path
 781
 782 .DE
 783 .fi
 784 .ec
 785 .ft P
 786 .sp
 787 .Pp
 788 Removed format specifications:
 789 .DS
 790 .sp
 791 .ft RR
 792 .nf
 793     %ACL, not yet ported to Squid-3
 794
 795     %DATA, not yet ported to Squid-3
 796
 797 .DE
 798 .fi
 799 .ec
 800 .ft P
 801 .sp
 802 .Pp
 803 New result keywords:
 804 .DS
 805 .sp
 806 .ft RR
 807 .nf
 808      tag=  Apply a tag to a request (for both ERR and OK results)
 809            Only sets a tag, does not alter existing tags.
 810
 811 .DE
 812 .fi
 813 .ec
 814 .ft P
 815 .sp
 816 .Pp
 817 .IP "refresh_pattern"
 818 .nr bi 1
 819 .Pp
 820 New options:
 821 .DS
 822 .sp
 823 .ft RR
 824 .nf
 825     ignore-no-store
 826     refresh-ims
 827
 828     ignore-no-store ignores any ``Cache-control: no-store''
 829     headers received from a server. Doing this VIOLATES
 830     the HTTP standard. Enabling this feature could make you
 831     liable for problems which it causes.
 832
 833     refresh-ims causes squid to contact the origin server
 834     when a client issues an If-Modified-Since request. This
 835     ensures that the client will receive an updated version
 836     if one is available.
 837
 838 .DE
 839 .fi
 840 .ec
 841 .ft P
 842 .sp
 843 .IP "acl"
 844 .nr bi 1
 845 .Pp
 846 New types:
 847 .DS
 848 .sp
 849 .ft RR
 850 .nf
 851     acl aclname http_status 200 301 500- 400-403 ...     # status code in reply
 852
 853
 854 .DE
 855 .fi
 856 .ec
 857 .ft P
 858 .sp
 859 .Pp
 860 Removed types:
 861 .DS
 862 .sp
 863 .ft RR
 864 .nf
 865     acl aclname urllogin [-i] [^a-zA-Z0-9] ...      # regex matching on URL login field
 866
 867     acl urlgroup group1 ...
 868         # match against the urlgroup as indicated by redirectors
 869
 870
 871 .DE
 872 .fi
 873 .ec
 874 .ft P
 875 .sp
 876 .IP "short_icon_urls"
 877 .nr bi 1
 878 .Pp
 879 New default:
 880 .DS
 881 .sp
 882 .ft RR
 883 .nf
 884     Default: on
 885     (Old default: off)
 886
 887 .DE
 888 .fi
 889 .ec
 890 .ft P
 891 .sp
 892 .IP "delay_class"
 893 .nr bi 1
 894 .Pp
 895 New delay classes:
 896 .DS
 897 .sp
 898 .ft RR
 899 .nf
 900     class 4 Everything in a class 3 delay pool, with an
 901     additional limit on a per user basis. This
 902     only takes effect if the username is established
 903     in advance - by forcing authentication in your
 904     http_access rules.
 905
 906     class 5 Requests are grouped according their tag (see
 907     external_acl's tag= reply).
 908
 909 .DE
 910 .fi
 911 .ec
 912 .ft P
 913 .sp
 914 .Pp
 915 .IP "htcp_port"
 916 .nr bi 1
 917 .Pp
 918 New default to require the feature to be enabled in squid.conf:
 919 .DS
 920 .sp
 921 .ft RR
 922 .nf
 923     Default: 0 (disabled)
 924     (Old default: 4827)
 925
 926 .DE
 927 .fi
 928 .ec
 929 .ft P
 930 .sp
 931 .Pp
 932 .IP "icp_port"
 933 .nr bi 1
 934 .Pp
 935 New default to require the feature to be enabled in squid.conf:
 936 .DS
 937 .sp
 938 .ft RR
 939 .nf
 940     Default: 0 (disabled)
 941     (Old default: 3130)
 942
 943 .DE
 944 .fi
 945 .ec
 946 .ft P
 947 .sp
 948 .Pp
 949 .IP "snmp_port"
 950 .nr bi 1
 951 .Pp
 952 New default to require the feature to be enabled in squid.conf:
 953 .DS
 954 .sp
 955 .ft RR
 956 .nf
 957     Default: 0 (disabled)
 958     (Old default: 3401)
 959
 960 .DE
 961 .fi
 962 .ec
 963 .ft P
 964 .sp
 965 .Pp
 966 .IP "logformat"
 967 .nr bi 1
 968 .Pp
 969 New format tags:
 970 .DS
 971 .sp
 972 .ft RR
 973 .nf
 974     rp      Request URL-Path excluding hostname
 975
 976     et      Tag returned by external acl
 977
 978     <sH     Reply high offset sent
 979
 980     <sS     Upstream object size
 981
 982 .DE
 983 .fi
 984 .ec
 985 .ft P
 986 .sp
 987 .Pp
 988 .Pp
 989 Removed format tags:
 990 .DS
 991 .sp
 992 .ft RR
 993 .nf
 994     >st     Request size including HTTP headers, not yet ported to Squid-3.
