README.md

Canary Process demonstration

Please check the initial platform.

A Camunda 8 is started, and the Grafana page is accessible.

Principle

The creation is sent not to the Zeebe Gateway but to the CanaryApplication. This application offers the same API as the ZeebeGateway, so using this application is entirely transparent.

The redirection rule can be applied to this application. The key to the rule is the processId. If there is no rule for a process ID, the application sends the order directly to the ZeebeGateway.

A rule contains conditions. At this moment, the condition is only based on a percentage.

{
  "processId": "CustomerTickets",
  "conditions": [
    {
      "percent": 20,
      "versionTag": "V1",
      "version": 1
    },
    {
      "percent": 80,
      "versionTag": "V2",
      "version": 2
    }
  ]
}

This rule sends 20% of process creation to version V1 and 80% to version V2.

ATTENTION Camunda 8.6 does not offer an API to retrieve the version number from the version Tag. So, it's mandatory to give the actual version of the rule.

Preparation

Deploy the process

1. Deploy the process src/test/resources/Process/CustomerTicket-V1.bpmn, from the modeler.

2. Start the Canary application

kubectl create -f k8/CanaryProcess/CanaryApplication.yaml

Check that the application is started.

2024-10-22T23:39:43.861Z  INFO 1 --- [           main] i.c.c.canary.CanaryApplication           : InitCanaryApplication - enabled[true]
2024-10-22T23:39:43.966Z  INFO 1 --- [           main] i.c.c.c.RubyApplication                  : InitRubyApplication - enabled[false]
2024-10-22T23:39:43.970Z  INFO 1 --- [           main] i.c.c.worker.WorkerApplication           : Init WorkerApplication - enabled[false]

Port forward the Canary application to access the service

kubectl port-forward svc/canary-deployment 8095:8095 -n camunda

Access the rule via a browser on http://localhost:8095/canary/rules

or via

$ curl -X GET http://localhost:8095/canary/rules
[}]$

By default, there are no rules.

2. Start the Ruby application

kubectl create -f k8/CanaryProcess/RubyCustomerTickets.yaml

Check the pod starts correctly.

kubectl logs -f  <PodNameF rubypurchaserequest>
2024-10-22T22:15:57.065Z  INFO 1 --- [           main] i.c.c.c.CustomerApplication              : InitRubyApplication - enabled[true]
2024-10-22T22:15:57.066Z  INFO 1 --- [           main] i.c.c.c.CustomerApplication              : Schedule a task in 12000 ms

Check that the canary application received the order and created it.

2024-10-23T00:54:01.213Z  INFO 1 --- [nio-8095-exec-7] i.c.c.canary.CanaryApplication           : Process-instances created in processId[CustomerTickets] Version[latest] PID[6755399441175488]
2024-10-23T00:54:01.225Z  INFO 1 --- [nio-8095-exec-8] i.c.c.canary.CanaryApplication           : Process-instances created in processId[CustomerTickets] Version[latest] PID[2251799813805029]
2024-10-23T00:54:01.261Z  INFO 1 --- [nio-8095-exec-9] i.c.c.canary.CanaryApplication           : Process-instances created in processId[CustomerTickets] Version[latest] PID[4503599627490256]

Scenario

A new version must be deployed, and only 20 % of the process must be created in this version to validate it.

Install a new process version

When a new process version is deployed, Camunda will immediately send a new creation on this new process. To avoid that, a rule is created before the deployment to send 100% of the traffic to the current version.

Via Operate, check the current version of the process.

The current version is 1.

Add the rule via POSTMAN or the CURL.

curl -X POST http://localhost:8095/canary/addrule \
  -H "Content-Type: application/json" \
  -d '{"processId":"CustomerTickets","conditions":[{"percent":100,"versionTag":"V1","version":1}]}'

Response is

Rule added? New rule added. Number of rules: 1

Check the Grafana page; there is no disruption in the creation

In Operate, the number of process instances in the first process continues to grow.

Looking at the log-in Canary application, the process version is not the latest now, but version 1

2024-10-23T01:01:29.584Z  INFO 1 --- [nio-8095-exec-4] i.c.c.canary.CanaryApplication           : Process-instances created in processId[CustomerTickets] Version[1] PID[6755399441186065]

Deploy the new version of the process, tagged "V2"

There are now two versions in Operate; the new version has no process instance.

Send 20 % in the new version

Change the rule to send 20 % in the new version. Via Operate, the new version is named "2"

curl -X POST http://localhost:8095/canary/addrule \
  -H "Content-Type: application/json" \
  -d '{"processId":"CustomerTickets","conditions":[{"percent":80,"versionTag":"V1","version":1},{"percent":20,"versionTag":"V2","version":2}]}'

Result is

Rule added? Rule already exists, overrode. Number of rules : 1

Check the Grafana page: there is no disruption of service

Check to operate: now process instances appear in the second process

Send 80 % in the new version

curl -X POST http://localhost:8095/canary/addrule \
  -H "Content-Type: application/json" \
  -d '{"processId":"CustomerTickets","conditions":[{"percent":20,"versionTag":"V1","version":1},{"percent":80,"versionTag":"V2","version":2}]}'

Result is

Rule added? Rule already exists, overrided Number of rules : 1

Now, the new process receives more process instances.

At any time, you can check the rules

curl -X GET http://localhost:8095/canary/rules
[{"processId":"CustomerTickets","conditions":[{"percent":20,"versionTag":"V1","version":1},{"percent":80,"versionTag":"V2","version":2}]}]

Put the new version in production

To send all the data in the new process, delete the rule

curl -X POST http://localhost:8095/canary/deleterule/CustomerTickets 

Answer is

Rule Deleted. Number of rules : 0

Check with Operate: no more process instance is created in process version 1

Verify the complete throughput via Grafana:

Stop all

kubectl delete -f k8/CanaryProcess/RubyCustomerTickets.yaml

kubectl delete -f k8/CanaryProcess/CanaryApplication.yaml

Conclusion

The Canary application is used as a front end to create process instance. A simple rule mechanism, based on percentage, is implemented.

For this version, only the REST API is offering, not the GRPC API.

Search processes based on the versionTag is not implemented in Camunda 8.6, so the version created at deployment must be used.