Apache Camel ProducerTemplate

Question

Hi I am using apache camel + Spring and defined a configure like

public class MyOrderConsumerRouterBuilder extends RouteBuilder implements InitializingBean, ApplicationContextAware{

@Override
    public void configure() throws Exception {
        from("seda:asyncChannel?concurrentConsumers=20").id("asyncProcessChannelFromId")
    .to("bean:OrderProcessManager?method=processOrders").id("asyncProcessChannelToId");
    }
}

Is this Producer multithread? I see that consumers are multiple. In my case it is : concurrentConsumers=20

I checked below URL

How do I configure the default maximum cache size for ProducerCache or ProducerTemplate

As per source code DefaultCamelContext.createProducerTemplate() DefaultCamelContext DefaultProducerTemplate is being created with maximumCacheSize (default 1000)

As per this I understand this there can be multiple producers which are being defined using maximumCacheSize as LRU. In my case I have only one endpoint i.e SEDA so there will be only one producer.

So I think there will always be one single threaded producer. Please help me to understand it better.

Answer 1

The producer is not multithreaded, but there are multiple producers.

In your case 20 consumers (threads) are waiting for messages. If a message arrives, it is processed according to the route definition by one of these threads.

If another message arrives the thread who processes the first message is probably still occupied, but one of the other 19 free threads can process the message.

As long as there are no Splitters, Aggregators and similar EIPs, a single thread "walks" the message through your route and in your case finally sends the message to the OrderProcessManager bean. So this producing step (calling the bean method) is obviously done by a single thread for a single message.

BUT since you can have up to 20 threads processing messages in parallel, the OrderProcessManager bean can be called by up to 20 producers (threads) in parallel.