 995
 996     st      Request+Reply size including HTTP headers, not yet ported to Squid-3.
 997
 998 .DE
 999 .fi
1000 .ec
1001 .ft P
1002 .sp
1003 .Pp
1004 .IP "reply_body_max_size"
1005 .nr bi 1
1006 .Pp
1007 Syntax changed:
1008 .DS
1009 .sp
1010 .ft RR
1011 .nf
1012     reply_body_max_size size [acl acl...]
1013
1014 .DE
1015 .fi
1016 .ec
1017 .ft P
1018 .sp
1019 .Pp
1020 allow/deny no longer used.
1021 .Pp
1022 .IP "url_rewrite_program"
1023 .nr bi 1
1024 .Pp
1025 No urlgroup support in either requests or responese
1026 .if \n(ll>1 .RE
1027 .nr ll -1
1028 .Pp
1029 .Pp
1030 .Pp
1031 .Pp
1032 Removed tags
1033
1034 .Pp
1035 .nr ll +1
1036 .nr t\n(ll 2
1037 .if \n(ll>1 .RS
1038 .IP "broken_vary_encoding"
1039 .nr bi 1
1040 .Pp
1041 Not yet ported to Squid-3.
1042 .IP "cache_vary"
1043 .nr bi 1
1044 .Pp
1045 Not yet ported to Squid-3.
1046 .IP "collapsed_forwarding"
1047 .nr bi 1
1048 .Pp
1049 Not yet ported to Squid-3.
1050 .IP "follow_x_forwarded_for"
1051 .nr bi 1
1052 .Pp
1053 Not yet ported to Squid-3.
1054 .IP "*_uses_indirect_client"
1055 .nr bi 1
1056 .Pp
1057 Not yet ported to Squid-3.
1058 .IP "error_map"
1059 .nr bi 1
1060 .Pp
1061 Not yet ported to Squid-3.
1062 .IP "header_access"
1063 .nr bi 1
1064 .Pp
1065 This has been replaced by request_header_access and reply_header_access
1066 .IP "http_access2"
1067 .nr bi 1
1068 .Pp
1069 Not yet ported to Squid-3.
1070 .IP "httpd_accel_no_pmtu_disc"
1071 .nr bi 1
1072 .Pp
1073 Replaced by disable-pmtu-discovery http_port option
1074 .IP "location_rewrite_*"
1075 .nr bi 1
1076 .Pp
1077 Not yet ported to Squid-3.
1078 .IP "refresh_stale_hit"
1079 .nr bi 1
1080 .Pp
1081 Not yet ported to Squid-3.
1082 .IP "umask"
1083 .nr bi 1
1084 .Pp
1085 Not yet ported to Squid-3.
1086 .IP "wais_relay_*"
1087 .nr bi 1
1088 .Pp
1089 equivalent to cache_peer + cache_peer_access.
1090 .if \n(ll>1 .RE
1091 .nr ll -1
1092 .Pp
1093 .Pp
1094 .SH Changes to ./configure Options
1095
1096 .Pp
1097 There have been some changes to Squid's build configuration since Squid-2.6.
1098 .Pp
1099 This section gives an account of those changes in three categories:
1100 .Pp
1101 .nr ll +1
1102 .nr t\n(ll 0
1103 .if \n(ll>1 .RS
1104 .nr bi 1
1105 .Pp
1106 .nr bi 1
1107 .Pp
1108 .nr bi 1
1109 .Pp
1110 .nr bi 1
1111 .Pp
1112 .if \n(ll>1 .RE
1113 .nr ll -1
1114 .Pp
1115 .Pp
1116 .Pp
1117 New options
1118
1119 .Pp
1120 .nr ll +1
1121 .nr t\n(ll 2
1122 .if \n(ll>1 .RS
1123 .IP "--enable-shared[=PKGS]"
1124 .nr bi 1
1125 .Pp
1126 Build shared libraries. The default is to build without.
1127 .Pp
1128 .IP "--enable-static[=PKGS]"
1129 .nr bi 1
1130 .Pp
1131 Build static libraries. The default is on.
1132 .Pp
1133 .IP "--enable-fast-install[=PKGS]"
1134 .nr bi 1
1135 .Pp
1136 .DS
1137 .sp
1138 .ft RR
1139 .nf
1140 Optimize for fast installation
1141         default: yes
1142 .DE
1143 .fi
1144 .ec
1145 .ft P
1146 .sp
1147 .Pp
1148 .IP "--disable-libtool-lock"
1149 .nr bi 1
1150 .Pp
1151 Avoid locking (might break parallel builds)
1152 .Pp
1153 .IP "--disable-optimizations"
1154 .nr bi 1
1155 .Pp
1156 Don't compile Squid with compiler optimizations enabled.
1157 Optimization is good for production builds, but not
1158 good for debugging. During development, use
1159 --disable-optimizations to reduce compilation times
1160 and allow easier debugging. This option implicitly
1161 also enables --disable-inline
1162 .Pp
1163 .IP "--disable-inline"
1164 .nr bi 1
1165 .Pp
1166 Don't compile trivial methods as inline. Squid
1167 is coded with much of the code able to be inlined.
