The most important of these are:
Most user-facing changes are reflected in squid.conf (see below).
TO BE WRITTEN
+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:
++
+icap_enable on +icap_service service_req reqmod_precache 1 icap://127.0.0.1:1344/request +icap_service service_resp respmod_precache 0 icap://127.0.0.1:1344/response +icap_class class_req service_req +icap_class class_resp service_resp +icap_access class_req allow all +icap_access class_resp allow all ++ + +
Please see squid.conf.default for more details about these and many other icap_* options.
+ +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.
+ +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.
+ +Proxy-directed data trickling and patience pages are not supported yet.
+ +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).
+ +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.
More information about ICAP can be found from the ICAP-forum website http://www.icap-forum.org
@@ -94,10 +116,8 @@ Some has been dropped as they are not needed. Some has not yet been forward-portThe 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:
The requested object was cached but STALE. The IMS query for the object resulted in "304 not modified".
-The requested object was cached but STALE. The IMS query returned the new content.
+The requested object was cached but STALE. The IMS query for the object resulted in "304 not modified".
+The requested object was cached but STALE. The IMS query returned the new content.
See @@ -130,8 +150,7 @@ Some has been dropped as they are not needed. Some has not yet been forward-port
+
Default: 5
@@ -145,8 +164,7 @@ of a dynamic) timeout value. To set a fixed timeout see the
-+
Default: 10 seconds @@ -156,8 +174,7 @@ have background-ping set.-
+
Default: unset @@ -169,8 +186,7 @@ an identification token.-
+
Default: off @@ -180,8 +196,7 @@ Set this to on to have squid behave as a remote surrogate.-
+
Default: custom @@ -192,8 +207,7 @@ encodings.-
+
Default: on @@ -205,8 +219,7 @@ Syntax is <A HREF="mailto:%w%W">%w</A>-
+
Default: off
@@ -221,13 +234,10 @@ based on the age of the cached version.
-Replaces the header_access directive of Squid-2.6 and earlier, but applies to requests only.
-Replaces the header_access directive of Squid-2.6 and earlier, but applies to replies only.
+Replaces the header_access directive of Squid-2.6 and earlier, but applies to requests only.
+Replaces the header_access directive of Squid-2.6 and earlier, but applies to replies only.
-+
Default: off
@@ -235,8 +245,7 @@ If you want to enable the ICAP module support, set this to on.
-+
Default: off
@@ -245,8 +254,7 @@ feature in Squid.
-+
Default: -1
@@ -256,8 +264,7 @@ basis by OPTIONS requests.
-+
Default: 60
@@ -266,8 +273,7 @@ an Options-TTL header.
-+
Default: on
@@ -276,8 +282,7 @@ an ICAP server.
-+
Default: off
@@ -285,8 +290,7 @@ This adds the header "X-Client-IP" to ICAP requests.
-+
Default: off
@@ -295,8 +299,7 @@ if proxy access is authentified.
-+
Default: none
@@ -320,8 +323,7 @@ icap_service service_2 respmod_precache 0 icap://icap2.mydomain.net:1344/respmod
-+
Default: none
@@ -336,8 +338,7 @@ icap class class_2 service_1 service_3
-+
Default: none @@ -361,8 +362,7 @@ icap_access class_1 allow all-
+
The name of an accept(2) filter to install on Squid's listen socket(s). This feature is perhaps specific to @@ -382,8 +382,7 @@ See the accf_http(9) man page.
New options: +
New options:
disable-pmtu-discovery=
Control Path-MTU discovery usage:
@@ -409,15 +408,13 @@ See the accf_http(9) man page.
-Removed options: +
Removed options:
urlgroup=, not yet ported to Squid-3.
-New options: +
New options:
basetime=n
@@ -457,8 +454,7 @@ See the accf_http(9) man page.
-Common options +
Common options
no-store, replaces the older read-only option
@@ -481,8 +477,7 @@ See the accf_http(9) man page.
-Removed Basic auth option +
Removed Basic auth option
blankpasswor, not yet ported to squid-3.
auth_param basic concurrency 0
@@ -496,8 +491,7 @@ See the accf_http(9) man page.
-New format specifications: +
New format specifications:
%URI Requested URI
@@ -521,8 +515,7 @@ See the accf_http(9) man page.
