.. _whatsnew_upgrading_4_0:
%%%%%%%%%%%%%%%%%%%%%%%%
Upgrading to Varnish 4.0
%%%%%%%%%%%%%%%%%%%%%%%%
Changes to VCL
==============
The backend fetch parts of VCL have changed in Varnish 4. We've tried to
compile a list of changes needed to upgrade here.
Version statement
~~~~~~~~~~~~~~~~~
To make sure that people have upgraded their VCL to the current
version, Varnish now requires the first line of VCL to indicate the
VCL version number::
vcl 4.0;
req.request is now req.method
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To align better with RFC naming, `req.request` has been renamed to
`req.method`.
vcl_fetch is now vcl_backend_response
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Directors have been moved to the vmod_directors
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To make directors (backend selection logic) easier to extend, the
directors are now defined in loadable VMODs.
Setting a backend for future fetches in `vcl_recv` is now done as follows::
sub vcl_init {
new cluster1 = directors.round_robin();
cluster1.add_backend(b1, 1.0);
cluster1.add_backend(b2, 1.0);
}
sub vcl_recv {
set req.backend_hint = cluster1.backend();
}
Note the extra `.backend()` needed after the director name.
Use the hash director as a client director
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Since the client director was already a special case of the hash director, it
has been removed, and you should use the hash director directly::
sub vcl_init {
new h = directors.hash();
h.add_backend(b1, 1);
h.add_backend(b2, 1);
}
sub vcl_recv {
set req.backend_hint = h.backend(client.identity);
}
vcl_error is now vcl_backend_error
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To make a distinction between internally generated errors and
VCL synthetic responses, `vcl_backend_error` will be called when
varnish encounters an error when trying to fetch an object.
error() is now synth()
~~~~~~~~~~~~~~~~~~~~~~
And you must explicitly return it::
return (synth(999, "Response"));
Synthetic responses in vcl_synth
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Setting headers on synthetic response bodies made in vcl_synth are now done on
resp.http instead of obj.http.
The synthetic keyword is now a function::
if (resp.status == 799) {
set resp.status = 200;
set resp.http.Content-Type = "text/plain; charset=utf-8";
synthetic("You are " + client.ip);
return (deliver);
}
obj in vcl_error replaced by beresp in vcl_backend_error
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To better represent a the context in which it is called, you
should now use `beresp.*` vcl_backend_error, where you used to
use `obj.*` in `vcl_error`.
hit_for_pass objects are created using beresp.uncacheable
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Example::
sub vcl_backend_response {
if (beresp.http.X-No-Cache) {
set beresp.uncacheable = true;
set beresp.ttl = 120s;
return (deliver);
}
}
req.* not available in vcl_backend_response
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
req.* used to be available in `vcl_fetch`, but after the split of
functionality, you only have 'bereq.*' in `vcl_backend_response`.
vcl_* reserved
~~~~~~~~~~~~~~
Any custom-made subs cannot be named 'vcl_*' anymore. This namespace
is reserved for builtin subs.
req.backend.healthy replaced by std.healthy(req.backend_hint)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Remember to import the std module if you're not doing so already.
client.port, and server.port replaced by respectively std.port(client.ip) and std.port(server.ip)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`client.ip` and `server.ip` are now proper data types, which renders
as an IP address by default. You need to use the `std.port()`
function to get the port number.
Invalidation with purge
~~~~~~~~~~~~~~~~~~~~~~~
Cache invalidation with purges is now done via `return(purge)` from `vcl_recv`.
The `purge;` keyword has been retired.
obj is now read-only
~~~~~~~~~~~~~~~~~~~~
`obj` is now read-only. `obj.last_use` has been retired.
Some return values have been replaced
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Apart from the new `synth` return value described above, the
following has changed:
- `vcl_recv` must now return `hash` instead of `lookup`
- `vcl_hash` must now return `lookup` instead of `hash`
- `vcl_pass` must now return `fetch` instead of `pass`
Backend restarts are now retry
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In 3.0 it was possible to do `return(restart)` after noticing that
the backend response was wrong, to change to a different backend.
This is now called `return(retry)`, and jumps back up to `vcl_backend_fetch`.
This only influences the backend fetch thread, client-side handling is not affected.
default/builtin VCL changes
~~~~~~~~~~~~~~~~~~~~~~~~~~~
The VCL code that is appended to user-configured VCL automatically
is now called the builtin VCL. (previously default.vcl)
The builtin VCL now honors Cache-Control: no-cache (and friends)
to indicate uncacheable content from the backend.
The `remove` keyword is gone
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Replaced by `unset`.
X-Forwarded-For is now set before vcl_recv
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In many cases, people unintentionally removed X-Forwarded-For when
implementing their own vcl_recv. Therefore it has been moved to before
vcl_recv, so if you don't want an IP added to it, you should remove it
in vcl_recv.
