I have Apache Camel application deployed on two servers and they consume from JMS endpoint. I want to make sure that only one camel route is consuming from jms endpoint at a time. The only option that I can use for clustering is using database as a lock store. Does Apache Camel provide such a feature?
I think the easiest way is to consume from a topic and not a queue.
On connection, use the same subscriptionName. Only the first connection will be allowed as far i know.
Related
Background: We have written a Spring Boot Apache Camel based ingestion service which runs Camel routes that ingest data from shared directory (Excel files) and Jira (API calls). Jira based routes are fired using Scheduler at pre-defined frequency. User configures multiple integrations in the system and each integration maps to one Camel route. In production, there shall be 10 instances of the ingestion service running.
Problem Statement: For each integration using Jira, only one ingestion instance should fire a route, process it and rest should not if there is already a running instance for that specific route.
Question: How to make sure only one ingestion instance processes a route and rest ignore it (i.e. may start but stop after doing nothing)?
Analysis: It seems Camel Cluster component can be used but not sure if it can be used in conjunction with scheduler component. In addition, since cluster component can rely on standalone components such as cache, file etc., preferred solution would be to use something that does not require any new components in the architecture. Also it may be possible to use a custom solution but preference is to use an out-of-box solution.
I am trying to connect single qpid broker via to clients.
I want only one of these two client should listen the qpid queue.
I am trying this with apache camel
I don't believe QPID supports exclusive consumer on queues. An alternative option is to deploy your Camel route in Karaf in a primary+failover setup. The failover karaf container will be running in a "warm" mode where the Camel route is not started. If the primary fails, the failover will take over and start up all Camel routes. Works great for Highly Available database and file pollers as well!
ref: Karaf HA / Cluster setup
I am still struggling with undertsanding some of Camel's main features and limitations.
My objective is to implement a demo application that can migrate camel endpoints. To achieve this everyone suggested that I should use the camel load-balancer pattern with the failover construct.
To achieve this objective people have suggested Fuse and ActiveMQ. Some have even suggested JBoss, but I am lost.
I understand that Camel needs the an implementation of a JMS server. To achieve this I can use ActiveMQ - a free implementation of a JMS server.
However camel also provies the jms-component. What is this? Is this a client implementation of JMS? If so, should I not be using an ActiveMQ client for JMS? Could someone provide a working example?
With ActiveMQ and JMS understood I can then try to find out why people suggest Fuse. I want my implementation to be as simple as possible. Why do I need Fuse? The Camel+ActiveMQ combination has the load balancer pattern with the failover mechanism right?
I am lost in this sea of new technologies, if someone could give a direction I would be thankful.
Camel provides two components. The first is the jms component, which is a generic API for working against JMS servers. The other is the activemq component, which uses the activemq API for working with activemq message brokers. The activemq component is the default component within things like servicemix/fuse, using an internal broker (not a networked/external broker).
If you are connecting to activemq, you can use either the activemq component or the jms component. The jms component will not start up a broker automatically, you would need to do this yourself.
Fusesource == JBoss Fuse == Apache ServiceMix + some addons. For argument sake, i'm going to refer to all three of these as ServiceMix.
ServiceMix is an enterprise service bus, you can lookup the term on wikipedia if you're not familiar with the concept. It uses Apache Camel to define routes between your components, implementing a number of integration patterns as you so need. ServiceMix deploys by default with Apache CXF, for JAX-RS and JAX-WS services and Apache ActiveMQ, a JMS message broker. Using Camel, you can tell service mix that when a REST API is called, do a series of steps, each step decoupled from the one before it.
JBoss Fuse (the enterprisey, costs money edition) comes with some additional components around fail over. Some of these are present in servicemix (namely, you can run servicemix in a hot stand by mode, waiting for the primary to go down). The Camel load balancer pattern doesn't really mean anything around replication, except that a message coming from one endpoint can be delivered to any of a set of a N endpoints. http://camel.apache.org/load-balancer.html
On the flipside, take a look at ServiceMix's failover http://servicemix.apache.org/docs/4.4.x/users-guide/failover.html
I think based on your question you're referring to system failure failover (needing to work against a new instance), and not a Camel Loadbalancer component (which is likely where the confusion is coming from, on the community side and your side).
start by reading these...Camel In Action, ActiveMQ In Action
Can Camel connect to Sonic ESB?
I could not find any camel-sonic integration specific example. That's why I am confused if it is possible at all.
Connecting ESBs in general does not require specific transports since ESBs are connectivity software packages. You could probably pick and choose which transport fits you best and get started.
I had a look at Sonic ESB as I have never worked with it. However I can see a couple of ways you can integrate camel routes with the ESB.
Web services: If you are hosting web services on the Sonice ESB camel is more than capable of calling these web services from a camel route.
JMS: If Sonic ESB can host a JMS route (I am sure it can but could be wrong) you can just send JMS messages from your Camel route to the JMS queues hosted by Sonic ESB.
The JBI Component: Some ESB's such as Apache ServiceMix and OpenESB is based on the JBI standard. IF Sonic ESB uses this standard you should be able to send JBI messages directly to the Sonic ESB system.
Hope this gives you some pointers to look at.
in CXF is it possible to publish and subscribe Multiple Web Services one JMS queue ?
It is possible.
The behavior depend of the jms agent and configuration you use. But, if you want to do asynchronous WS over a broker this ability can be necessary.
You can look here asynchronous-client-http-transport for more information on this.
The multi-ws on one queue can be usefull for some case of failover service or reporting.
If its become too complex you can look at camel camel examples page, to control finer patterns.