-New options: +
New options:
ignore-no-store
refresh-ims
@@ -539,8 +532,7 @@ See the accf_http(9) man page.
-New types: +
New types:
acl aclname http_status 200 301 500- 400-403 ... # status code in reply
@@ -557,16 +549,14 @@ See the accf_http(9) man page.
-New default: +
New default:
Default: on
(Old default: off)
-New delay classes: +
New delay classes:
class 4 Everything in a class 3 delay pool, with an
additional limit on a per user basis. This
@@ -580,8 +570,7 @@ See the accf_http(9) man page.
-New default to require the feature to be enabled in squid.conf: +
New default to require the feature to be enabled in squid.conf:
Default: 0 (disabled)
(Old default: 4827)
@@ -589,8 +578,7 @@ See the accf_http(9) man page.
-New default to require the feature to be enabled in squid.conf: +
New default to require the feature to be enabled in squid.conf:
Default: 0 (disabled)
(Old default: 3130)
@@ -598,8 +586,7 @@ See the accf_http(9) man page.
-New default to require the feature to be enabled in squid.conf: +
New default to require the feature to be enabled in squid.conf:
Default: 0 (disabled)
(Old default: 3401)
@@ -607,8 +594,7 @@ See the accf_http(9) man page.
-New format tags: +
New format tags:
rp Request URL-Path excluding hostname
@@ -630,8 +616,7 @@ See the accf_http(9) man page.
-Syntax changed: +
Syntax changed:
reply_body_max_size size [acl acl...]
@@ -639,8 +624,7 @@ See the accf_http(9) man page.
allow/deny no longer used.
-No urlgroup support in either requests or responese
+No urlgroup support in either requests or responese
Not yet ported to Squid-3.
-Not yet ported to Squid-3.
-Not yet ported to Squid-3.
-Not yet ported to Squid-3.
-Not yet ported to Squid-3.
-Not yet ported to Squid-3.
-This has been replaced by request_header_access and reply_header_access
-Not yet ported to Squid-3.
-Replaced by disable-pmtu-discovery http_port option
-Not yet ported to Squid-3.
-Not yet ported to Squid-3.
-Not yet ported to Squid-3.
-equivalent to cache_peer + cache_peer_access.
+Not yet ported to Squid-3.
+Not yet ported to Squid-3.
+Not yet ported to Squid-3.
+Not yet ported to Squid-3.
+Not yet ported to Squid-3.
+Not yet ported to Squid-3.
+This has been replaced by request_header_access and reply_header_access
+Not yet ported to Squid-3.
+Replaced by disable-pmtu-discovery http_port option
+Not yet ported to Squid-3.
+Not yet ported to Squid-3.
+Not yet ported to Squid-3.
+equivalent to cache_peer + cache_peer_access.
Build shared libraries. The default is to build without.
+Build shared libraries. The default is to build without.
-Build static libraries. The default is on.
+Build static libraries. The default is on.
-+
Optimize for fast installation
default: yes
-Avoid locking (might break parallel builds)
+Avoid locking (might break parallel builds)
-Don't compile Squid with compiler optimizations enabled. +
Don't compile Squid with compiler optimizations enabled. Optimization is good for production builds, but not good for debugging. During development, use --disable-optimizations to reduce compilation times and allow easier debugging. This option implicitly also enables --disable-inline
-Don't compile trivial methods as inline. Squid +
Don't compile trivial methods as inline. Squid is coded with much of the code able to be inlined. Inlining is good for production builds, but not good for development. During development, use @@ -739,18 +706,15 @@ production builds, or load tests, use --enable-inline to have squid make all trivial methods inlinable by the compiler.
-Provide some debug information in cbdata
+Provide some debug information in cbdata
-Build support for the list of disk I/O modules. +
Build support for the list of disk I/O modules. The default is only to build the "Blocking" module. See src/DiskIO for a list of available modules, or Programmers Guide for details on how to build your custom disk module.
-Enable ESI for accelerators. Requires libexpat. +
Enable ESI for accelerators. Requires libexpat. Enabling ESI will cause squid to follow the Edge Acceleration Specification (www.esi.org). This causes squid to IGNORE client Cache-Control headers.
