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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
*****************************
Imhiredis: Redis input plugin
*****************************
==================== =====================================
**Module Name:** **imhiredis**
**Author:** Jeremie Jourdin <jeremie.jourdin@advens.fr>
==================== =====================================
Purpose
=======
Imhiredis is an input module reading arbitrary entries from Redis.
It uses the `hiredis library <https://github.com/redis/hiredis.git>`_ to query Redis instances using 2 modes:
- **queues**, using `LIST <https://redis.io/commands#list>`_ commands
- **channels**, using `SUBSCRIBE <https://redis.io/commands#pubsub>`_ commands
.. _imhiredis_queue_mode:
Queue mode
----------
The **queue mode** uses Redis LISTs to push/pop messages to/from lists. It allows simple and efficient uses of Redis as a queueing system, providing both LIFO and FIFO methods.
This mode should be preferred if the user wants to use Redis as a caching system, with one (or many) Rsyslog instances POP'ing out entries.
.. Warning::
This mode was configured to provide optimal performances while not straining Redis, but as imhiredis has to poll the instance some trade-offs had to be made:
- imhiredis POPs entries by batches of 10 to improve performances (this is currently not configurable)
- when no entries are left in the list, the module sleeps for 1 second before checking the list again. This means messages might be delayed by as much as 1 second between a push to the list and a pop by imhiredis (entries will still be POP'ed out as fast as possible while the list is not empty)
.. _imhiredis_channel_mode:
Channel mode
------------
The **subscribe** mode uses Redis PUB/SUB system to listen to messages published to Redis' channels. It allows performant use of Redis as a message broker.
This mode should be preferred to use Redis as a message broker, with zero, one or many subscribers listening to new messages.
.. Warning::
This mode shouldn't be used if messages are to be reliably processed, as messages published when no Imhiredis is listening will result in the loss of the message.
Master/Replica
--------------
This module is able to automatically connect to the master instance of a master/replica(s) cluster. Simply providing a valid connection entry point (being the current master or a valid replica), Imhiredis is able to redirect to the master node on startup and when states change between nodes.
Configuration Parameters
========================
.. note::
Parameter names are case-insensitive
Input Parameters
----------------
.. _imhiredis_mode:
mode
^^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"word", "subscribe", "yes", "none"
Defines the mode to use for the module.
Should be either "**subscribe**" (:ref:`imhiredis_channel_mode`), or "**queue**" (:ref:`imhiredis_queue_mode`) (case-sensitive).
.. _imhiredis_key:
key
^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"word", "none", "yes", "none"
Defines either the name of the list to use (for :ref:`imhiredis_queue_mode`) or the channel to listen to (for :ref:`imhiredis_channel_mode`).
.. _imhiredis_socketPath:
socketPath
^^^^^^^^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"word", "no", "if no :ref:`imhiredis_server` provided", "none"
Defines the socket to use when trying to connect to Redis. Will be ignored if both :ref:`imhiredis_server` and :ref:`imhiredis_socketPath` are given.
.. _imhiredis_server:
server
^^^^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"ip", "127.0.0.1", "if no :ref:`imhiredis_socketPath` provided", "none"
The Redis server's IP to connect to.
.. _imhiredis_port:
port
^^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"number", "6379", "no", "none"
The Redis server's port to use when connecting via IP.
.. _imhiredis_password:
password
^^^^^^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"word", "none", "no", "none"
The password to use when connecting to a Redis node, if necessary.
.. _imhiredis_uselpop:
uselpop
^^^^^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"boolean", "no", "no", "none"
When using the :ref:`imhiredis_queue_mode`, defines if imhiredis should use a LPOP instruction instead of a RPOP (the default).
Has no influence on the :ref:`imhiredis_channel_mode` and will be ignored if set with this mode.
ruleset
^^^^^^^
.. csv-table::
:header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
:widths: auto
:class: parameter-table
"word", "none", "no", "none"
Assign messages from this input to a specific Rsyslog ruleset.
|
