CODEWITHSUNDEEP
javainstancevert.x
ZAID SAHIL
ZAID SAHIL

Reputation: 31

Vertx - Stop a verticle instance

I have this vertx code :

DeploymentOptions deploymentOptions=new DeploymentOptions();
deploymentOptions.setInstances(2);

I want to know how to stop or kill one instance of the set instances.

Thanks.

Upvotes: 2

Views: 2457

Answers (2)

Mr__Steel
Mr__Steel

Reputation: 156

As far as I know you cannot undeploy just one instance. You'll receive one deploymentId after the successful deployment of the verticles for which you provided the deploymentOptions.

    DeploymentOptions deploymentOptions = new DeploymentOptions();
    deploymentOptions.setInstances(3);            
    vertx.deployVerticle("com.example.MyVerticle", deploymentOptions, res -> {
            if (res.succeeded()) {
                String deploymentId = res.result();
                System.out.println("Deployment id is: " + deploymentId);
                vertx.undeploy(deploymentId);
            } else {
                System.out.println("Deployment failed!");
            }
        });

So you just have the option to undeploy all the verticles at once for which you have received the deploymentId.

Upvotes: 0

Alexey Soshin
Alexey Soshin

Reputation: 17731

If you want to downscale vertices, you'll need to deploy a new set, then undeploy the old ones. This is a bit tricky, though:

final String[] myId = {""};
vertx.deployVerticle("my.Verticle", new DeploymentOptions().setInstances(2), (h) -> {
            if (h.succeeded()) {
                // This is deployment ID for both. Store it in some holder, because Java
                myId[0] = h.result();
            }
            else {
                System.out.println("CAUSE " + h.cause());
            }
});
// ...
// Here you decide to downscale
vertx.undeploy(myId[0], (h) -> { /* Deploy again with less instances */ });

In real application, you probably would like to first deploy new set of verticles, then in their completion handler undeploy the old ones. But for clarity I reversed this part.

Upvotes: 2

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