Simple local Publisher-Subscriber utility for InterSystems IRIS.

QuickStart

• Run sample container

docker-compose up -d

• PubSub uses dc.PubSub.Interop.Production. It’s empty.
• Create some partitions. This is only needed the first time. Check the production again.

do ##class(dc.PubSub.API).AddPartitions(3)

• Create a topic:
  • You will create a topic called simple/topic.
  • Optionally, you can add a PartitionKey in your topic. This allows you to define which field, in a message published in your topic, will be used to determine the partition that will handle the message.
  • All messages in same partition are processed in order.

set topic = ##class(dc.PubSub.API).CreateTopic("simple/topic", { "PartitionKey": "patientId" })

• Create some subscribers to your topic.
• These subscribers are class methods that will be called each time a message is published in the topic you created.
• The endpoint to specify your subscriber goes like this: <namespace>:<package>:<classmethod>

do ##class(dc.PubSub.API).CreateSubscription("simple/topic", { "Protocol": "ClassMethod", "Endpoint": "USER:dc.PubSub.Test.Simple:Subscriber"})
do ##class(dc.PubSub.API).CreateSubscription("simple/topic", { "Protocol": "ClassMethod", "Endpoint": "USER:dc.PubSub.Test.Simple:Sub2"})

• Publish some messages to your topic

do ##class(dc.PubSub.API).Publish("simple/topic", {"patientId": "HA98744455", "data": "dummy" } )
do ##class(dc.PubSub.API).Publish("simple/topic", {"patientId": "12TFFFHM88", "data": "dummy999" } )

• Check messages in your production

• Also, check included ^zlog global:

zw ^zlog
^zlog=4
^zlog(1)="[dc.PubSub.Test.Simple:Subscriber] Received: {""patientId"":""HA98744455"",""data"":""dummy""}"
^zlog(2)="[dc.PubSub.Test.Simple:Sub2] Received: {""patientId"":""HA98744455"",""data"":""dummy""}"
^zlog(3)="[dc.PubSub.Test.Simple:Subscriber] Received: {""patientId"":""12TFFFHM88"",""data"":""dummy999""}"
^zlog(4)="[dc.PubSub.Test.Simple:Sub2] Received: {""patientId"":""12TFFFHM88"",""data"":""dummy999""}"

Installation

1. Install IPM package manager if you don’t have already done it.
2. Create a new namespace (e.g. TEST). iris-pubsub needs to be installed in a new namespace because it runs its own interoperability production.
3. Switch to your new namespace and run:

TEST> zpm
zpm:TEST> install iris-pubsub

4. Setup how many partitions (Business Service - Business Operation) you want to run:

TEST> do ##class(dc.PubSub.API).AddPartitions(3)

And you are done, check the QuickStart section for some examples.