[experimental-ims] b23cb23 cleaned out some cruft. Added links to the actual docs

Geoff Simmons geoff at varnish-cache.org
Mon Jan 30 16:09:52 CET 2012


commit b23cb230ad691426096bac155d5230e00ea928cc
Author: Per Buer <perbu at varnish-software.com>
Date:   Wed Jan 25 09:56:41 2012 +0100

    cleaned out some cruft. Added links to the actual docs

diff --git a/doc/sphinx/faq/general.rst b/doc/sphinx/faq/general.rst
index b30f093..2444394 100644
--- a/doc/sphinx/faq/general.rst
+++ b/doc/sphinx/faq/general.rst
@@ -5,25 +5,7 @@ General questions
 What is Varnish?
 ================
 
-Varnish is a state-of-the-art, high-performance `web accelerator <http://en.wikipedia.org/wiki/Web_accelerator>`_. It uses the advanced features in Linux 2.6, FreeBSD 6/7 and Solaris 10 to achieve its high performance.
-
-Some of the features include
-
-* A modern design
-* VCL - a very flexible configuration language
-* Load balancing with health checking of backends
-* Partial support for ESI
-* URL rewriting
-* Graceful handling of "dead" backends
-
-Features to come (Experimental):
-
-* Support for Ranged headers
-* Support for persistent cache
-	
-
-Varnish is free software and is licenced under a modified BSD licence. Please read the introduction to get started with Varnish.
-
+Please see ref:`tutorial-intro`.
 
 How...
 ======
@@ -59,7 +41,9 @@ This can be achieved by removing the query parameters using a regexp::
 
 **How can I force a refresh on a object cached by varnish?**
 
-Refreshing is often called `purging <http://dictionary.reference.com/browse/PURGE>`_ a document.  You can purge at least 2 different ways in Varnish:
+Refreshing is often called `purging
+<http://dictionary.reference.com/browse/PURGE>`_ a document.  You can
+purge at least 2 different ways in Varnish:
 
 1. Command line
 
@@ -118,23 +102,6 @@ You can use the ``bereq`` object for altering requests going to the backend, but
                 return(fetch);
         }
 
-**How do I force the backend to send Vary headers?**
-
-We have anecdotal evidence of non-RFC2616 compliant backends, which support content negotiation, but which do not emit a Vary header, unless the request contains Accept headers.
-
-It may be appropriate to send no-op Accept headers to trick the backend into sending us the Vary header.
-
-The following should be sufficient for most cases::
-
-        Accept: */*
-        Accept-Language: *
-        Accept-Charset: *
-        Accept-Encoding: identity
-
-Note that Accept-Encoding can not be set to ``*``, as the backend might then send back a compressed response which the client would be unable to process.
-
-This can of course be implemented in VCL.
-
 **How can I customize the error messages that Varnish returns?**
 
 A custom error page can be generated by adding a ``vcl_error`` to your configuration file. The default error page looks like this::
@@ -171,32 +138,9 @@ This can be achieved by removing the query parameters using a regexp::
         }
 
 
-Where...
-========
-
-**Can I find varnish for my operating system?**
-
-We know that Varnish has been packaged for Debian, Ubuntu, RHEL,
-CentOS, (Open)SUSE, Gentoo and FreeBSD, possibly more.  Check whatever
-package manager you use. Or read :ref:`Installing Varnish on your computer <install-doc>`.
-
 Can I...
 ========
 
-**Can I use Varnish as a client-side proxy?**
-
-No.  Varnish needs all backends configured in the VCL.  Look at squid
-instead.
-
-**Can I run Varnish on a 32bit system?**
-
-Yes, recently somebody even claimed to run Varnish on his N900 mobile
-phone recently, but if you have the choice, go 64 bit from the start.
-
-Varnish is written to use Virtual Memory and on a 32bit system that
-really cramps your style, and you will have trouble configuring more
-than 2 GB of storage.
-
 **Can I run Varnish on the same system as Apache?**
 
