Squid 2.5.STABLE12 release notes

Squid Developers

$Id: release-2.5.html,v 2006/03/12 11:04:41 hno Exp $
This document contains the release notes for version 2.5 of Squid. Squid is a WWW Cache application developed by the National Laboratory for Applied Network Research and members of the Web Caching community.

1. Key changes from squid 2.4:

2. Changes to squid.conf


Allows ip address specification.


This is an option for use with SSL acceleration - it determines where squid listens for SSL requests.


This is used to handle some bugs in browsers that don't fully support SSL.


This has been removed - use the http_port line to specify ip address's.


login= has been extended to allow pass through authentication, fixed password authentication and maximum connection limits.


Directs squid to read in a set of name-address associations upon startup and reconfiguration.


Removed. See auth_param.


This replaces the authenticate_program directive. It allows configuration of multiple authentication helpers, one for each of the supported authentication schemes. Such schemes include "NTLM", "Digest (from RFC 2617)", and "Basic".


This directive sets the garbage collection interval for the authentication cache.


This directive configures the new external ACL Helper interface. VERY useful for authenticating by group membership - i.e. from an LDAP server or NT domain.


The default for this is now 0 - unlimited.


Now multiple size limits are allowed based on ACL lists.


The default is now blank - users must uncomment the suggested default to use it. This allows the use of a blank refresh pattern if desired.


Raised the default to 5 minutes.


New directive - how long to wait after a reply is completed before closing the connection.


New acl types


Limit HTTP replies based on ACL's. This is complementary to http_access.


These three directives allow marking of outbound connections at the IP level - i.e. for choosing routes based on the usercode.


Allows mapping of requests onto specific outbound IP address's.


Removed. See header_access.


Allow granular filtering of HTTP headers.


Replace specific headers with custom values.


Now defaults to off for bandwidth management and access logging reasons.


Enables a workaround for web servers that immediately expire Varied objects because they think squid is unable to handle Vary:.


Give the OS a small amount of time to accomodate the fork+exec used to launch helpers - if squid has a lot of virtual memory allocated the OS may run out of virtual memory during helper spawning otherwise.


This has been removed - starting with Squid-2.4 this directive have had no effect and has now been fully removed to avoid confusion.


This has been removed - it is not referenced anywhere in the source code.


This has been removed - it is not referenced anywhere in the source code.


New directive in 2.5.STABLE5 complement connect_timeout in management of timeouts while connecting to origin servers or peers


New directive in 2.5.STABLE5 to enable an alternative way of referring to icons in FTP directory listings etc.

acl urllogin

New acl type in 2.5.STABLE5 to match the login component of Internet style URLs (protocol://user:password@host/path/to/file)


New directive in 2.5.STABLE7 to make it possible to disable the automatic round-robin load balancing on multiple IP addresses normally done by Squid.


New directive in 2.5.STABLE7 limiting the size of HTTP reply headers, similar to request_header_max_size but in the reply direction (from servers to clients). Default is 20KB.

acl req_hdr/resp_hdr

New acl types in 2.5.STABLE7 to match arbitrary HTTP headers, useful to block certain malware/spyware etc.


New directive in 2.5.STABLE8 to control how strict the HTTP parser should be.


New directive in 2.5.STABLE9 to aggressive retry requests on errors (was the default in earlier versions)

acl dst

No longer matches invalid hosts. Was previously using the IP address "" on invalid hosts.


New directive in 2.5.STABLE13 to allow disabling the use of persistent connections after error pages (access denied etc).

3. Known issues and limitations

There is a few known issues in this version of Squid which we hope to correct in a later release

Bug #761

assertion failed: cbdata.c:249: "c->locks > 0" when using diskd

Bug #649

Problems refreshing pages stored with 'vary' information

Bug #888

ntlm_user_pool assertion error on shutdown

Bug #1420

302 responses with an Expires header is always cached

Bug #1500

diskd related memory corruption under heavy load

Ipfilter 4.x compile problem on HP Tru64

In addition there is a set of limitations in this version of Squid which we hope to correct later

Bug #1059

mime.conf and referenced icons must be within chroot

Bug #692

tcp_outgoing_address using an ident ACL does not work

Bug #581

acl max_user_ip and multiple authentication schemes

Bug #528

miss_access fails on "slow" acl types such as dst.

Bug #513

squid -F is starting server sockets to early

Bug #457

does not handle swap.state corruption properly

Bug #410

unstable if runs out of disk space

Bug #355

diskd may appear slow on low loads

Bug #219

delay_pools stops working on -k reconfigure

4. Key changes squid-2.5.STABLE1 to 2.5.STABLE2:

5. Key changes squid-2.5.STABLE2 to 2.5.STABLE3:

6. Key changes squid-2.5.STABLE3 to 2.5.STABLE4:

7. Key changes squid-2.5.STABLE4 to 2.5.STABLE5:

8. Key changes squid-2.5.STABLE5 to 2.5.STABLE6:

9. Key changes squid-2.5.STABLE6 to 2.5.STABLE7:

10. Key changes squid-2.5.STABLE7 to 2.5.STABLE8:

11. Key changes squid-2.5.STABLE8 to 2.5.STABLE9:

12. Key changes squid-2.5.STABLE9 to 2.5.STABLE10:

13. Key changes squid-2.5.STABLE10 to 2.5.STABLE11:

14. Key changes squid-2.5.STABLE11 to 2.5.STABLE12:

15. Key changes squid-2.5.STABLE12 to 2.5.STABLE13: