Redis (om_redis)
This module can store data in a Redis server. It issues RPUSH commands using the Redis Protocol to send data.
The input counterpart, im_redis, can be used to retrieve data from a Redis server.
Configuration
The om_redis module accepts the following directives in addition to the common module directives. The Host directive is required.
Required directives
The following directives are required for the module to start.
This mandatory directive specifies the IP address or DNS hostname of the Redis server to connect to. |
Optional directives
This directive is interpreted the same way as the Key directive, i.e., it can be an expression that evaluates to a string.
The module will publish records to a Redis channel with this name.
The default is |
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This optional directive specifies the command to be used. The possible commands are LPUSH, RPUSH (the default), LPUSHX, RPUSHX, and PUBLISH. |
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This specifies the Key used by the RPUSH command.
It must be a string type expression.
If the expression in the Key directive is not a constant string (it contains functions field names, or operators), it will be evaluated for each event to be inserted.
The default is |
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This optional directive specifies the local port number of the connection. If this is not specified, a random high port number will be used, which is not always ideal in firewalled network environments.
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See the OutputType directive in the list of common module directives.
If this directive is not specified, the default |
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This specifies the port number of the Redis server. The default is port 6379. |
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This optional directive sets the reconnect interval in seconds. If it is set, the module attempts to reconnect in every defined second. If it is not set, the reconnect interval will start at 1 second and doubles with every attempt. If the duration of the successful connection is greater than the current reconnect interval, then the reconnect interval will be reset to 1 sec.
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Procedures
The following procedures are exported by om_redis.
reconnect();
-
Force a reconnection. This can be used from a Schedule block to periodically reconnect to the server.
The reconnect() procedure must be used with caution. If configured, it can attempt to reconnect after every event sent, potentially overloading the destination system.
Examples
This configuration only sets the mandatory Host directive to the Redis server IP address.
The module default will use the RPUSH
command to write the logs to a key named nxlog
.
<Input test_input>
Module im_testgen
MaxCount 2
</Input>
<Output redis>
Module om_redis
Host 192.168.1.213
</Output>
127.0.0.1:6379> lrange nxlog 0 -1
1) "0@Wed Jul 13 16:47:59 2022"
2) "1@Wed Jul 13 16:47:59 2022"
The configuration below sets the mandatory Host directive to the Redis server IP address.
It also specifies the Command and Key directives to use the LPUSH
command for writing logs to a key named event_logs
.
<Input test_input>
Module im_testgen
MaxCount 2
</Input>
<Output redis>
Module om_redis
Host 192.168.1.213
Command LPUSH
Key 'event_logs'
</Output>
127.0.0.1:6379> lrange event_logs 0 -1
1) "1@Wed Jul 13 16:52:39 2022"
2) "0@Wed Jul 13 16:52:39 2022"
The configuration below sets the mandatory Host directive to the Redis server IP address.
It also specifies the Command and Channel directives for publishing logs to the event_logs
Redis channel.
<Input test_input>
Module im_testgen
MaxCount 2
</Input>
<Output redis>
Module om_redis
Host 192.168.1.213
Command PUBLISH
Channel 'event_logs'
</Output>
127.0.0.1:6379> subscribe event_logs
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "event_logs"
3) (integer) 1
1) "message"
2) "event_logs"
3) "0@Wed Jul 13 17:00:56 2022"
1) "message"
2) "event_logs"
3) "1@Wed Jul 13 17:00:56 2022"