doc/release-notes/release-4.sgml

   1 <!doctype linuxdoc system>
   2 <article>
   3 <title>Squid 4.0.0 release notes</title>
   4 <author>Squid Developers</author>
   5
   6 <abstract>
   7 This document contains the release notes for version 4 of Squid.
   8 Squid is a WWW Cache application developed by the National Laboratory
   9 for Applied Network Research and members of the Web Caching community.
  10 </abstract>
  11
  12 <toc>
  13
  14 <sect>Notice
  15 <p>
  16 The Squid Team are pleased to announce the release of Squid-4.0.0 for testing.
  17
  18 This new release is available for download from <url url="http://www.squid-cache.org/Versions/v4/"> or the
  19  <url url="http://www.squid-cache.org/Download/http-mirrors.html" name="mirrors">.
  20
  21 <p>While this release is not deemed ready for production use, we believe it is ready for wider testing by the community.
  22
  23 <p>We welcome feedback and bug reports. If you find a bug, please see <url url="http://wiki.squid-cache.org/SquidFaq/BugReporting">
  24    for how to submit a report with a stack trace.
  25
  26 <sect1>Known issues
  27 <p>
  28 Although this release is deemed good enough for use in many setups, please note the existence of
  29 <url url="http://bugs.squid-cache.org/buglist.cgi?query_format=advanced&amp;product=Squid&amp;bug_status=UNCONFIRMED&amp;bug_status=NEW&amp;bug_status=ASSIGNED&amp;bug_status=REOPENED&amp;version=4" name="open bugs against Squid-4">.
  30
  31 <sect1>Changes since earlier releases of Squid-4
  32 <p>
  33 The Squid-4 change history can be <url url="http://www.squid-cache.org/Versions/v4/changesets/" name="viewed here">.
  34
  35
  36 <sect>Major new features since Squid-3.5
  37 <p>Squid 4 represents a new feature release above 3.5.
  38
  39 <p>The most important of these new features are:
  40 <itemize>
  41         <item>Helper concurrency channels changes
  42         <item>Configurable helper queue size
  43         <item>SSLv2 support removal
  44         <item>MSNT-multi-domain helper removal
  45 </itemize>
  46
  47 Most user-facing changes are reflected in squid.conf (see below).
  48
  49
  50 <sect1>Configurable helper queue size
  51 <p>The new queue-size=N option to helpers configuration, allows users
  52 to configure the maximum number of queued requests to busy helpers.
  53
  54 <sect1>Helper concurrency channels changes
  55 <p> helper-mux.pl we have been distributing for the past few years to
  56     encourage use of concurrency is no longer compatible with Squid. If
  57     used it will spawn up to 2^64 helpers and DoS the Squid server.
  58
  59 <p> Helpers utilizing arrays to handle fixed amounts of concurrency
  60     channels MUST be re-written to use queues and capable of handling a
  61     64-bit int as index or they will be vulnerable to buffer overrun and
  62     arbitrary memory accesses.
  63
  64 <p> 32-bit helpers need re-writing to handle the concurrency channel ID
  65     as a 64-bit integer value. If not updated they will cause proxies to
  66     return unexpected results or timeout once crossing the 32-bit wrap
  67     boundary. Leading to undefined behaviour in the client HTTP traffic.
  68
  69 <sect1>SSLv2 support removal
  70 <p>Details in <url url="https://tools.ietf.org/html/rfc6176" name="RFC 6176">
  71
  72 <p>SSLv2 is not fit for purpose. Squid no longer supports being configured with
  73 any settings regarding this protocol. That includes settings manually disabling
  74 its use since it is now forced to disable by default. Also settings enabling
  75 various client/server workarounds specific to SSLv2 are removed.
