-
Notifications
You must be signed in to change notification settings - Fork 381
/
Copy pathvmod_purge.vcc
146 lines (119 loc) · 4.65 KB
/
vmod_purge.vcc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
#-
# Copyright (c) 2017 Varnish Software AS
# All rights reserved.
#
# Author: Dridi Boukelmoune <[email protected]>
#
# SPDX-License-Identifier: BSD-2-Clause
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
$ABI strict
$Module purge 3 "Varnish Purge Module"
DESCRIPTION
===========
*vmod_purge* contains functions that offer a finer-grained control
than ``return(purge)`` from ``vcl_recv{}``. The functions can only be
called from ``vcl_hit{}`` or ``vcl_miss{}`` and they should in general
be used in both to ensure that all variants of a same object are taken
care of.
EXAMPLE
=======
::
sub vcl_recv {
if (req.method == "PURGE") {
if (client.ip !~ purge_acl) {
return (synth(405));
}
return (hash);
}
}
sub my_purge {
set req.http.purged = purge.hard();
if (req.http.purged == "0") {
return (synth(404));
}
else {
return (synth(200));
}
}
sub vcl_hit {
if (req.method == "PURGE") {
call my_purge;
}
}
sub vcl_miss {
if (req.method == "PURGE") {
call my_purge;
}
}
sub vcl_synth {
if (req.method == "PURGE") {
if (req.http.purged) {
set resp.http.purged = req.http.purged;
}
return (deliver);
}
}
$Function INT hard()
This is equivalent to ``return(purge)`` but explicitly called from
``vcl_hit{}`` and ``vcl_miss{}``. It returns the number of purged
objects.
Example::
set req.http.purged = purge.hard();
$Restrict vcl_hit vcl_miss
$Function INT soft(DURATION ttl = 0, DURATION grace = -1, DURATION keep = -1)
Sets the *ttl*, *grace* and *keep*. By default, *ttl* is set to ``0`` with
*grace* and *keep* periods left untouched. Setting *grace* or *keep* to a
negative value or to something higher than the objects current value leaves them
untouched. Setting all three parameters to ``0`` is equivalent to a hard purge.
Returns the number of soft-purged objects.
A soft-purge can only decrease the lifetime of an object. Let's consider an
object in cache created with *ttl*, *grace*, and *keep* of 60 seconds each:
``purge.soft(ttl = 0s, grace = -1s, keep = -1s);``
* If the object is **fresh**, the *ttl* is reduced to 0 seconds and the object
expires after 120 seconds.
* If the object is **stale**, the expiry time is not changed.
``purge.soft(ttl = 0s, grace = 10s, keep = 10s);``
* If the object is **fresh**, the *ttl* is reduced to 0 seconds, *grace* and
*keep* are reduced to 10 seconds. The object expires after 20 seconds.
* If the object has been **stale** for 5 seconds, *grace* is reduced to 5
seconds and *keep* is reduced to 10 seconds. The object expires after 15
seconds.
* If the object has been **stale** for 15 seconds, *grace* is reduced to 0
seconds and *keep* is reduced to 5 seconds. The object expires after 5
seconds.
* If the object has been **stale** for 20 seconds or more, the object
immediately expires.
``purge.soft(ttl = 10s, grace = -1s, keep = -1s);``
* If the object has been **fresh** for 5 seconds, the *ttl* is reduced to 10
seconds. The object expires after 130 seconds.
* If the object has been **fresh** for 55 seconds, the *ttl* is not changed. The
object expires after 125 seconds.
* If the object is **stale**, the expiry time is not changed.
When the expiry time of an object is reduced due to a softpurge, an
``EXP_Reduce`` entry is logged under the ``ExpKill`` VSL tag. If a softpurge
does not reduce the expiry time of an object, an ``EXP_Unchanged`` entry is
logged instead.
$Restrict vcl_hit vcl_miss
SEE ALSO
========
* :ref:`vcl(7)`