1168 Inlining is good for production builds, but not
1169 good for development. During development, use
1170 --disable-inline to reduce compilation times and
1171 allow incremental builds to be quick. For
1172 production builds, or load tests, use
1173 --enable-inline to have squid make all trivial
1174 methods inlinable by the compiler.
1175 .Pp
1176 .IP "--enable-debug-cbdata"
1177 .nr bi 1
1178 .Pp
1179 Provide some debug information in cbdata
1180 .Pp
1181 .IP "--enable-disk-io=\e\&"list of modules\e\&""
1182 .nr bi 1
1183 .Pp
1184 Build support for the list of disk I/O modules.
1185 The default is only to build the \&"Blocking\&" module.
1186 See src/DiskIO for a list of available modules, or
1187 Programmers Guide for details on how to build your
1188 custom disk module.
1189 .Pp
1190 .IP "--enable-esi"
1191 .nr bi 1
1192 .Pp
1193 Enable ESI for accelerators. Requires libexpat.
1194 Enabling ESI will cause squid to follow the Edge
1195 Acceleration Specification (www.esi.org). This
1196 causes squid to IGNORE client Cache-Control headers.
1197 .Pp
1198 \fIDO NOT\fP use this in a squid configured as a web
1199 proxy, ONLY use it in a squid configured for
1200 webserver acceleration.
1201 .Pp
1202 .IP "--enable-icap-client"
1203 .nr bi 1
1204 .Pp
1205 Enable the ICAP client.
1206 .Pp
1207 .IP "--disable-snmp"
1208 .nr bi 1
1209 .Pp
1210 Disable SNMP monitoring support which is now built by default.
1211 .Pp
1212 .IP "--disable-htcp"
1213 .nr bi 1
1214 .Pp
1215 Disable HTCP protocol support which is now built by default.
1216 .Pp
1217 .IP "--enable-kqueue"
1218 .nr bi 1
1219 .Pp
1220 Enable kqueue() support. Marked as experimental in 3.0.
1221 .Pp
1222 .IP "--enable-ipfw-transparent"
1223 .nr bi 1
1224 .Pp
1225 Enable Transparent Proxy support for systems
1226 using FreeBSD IPFW style redirection.
1227 .Pp
1228 .IP "--disable-mempools"
1229 .nr bi 1
1230 .Pp
1231 Disable memPools. Note that this option now simply sets the
1232 default behaviour. Specific classes can override this at runtime, and
1233 only lib/MemPool.c needs to be altered to change the squid-wide
1234 default for all classes.
1235 .Pp
1236 .IP "--enable-cpu-profiling"
1237 .nr bi 1
1238 .Pp
1239 This option allows you to see which internal functions
1240 in Squid are consuming how much CPU. Compiles in probes
1241 that measure time spent in probed functions. Needs
1242 source modifications to add new probes. This is meant
1243 for developers to assist in performance optimisations
1244 of Squid internal functions.
1245 .Pp
1246 If you are not developer and not interested in the stats
1247 you shouldn't enable this, as overhead added, although
1248 small, is still overhead. See lib/Profiler.c for more.
1249 .Pp
1250 .IP "--with-gnu-ld"
1251 .nr bi 1
1252 .Pp
1253 Assume the C compiler uses GNU ld. The default is to auto-detect.
1254 .Pp
1255 .IP "--with-pic"
1256 .nr bi 1
1257 .Pp
1258 Try to use only PIC/non-PIC objects. The default is to use both.
1259 .Pp
1260 .IP "--with-tags[=TAGS]"
1261 .nr bi 1
1262 .Pp
1263 Include additional configurations. The default is automatic.
1264 .Pp
1265 .IP "--with-default-user=USER"
1266 .nr bi 1
1267 .Pp
1268 Sets the default System User account for squid permissions.
1269 The default is 'nobody' as in other releases of squid.
1270 .Pp
1271 .IP "--with-cppunit-basedir=[PATH]"
1272 .nr bi 1
1273 .Pp
1274 Path where the cppunit headers and libraries are found
1275 for unit testing. The default is automatic detection.