  76
  77
  78 <sect1>MSNT-multi-domain helper removal
  79
  80 <p>The <em>basic_msnt_multi_domain_auth</em> helper has been removed. The
  81    <em>basic_smb_lm_auth</em> helper performs the same actions without extra
  82    Perl and Samba dependencies.
  83
  84
  85 <sect>Changes to squid.conf since Squid-3.5
  86 <p>
  87 There have been changes to Squid's configuration file since Squid-3.5.
  88
  89 This section gives a thorough account of those changes in three categories:
  90
  91 <itemize>
  92         <item><ref id="newtags" name="New tags">
  93         <item><ref id="modifiedtags" name="Changes to existing tags">
  94         <item><ref id="removedtags" name="Removed tags">
  95 </itemize>
  96 <p>
  97
  98 <sect1>New tags<label id="newtags">
  99 <p>
 100 <descrip>
 101         <tag>tls_outgoing_options</tag>
 102         <p>New tag to define TLS security context options for outgoing
 103            connections. For example to HTTPS servers.
 104
 105         <tag>url_rewrite_timeout</tag>
 106         <p>Squid times active requests to redirector. This option sets
 107            the timeout value and the Squid reaction to a timed out
 108            request.
 109
 110 </descrip>
 111
 112 <sect1>Changes to existing tags<label id="modifiedtags">
 113 <p>
 114 <descrip>
 115         <tag>auth_param</tag>
 116         <p>New parameter <em>queue-size=</em> to set the maximum number
 117            of queued requests.
 118
 119         <tag>cache_peer</tag>
 120         <p>All <em>ssloption=</em> and <em>sslversion=</em> values for
 121            SSLv2 configuration or disabling have been removed.
 122         <p>Manual squid.conf update may be required on upgrade.
 123
 124         <tag>external_acl_type</tag>
 125         <p>New parameter <em>queue-size=</em> to set the maximum number
 126            of queued requests.
 127
 128         <tag>http_port</tag>
 129         <p>All <em>version=</em> <em>option=</em> values for SSLv2
 130            configuration or disabling have been removed.
 131         <p>Manual squid.conf update may be required on upgrade.
 132
 133         <tag>https_port</tag>
 134         <p>All <em>version=</em> <em>option=</em> values for SSLv2
 135            configuration or disabling have been removed.
 136         <p>Manual squid.conf update may be required on upgrade.
 137
 138         <tag>sslcrtd_children</tag>
 139         <p>New parameter <em>queue-size=</em> to set the maximum number
 140            of queued requests.
 141
 142         <tag>sslcrtvalidator_children</tag>
 143         <p>New parameter <em>queue-size=</em> to set the maximum number
 144            of queued requests.
 145
 146         <tag>sslproxy_options</tag>
 147         <p>All values for SSLv2 configuration or disabling have been removed.
 148         <p>Manual squid.conf update may be required on upgrade.
 149
 150         <tag>sslproxy_version</tag>
 151         <p>Value '2' for SSLv2-only operation is no longer supported.
 152
 153         <tag>url_rewrite_children</tag>
 154         <p>New parameter <em>queue-size=</em> to set the maximum number
 155            of queued requests.
 156
 157 </descrip>
 158
 159 <sect1>Removed tags<label id="removedtags">
 160 <p>
 161 <descrip>
 162         <tag>cache_peer_domain</tag>
 163         <p>Superceded by <em>cache_peer_access</em>. Use dstdomain ACL
 164            in the access control list to restrict domains requested.
 165
 166         <tag>refresh_pattern</tag>
 167         <p>Option <em>ignore-auth</em> removed. Its original intent was
 168            to improve caching. HTTP/1.1 permits caching of authenticated
 169            messages under conditions which Squid does check for and obey.
 170
 171         <tag>sslproxy_cafile</tag>
 172         <p>Replaced by <em>tls_outgoing_options cafile=</em>.
 173
 174         <tag>sslproxy_capath</tag>
 175         <p>Replaced by <em>tls_outgoing_options capath=</em>.
 176
 177         <tag>sslproxy_cipher</tag>
 178         <p>Replaced by <em>tls_outgoing_options cipher=</em>.
 179
 180         <tag>sslproxy_client_certificate</tag>
 181         <p>Replaced by <em>tls_outgoing_options cert=</em>.
