pliesveld / caching

Source code from my microservices caching session at NFJS

caching

Source code examples and demo from Mark Richards microservices caching session at NFJS.

See the demo folder for a recording.

The presentation slides are available here.

environment setup

Run the RabbitMQ server:

docker run -p 5672:5672 -d --hostname my-rabbit --name some-rabbit rabbitmq:3

Initialize Queue

To setup all of the exchanges, queues, and bindings used by these examples, run the following:

./gradlew initQueue

Start the DataWriter

The DataWriter receives update requests over the datapump.q queue and simulates a slow operation such as writing to a backend data store.

./gradlew runDataWriter

Start multiple CustomerInfoService

CustomerInfoService consumes client requests to update the name. Each service instance listens for update events over the queue name.q. When an event occurs, an distributed in-memory cache is updated first. The hazlecast distributed in-memory cache updates the memory of the other service instances currently running. In addition, the name update is routed to the DataWriter for persistent storage over the datapump.q queue.

Open a new terminal and run the following to start the service and initialize the cache:

./gradlew runService --args load

Open two new terminals run the following in each:

./gradlew runService

Send Update Name Event

Run the following multiple times each with a different placeholder value for the argument:

./gradlew update --args <Name>

Diagnostics

The following command examines the queues inside the RabbitMQ server:

watch docker exec some-rabbit rabbitmqctl list_queues