@@ -758,30 +722,23 @@ causes squid to IGNORE client Cache-Control headers. proxy, ONLY use it in a squid configured for webserver acceleration. -Enable the ICAP client.
+Enable the ICAP client.
-Disable SNMP monitoring support which is now built by default.
+Disable SNMP monitoring support which is now built by default.
-Disable HTCP protocol support which is now built by default.
+Disable HTCP protocol support which is now built by default.
-Enable kqueue() support. Marked as experimental in 3.0.
+Enable kqueue() support. Marked as experimental in 3.0.
-Enable Transparent Proxy support for systems +
Enable Transparent Proxy support for systems using FreeBSD IPFW style redirection.
-Disable memPools. Note that this option now simply sets the +
Disable memPools. Note that this option now simply sets the default behaviour. Specific classes can override this at runtime, and only lib/MemPool.c needs to be altered to change the squid-wide default for all classes.
-This option allows you to see which internal functions +
This option allows you to see which internal functions in Squid are consuming how much CPU. Compiles in probes that measure time spent in probed functions. Needs source modifications to add new probes. This is meant @@ -791,21 +748,16 @@ of Squid internal functions.
you shouldn't enable this, as overhead added, although small, is still overhead. See lib/Profiler.c for more. -Assume the C compiler uses GNU ld. The default is to auto-detect.
+Assume the C compiler uses GNU ld. The default is to auto-detect.
-Try to use only PIC/non-PIC objects. The default is to use both.
+Try to use only PIC/non-PIC objects. The default is to use both.
-Include additional configurations. The default is automatic.
+Include additional configurations. The default is automatic.
-Sets the default System User account for squid permissions. +
Sets the default System User account for squid permissions. The default is 'nobody' as in other releases of squid.
-Path where the cppunit headers and libraries are found +
Path where the cppunit headers and libraries are found for unit testing. The default is automatic detection.
NOTE: Since 3.0-PRE6 and 2.6STABLE14 squid no longer comes bundled with CPPUnit. Compile-time validation will be disabled @@ -817,79 +769,66 @@ if it is not installed on your system.
CARP support is now built by default. +
CARP support is now built by default. --disable-carp can be used to buidl without it.
-HTCP protocol support is now built by default. +
HTCP protocol support is now built by default. Use --disable-htcp to build without it.
-SNMP monitoring is now build by default. +
SNMP monitoring is now build by default. Use --disable-snmp to build without it.
-Name changed to --with-valgrind
- -Please use --enable-removal-policies directive instead.
+Please use --enable-removal-policies directive instead.
-Replaced by --with-filedescriptors=N
+Replaced by --with-filedescriptors=N
Override maximum number of filedescriptors. Useful if you build as another user who is not privileged to use the number of filedescriptors you want the resulting binary to support
-Deprecated. +
Deprecated. Automatic checks will enable best I/O loop method available.
-Deprecated. +
Deprecated. Automatic checks will enable best I/O loop method available.
-Deprecated. +
Deprecated. Automatic checks will enable best I/O loop method available.
-Deprecated. -Automatic checks will enable best I/O loop method available.
+kqueue support is marked Experimental in Squid 3.0. Known to have some issues under load.
-Deprecated. -Automatic checks will enable best I/O loop method available.
+kqueue support is marked Experimental in Squid 3.0 -Automatic configuration checks may enable if it is found as the best method on your OS.
+These configure options have not yet been ported to Squid-3. If you need something to do then +porting one of these from Squid-2 to Squid-3 is most welcome.
++
Support for Solaris /dev/poll
-Marked as Still Experimental in Squid 3.0
+Basic POSIX select() loop without any binary fd_set optimizations.
+Support following the X-Forwarded-For HTTP header for determining the +client IP address
The following configure options have been removed.
-
Most OS:es have good malloc implementations these days, and the version we used to ship with Squid was very very old..
+Debug option, not needed and therefore removed.
+Rarely used extra log file. Removed.
+Rarely used feature, and multicast ICP acheives almost the same result. Removed.
+Specific to the COSS implementation in Squid-2
+Now enabled by default. Configure option was redundant and therefore removed.
+Known to cause race conditions where cache objects may get corrupted, and this for at most a marginal performance improvement. Removed.