 Yes, and many people do that with good success.
@@ -243,83 +187,28 @@ Yes, you need VCL code like this::
 		set req.backend = foobar;
 	}
 
-    (XXX: reference to docs, once written)
+    Please see :ref:`tutorial-advanced_backend_servers-directors_`.
+
 
 Why ...
 =======
 
 **Why does it look like Varnish sends all requests to the backend? I thought it was a cache?**
 
-There are 2 common reasons for this:
-	1. The object's ``ttl expired``. A common situation is that the backend does not set an expiry time on the requested image/file/webpage, so Varnish uses the default TTL (normally 120s).
-	2. Your site uses ``cookies``:
-            * By default, varnish will not cache ``responses`` from the backend that come with a ``Set-Cookie``: header.
-            * By default, varnish will not serve ``requests`` with a ``Cookie:`` header, but pass them to the backend instead. Check out [wiki:VCLExamples these VCL examples] on how to make varnish cache cookied/logged in users sanely.
-
-
-**Why are regular expressions case-sensitive?**
-
-Some HTTP headers, such as ``Host:`` and ``Location:`` contain fully
-qualified domain names, which by definition is not case-sensitive.
-Other HTTP headers are case-sensitive, most notably the URLs.
-Therefore a "one size fits all" solution is not possible.
-
-In previous releases, we used the POSIX regular expressions
-supplied with the operating system, and decided, because the
-most common use of regexps were on ```Host:``` headers, that
-they should not be case-sensitive.
-
-From version 2.1.0 and forward, we use PCRE regular expressions,
-where it *is* possible to control case-sensitivity in the
-individual regular expressions, so we decided that it would
-probably confuse people if we made the default case-insensitive.
-(We promise not to change our minds about this again.)
-
-To make a PCRE regex case insensitive, put ``(?i)`` at the start::
-
-	if (req.http.host ~ "(?i)example.com$") {
-		...
-	}
-
-See the `PCRE man pages <http://www.pcre.org/pcre.txt>`_ for more information.
-
-**Are regular expressions case sensitive or not? Can I change it?**
-
-In 2.1 and newer, regular expressions are case sensitive by default.  In earlier versions, they were case insensitive.
-
-To change this for a single regex in 2.1, use ``(?i)`` at the start.
-
-See the `PCRE man pages <http://www.pcre.org/pcre.txt>`_ for more information.
-
-
-**Why does the ``Via:`` header say 1.1 in Varnish 2.1.x?**
-
-The number in the ``Via:`` header is the HTTP protocol version
-supported/applied, not the software's version number.
-
-**Why did you call it *Varnish*?**
-
-Long story, but basically the instigator of Varnish spent a long
-time staring at an art-poster with the word "Vernisage" and ended
-up checking it in a dictionary, which gives the following three
-meanings of the word:
-
-r.v. var·nished, var·nish·ing, var·nish·es
-
-	  1. To cover with varnish.
-	  2. To give a smooth and glossy finish to.
-	  3. To give a deceptively attractive appearance to; gloss over.
 
-The three point describes happens to your backend system when you
-put Varnish in front of it.
+Please see ref:`tutorial-increasing_your_hitrate`.
 
 **Why does Varnish require the system to have a C compiler?**
 
-The :ref:`VCL <faq-vcl>` compiler generates C source as output (your config file), and uses the systems C-compiler to compile that into a shared library.  If there is no C compiler, Varnish will not work.
+The :ref:`VCL <faq-vcl>` compiler generates C source as output (your
+config file), and uses the systems C-compiler to compile that into a
+shared library.  If there is no C compiler, Varnish will not work.
 
 **Isn't that security problem?**
 
-The days when you could prevent people from running non-approved programs by removing the C compiler from your system ended roughly with the VAX 11/780 computer.
+The days when you could prevent people from running non-approved
+programs by removing the C compiler from your system ended roughly
+with the VAX 11/780 computer.
 
 Troubleshooting
 ===============



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