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8
9   http://www.apache.org/licenses/LICENSE-2.0
10
11   Unless required by applicable law or agreed to in writing,
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17
18.. include:: ../../../common.defs
19
20.. default-domain:: c
21
22TSHttpTxnParentSelectionUrlSet
23***********************************
24
25Traffic Server Parent Selection consistent hash URL manipulation API.
26
27Synopsis
28========
29
30.. code-block:: cpp
31
32    #include <ts/ts.h>
33
34.. function:: TSReturnCode TSHttpTxnParentSelectionUrlSet(TSHttpTxn txnp, TSMBuffer bufp, TSMLoc offset)
35.. function:: TSReturnCode TSHttpTxnParentSelectionUrlGet(TSHttpTxn txnp, TSMBuffer bufp, TSMLoc offset)
36
37Description
38===========
39
40The Parent Selection consistent hash feature selects among multiple
41parent caches based on hashing a URL (the HTTP request header URL).
42
43These API functions allow an over-ride URL to be defined such that the
44over-ride URL is hashed instead of the normal (header request) URL. In
45addition, any filtering options that may be applied to the normal URL
46(such as qstring) are NOT applied to the over-ride URL since it is
47assumed that custom filtering has already been performed prior to
48explicitly setting the over-ride URL.
49
50Note that the normal URL is only hashed on the path and query string
51portion (optionally excluded with the qstring option). However, the
52over-ride URL is hashed on the entire URL string as returned by
53URL::string_get_ref(). This includes the scheme and hostname such as
54"http://hostname" which occur prior to the path.
55
56If the non-path URL elements should not be hashed in a meaningful
57manner, then they should be normalized to some value (if they are
58required in a valid URL) or excluded (if they are optional) when
59generating the over-ride URL. For example, since the over-ride URL is
60arbitrary, the URL scheme and hostname can simply be set to
61"fake://fake.fake" when creating the over-ride URL.
62
63:func:`TSHttpTxnParentSelectionUrlSet` will set the over-ride URL.
64
65:func:`TSHttpTxnParentSelectionUrlGet` will get the over-ride URL.
66
67Return Values
68=============
69
70All these APIs returns a :type:`TSReturnCode`, indicating success
71(:data:`TS_SUCCESS`) or failure (:data:`TS_ERROR`) of the operation.
72
73See Also
74========
75
76:manpage:`TSAPI(3ts)`,
77:manpage:`TSUrlCreate(3ts)`,
78:manpage:`TSUrlStringGet(3ts)`
79