CODEWITHSUNDEEP
groovyredisvert.x
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Reputation: 9103

Vertx and Redis: I cannot make them working together

I have my simple Vertx script in Groovy that should send a request to Redis to get a value back:

def eb = vertx.eventBus
def config = [:]

def address = 'vertx.mod-redis-io'

config.address = address
config.host = 'localhost'
config.port = 6379

container.deployModule("io.vertx~mod-redis~1.1.4", config)

eb.send(address, [command: 'get', args: ['mykey']]) { reply ->
    if (reply.body.status.equals('ok')) {
        println 'ok'
        // do something with reply.body.value
    } else {
        println("Error ${reply.body.message}")
    }
}

The value for 'mykey' is stored regularly on my Redis (localhost:6379):

127.0.0.1:6379> get mykey
"Hello"

The script starts correctly but no values are returned (reply).

Am I missing something?

Upvotes: 1

Views: 783

Answers (1)

INsanityDesign
INsanityDesign

Reputation: 141

The issue is that you deployModule and send to the EventBus sequentially, even if the call is asynchronous.

So, when you call deployModule the module deployment gets triggered, but is not guaranteed before eb.send is called. By that you are sending the right command but it does not get computed because the module is not there.

Try the following in adding your test command to the AsyncHandler of the deployModule

container.deployModule("io.vertx~mod-redis~1.1.4", config) { asyncResult ->
    if(asyncResult.succeeded) {
        eb.send(address, [command: 'get', args: ['mykey']]) { reply ->
            if (reply.body.status.equals('ok')) {
                println 'ok'
                // do something with reply.body.value
            } else {
                println("Error ${reply.body.message}")
            }
        }
    } else {
        println 'Deployment broken!'
    }
}

The example from the https://github.com/vert-x/mod-redis is maybe not the best because it is just a snippet to point the direction.

This works as it only sends the request to the Bus as soon as the module is deployed and by that someone listening to it. I tested it locally on a Vagrant installment with Redis.

Overall, development in Vert.x is close to always asynchronous because of its key concept. It takes some time to get acquainted with it, but it has its benefits :)

Hope this helps.

Best

Upvotes: 1

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