Changes to existing parameters
==============================
session_linger
~~~~~~~~~~~~~~
`session_linger` has been renamed to `timeout_linger` and it is in
seconds now (previously was milliseconds).
sess_timeout
~~~~~~~~~~~~
`sess_timeout` has been renamed to `timeout_idle`.
sess_workspace
~~~~~~~~~~~~~~
In 3.0 it was often necessary to increase `sess_workspace` if a
lot of VMODs, complex header operations or ESI were in use.
This is no longer necessary, because ESI scratch space happens
elsewhere in 4.0.
If you are using a lot of VMODs, you may need to increase
either `workspace_backend` and `workspace_client` based on where
your VMOD is doing its work.
thread_pool_purge_delay
~~~~~~~~~~~~~~~~~~~~~~~
`thread_pool_purge_delay` has been renamed to `thread_pool_destroy_delay`
and it is in seconds now (previously was milliseconds).
thread_pool_add_delay and thread_pool_fail_delay
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
They are in seconds now (previously were milliseconds).
New parameters since 3.0
========================
vcc_allow_inline_c
~~~~~~~~~~~~~~~~~~
You can now completely disable inline C in your VCL, and it is
disabled by default.
Other changes
=============
New log filtering
~~~~~~~~~~~~~~~~~
The logging framework has a new filtering language, which means that
the -m switch has been replaced with a new -q switch. See
:ref:`vsl-query(7)` for more information about the new query language.
Henceforth, whatever our philosopher says about Matter will apply to extension and to extension alone. It cannot be apprehended by sight, nor by hearing, nor by smell, nor by taste, for it is neither colour, nor sound, nor odour, nor juice. Neither can it be touched, for it is not a body, but it becomes corporeal on being blended with sensible qualities. And, in a later essay, he describes it as receiving all things and letting them depart again without retaining the slightest trace of their presence.483 Why then, it may be asked, if Plotinus meant extension, could he not say so at once, and save us all this trouble in hunting out his meaning? There were very good reasons why he should not. In the first place, he wished to express himself, so far as possible, in Aristotelian phraseology, and this was incompatible with the reduction of Matter to extension. In the next place, the idea of an infinite void had been already appropriated by the Epicureans, to whose system he was bitterly opposed. And, finally, the extension of ordinary327 experience had not the absolute generality which was needed in order to bring Matter into relation with that ultimate abstraction whence, like everything else, it has now to be derived. That the millionaire was genuine, ¡°in person and not a caricature,¡± as Dick put it, was evident. Both the nurse, his relative, and his wife, were chatting with him as Jeff delivered the heavy packed ball made up of the gum. 233 "I guess not," said Landor, tolerantly, as he turned[Pg 106] his horse over to his orderly; "but, anyway," he added to Ellton, "we had a picnic¡ªof a sort." Si, unable to think of anything better, went with him. The train had stopped on a switch, and seemed likely to rust fast to the rails, from the way other trains were going by in both directions. The bridge gang, under charge of a burly, red-faced young Englishman, was in the rear car, with their tools, equipments, bedding and cooking utensils. THE DEACON HAS SOME EXPERIENCES WITH THE QUADRUPED. "You are not within a mile of the truth. I know it. Look here: I believe that is Gen. Rosecrans's own cow. She's gone, and I got an order to look around for her. I've never seen her, but from the description given me I believe that's she. Who brought her here?" "Deacon, these brothers and sisters who have come here with me to-night are, like myself, deeply interested in the moral condition of the army, where we all have sons or kinsmen. Now, can't you sit right there and tell us of your observations and experiences, as a Christian man and father, from day to day, of every day that you were down there? Tell us everything, just as it happened each day, that we may be able to judge for ourselves." HAS AN ENCOUNTER WITH THE PROVOST-MARSHAL. "Wonder which one o' them is the 200th Injianny's?" said Si to Shorty. "And your mother, and Harry?" The daughter must be the girl who was talking to him now. She sat on a little stool by the fire, and had brought out some sewing. "Over at Grandturzel¡ªcan't see wot's burning from here. Git buckets and come!" These things, however, gave little concern to the worthy who commanded the Kentish division. Tyler, though an excellent blacksmith, possessed few of the qualities requisite for forming a good general. Provided there was no very sensible diminution in the number of his followers, he cared not a straw for the score or two who, after quarrelling, or perhaps fighting, withdrew in such disgust that they vowed rather to pay the full tax for ever than submit to the insolence of the rebels. One man could fight as well as another, reasoned he; and, provided he was obeyed, what mattered it by whom. Dick went and Tom came¡ªit was sure to be all one in the end. But this burst of indignation soon passed away, and upon the suggestion of the prudent Sir Robert Hailes, he sent an evasive answer, with a command that the Commons should attend him at Windsor on the Sunday following. That it was a stratagem to gain entrance to the Tower, was the opinion of several, but, after much discussion, it was decided that the man should be admitted, and that the monk should be exhibited merely to intimidate the rebels, until the result of this promised communication should be known. HoMEŮͬÐÔÁµcbcb
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