1276 .Pp
1277 NOTE: Since 3.0-PRE6 and 2.6STABLE14 squid no longer comes
1278 bundled with CPPUnit. Compile-time validation will be disabled
1279 if it is not installed on your system.
1280 .Pp
1281 .if \n(ll>1 .RE
1282 .nr ll -1
1283 Changes to existing options
1284
1285 .Pp
1286 .nr ll +1
1287 .nr t\n(ll 2
1288 .if \n(ll>1 .RS
1289 .IP "--enable-carp"
1290 .nr bi 1
1291 .Pp
1292 CARP support is now built by default.
1293 --disable-carp can be used to build without it.
1294 .Pp
1295 .IP "--enable-htcp"
1296 .nr bi 1
1297 .Pp
1298 HTCP protocol support is now built by default.
1299 Use --disable-htcp to build without it.
1300 .Pp
1301 .IP "--enable-snmp"
1302 .nr bi 1
1303 .Pp
1304 SNMP monitoring is now build by default.
1305 Use --disable-snmp to build without it.
1306 .Pp
1307 .IP "--enable-heap-replacement"
1308 .nr bi 1
1309 .Pp
1310 Please use --enable-removal-policies directive instead.
1311 .Pp
1312 .IP "--with-maxfd=N"
1313 .nr bi 1
1314 .Pp
1315 Replaced by --with-filedescriptors=N
1316 .Pp
1317 Override maximum number of filedescriptors. Useful
1318 if you build as another user who is not privileged
1319 to use the number of filedescriptors you want the
1320 resulting binary to support
1321 .Pp
1322 .IP "--enable-select"
1323 .nr bi 1
1324 .Pp
1325 Deprecated.
1326 Automatic checks will enable best I/O loop method available.
1327 .Pp
1328 .IP "--enable-epoll"
1329 .nr bi 1
1330 .Pp
1331 Deprecated.
1332 Automatic checks will enable best I/O loop method available.
1333 .Pp
1334 .IP "--enable-poll"
1335 .nr bi 1
1336 .Pp
1337 Deprecated.
1338 Automatic checks will enable best I/O loop method available.
1339 .Pp
1340 .IP "--enable-kqueue"
1341 .nr bi 1
1342 .Pp
1343 kqueue support is marked Experimental in Squid 3.0. Known to have some issues under load.
1344 .Pp
1345 .if \n(ll>1 .RE
1346 .nr ll -1
1347 Not yet available options
1348
1349 .Pp
1350 These configure options have not yet been ported to Squid-3. If you need something to do then
1351 porting one of these from Squid-2 to Squid-3 is most welcome.
1352 .Pp
1353 .nr ll +1
1354 .nr t\n(ll 2
1355 .if \n(ll>1 .RS
1356 .IP "--enable-devpoll"
1357 .nr bi 1
1358 .Pp
1359 Support for Solaris /dev/poll
1360 .Pp
1361 .IP "--enable-select-simple"
1362 .nr bi 1
1363 .Pp
1364 Basic POSIX select() loop without any binary fd_set optimizations.
1365 .Pp
1366 .IP "--enable-follow-x-forwarded-for"
1367 .nr bi 1
1368 .Pp
1369 Support following the X-Forwarded-For HTTP header for determining the
1370 client IP address
1371 .if \n(ll>1 .RE
1372 .nr ll -1
1373 .Pp
1374 Removed options
1375
1376 .Pp
1377 The following configure options have been removed.
1378 .Pp
1379 .nr ll +1
1380 .nr t\n(ll 2
1381 .if \n(ll>1 .RS
1382 .IP "--enable-dlmalloc"
1383 .nr bi 1
1384 .Pp
1385 Most OS:es have good malloc implementations these days, and the version we used to ship with Squid was very very old..
1386 .IP "--enable-mempool-debug"
1387 .nr bi 1
1388 .Pp
1389 Debug option, not needed and therefore removed.
1390 .IP "--enable-forward-log"
1391 .nr bi 1
1392 .Pp
1393 Rarely used extra log file. Removed.
1394 .IP "--enable-multicast-miss"
1395 .nr bi 1
1396 .Pp
1397 Rarely used feature, and multicast ICP acheives almost the same result. Removed.
1398 .IP "--enable-coss-aio-ops"
1399 .nr bi 1
1400 .Pp
1401 Specific to the COSS implementation in Squid-2
1402 .IP "--enable-large-cache-files"
1403 .nr bi 1
1404 .Pp
1405 Now enabled by default. Configure option was redundant and therefore removed.
1406 .IP "--enable-truncate"
1407 .nr bi 1
1408 .Pp
1409 Known to cause race conditions where cache objects may get corrupted, and this for at most a marginal performance improvement. Removed.
1410 .Pp
1411 .if \n(ll>1 .RE
1412 .nr ll -1
1413 .Pp