 182
 183         <tag>sslproxy_client_key</tag>
 184         <p>Replaced by <em>tls_outgoing_options key=</em>.
 185
 186         <tag>sslproxy_flags</tag>
 187         <p>Replaced by <em>tls_outgoing_options flags=</em>.
 188
 189         <tag>sslproxy_options</tag>
 190         <p>Replaced by <em>tls_outgoing_options options=</em>.
 191
 192         <tag>sslproxy_version</tag>
 193         <p>Replaced by <em>tls_outgoing_options version=</em>.
 194
 195 </descrip>
 196
 197
 198 <sect>Changes to ./configure options since Squid-3.5
 199 <p>
 200 There have been some changes to Squid's build configuration since Squid-3.5.
 201
 202 This section gives an account of those changes in three categories:
 203
 204 <itemize>
 205         <item><ref id="newoptions" name="New options">
 206         <item><ref id="modifiedoptions" name="Changes to existing options">
 207         <item><ref id="removedoptions" name="Removed options">
 208 </itemize>
 209
 210
 211 <sect1>New options<label id="newoptions">
 212 <p>
 213 <descrip>
 214
 215 </descrip>
 216
 217 <sect1>Changes to existing options<label id="modifiedoptions">
 218 <p>
 219 <descrip>
 220         <tag>--enable-auth-basic</tag>
 221         <p>The <em>MSNT-multi-domain</em> helper has been removed.
 222
 223 </descrip>
 224 </p>
 225
 226 <sect1>Removed options<label id="removedoptions">
 227 <p>
 228 <descrip>
 229
 230 </descrip>
 231
 232
 233 <sect>Regressions since Squid-2.7
 234
 235 <p>Some squid.conf options which were available in Squid-2.7 are not yet available in Squid-4
 236
 237 <p>If you need something to do then porting one of these from Squid-2 to Squid-3 is most welcome.
 238
 239 <sect1>Missing squid.conf options available in Squid-2.7
 240 <p>
 241 <descrip>
 242         <tag>broken_vary_encoding</tag>
 243         <p>Not yet ported from 2.6
 244
 245         <tag>cache_peer</tag>
 246         <p><em>monitorinterval=</em> not yet ported from 2.6
 247         <p><em>monitorsize=</em> not yet ported from 2.6
 248         <p><em>monitortimeout=</em> not yet ported from 2.6
 249         <p><em>monitorurl=</em> not yet ported from 2.6
 250
 251         <tag>cache_vary</tag>
 252         <p>Not yet ported from 2.6
 253
 254         <tag>error_map</tag>
 255         <p>Not yet ported from 2.6
 256
 257         <tag>external_refresh_check</tag>
 258         <p>Not yet ported from 2.7
 259
 260         <tag>location_rewrite_access</tag>
 261         <p>Not yet ported from 2.6
 262
 263         <tag>location_rewrite_children</tag>
 264         <p>Not yet ported from 2.6
 265
 266         <tag>location_rewrite_concurrency</tag>
 267         <p>Not yet ported from 2.6
 268
 269         <tag>location_rewrite_program</tag>
 270         <p>Not yet ported from 2.6
 271
 272         <tag>refresh_pattern</tag>
 273         <p><em>stale-while-revalidate=</em> not yet ported from 2.7
 274         <p><em>ignore-stale-while-revalidate=</em> not yet ported from 2.7
 275         <p><em>negative-ttl=</em> not yet ported from 2.7
 276
 277         <tag>refresh_stale_hit</tag>
 278         <p>Not yet ported from 2.7
 279
 280         <tag>update_headers</tag>
 281         <p>Not yet ported from 2.7
 282
 283 </descrip>
 284
 285 <sect>Copyright
 286 <p>
 287 Copyright (C) 1996-2015 The Squid Software Foundation and contributors
 288 <p>
 289 Squid software is distributed under GPLv2+ license and includes
 290 contributions from numerous individuals and organizations.
 291 Please see the COPYING and CONTRIBUTORS files for details.
 292
 293 </article>