dfsilva/actor_bank

Actor project simulating thousands of concurrent operations in a bank account

This project contains a sample illustrating an CQRS design with Akka Cluster Sharding, Akka Cluster Singleton, Akka Persistence and Akka Persistence Query.

Overview

This sample application implements a CQRS-ES design that will side-effect in the read model on selected events persisted to Cassandra by the write model. In this sample, the side-effect is logging a line. A more practical example would be to send a message to a Kafka topic or update a relational database.

Write model

The write model is a bank.

The implementation is based on a sharded actor: each actors.account.BankAccount is an Akka Cluster Sharding entity. The entity actor BankAccount is an EventSourcedBehavior.

Read model

The read model is implemented in such a way that 'load' is sharded over a number of processors. This number is event-processor.parallelism.

The implementation is resilient: it uses an Akka Cluster Singleton in combination with Akka Cluster Sharding to always keep the event processors alive.

Running the sample code

1. Start the infrastructure ambiente running docker-compose:

docker-compose

2. Start a node that runs the write model:

mvn compile -Dakka.cluster.roles.0=write-model exec:java -Dexec.mainClass="br.com.diegosilva.bank.Main" -Dexec.args="2551"

3. Start a node that runs the read model:

mvn compile -Dakka.cluster.roles.0=read-model exec:java -Dexec.mainClass="br.com.diegosilva.bank.Main" -Dexec.args="2552"

4. More write or read nodes can be started by defining roles and port:

mvn compile -Dakka.cluster.roles.0=write-model exec:java -Dexec.mainClass="br.com.diegosilva.bank.Main" -Dexec.args="2553"
mvn compile -Dakka.cluster.roles.0=read-model exec:java -Dexec.mainClass="br.com.diegosilva.bank.Main" -Dexec.args="2554"

Try it with curl:

# create account 1
curl -X POST -H "Content-Type: application/json" -d '{"number":"000001", "uid":"98379720172", "name":"Diego Ferreira", "ammount":100}' http://127.0.0.1:8051/bank/account
curl -X POST -H "Content-Type: application/json" -d '{"number":"000002", "uid":"02218035138", "name":"Mariana Araújo", "ammount":100}' http://127.0.0.1:8051/bank/account

curl -X POST -H "Content-Type: application/json" -d '{"from":"000001", "to":"000001", "type":"C", "description":"Deposito em proprio favorecido", "ammount":100}' http://127.0.0.1:8051/bank/transaction | json_pp

curl -X POST -H "Content-Type: application/json" -d '{"from":"000001", "to":"000001", "type":"D", "description":"Saque", "ammount":35}' http://127.0.0.1:8051/bank/transaction | json_pp

curl -X GET -H "Content-Type: application/json" http://127.0.0.1:8051/bank/account/000001 | json_pp

or same curl commands to port 8052.