Redis Pub/Sub listener endpoint
The Redis Pub/Sub listener endpoint enables developers to write applications that react to messages received via a channel managed by Redis.
Properties
General configuration
Property | Default | Description |
---|---|---|
Name | (required) | The name of the endpoint. |
Service | (required) | The service to execute when the endpoint is triggered. |
Run As | Anonymous |
The user to run the service in behalf of. This is logged to Tracker. |
Document Type | <Name of endpoint type> | The document type to be used when adding documents to Tracker as this endpoint is triggered. |
Auto Start | true |
Whether or not to automatically start the endpoint upon package startup. |
Log To Tracker | false |
Flag determining whether executions should be logged to Tracker. |
Replicated | true |
If this endpoint is configured on a Martini instance that's running in a cluster, replicated will determine whether to run the endpoint on all instances, or only the elected leader node in the cluster. When this is checked, all instances will run the endpoint. When it's unchecked, only the leader node will run the endpoint. |
Redis Pub/Sub listener-specific configuration
Properties | Default | Description |
---|---|---|
Connection Name | (required) | Name of the Redis database connection. |
Channel | (optional) | Name of the channel this endpoint should listen to. If this is specified, the patterns list must be empty. |
Patterns | (optional) | A list of Redis patterns that this endpoint should listen to. If a list of patterns is specified, the channel name must be empty. |
Ad hoc message publishing
Redis Pub/Sub messages can be sent by:
- (1) Clicking on the envelope icon next to the Channel text field in the Redis endpoint editor; or
- (2) Right-clicking on a Redis listener endpoint and then selecting Send Redis Channel Message. This prompts a dialog where you can enter a channel name, and the message you would like to send.
Service
When the endpoint is triggered, the following variables are exposed to the configured service:
General parameters
Name | Type | Description |
---|---|---|
$trackerId |
java.lang.String |
The Tracker document internal ID. If the endpoint was configured to not track, this value will be null . |
$tracker |
io.toro.martini.tracker.Tracker |
The Tracker object. If the endpoint was configured to not track, this value will be null . |
martiniPackage |
MartiniPackage |
The Martini package that contains the endpoint. |
parameters |
java.util.Map |
A map containing all the endpoint specific parameters. |
properties |
java.util.Map |
A map containing containing all the properties associated with the endpoint. |
Redis Pub/Sub listener-specific parameters
Name | Type | Description |
---|---|---|
databaseName |
java.lang.String |
The name of the Redis database connection where the message was received from. |
channel |
java.lang.String |
The name of the channel that the message was sent to. |
pattern |
java.lang.String |
The matching pattern that triggered this endpoint to receive the message. |
message |
java.lang.String |
The content of the message. |
content |
java.lang.String |
Alias for message . |
Example
Gloop as service
Consider this application using Gloop. This is invoked when the Redis channel configured for the endpoint receives a message.
(1) This line simply prints the channel name and message content to the Martini INFO
log.
Groovy script as service
Consider this Groovy script that simply prints the available variables in the context:
1 2 3 4 5 6 7 8 9 10 11 12 |
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When the endpoint is triggered - in this case, a Redis message sent to the configured channel - the console will show logs similar to the following:
1 2 3 4 5 6 7 8 |
|
Groovy method as service
We can configure the endpoint to use Groovy methods as services as well. Consider the following example:
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Assuming the service TestRedis#helloRedis
is configured in the endpoint, we can trigger it by sending a
message to a matching channel.